15th International Conference on

Sustainable Use and Management of Soil, Sediment and Water Resources

20–24 May 2019 • Antwerp • Belgium

AquaConSoilAntwerp 2019

BOOK OF ABSTRACTS

1

Content

Content ..................................................................................................................................................................1

Special Sessions (SpS)

2bSps – Harmonization of analytical protocols for chemical analysis of contaminants ..................................................................... 16

2dSpS | Towards a decent and efficient procedure for groundwater quality assessment ................................................................... 16

4bSpS | Workshop Bio-Geotechnology .................................................................................................................................................... 16

4cSps1: Foams for in-situ treatments of vadose zones contaminated by hydrocarbons .................................................................... 17

The MOUSTIC project: Foams for in-situ treatments of vadose zones contaminated by hydrocarbons ..................................................................... 17

Assessment of a new foam-based technology for enhanced oxidant delivery and treatment in unsaturated anisotropic hydrocarbon-contaminated soils .......................................................................................................................................................................................................... 17

Selection of Micro-organisms and Transport with surfactant Foams for Enhanced In Situ Biological Treatment of Petroleum Hydrocarbon in Soil .............................................................................................................................................................................................................. 18

Field-tests: Enhanced in situ chemical oxidation of an anisotropic hydrocarbon-contaminated plant using foams ............................................ 18

3D Numerical Foam Flow and Transport Modelling in the Porous Media Vadose Zone with the new simulator TMVOC++ .............................. 19

4cSps2 & 4cSps3 | How to bridge the innovation gap – From pilots and prototypes to price labeled products ............................... 19

4dSps1 | Nature based remediation solutions: Project examples of the power of bioremediation ..........................................................20

Nature based remediation solutions .................................................................................................................................................................................................... 20

Nature based remediation of 1,4 Dioxane at a chemical plant (NL) – phytocontainment and biological source zone treatment ................... 20

Innovative bioremediation of MTBE and organics: in situ bio-sparging and high yield MTBE bioreactor development ..................................... 21

Cyclic bioremediation of a heavily impacted Xylene site in Westerlo (BE) – 100% on site biological treatment of soil, groundwater and soil vapor .................................................................................................................................................................................................................... 21

4dSpS2 | Our precious groundwater goes grey… what can we do? ....................................................................................................... 22

Constructed Wetlands for cost-effective and energy-efficient remediation of plumes .................................................................................................... 22

4dSps3 | Improving the management and rehabilitation of contaminated soils with low-cost technologies and methods ....................................................................................................................................................................... 22

Development of a Decision Support System (DSS) in a GIS platform to integrate transport modelling results of soil-surface and groundwater contaminants .................................................................................................................................................................................... 23

The hidden socioeconomical costs of pollution. Surveying vulnerabilities and coping tactics in a French industrial town .............................. 23

Transfer of heavy metals to agricultural and natural plants and selection of plant species most suitable for phytostabilization trials................ 24

Investigating the relationship between speciation and oral/lung bioaccessibility of highly contaminated tailings and soils: a technical tool for health risk assessment ........................................................................................................................................................................................ 24

Copper soil content, soil characterization and plant vigor: what link? Application to a vineyard ................................................................................ 24

Tillandsias usneoides for air quality biomonitoring in the mining district of La Unión - Cartagena, Spain: New insights for epiphyte’s uptake mechanims and pollution source tracing by the use of Zn and Pb isotopes .................................................. 25

Evaluation of the risk for contaminants mobilization in a massive way .................................................................................................................................. 25

Atmospheric dusts characterisation in the mining district of La Unión - Cartagena, Spain: Air quality and health risks assessment ............ 25

Application of the GNSS-Reflectometry to map surface properties of mine waste – example of the Cartagena – La Union district (Spain) ............................................................................................................................................................................................................................ 26

Assessment of the bioaccessibility of metals in soils through inhalation and ingestion pathway for risk assessment ......................................... 26

Legal 1– 5aSps1 | International developments soil pollution ............................................................................................................... 27

Legal aspects of the management of contaminated land ........................................................................................................................................................... 27

Pillars of a precautionary policy in the EU to avoid harmful soil and groundwater changes on installations according to IED ........................ 27

Management of remediation programs at fuel retail stations in a selection of different European countries: from identification to delivery of remediation works .................................................................................................................................................................... 28

How to manage heavily impacted sites and complex remediation in fast evolving markets locked by legal and technology constrains. .. 28

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Content

Legal 2 – 5aSps2 | International developments policy on soil, land and groundwater ....................................................................... 28

Decision-making on groundwater quality management: perspectives from competent authorities in the Netherlands .................................. 28

Luxembourg’s cumbersome way towards a national soil law..................................................................................................................................................... 29

Barriers limiting the remediation of contaminated sites in italy and possible solutions .................................................................................................. 29

Legal 3 – 5aSps3 | Soil, sediments and waste .......................................................................................................................................... 30

Legal framework for sediment study and remediation of water bodies in Flanders. ......................................................................................................... 30

Who should pay for sediment cleanup? ............................................................................................................................................................................................. 30

Waterfront contribution: a new finance paradigm for cleanup of contaminated sediments ......................................................................................... 30

How to manage both costs, acceptable risk and stakeholders when excavating material containing asbestos in a context of Big Urban Projects?................................................................................................................................................................................................................................ 31

Legal 4 – 5aSps4 | Technician meets lawyer ............................................................................................................................................ 31

Bio-engineering solutions as catalyst for redevelopment of impacted sites ........................................................................................................................ 31

Bioengineering as solution for conflicting site clean-up and windmill constructions ...................................................................................................... 32

Ramboll and GreenSoil unlock development potential of a chlorinated solvent impacted land, using enhanced bioremediation techniques ..................................................................................................................................................................................................................... 32

Acquisition of liability becomes possible through the use of an integral cyclical design ................................................................................................ 33

Application of environmental forensic investigations to define the allocation of liabilities in insurance claims .................................................... 33

Mass balance of a chlorinated solvent source zone: evaluation of uncertainties to secure remediation contracting terms .............................. 34

From the perspective of the soil-expert: how to stimulate the development of brownfields ........................................................................................ 34

Panel Discussion .......................................................................................................................................................................................................................................... 34

Economic 1 – 5aSpS5 | Accounting rules ................................................................................................................................................. 34

Economic 2 – 5aSpS6 | Due Diligence ...................................................................................................................................................... 35

Economic 3 – 5aSpS7 | Round table with stakeholders .......................................................................................................................... 35

Flemish Session – 5aSpS8 ......................................................................................................................................................................... 35

5cSps1 – Ports session: Dealing with pollution and land transition in times of the energy transition .............................................. 35

Coordinated approach remediation of the port of Rotterdam .................................................................................................................................................. 36

5cSps2 – Progress in sustainable land management worldwide .......................................................................................................... 36

Debunking myths about sustainable remediation ......................................................................................................................................................................... 36

Parallels between ISO 14001:2015 and the SuRF UK framework ............................................................................................................................................... 37

5cSpS3 | Nature-based remediation workshop ...................................................................................................................................... 37

Applying Working with Nature to Navigation Infrastructure Projects ..................................................................................................................................... 38

6bSps1 | The implementation of soil and land-related Sustainable Development Goals at EU level ................................................ 38

6bSps2 | Towards land stewardship: The INSPIRATION Strategic Research Agenda on soil and land 1 year on... ............................ 39

SOILveR - Soil and Land Research Funding Platform for Europe ............................................................................................................................................... 39

6cSpS | Water Nexus as a source for innovation in the water security challenge ................................................................................. 40

6dSps | Exploring care, knowledge and agency as levers to Soil+Land stewardship .......................................................................... 40

Introduction to the topic and lessons learnt so far ......................................................................................................................................................................... 41

7aSps | How to implement innovative environmental technologies in society to gain value from degraded and polluted sites? ......41Innovation for a green future for brownfields .................................................................................................................................................................................. 41

Redevelopment of rare-earth mining sites ........................................................................................................................................................................................ 41

Redevelopment of former coking plant site - the LORVER and TANIA projects ................................................................................................................... 41

Implementation of ATES & Bioremediation in society by the Living Lab approach .......................................................................................................... 41

Panel discussion: which strategies to promote innovation and gain value from abandoned sites? ............................................................................ 41

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Content

7bSps1 | Soil, sediment and groundwater in the circular economy – perspectives and opportunities ............................................. 42

7bSpS2 | Soil energy as smart low carbon technology for cost-effective climate mitigation ............................................................. 42

7cSps | Beneficial and nature-based sediment use as a resource for circular economy ...................................................................... 43

Sessions from a business perspective

4aCom1 | New advances in the implementation of (bio)remediation additives: a policy perspective .............................................. 44

Engineered Retardation Factor Manipulation using Liquid Activated Carbon for Passive Management of Plume Dynamics ........................... 44

Production and use of a biosurfactant for the remediation of soils impacted by Polycyclic Aromatic Hydrocarbons.......................................... 44

In-situ solutions using Zero Valent Iron for the remediation of sites contaminated with chlorinated solvents....................................................... 45

Performance of a New Activated Carbon Amendment for Bioremediating Petroleum-Impacted Sites ..................................................................... 45

Successful biostimulation and bioaugmentation treatment of DNAPL and dissolved phase mixed chlorinated solvent contamination under an active commercial site ............................................................................................................................................................................. 46

4cCom1 | Surfactant enhanced remediation as a lead-out for ISCO or ISCR ........................................................................................ 46

4cCom2 | Combined treatment technologies and technology trains ................................................................................................... 46

Treatment of a large industrial site impacted with chlorinated solvents using a combination of electron-donor substrates and a liquid activated carbon barrier. .................................................................................................................................................................................................. 46

Surfactant Enhanced Extraction to Expedite Remediation of a Carbon Tetrachloride Source Zone at an Active Grain Elevator Facility ............. 47

Combined Remedy: Alkaline Activated Persulfate with In Situ Solidification/Stabilization (ISCO-ISS) in a Single Application ......................... 47

5bCom1 | Understanding Best Practices: ISCO with activated persulfates .......................................................................................... 48

The value of bench testing – Lessons learned examining activated persulfate technologies. ....................................................................................... 48

Sodium and potassium persulfates: Characteristics, chemistries, and applications .......................................................................................................... 49

Integrated remediation - Redevelopment of contaminated sites using ISCO-ISS soil mixing technology ................................................................ 49

Targeted soils emplacement into low permeability lithologies ................................................................................................................................................. 50

Projecting into the future: Where does ISCO fit into remediation in years ahead? ............................................................................................................ 50

Thematic Session (ThS)

Topic 1 | Soil and water in the digital world

ThS 1a | Big data, smart data combinations ............................................................................................................................................ 51

Statistical modelling of groundwater contamination monitoring data using GWSDAT: A comparison of spatial and spatiotemporal methods ................................................................................................................................................................ 51

Integrated implementation of the environmental database platform EQuIS and the geostatistical software Kartotrak to perform pollution characterization and to design the remediation of industrial sites ................................................................................................ 51

Using spill modelling to better predict environmental risk ......................................................................................................................................................... 51

Optimization of a groundwater monitoring network using geostatistics and simulated annealing ........................................................................... 52

Making sense of environmental big data: applications for the sustainable management of contaminated soil and groundwater ............... 52

ThS 1b | Artificial intelligence ................................................................................................................................................................... 53

Data driven conceptual site models using Groundhog Professional ....................................................................................................................................... 53

Application of machine learning models to predict bioavailability and toxicity of complex chemical mixtures in a lab-based trial ............. 53

Innovative modelling and visualization methods in optimizing is situ remediation of contamination source: Way of working, opportunities and risks ............................................................................................................................................................................................ 54

Remediation Dashboards – Real time remediation follow up and decision making ......................................................................................................... 54

Water Management 4.0 ............................................................................................................................................................................................................................. 55

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Content

ThS 1c | New technological developments .............................................................................................................................................. 55

BIM : The Dunkerque refinery cleaned up using an innovative digital tool ........................................................................................................................... 55

Combining geostatistics and data from numerical simulations to improve estimations of pollution plumes in groundwater or soils ............... 55

What’s the potential of geophysics for mapping landfills and industrial sites? ................................................................................................................... 56

Use of drone as a sustainable solution for surveys ......................................................................................................................................................................... 56

Fieldworker of the future - combination of sensing and augmented reality ....................................................................................................................... 57

Topic 2 | Advances in assessment of risk and monitoring of soil, sediment and water quality

ThS 2a | Advances in sampling, monitoring techniques and methods ................................................................................................. 58

A novel active-passive sampling approach for monitoring a broad range of pollutants in water ................................................................................ 58

Estimation of sorbed-phase biodegradation rate in activated carbon barriers using microbial diagnostics, CSIA and in situ microcosms ................................................................................................................................................................................................................... 58

Integrated approach in the management of a jet fuel contaminated site. The Decimomannu Air Base (CA, Sardinia) ....................................... 58

Innovative characterization solutions for monitoring of groundwater and dissolved contaminants dynamic ....................................................... 59

Rapid assessment of potential inhalation risks due to the vapour intrusion pathway using building pressure cycling and high volume subslab testing .......................................................................................................................................................................................................... 59

Advanced monitoring tools for in situ remediation measures - Conclusions from 233 contaminated site investigations ................................. 60

Risk of vapor intrusion to the indoor climate from groundwater contamination ............................................................................................................... 60

High resolution site characterization: The basis of your conceptual site model .................................................................................................................. 61

Advances in in-situ automatous LNAPL and water level monitoring by guided wire radar: Detailed analysis of LNAPL behaviour and improved site understanding ............................................................................................................................. 61

Field scale comparison of four passive sampling techniques for monitoring contaminant flux in groundwater CVOC plumes ...................... 61

Reliable and cost-effective site characterization using a Dual LIF (simultaneous UVOST-TarGOST)-CPT approach ............................................... 62

Contaminant mass flux measurement in groundwater with passive samplers coupled with flowmeter measurements ................................... 62

The use of in situ biosensors to monitor a biostimulation pilot at a chlorinated solvents plume ................................................................................. 63

Innovative, multi technique investigation for residual NAPL presence in order to assess bedrock remediation at a site in Sweden ............. 63

Why the US EPA is promoting the collection ................................................................................................................................................................................... 64

of time-integrated, passive indoor air samples for vapor intrusion risk assessments ........................................................................................................ 64

Multiple lines of evidence approach to assess chlorinated ethenes degradation during treatment with liquid activated carbon and bioamendments ........................................................................................................................................................................ 64

Biosensors for measuring the bioavailability of heavy metals in the remediation of biochar-amended soil .......................................................... 65

Quantification of PCE from contaminated building materials to indoor air – Tools and NxtGen conceptual understanding ........................... 65

Direct distribution of soil gas in an older industrial building ...................................................................................................................................................... 66

Pollution flux measurements as part of risk assessment for the spreading of groundwater pollution ....................................................................... 66

ThS 2b | Advances in in-situ measurement and analytical techniques ................................................................................................. 67

Application of EnISSA-MIP at coal tar or creosote contaminated sites: Individual GCMS detection of (s)VOC’s can tackle differences in trip time in the MIP system ..................................................................................................................................................................... 67

Applications of the new Geoprobe® OIP systems for NAPL and tracer detection ............................................................................................................... 67

Comprehensive target and non-target analyses of Hg-As compounds and organic contaminants of mining, metallurgy and demolition waste in a brownfield ................................................................................................................................................................................................. 67

On-site analysis of metal concentrations of natural waters ......................................................................................................................................................... 68

Screening for 21 perfluorinated organic compounds in Czech wastewater treatment plants ...................................................................................... 68

Use of a fiber optic temperature sensor system to evaluate EMNR/MNR at a sediment remediation site ................................................................. 69

ThS 2c | Soil-sediment-water interaction and system dynamics ........................................................................................................... 69

Transport, fate and risk assessment of groundwater contaminants discharging to a stream: Novel approaches and current understanding ................................................................................................................................................................................ 69

Lower metal fluxes from fiberbank deposits than expected ....................................................................................................................................................... 70

Turnover of organic matter in river sediments - The BIOMUD project .................................................................................................................................... 70

How influence metal concentrations in soils and in river beds the metal accumulation in a reservoir? .................................................................... 70

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Content

ThS 2d | Human health and environmental risk assessment ................................................................................................................. 71

A Triad based framework for ecological risk assessment (ERA) that accounts for inherent soil quality effects ........................................................ 71

Linking bioavailability of complex chemical mixtures to toxicity changes to assess recovery of multi-contaminated soils .............................. 71

Polluted sites. French methodology,example of a best practice ............................................................................................................................................... 72

Mercury transfer through the food web of the three-spined stickleback (Gasterosteus aculeatus) .............................................................................. 72

To use or not to use: Handling sewer overflow sludge .................................................................................................................................................................. 73

How to deal with a “cocktail” of contaminants - Risk assessment as a key tool for effective remedial strategy implementation in the new regulatory framework ........................................................................................................................................................................ 73

Industrial scale destruction of old chemical ammunition of the Great War on the western front the hundred-year-old forgotten contami-nations ............................................................................................................................................................................................................................................................. 74

Mixture exposure to PFAS: A relative potency factor approach ................................................................................................................................................. 74

Vapor intrusion study in a densely populated residential area (Mechelen, Belgium) impacted by a soil and groundwater pollution of turpentine and chlorinated ethenes beneath private homes ............................................................................................................................ 74

Developing a Flemish risk assessment tool for contaminated sediments ............................................................................................................................. 75

Topic 3 | Diffuse and emerging contaminants

ThS 3a | Transport processes of emerging contaminants ...................................................................................................................... 76

Using groundwater mass flux tools for evaluating complex issues associated with PFAS – lessons learnt at multiple PFAS impacted sites ................................................................................................................................................................................ 76

Evaluation of sources and sinks for chiral pesticides in groundwater – a case study......................................................................................................... 76

Mapping PFAS contamination in the Netherlands.......................................................................................................................................................................... 76

Transport of selected neonicotinoids in groundwater: column experiment ........................................................................................................................ 77

ThS 3b | Risk management of diffuse and emerging contamination .................................................................................................... 78

Exploring the pesticide biodegradation potential in aquifers used for drinking water production ............................................................................ 78

Sediments as a source of PFAS in biota – Two case studies from Norway .............................................................................................................................. 78

Prioritization model for risk management of groundwater bodies with poor chemical status in Finland – A new approach ........................... 78

Pharmaceuticals, trace metals and metalloids in the surface water used for crop irrigation: Natural attenuation or risk to health? ............. 79

The management of diffuse lead contaminated soil in Flanders and The Netherlands. A literature study for the development of effective strategies for the management of diffuse soil pollution in Flanders and The Netherlands ..................................................................... 79

Atmospheric deposition of PFOA and GenX around fluorochemical processing plants in Dordrecht and Helmond in the Netherlands ........... 80

Improving decision making for contaminated land management using environmental risk levels ............................................................................ 80

Screening values for polyfluoroalkyl substances (PFAS) PFOS and PFOA in soil and groundwater.............................................................................. 81

Developing MNA and remedial strategies for norbornene flame retardants and insecticides ...................................................................................... 81

ThS 3d | Policy strategies of environmental concerns of emerging contaminations ........................................................................... 82

PFAS: a stress test for sustainable soil management in the Netherlands ................................................................................................................................ 82

How compounds become identified as emerging/new contaminants, and the implications for stakeholders ...................................................... 82

Towards a less stringent groundwater body objective? Feedback from a French heavily industrial and urban study area ............................... 83

Towards a remedial action plan for PFAS in soil and groundwater at an industrial site in Antwerp: results on research for treatment and reuse of soil and discharge of groundwater ........................................................................................................................................................ 83

Geochemical baseline of urban soils with undedicated datasets: Link between methodology and environmental policies ............................ 84

Multi-national perspectives and remedial considerations for 1,4–Dioxane as co-contaminant at chlorinated solvent sites ............................. 84

Policy on diffuse soil contamination and emerging contaminants: New sounds from Flanders................................................................................... 84

A framework for dealing with PFAS in the Netherlands ................................................................................................................................................................ 85

Topic 4 | Advances in remediation technologies

ThS 4a Bio-, nano-, and chemical remediation ....................................................................................................................................... 86

Comparative evaluation of the polyhydroxylalkanoates (PHAs) fermentability from different sources for bioremediation applications ........... 86

6

Content

Enhanced in-situ bioremediation (EISB) combined with in-situ chemical reduction (ISCR) for the remediation of a heavy contaminated chlorinated solvents source zone in an industrial site in South of Italy ..................................................................................................... 86

Innovative solution for difficult to treat a large TEX contamination: Stimulation of the anaerobic bioremediation ............................................. 87

Comparing zero valent iron, magnetite and goethite nanoparticles to remediate concurrent inorganic and organic pollution in brownfield soil ..................................................................................................................................................................................................................... 87

Cathodic autotrophic microbial communities able to stimulate hexavalent chromium reduction ............................................................................. 87

Removal of polycyclic aromatic hydrocarbons from contaminated marine sediments by biostimulation and thermal desorption .................... 88

Enhanced anaerobic bioremediation of a site contaminated with chlorinated ethenes: From lab studies to full-scale implementation ................................................................................................................................................................................. 88

Innovative bioremediation of MTBE and organics: in situ bio-sparging and high yield MTBE bioreactor development ..................................... 89

A review of chemical treatment methods for soil and groundwater containing arsenic and chromium ................................................................... 89

Evaluation of potassium persulfate as an ISCO based permeable reactive barrier for treatment of comingled contaminated plumes ........ 89

Transport of sulfidized zerovalent iron particles in porous media: Need for a particle stabilizer .................................................................................. 90

Complete dechlorination of chlorinated ethenes and chloroform in a brackish environment ..................................................................................... 90

Full-scale in situ remediation of chlorinated solvents in clay till by microscale ZVI emplaced by direct push jet injection: Results after 4 years .................................................................................................................................................................................................................................... 91

Sustainable activated carbon for the remediation of insensitive high explosive contaminated water ...................................................................... 91

In-situ remediation of atrazine- and bromacil-contaminated groundwater: Application screening for two iron-containing reactive particles at the lab-scale .......................................................................................................................................................................................................... 92

Combination of in situ injection of nanoparticles to fix heavy metals, with in situ thermal desorption to address the organics .................... 92

Development of a sustainable soil mixing technique using energy efficient binders and iron based reductive dechlorination ..................... 92

Investigation of electrochemistry as a remedy for tetrachloroethylene plumes ................................................................................................................. 93

Biodegradation of crude oil by microbial consortia from Nigerian soils ................................................................................................................................ 93

Oxidation of PAHs and their by-products (polar PACs) in the saturated zone of DNAPL-contaminated sub-soils batch and column experiments .................................................................................................................................................................................................................................. 94

Developing zero-valent iron nanoparticles (nZVI) suspensions from plant extracts and assessing their reactivity to hexavalent chromium ................................................................................................................................................................................................................................ 94

Impact of the soil mineralogy on the contamination and the microbial communities during lab-scale bioremediation of petroleum-contaminated soil ............................................................................................................................................................................................................ 95

The effects of hydraulic/pneumatic fracturing enhanced remediation (FRAC IN) at a site contaminated by chlorinated ethenes ................. 95

An integrated biogeochemical/electrochemical method for remediation of contaminated groundwater .............................................................. 95

Comparative adsorption of groundwater contaminants onto differents sizes of particles obtained by two top-down approaches ............. 96

Enhanced anaerobic dechlorination of TCE via recirculation and batch injection pilot systems near São Paulo, Brazil ....................................... 96

Removal of heavy metal contamination from groundwater using iron-oxide nanoparticles: A field application .................................................. 97

Cheese whey injection in groundwater: Use of an economically and eco-friendly substrate for in-situ bioremediation of chlorinated solvents ................................................................................................................................................................................................................................... 97

Replacing pump and treat system with sustainable in situ bioremediation strategy for chlorinated solvent plume ........................................... 98

Penicillium sp. removes pharmaceutical compounds from hospital wastewater and outcompetes native bacterial and fungal community in fluidized batch bioreactors ........................................................................................................................................................................... 98

Synthesis, characterization and reactivity of hydroxyapatite coatings deposited on calcium carbonate micro- and nano-particles for the removal of heavy metals from contaminated water .......................................................................................................................... 99

Mechanisms involved in the remediation of PAH-polluted soil using a slurry bioreactor ............................................................................................... 99

Comparison of ZVI-products for combined abiotic and biotic treatment of chlorinated solvents ............................................................................... 99

The use of in-situ chemical oxidation (ISCO) : the application of ozone in combination with hydrogen peroxide ..............................................100

Interactions of sulfidized nano-zero-valent-iron with microbes ..............................................................................................................................................100

The power of power: effects of electric fields on bacterial deposition and transport in porous media ...................................................................101

ISCO with fracturing: Challenges of full-scale application at an operative site ..................................................................................................................101

Application of the novel sulfidated iron nanoparticles (S-nZVI) on a site heavily polluted by trichloroethene (TCE) .........................................102

Biochar properties influence heavy metal immobilization on polluted soils and plant growth ..................................................................................102

Electro-kinetically enhanced nZVI: Experiences from France and Switzerland ..................................................................................................................102

Superoxide radical as a green reagent and an ultimate solution for soil and water contamination ..........................................................................103

7

Content

Iron minerals as catalytic activators for persulfate: performance and mechanistic studies ..........................................................................................103

In-situ remediation of pesticides in groundwater used for drinking water production: The potential of DOM ....................................................104

Nanoparticles in remediation of heterogeneous aquifers: laboratory tests and numerical simulations ..................................................................104

Hexavalent chromium remediation by green rust sulfate: How µm-scale structure of reaction byproducts can be used to evaluate stability .......................................................................................................................................................................................................................105

Reduction of aqueous mercury in contaminated sediment by activated carbon/clay-based active caps: a microcosm study with the horizontal flow and artificial turbation .....................................................................................................................................105

Active recirculation for enhanced reductive dechlorination of chlorinated VOCs in glauconitic sand on a Belgian site ...................................105

Microbial degradation of fuel components .....................................................................................................................................................................................106

Implementation of zerovalent iron for source zone treatment via soil mixing ..................................................................................................................106

Enhanced reductive dechlorination of PCE and TCE in a source zone via recirculation: Pilot test and results .......................................................107

Upgrading biosparging from plume to source treatment for an ETBE/TBA impacted site ............................................................................................107

Improve subsequent bioremediation of long-chain crude oil in soil using bio-stimulated Fe-SOM Fenton pre-oxidation .............................107

Horizontal permeable reactive barriers with zero-valent iron for preventing upward diffusion of chlorinated solvent vapors in the unsaturated zone ...........................................................................................................................................................................................................108

ThS 4b | Physical, thermal and stabilization techniques ...................................................................................................................... 109

Using the blocking effect of foam for remediation of high permeability contaminated aquifers ..............................................................................109

Sustainable Low Temperature Thermal Remediation of Pesticides ........................................................................................................................................109

Remediation of a chemical waste landfill by means of immobilisation ................................................................................................................................110

Full-scale remediation of a coal tar source area using combined in situ chemical oxidation and stabilization/solidification at the former Søllerød gaswork in Denmark ...................................................................................................................................................................................110

Pilot scale “in pile” thermal desorption remediation of mercury and mixed pesticides contaminated soil .............................................................110

Smouldering combustion (STAR): Meeting remedial goals in complex environments ...................................................................................................111

Between caravans and boreholes - Challenges of performing in-situ remedia-tion on a camping site in the Black Forest, Germany .........111

Thermal Desorption of Highly-impacted mercury soils in an Urban Area ...........................................................................................................................112

Scaling up of Dioxin Contaminated Soil Thermal Desorption Treatment: Laboratory tests and pilot conception at Bien Hoa Airbase, Vietnam .....................................................................................................................................................................................................................112

Electro Bio Reclamation (EBR) as part of a full scale soil remediation project in Ghent ..................................................................................................113

Sustainable sediment solutions: Stabilization of contaminated sediment ..........................................................................................................................113

In situ thermal remediation ~ AMCO superfund site ...................................................................................................................................................................113

Thermal desorption with smart burners – Case study for the in-situ treatment of unsaturated soils at the refinery of Gela (Italy) ..............114

Integration of innovative geotechnical and environmental solutions enables site redevelopment and protects sensitive off-site receptor from petroleum hydrocarbons ............................................................................................................................................................................114

First European thermal remediation of crystalline bedrock ......................................................................................................................................................115

Remediation of a site polluted with lindane wastes: Soil flushing pilot test ......................................................................................................................115

Smouldering remediation and resource recovery from contaminated soils and waste materials ..............................................................................116

Formation of PAH derivatives, increased developmental toxicity and risk assessment after SEE remediation of creosote contaminated soil from the Wyckoff/Eagle Harbor Superfund site ........................................................................................................................................116

In-situ zinc precipitation using inorganic sulphides ....................................................................................................................................................................117

Best methods for developing a thermal remediation project ..................................................................................................................................................117

ThS 4c | Combined treatment technologies and technology trains .................................................................................................... 118

Technical solution for the removal of PFAS from water...............................................................................................................................................................118

Combination of enhanced reductive dechlorination and aquifer thermal energy storage – pilot test ....................................................................118

The first completed example in Europe for the remediation of an aquifer contaminated with chlorinated solvents by a combination of adsorption and biodegradation .................................................................................................................................................................119

Use of permittivity, resisitivity and optical density to quantify the efficiency of free product recovery of heavy chlorinated compounds (with chemical and thermal enhancements) .........................................................................................................................................................119

Taguchi optimization of process parameters in electro-chemical PFOS removal from contaminated groundwater ..........................................120

PFAS Treatment of Soil: Demonstration of Multiple Pilot Tests.................................................................................................................................................120

8

Content

Evaluation of Established and Upcoming Remediation Technologies ..................................................................................................................................120

An Adaptive Remediation Strategy to Mitigate Biofouling in a Hydraulic Containment and Ex-situ Treatment System ...................................121

Application of Sequenced Chemical Oxidation and Bioremediation for Treatment of a Pharmaceutical Waste Mixture – Full Scale Application ...............................................................................................................................................................................................................................121

PFAS Destruction through Smoldering Combustion (STARx) ...................................................................................................................................................122

Full-scale application of EHC Liquid technology for the ISCR and ERD treatment of an aquifer contaminated with Tetrachloromethane and Chloroform ................................................................................................................................................................................................122

A Field Comparison of Biogeochemically Enhanced, Biological and Chemical Reduction for Treatment of Chlorinated Organics ...............123

Combining Strategies for Remediation of Different Gas Work DNAPL and LNAPL Groundwater Contaminants ..................................................123

Electrochemical Oxidation Pilot Reactor Demonstration Project, Coupling Technology for PFAS Destruction .....................................................124

Tuning activated carbon adsorption by surface chemistry and electric potentials: Perfluorinated alkyl surfactants as target pollutants ........................................................................................................................................................................................................................................124

In situ remediation of PFAS using colloidal activated carbon: A review of multiple case studies ...............................................................................125

In situ chemical oxidation to enhance the performance of an air sparging and soil vapour extraction treatment of chlorinated VOCS in glauconitic sands on a Belgian site ............................................................................................................................................................125

Perfluoroalkyl and polyfluoroalkyl substances in the environment: origins and feasability in thermal desorption ............................................126

Emerging impact of PFAS in Flanders - prioritization of risk locations and sampling campaigns to develop soil management strategies ..........................................................................................................................................................................................................................126

Innovative Spin® injection technology pushes boundaries of in situ remediation...........................................................................................................126

ThS 4d | Phytoremediation and ecological engineering and nature-based solutions ..................................................................... 127

Planting trees at phytomanagement sites : Recommendations from field trials ...............................................................................................................127

Bacteria-assisted phytoremediation for soils and groundwater polluted with organics ................................................................................................128

PHYTO-INTEGRATED® Remediation: Expanding phytoremediation by combining engineering, treatment media & vegetation.................128

Fate and distribution of pharmaceutically active compounds in mesocosm constructed wetlands .........................................................................128

Use of organic amendment and endomycorrhizal fungi for steel slags phytostabilization ..........................................................................................129

Co-remediation of Pb and PAHs with fungi in urban soil ...........................................................................................................................................................129

Phytoremediation: a practical guideline with decision tools for design, implementation, maintenance and monitoring ...............................130

Sustainable organic subproducts to enhance denitrification in constructed wetlands treating highly nitrate polluted leachates from nurseries .........................................................................................................................................................................................................................130

Hybrid constructed wetlands for the pre-treatment of cooling tower water prior to desalination ...........................................................................131

Comparison of four soil remediation techniques applied to trace elements contaminated soil: a three-year field experiment ....................131

Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

ThS 5b | Remediation goals and strategies ........................................................................................................................................... 132

Using lower threshold limits as a stop criteria to prevent overdoing remediation. When is it good enough?.......................................................132

Understanding potentially toxic element mobility as a first step toward remediation and restoration of land occupied with copper mine tailings ......................................................................................................................................................................................................................132

Sustainable remediation in the Latin American context ............................................................................................................................................................132

Blue Gate Antwerp ....................................................................................................................................................................................................................................133

From stand-and-hold towards enhanced bioremediation: bioremediation and 3d modelling at a former manufactured gas plant in Utrecht, the Netherlands ................................................................................................................................................................................................133

Australia’s National framework for the remediation and management of contaminated sites in Australia ............................................................134

Chlorinated solvents and redevelopment of an industrial site: the importance of characterisation in the definition of an appropriate treatment strategy ........................................................................................134

Sustainable risk management and remediation strategy for a large 21 ha urban brownfield site .............................................................................135

Governance strategies for finalizing contaminated areas ..........................................................................................................................................................135

Evaluation of the key success factor of complex remediations based on a case study: “The Mariakerke acid tar dumpsite, Belgium” .................................................................................................................................................................................135

From contaminated site containment and pump and treat, towards less intensive site management through biodegradation ..................136

Intensive historical review and sampling campaigns to validate potential hotspots of sediment pollution linked

9

Content

with (former) risk activities ....................................................................................................................................................................................................................136

A Management Strategy to deal with Soil and Groundwater Contamination ....................................................................................................................137

A digital explorer for contaminated stream sediments...............................................................................................................................................................137

Flux-controlled remediation & risk management: strategy and examples ..........................................................................................................................138

Defining Site specific water discharge values for 1,4-Dioxane and other compounds – Applying the BATNEEC approach and sustainability principles to improve the overall performance of an ongoing P&T system .................138

ThS 5c | Sustainable and socio-economic evaluation & public perception related to remediation, societal participatory approaches .................................................................................................................................. 139

Gone with the wind - Soil gas diffusion to street level mitigation plan during tunnel excavation in the TLV LRT Red Line project ..............139

Do we have sufficient information to assess the sustainability? ..............................................................................................................................................139

How SuRF-UK’s detailed checklist of sustainability assessment criteria / indicators has been used to date in the UK and elsewhere and its 2019 revision ..................................................................................................................................................................................................140

Applying sustainability principles in evaluating alternatives for remediation projects in South Africa ...................................................................140

Sustainability assessment of in-situ remediation techniques using the SCORE method ...............................................................................................140

Indicator use in soil remediation investments: views from policy, academics and practice .........................................................................................141

Designing a sustainable remediation project with deep socio-economic impact ...........................................................................................................141

Stakeholder involvement in sustainability assessment of remediation strategies – method and application ......................................................142

Can sustainable remediation be efficient and effective? ............................................................................................................................................................142

Relieving community stress related to soil remediation by performing an elaborated on-site GC-MS air monitoring ......................................143

Topic 6 | Land stewardship

ThS 6a | Valuations of SSW systems: natural capital accounting, ecosystem service assessment and soc-ec CBA ......................... 144

The Nature Value explorer: valuing the benefits of green and blue infrastructure. ..........................................................................................................144

LAND STEWARDSHIP, Investing in the Natural, Societal and Economical capital of Industrial Land .........................................................................144

Towards multifunctional urban surface water: understanding current and future surface water uses ....................................................................144

Assessing costs and benefits of improved soil quality management in remediation projects: A case study from Sweden..............................145

Topic 7 | Land, soil, water and sediment in the circular economy

7a1 | Circular land use and brownfield regeneration ........................................................................................................................... 146

Sustainable soil management ..............................................................................................................................................................................................................146

Sustainable conversion of a former sewage plant to “liveable nature”. A new recreational industrial landscape ................................................146

Reuse of thermally-cleaned soil and tarmac granulate: health, environment and public emotions .........................................................................146

Soil and circular Economy: state of the art on the reuse of excavated soil in Europe .....................................................................................................147

Circular land use: every step counts ...................................................................................................................................................................................................147

Geochemical background over the Parisian Basin: from the setting up to the practical use for circular reuse of excavated soils .................148

The SURICATES project – Pilot reallocation of 200.000 tons of sediment within the river in Port of Rotterdam, the Netherlands .................148

Challenges of brownfields regeneration for housing needs in urban space (case study area: Brno city in the Czech Republic) ..........................................................................................................................................................................................................149

Remediation strategy for Gdansk Shipyard as an example of brownfield management in Poland ...........................................................................149

Rawfill-project : Innovative characterization(or investigation) of landfills and smart decision-making as part of the circular economy. ...149

ThS 7b | Reuse and upgrading of SSW & products; recovery of valuable resources; improving ecological functioning ............... 150

How does contaminants bioavailability help sustainable soil use - science vs reality .....................................................................................................150

Monitoring of soil-like materials in view of potential re-use .....................................................................................................................................................150

Environmental Impacts of Lake Sediment Reuse as A Phosphorus-Rich Soil Amendment ...........................................................................................151

ZuNurec: purification and recupuration of nutrients for Flemish greenhouse wastewater ..........................................................................................151

ThS 7c | Nature based solutions: effectiveness for long term ecosystem services for soil & water .................................................. 151

From contaminated space toward a meaningful place: reactivating soil, land and cities ..............................................................................................151

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Content

Long-term benefits of using green waste compost in land restoration as part of the Circular Economy ................................................................152

Amended vegetation filters: a new nature based solution to treat wastewater, increase groundwater resources, recover nutrients and produce biomass .......................................................................................................................................................................................................................................152

To what extent can secondary mineral resources replace primary mineral resource ? ...................................................................................................153

Tidal wetland restoration projects as a nature-based solution: characterization & design considerations .............................................................153

Posters

Topic 1 | Soil and water in the digital world

1a | Big data, smart data combinations ................................................................................................................................................. 154

The application of passive sampling to monitoring of plant protection substances and pharmaceuticals in ground water ..........................154

Database of risk-sites in Flanders: Tracing and tackling historical soil contamination to safeguard a fit for purpose soil for our future generation ........................................................................................................................................................................................................................154

Groundwater model of a large desert area in Algeria for groundwater resources impact assessment ....................................................................154

Risk at the intersection of climate variability and contaminated site management ........................................................................................................155

Interreg project sullied sediments: Set-up of a decision support tool on remediation techniques for contaminated sediments .................155

1c | New technological developments ................................................................................................................................................... 156

Use of drone technology for single beam bathymetric survey of a hydroelectric dam reservoir located on the Tuscan-Emilian Appennine ......................................................................................................................................................................................................156

Pollution assessment by means of multivariate analysis and multispectral imagery in the surrounding soils of a derelict Hg-As mine ...........156

Modelling of air flow in capillary break layers - A new approach to determine governing mechanisms in balanced ventilation systems preventing vapor intrusion of volatile pollutants ..................................................................................................................................157

Topic 2 | Advances in assessment of risk and monitoring of soil, sediment and water quality

2a | Advances in assessment of risk and monitoring of soil, sediment and water quality ............................................................... 158

A forensics-multivariate approach to the complex pollution affecting the environmental compartments in an industrial area ...................158

Combined geophysical and geochemical tools to monitor DNAPL decontamination processes...............................................................................158

Improvement of traditional investigations by prior geophysical measurements .............................................................................................................158

Sources, fate and impact of polycyclic aromatic hydrocarbons in soils of a broad industrialized area in Northern Spain ................................159

In sights within a remediation project: Use of data dashboards to interrogate and understand a modern groundwater remediation project ....................................................................159

On the use of geophysical monitoring to monitored DNAPL extraction .............................................................................................................................160

Evaluation of biodegradation and biostimulation potential within a chlorinated ethene-contaminated aquifer using advanced monitoring tools ...................................................................................................................................................................................................................160

A sensitive method for determination of legacy and emerging perfluorinated alkyl acids (PFAAs) in environmental samples (water, soil, sediments, and sludge) using liquid chromatography tandem mass spectrometry .......................................................................................................161

AMIIGA project as an example of advanced investigation, assessment and remediation of groundwater contamination crossing the urban areas and adjacent hinterlands ...............................................................................................................................................................................................161

Development of vertical cross section distribution investigation for chlorinated hydrocarbons in gravel geology ...........................................161

Hydrocarbon background levels in Denmark in indoor and outdoor air .............................................................................................................................162

Functional bacteria for phenanthrene degradation in petroleum-contaminated soil during nature attenuation (NA) and bioaugmentation (BA) processes revealed by DNA-stable isotope probing .......................................................................................................................162

A contaminant mass recovery model for electrical resistance heating sites: Comparison with actual data ..........................................................163

Characterizing NAPL conditions and chemical risks in support of river sediment cleanup ..........................................................................................163

Innovative, multi technique investigation for residual NAPL presence in order to assess bedrock remediation at a site in Sweden ...........163

Use of innovative techniques to determinate volumes of contaminated sediments in Flanders ...............................................................................164

Application of decision unit multi-increment sampling (DUMIS) in performance evaluation of immobilization of a nickel and lead contaminated site: a case study in China .......................................................................................................................................................................164

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Content

37Cl- and 13C-compound specific isotope analysis and biomolecular tools to monitor chlorobenzene biodegradation .............................164

Chemical characteristics and toxic elemental release from excavated shale and its variation.....................................................................................165

Enhanced data collection in the field: Onsite, high resolution VOC analysis in soil and ambient air during investigation and remediation of a chlorinated solvent contaminated site ...................................................................................................................................................165

Leaching characteristics of Fluorine and Boron from artificial and non-artificial contaminated soils using up-flow percolation test .........166

2b | Analysis techniques. ........................................................................................................................................................................ 167

LDPE passive samplers for assessing risks for groundwater related to hydrocarbons leaching from soil ................................................................167

An innovative technique to evaluate commingled plumes and assess remedial progress - A case study ..............................................................167

Development of a fast determination of PFAS as a sum parameter in soil and aqueous samples ..............................................................................168

Detailed direct-sensing investigation of contamination at an old landfill site Brezinka .................................................................................................168

Oil spill forensics: Polluter does (not) get away with it ................................................................................................................................................................168

Temperature and exposure history strongly influence gasoline ether oxygenate (ETBE) biodegradation in groundwater .............................169

XRF data as big data opportunitie ......................................................................................................................................................................................................169

Screening for 21 perfluorinated organic compounds in Czech wastewater treatment plants ....................................................................................169

Development and implementation of a “rapid site-specific LNAPL screening protocol” at a former petrochemical cluster in Antwerp, Belgium ..................................................................................................................................................................................................................170

2c | Soil-sediment-water interaction and system dynamics ................................................................................................................ 171

Cross pumping test applied to characterize the hetero-geneity of hydraulic properties of a contaminated aquifer .........................................171

Heavy metal binding behavior in sediments and suspended matter as a factor of water quality in the catchment area of the lower Lahn River (Germany) during an extremely low water period ........................................................................................................................171

Evaluation of the effect of soil properties and experi-mental parameters on cadmium sorption in soil using the multiple linear regression approach ....................................................................................................................................................................................................................171

Archaeology as a tool in soil studies ..................................................................................................................................................................................................172

Resilient soil and water ressources, understanding the water beneath your feet - in a changing climate .............................................................172

Re-release and phases of arsenic temporarily re-sorbed on excavated marine sedimentary rock under redox condition ...............................172

Role of perched aquifer in the fate of the contaminants: Case study ....................................................................................................................................173

A geological approach to model and visualize contamination pathways; traditional modelling versus Environmental Sequence Stratigraphy (ESS) .................................................................................................................................................................................................................173

Oxygenated polycyclic aromatic compounds (O-PACs) transfer in soil and groundwater - Experiments at the laboratory scale ..................174

Characterization of water flow in the unsaturated zone of vegetated lysimeters using stable water isotopes and modelling ......................174

Heavy metals in Technosols under different aquatic conditions - risk assessment for an former mining area in Hessen (Germany) ............175

2d | Human and environmental health risk assessment ...................................................................................................................... 175

Methodological approach for the protection of workers at an active industrial contaminated site in Mantua (Italy) ........................................175

Impact of mercury contamination at a chlor-alkali site on Apis mellifera and its products ..........................................................................................175

Mercury transfer in Solanaceae species ............................................................................................................................................................................................176

Assessment of the bioaccessibility of metals in soils through inhalation and ingestion pathway for human health risk assessment .........176

Investigation and risk assessment of chemical plant effluent spill .........................................................................................................................................176

Topic 3 | Diffuse and emerging contaminants

3a | Sampling and analysis of diffuse and emerging contaminants .................................................................................................... 177

Dynamics of mikroplastic and interactions with heavy metals in floodplain soils – Conception of a PhD project ..............................................177

Ecological risk associated with persistent free radicals in contaminated soil .....................................................................................................................177

3b | Risk assessment and strategies for prioritization and monitoring of diffuse and emerging contaminants . ......................... 178

Pharmaceuticals: Critical or negligible? ............................................................................................................................................................................................178

PFAS impacts on solid waste landfills ................................................................................................................................................................................................178

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Content

PFAS site investigations at two airports in Norway .......................................................................................................................................................................178

Addressing challenges/uncertainties in PFAS risk assessment ................................................................................................................................................179

The use of risk assessment in developing remedial strategies for PFAS contamination .................................................................................................179

3c | Reactive interfaces: unsaturated zone, sediments and groundwater . ....................................................................................... 180

Occurrence of pesticides in groundwater in and around graveyards and pesticide biodegradation capacity of the corresponding topsoils ...........................................................................................................................................................................................................................180

RESPONSE project: Reactive transport modelling of point source contamination in soils and groundwater ........................................................180

3d | Policy strategies and governance of diffuse and contaminants of emerging concern .............................................................. 181

The evolution of global regulation for per- and poly-fluorinated alkyl substances (PFAS) ...........................................................................................181

POLLUSOLS: diffuse contamination from land to sea ..................................................................................................................................................................181

Knowledge impulse for Dutch delta approach for water quality ............................................................................................................................................181

Treatability of PFAS in soil and groundwater: results of bench-scale tests and full scale experience ........................................................................182

The ENSOr stakeholder platform -Emerging policy challenges on New SOil contaminants .........................................................................................182

Topic 4 | Advances in remediation technologies

4a | Bio-, nano-, and chemical remediation. ......................................................................................................................................... 183

Organo-layered double hydroxides nanoparticles as sorbents for chlorinated hydrocarbons in natural systems: sorption capacity and long-term stability studies ..........................................................................................................................................................................................183

The Rate of lindane biodegradation in different constructed wetlands ...............................................................................................................................183

Enhanced reductive Dechlorination Pilot Test: Importance of the preliminary investigations to improve the design of the intervention ............................................................................................183

Dual C–Cl isotopic assessment to elucidate origin, fate, and potential bioremediation treatment of chlorinated methanes at two industrial multi-contaminated aquifers ..............................................................................................................................................................................184

Composting of wastewater treatment sludge containing various new emerging pollutants......................................................................................184

Remediation of soil polluted with lindane wastes by using persulfate activated by alkali: Kinetic Model Discrimination ...............................185

Nanoremediation of chlordecone polluted soils ...........................................................................................................................................................................185

Multi-dimensional (carbon and chlorine) stable isotope analysis for the assessment of chlorinated compounds remediation ....................186

Two in situ remediation innovations: (1) Wide distribution micro-scale colloidal zero valent iron and (2) Source-area petroleum hydrocarbon retardation and degradation ...............................................................................................................................................................186

Soil remediation of a Chloride contaminated site in Nangtong, China, using Electro-Reclamation ..........................................................................186

Endocrine disruption potential of widely used antimicrobial compounds revealed. Can they be biodegraded? ................................................187

Influence of sulfate reduction and biogenic reactive minerals on long-term PRB performance in a sulfate rich, high flow aquifer .............187

Clean-up of an Israeli site contaminated with petroleum hydrocarbons – Case study ...................................................................................................187

Coupling bioremediation-chemical oxidation for TPHs removal from industrial soils ....................................................................................................188

Intelligent integration of innovative geotechnical and environmental solutions enables site redevelopment and protects sensitive off-site receptor from petroleum hydrocarbons .........................................................................................................................................................188

Lab scale micro and nano ZVI remediation of groundwater polluted with highly concentrated organochlorides .............................................189

The removal of PCBs from contaminated water using spent oyster mushroom substrate ............................................................................................189

Fixed-bed column studies for the biosorption of methylene blue onto banana, cucumber and potato peels .....................................................190

Superoxide radical as a green reagent and an ultimate solution for soil and water contamination ..........................................................................190

Structural insights into how sulfidation of zerovalent iron enhance reactivity and long-term performance ........................................................191

Sustainability as a key driver in selecting a site remedial strategy: Installing a reactive zone to mitigate off-site migration ...........................191

Application of combined LDH-biochar derived from waste materials for mine water remediation: A case study from Slovakia ...................191

New insights into biostimulation of highly dichloro-methane-polluted sites: from the lab to the field ..................................................................192

Planning of a nano remediation: From mobility and reactivity tests to field application ..............................................................................................192

Post-treatment monitoring: an essential tool to highlight and react to unexpected evolution of pollutant concentrations ..........................193

Posters – 4b | Physical, thermal and stabilization techniques. ........................................................................................................... 194

Evaluation of surfactant as useful tool for groundwater remediation ...................................................................................................................................194

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Content

Sustainable combination heating: An innovative approach for in situ thermal remediation in challenging lithology ......................................194

Lab-scale thermodesorption tests used to estimate the evolution of available aliphatic hydrocarbons in contaminated soils during pilot-scale remediation experiments .........................................................................................................................................................................194

Past, current and new application for removal of acid tar pits from contaminated land ...............................................................................................195

Upscaling in soil remediation: Multi-scale two-phase flow modelling in high permeable aquifers ..........................................................................195

Thermal Conductive Heating (TCH): Comparison of power consumption to heat the soil between electrical resistance heating and gas fired burners ..............................................................................................................................................................................................................196

Biochar - from organic waste to resource for treatment of contaminated soil ...................................................................................................................196

Solubilization of dense non aqueous phase liquids produced as lindane wastes using non-ionic surfactants ....................................................196

Between caravans and boreholes - Challenges of performing in-situ remedia-tion on a camping site in the Black Forest, Germany .........197

Elimination of threat to one of Scandinavia’s largest groundwater resources ...................................................................................................................197

Electrical Resistance Heating (ERH) remediation at an active industrial site .......................................................................................................................198

Toward the development of photo-reactors for the efficient treatment of water polluted with dyes ......................................................................198

Efficiency assessment of immobilization measures for PFAS in soil .......................................................................................................................................199

In situ geochemical stabilization (ISGS) for NAPL management .............................................................................................................................................199

In situ remediation of PFAS using colloidal activated carbon: A review of multiple case studies ...............................................................................199

ERH experience in Europe, the added value of the consultant ................................................................................................................................................200

Modelling adsorption of binary mixtures of volatile organic compounds (VOCs) onto activated carbon from contaminated groundwater treatment emissions ........................................................................................................................................................................200

In situ Stabilization and Solidification (ISS) optimized: benefits of adding sodium persulfate ....................................................................................201

In-Situ metal precipitation of a nickel groundwater contamination. Results of a comparative lab study on the immobilization of nickel using a carbon source and a permanganate solution ...............................................................................................................................................201

Analysis of work coil dynamics for induction heating applications........................................................................................................................................202

Adsorption of contaminants onto a char obtained by pyrolysis of used tyres and rubber wastes: a possible low-cost alternative in the groundwater technologies ....................................................................................................................................................................................................................202

Can Biochar be used as a cost-effective sorbent for groundwater remediation? ..............................................................................................................202

Sustainable Remediation of Diesel-Contaminated Soil by Low-Temperature Thermal Desorption ...........................................................................203

Thermally enhanced in-situ remediation using steam-air injection – 20 yeares of remediation experience and improvement of the “DLI-Design-Tool” ..............................................................................................................................................................................................203

Thermally enhanced in-situ remediation using steam-air injection – background and improvement of the “DLI-Design-Tool” software for remedial design ............................................................................................................................................................................203

4c | Combined treatment technologies and technology trains. ......................................................................................................... 204

In-situ Zinc precipitation using inorganic sulphides ....................................................................................................................................................................204

Enhanced magnetic separation with Fe-Ni nanoparticles: A novel tool for soil washing ..............................................................................................205

In situ and on site bioremediation of MTBE .....................................................................................................................................................................................205

Remediation of low-permeability soils by an innovative technology-train .........................................................................................................................205

Remediation of TCE contaminated groundwater in low permeability media using Targeted Solids Emplacement at the former “Atlas 12” U.S. Air Force Site.........................................................................................................................................................................................206

Remediation of a jet fuel contaminated aquifer through enhanced chemical desorption ...........................................................................................206

Successful closure of a DNAPL site - Lessons learned ..................................................................................................................................................................207

Air treatment methods as possible alternatives to activated carbon ....................................................................................................................................207

Biological alternatives to conventional activated carbon or catox air treatment ..............................................................................................................208

The LIFE+ SURFING project: Surfactant enhanced chemical oxidation for remediation DNAPL .................................................................................208

The LIFE+ SURFING project: On site treatment for recovery surfactant and eliminate COPs in DNAPL remediation ..........................................209

Surfactant Enhanced Remedation (SER) for in-situ soil and groundwater remediation of petroleum and chlorinated NAPL impacts at brownfield sites in Belgium ...................................................................................................................................................................................................................209

Surfactant enhanced recovery of separate-phase petroleum hydrocarbons .....................................................................................................................210

Modeling the phosphate dynamics during electro-coagulation process with aluminium electrodes .....................................................................210

Frac-In: Development and pilot testing of a technology for combined direct push and fracturing of contaminated soil ................................210

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Content

Successful transition from ex situ to in situ remediation for CVOC-impacted groundwater ........................................................................................211

Phased remedial approach following the BATNEEC principle to address off-site migration risks ...............................................................................211

Targeting 95% reuse: onsite ex-situ washing of multi-contaminated soils - from pilot testing to full-scale remediation .................................212

Remediation of soil and acid tar at a former refinery in Valloy Norway ................................................................................................................................212

The Taranto Prpject: Maintenance dredging of discharge canals of a steel mill and innovative in-line processing of run-off sediments ......................................................................................................................................................................................................................................212

HYdrometallurgy and phytomanagement approaches for steel slag management ........................................................................................................213

Post-treatment of aqueous solution containing surfactant and chlorinated organic compounds from lindane wastes ..................................213

Integrated remediation - redevelopment of contami-nated sites: the ISCO-SS soil mixing technology ..................................................................214

Full-scale remediation of a large groundwater pollution of trichloroethene: a combination of biobarriers and hydraulic containment .........214

Biological anaerobic degradation of VOCs combined with recirculated groundwater heating ..................................................................................214

Cyclic bioremediation of a heavily impacted Xylene site in Westerlo (BE) – 100% on site biological treatment of soil, groundwater and soil vapor ..................................................................................................................................................................................................................215

4d | Phytoremediation and ecological engineering and nature-based solutions. ............................................................................ 216

Phytoremediation and mycoremediation of contaminated land at industrial scale: A complete toolkit for nature-based solutions..........216

Biocascade: The next generation of sustainable puri-fication of polder water and post-purification of WWTPs ..................................................216

Global approach to recover rare earth elements from mine tailings by an hyperaccumulating plant ....................................................................216

Nature based solutions to manage the soil contamination of urban allotment gardens: examples from Nantes (France) ..............................216

Efficiency of Phytosuc-separation System (PSS) for simultaneous removal pb and sb at shooting range soil .......................................................217

4e | Post-treatment monitoring in relation to long term site management ...................................................................................... 218

Demonstration to support approval of monitored natural attenuation remedy for a 1,1-DCE plume in fractured limestone ........................218

Application of CSIA on evaluating in situ bioremediation effectiveness of chlorinated ethenes ...............................................................................218

Mass discharge for vapor intrusion site assessment and vapor intrusion mitigation system analysis ......................................................................218

Transfer of Hg within a sediment-nettle-insect food web at a chlor-alkali landfill ...........................................................................................................219

Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

5a | Legal and economic aspects of the management of contaminated land .................................................................................... 220

Application of environmental forensic investigations to define the allocation of liabilities in insurance claims ..................................................220

5b | Remediation goals and strategies .................................................................................................................................................. 220

Remediation goals and moving goal posts .....................................................................................................................................................................................220

ISCR-based remediation of herbicide/pesticide-impacted soils in Canada, China, Colombia, Sweden, and the United States: 22 years of success and surprises ........................................................................................................................................................................................................221

Remediation of chlorinated ethenes via ISCR in a fractured bedrock aquifer at a redevelopment site ...................................................................221

Urban soil remediation: In situ thermal desorption under a building, in the centre of Brussels ................................................................................221

TreAting contamination through NanoremedIAtion: the TANIA project ..............................................................................................................................222

The ISO 18504 standard on sustainable remediation ..................................................................................................................................................................222

5c | Sustainable and socio-economic evaluation & public perception related to remediation. ...................................................... 223

A top-down approach for the development and implementation of GSR in Taiwan: ....................................................................................................223

Progress and challenges .........................................................................................................................................................................................................................223

A Trial of Sustainable Remediation by SuRF-Japan .......................................................................................................................................................................223

Stakeholder engagement: environmental and social impact assessment vs sustainable remediation projects: Comparison and benchmarking from case studies ......................................................................................................................................................................223

Use of sustainability principles to reduce, reuse and recycle during a landfill excavation project in India .............................................................224

5d | Managing large scale industrial and agricultural pollution (water soil energy food nexus) ..................................................... 225

Overview of feasible remedial actions to tackle the regional heavy metal soil and groundwater pollution related to former non-ferro industrie in the Campine area (NE Belgium) .................................................................................................................................................225

15

Content

From Stand-and-Hold towards Enhanced Bioremediation: Bioremediation and 3D modelling at a former manufactured gas plant in Utrecht, the Netherlands ................................................................................................................................................................................................225

Topic 7 | Land, soil, water and sediment in the circular economy

7a | Circular land use and brownfield regeneration ............................................................................................................................. 226

Opportunities for preparing urban contaminated land for bio-based production ..........................................................................................................226

Sustainable redevelopment of brownfields. More than choosing the best soil remediation technology. ..............................................................226

7b | Reuse and upgrading of SSW & products; recovery of valuable resources; improving ecological functioning ...................... 227

Feasibility project for the remediation and the reuse of sediments resulting from the hydraulic restoration of the infiltration basins of the Arno torrent ......................................................................................................................................................................................................................227

On-site or commercial topsoil manufacture using excavated soils or inert materials: full-scale experience of a pre-European network .........227

Current concerns of using struvite-based fertilizer in horticulture .........................................................................................................................................227

Phytomanagement: towards a reuse of abandoned sites in Wallonia ..................................................................................................................................228

Land mangement issues and mining activities ..............................................................................................................................................................................228

Phytoextraction capacity of Phragmites australis in constructed wetland to reduce pollutants from industrial wastewater .........................228

Reuse of sediments in landscape development: ecotoxicological monitoring of a mound in Wallonia (Belgium) ..............................................229

Thermally enhanced reductive dechlorination at an industrial site in Nevele, Belgium.................................................................................................229

From static waste towards dynamic resources landfill management ....................................................................................................................................229

Exhausted granulated activated carbon from fresh water production reactivation by use of microwave heating .............................................230

Biological Restoration of Soil Function after Smouldering Remediation .............................................................................................................................230

Real time monitoring and modelling web platform for water reuse optimization in a context of Managed Aquifer Recharge and Soil Aquifer Treatment ................................................................................................................................................................................................230

7c | Nature based solutions: Effectiveness for long term ecosystem services for soil & water. ........................................................ 231

The Long-term Assessment of Rain Garden from the View of Sustainable Land Use ......................................................................................................231

Special Sessions (SpS)

16

This session will include seven short - ten minutes - presentations, directly focusing on how to assess the risk from groundwater pollution and to develop adequate groundwater screening values, beyond the requirement ‘that all groundwater should be directly suitable as drinking water’. The presentations are the prelude to a 20 minutes discussion with the participation of audience and speakers.

PROGRAM

Setting the sceneFrank Swartjes (Nat. Institute for Public Health and the Environment; RIVM, the Netherlands)

Groundwater quality assessment from a contaminated land perspectiveJussi Reinikainen (Finnish Environment Institute; SYKE, Finland)

What European Directives want from us – “Good status” – going beyond good quality?Dietmar Műller-Grabherr (Environment Agency Austria, Austria/ Common Forum)

The importance of understanding the chemistry in groundwater risk assessment – Arsenic as an exampleCharlotta Tiberg (Swedish Geotechnical Institute, Sweden)

Natural source zone depletion (NSZD) in groundwater managementPeter Nadebaum (GHD Pty Ltd, Australia)

Groundwater quality assessment from an area-wide perspectiveHans Slenders (Arcadis, the Netherlands)

The vapor intrusion pathway from petroleum contaminated groundwaterIason Verginelli (University of Rome Tor Vergata, Italy)

4bSpS | Workshop Bio-Geotechnology

Timo Heimovaara¹; Susanne Laumann²; Frank Volkering³¹ Delft University of Technology, Department of Geoscience and Engineering; ² Delft University of Technology; ³ Tauw bv

The field of BioGeoTechnology studies the development and application of bio-based, sustainable alternatives for classical geotechnological methods. Biogeotechnological methods are often inspired on natural processes. Promising examples are :

• Soil Sealing by Enhanced Aluminum and DOM Leaching (SoSEAL),

• Microbially Induced Calcite Precipitation (MICP) ,

• the Iron Ore Barrier

• In Situ Geochemical Stabilization

These technologies can provide cost-effective and sustainable alternatives to classical geotechnical solutions such as sheet pile walls, bentonite cement walls, et cetera, but also create completele new opportunities in fields such as:

• Water safety (dikes, sluices, etc)

• Preventing leakage from surface waters

• Isolation of contaminants source zones

2bSps – Harmonization of analytical protocols for chemical analysis of contaminants

Stany Pensaert¹; Hendrik Van De Weghe²¹ DEME; ² V.I.T.O.

In general the results of contaminant analysis have to be inter-preted in relation with the analysis protocol. This is obvious for contaminants that are method defined, like “mineral oil”, but it also applies to well defined compounds like PAH or pesticides. Today we see that between countries, but even within countries, protocols can differ. This makes that an analysis of any contaminant has to be interpreted differently and the user (contractor, government agencies…) almost has to know the analysis protocols to do the interpretation. Through harmonization the result of an analysis should preferably mean the same for everyone, and the user of the result should be able to do so without knowledge of the under-lying analysis protocols.

This free session aims to give an insight in the situation with regard to harmonization of analytical methods through a few short presen-tations of the players in the field. Speakers from commercial and reference laboratories, from contractors and government agencies, will present case studies that illustrate the needs, the efforts and the challenges. The session will be highly interactive as each short presentation will be followed by a panel and audience discussion.

The session will be organised by VITO, contact person is Hendrik Van De Weghe. The panel discussion will be moderated by Stany Pensaert (DEME Group).

2dSpS | Towards a decent and efficient proce-dure for groundwater quality assessment

Frank Swartjes¹; Renato Baciocchi²¹ National Institute for Public Health and the Environment (RIVM); ² University of Rome Tor Vergata, Italy

Soil quality assessment generally relies on exposure models. Worldwide, several exposure models that focus on exposure to soil contaminants exist. But what about groundwater quality assessment? Policies often use the requirement that groundwater must be directly suitable as drinking water. The WHO procedure in relation to drinking water quality involves oral exposure from water and assumes 80% of the Tolerable exposure as background exposure. This is a stringent requirement for general applications, but comfortable from a human health protection viewpoint. The question is whether this requirement is realistic from the perspec-tive of reasonable groundwater quality assessment in which societal, economical and technical aspects should also be consid-ered. In the present time, in which the Water Framework Directive provides important corner stones, several assumptions for assessing groundwater quality have to be taken into consideration.

In this session, the focus is on several aspects that contribute to a decent and efficient procedure for groundwater quality assess-ment. Issues of interest include: fate and transport of contaminants; the relation between the use of groundwater and risks; scale of groundwater protection and assessment (plumes versus ground-water bodies; site versus region); risks from volatile contaminants that may intrude from groundwater into buildings; identification of other vulnerable objects that may be affected by contaminants in groundwater; intrinsic value of groundwater quality; and gover-nance of groundwater protection.

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The MOUSTIC project: Foams for in-situ treatments of vadose zones contaminated by hydrocarbons

Nicolas Fatin-Rouge¹; Iheb Bouzid¹; Julien Maire¹; Yoan Pechaud²; Vincent Langlois²; Douglas Pino Herrera²; Jean-Noël Louvet²; Malorie Dierick³; Pierre-Yves Klein³; Benoit Paris⁴; Quentin Giraud⁴; Quentin Giraud⁴¹ Université de Bourgogne - Franche-Comté, Institut UTINAM − UMR CNRS 6213; ² Université Paris-Est Marne la Vallée- Laboratoire Géomatériaux et Environnement (EA 4508); ³ REMEA; ⁴ INTERA

The project aims at providing tools for the delivery of active matter throughout heterogeneous unsaturated hydrocarbon-contami-nated zones to improve in situ degradation. We have planned our efforts in one main direction: the use of foams as delivery fluids of controlled mobility. This first presentation will give an overview of the MOUSTIC project and of the main results obtained. The project has been divided in 4 main scientific complementary tasks:

- Mobility and distribution of active matter: This task aimed at linking foam transport to characteristics of physicochemically heterogeneous unsaturated soils, and at delivering rapidly and homogeneously active materials within them. An inno-vative surfactant foam-based technology was developed to deliver homogeneously the chemical (oxidant) and biological reactants (micro-organisms, nutrients).

- Controlled and optimized degradation of contaminants – This task deals with the optimization of delivered active matter for the degradation of hydrocarbon contaminants in unsaturated zones. It involved the strategies of oxidation, biodegradation and their synergistic combination. The delivery of oxidant like persulfate was strongly improved with a significant increase of the delivery radius of influence compared to the usual ISCO an S-ISCO methods. The delivery of biological reactants is currently under study.

- Field-tests and assessments – This task was dedicated to the set-up of surfactant foam-based technology in hydrocarbon-contaminated deep vadose zones, and its assessment in terms of feasibility and multi-criteria analysis with respect to reference technologies.

- Modelling of foam transport – In this task we were modelling the transport of foams, the delivery of active matter in vadose zones and degradation kinetics at the field-scale.

To conclude this project allowed to propose and assess a new in situ remediation technology that improve the control of the delivery and the reactivity of chemical and biological reactants compared to conventional approaches in unsaturated soils.

Assessment of a new foam-based technology for enhanced oxidant delivery and treatment in unsaturated anisotropic hydrocarbon-contaminated soils

Iheb Bouzid; Julien Maire; Nicolas Fatin-RougeUniversité de Bourgogne - Franche-Comté, Institut UTINAM − UMR CNRS 6213

The use of in situ treatments for soil regeneration is growing, but the successful remediation of anisotropic contaminated soils remains a challenge, since it is limited by the accessibility to contaminants. Among the available strategies, advanced chemical oxidation (ISCO), and its combination with bioremediation, is especially attractive for moderate to low concentrations of recal-citrant organic pollutants. However, the homogeneous delivery

• Sealing of tankpits or sewers

• Stabilization of roads

• Nature development

In the workshop, professor Time Heimovaara wil give an introduction into f the relatively new field of Bio-Geotechnology; the organizing partners TU Delft, Deltares, Tauw, and Peroxychem wil give short introductions into the four technologies mentioned above.

After these introductions, the session organizers will have a discussion with the participants on possible application of the bio-geotechnologies provided by the organizers. Participants can put forward their own cases or ideas, or can built upon a number of cases.

The session will be closed by a discussion on options for further option for applied scientific research on bio-geotechnology.

4cSps1: Foams for in-situ treatments of vadose zones contaminated by hydrocarbons

Organizers: Nicolas Fatin Rouge1, Iheb Bouzid, Yoan Pechaud, Vincent Langlois, Douglas Pino Herrera, Malorie Dierick, Pierre-Yves Klein, Benoit Paris, Quentin Giraud1Université de Bourgogne

This project deals with ‘Sustainable Methods and Technolo-gies for Remediation’. It is an inter-sectoral partnership involving public laboratories in environmental bioprocess, chemical and physico-chemical engineering laboratories (Université Franche Comté-UTINAM, Université Paris-Est Marne la Vallée-LGE), a soil remediation engineering company (INTERA) and a remediation operator (REMEA).

Finding technologies to remediate deep contaminated zones or those situated under building foundations represents a real challenge. Due to the low accessibility, there is a lack of efficient technologies for their clean-up and thus many contaminated sites cannot be brought to regulatory criteria within a reasonable time frame. The main hypothesis of the project was that, due to their unique properties, surfactant foams may potentially deliver remedial materials to low accessible and anisotropic contaminated vadose zones, with relative uniform distribution. In this context, the major attempt of the MOUSTIC project was thus to overcome the current limits in terms of efficiency, cost, sustainability and feasibility for the in situ regeneration of unsaturated zones contaminated with petroleum hydrocarbons through the development and the assess-ment of new foam delivery technology from lab to field.

The MOUSTIC project allowed to:

- use and to control the benefiting properties of these foams to deliver active matter (oxidants, micro-organisms, nutrients) more homogeneously and within the overall space, in order to warrant an effective contaminant degradation in anisotropic and unsaturated soils;

- investigate and identify the operational conditions allowing to selectively degrade and mineralize pollutants in presence of surfactants by oxidation and biodegradation and the syner-gistic effects between these two processes;

- test this technology at the pilot-scale in a real contaminated site and to make a benefits/costs/risks assessment with respect to established treatments;

- model properties for matter transport and transfer of those complex fluids, from the pore to the site scale using data from lab scale and pilot scale to calibrate the models.

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the field test contaminated soil has been cultivated in Erlenmeyer flasks in the presence of diesel and lauryl betaine at different concentrations and the selected bacteria consortia have been used to inoculate a chemostat reactor. The microorganisms were able to degrade the hydrocarbons in presence of high concentrations of surfactants. Moreover, the physical structuration of the biomass (formation of floc, of granules, etc.), that is a very important property for the transport of microorganisms, was dependent on the operational conditions.

Secondly, to study the foam assisted transport of selected micro-organisms, columns experiments were performed. The pressure gradient during injection was controlled. Tracer experiments were performed in order to study the column hydrodynamics and the transfer of microorganisms from the foam to the soil particles. Moreover, at the end of the injection the distribution of microor-ganisms through the column was measured and the results will be compared to those expected using the classical colloid filtra-tion theory. These experiments will allow finding the best injection strategies and improving the understanding of the mechanisms involved.

Finally the selected consortia will be injected with foam in soil columns containing diesel fuel in order to evaluate the bioaug-mentation strategy for in situ foam-assisted remediation of soils.

Field-tests: Enhanced in situ chemical oxidation of an anisotropic hydrocarbon-contaminated plant using foams

Malorie Dierick; Pierre-Yves KleinREMEA

After selection of the most promising active material and procedure of foam enhanced in situ oxidation, REMEA conducted field test operations.

These tests were performed in a former hydrocarbon storage plant located in France with a deep vadose zones (> 8 m depth). The selected tests-zone show contamination range around 2000 mg/kg MS for total hydrocarbons, 100 mg/kg MS for PAH and few BTEX (5-60 mg/kg MS) with a prevalence of benzene and xylene. Foams treatments tests were performed in thick heterogeneous sand layers, located between -2 m to -6 m below the ground surface.

Injections, performed through 5 injection points at low pressure, were multiphase. Foams were first injected, with small quantities of oxidant, to fill the soil porosity and avoid pollution dispersion: because hydrocarbons were free in the soil, foams injections were adapted to prevent the creation of a high hydrocarbon-concen-trated halo around the injection zone. The second step was oxidant injection inside foams network. Indeed, this network blocks the porosity and creates preferential fluid circulation paths located at the bubble-soil interface. Thus, the amount of oxidant injected to reach the pollution was much lower than it would be with classic ISCO technique which need all the soil porosity to be filled. Further-more, the closer contact between pollution and oxidant created by the bubble network improves the treatment efficiency. Finally, on-site microorganisms were injected after oxidation process to lower the concentration of recalcitrant organic pollutants.

Theses injection steps were monitored using electrical resis-tivity tomography supported by a 96 surface electrodes network. Treatment efficiency was determined by measuring the concen-tration of total hydrocarbons, PAHs and BTEX before and after remediation.

of remedial reagents into contaminated vadose zones is still a challenge, considering gravity effects, contrasts of permeability and contamination. Despite surfactant-assisted in situ chemical oxidation (S-ISCO) helps to improve pollutant availability and degradation kinetics, it is poorly effective for the control of reagent dispersion and usually decreases the selectivity of the targeted reactions. To overcome these limitations, a new surfactant foam-based technology was developed and assessed.

Despite various anisotropies of vadose zones contaminated by heavy petroleum hydrocarbons, this new technology was shown to spread homogeneously slow oxidizers like persulfate and strongly improve the delivery radius of influence compared to the usual ISCO an S-ISCO methods. Besides, degradation studies were very encouraging, since removal rates at low oxidant doses were as high as those obtained when mixing soil and reagent using the traditional methods. Moreover, it ensures much better selec-tivity of degradation reactions as compared to S-ISCO, the more complete oxidation of pollutants in less toxic metabolites thanks to the improved contact between oxidant and contaminants, and reduces risks of toxic emanations.

In conclusion, this new technology should allow to cut field costs and uncertainties associated to poor reagents delivery and controlled reactivity for in situ remediation carried out in aniso-tropic or unsaturated soils.

Selection of Micro-organisms and Transport with surfactant Foams for Enhanced In Situ Biological Treatment of Petroleum Hydrocarbon in Soil

Douglas Pino Herrera; Jean-Noël Louvet; Théo Isigkeit; Théo Isigkeit; Christopher Prochasson; Anne Perez; Vincent Langlois; Yoan PechaudUniversité Paris-Est Marne la Vallée- Laboratoire Géomatériaux et Envi-ronnement (EA 4508)

A novel approach to the problem of hydrocarbon contamination in soil is the use of foam as potential alternatives to solve transport problems throughout heterogeneous zones. Within the French RNA MOUSTIC project that involves academic and industrial partners, the development of foam as a carrier of active matter for oxidant, micro-organisms and nutrients is studied to overcome the current limits for the in situ regeneration of heterogeneous unsatu-rated zones contaminated by hydrocarbon. Several advantages of using foam technology in conjunction with bioremediation can be highlighted: (i) foams tend to flow through porous media more uniformly avoiding channeling effects, (ii) foams provide a transport carrier for dispersing nutrients and bacteria because of the adsorption of bacteria to gas/liquid interface, (iii) foams can deliver and retain air to enhance aerobic biodegradation.

In the present work, foam is studied as a carrier of micro-organisms, nutrients and oxygen in soil to enhance in situ bioremediation foam assisted strategies. In this context, the aims of this study are (i) to select micro-organisms able to degrade petroleum hydrocarbons in the presence of surfactant foam (ii) to carry those micro-organ-isms by foam and study their distribution in the soil column as well as the pressure gradient necessary for their transport (iii) to study biodegradation of the petroleum hydrocarbons when bio-augmentation is applied.

Due to the results of the partner UTINAM showing the good potential of lauryl betaine foam as carrier for oxidant in contami-nated soil, the first objective of this study was to select a microbial consortium able to degrade petroleum hydrocarbon in the presence of lauryl betaine. Indigenous microbial population from

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4cSps2 & 4cSps3 | How to bridge the innova-tion gap – From pilots and prototypes to price labeled products

Niels Døssing Overheu (chair)1, Hasse Milter (chair)2, Per Loll3, Julian Bosch4

1Capital Region of Denmark, Kongens Vænge 2, 3400 Hillerød, +45 3866 5563, niels.doessing.overheu@regionh.dk; 2Region Zealand, Denmark, hmi@region-sjaelland.dk; 3DMR A/S, Denmark, pl@dmr.dk; 4Intrapore GmbH, Germany, julian.bosch@intrapore.com

Introduction

Many public and private problem owners in Europe are directly involved in development and adaption of new technology to solve their tasks in better, cheaper and more sustainable ways. Likewise, tech developers and consultants aim to be on the forefront with the best technology to help their clients.

The contaminated sites industry excels at testing new technology and producing promising prototypes, but subsequent commer-cialization of the product or service is often a challenge. Some technologies are simply not competitive, but others could have survived with better maturation for the market.

The aim of the special session is to

- increase cross-border knowledge of common hindrances, tech-nology needs, cooperation models and technology adaption tools, that can help commercialize inventions.

- facilitate a European knowledge exchange network on how to adapt promising new technology to the market, anchored among problem owners and technology developers in the contaminated sites industry.

After the workshop you will receive a summary of contribu-tions from group debates and contact information regarding a knowledge exchange network.

Remember your mobile device so you can participate in online polling during the workshop.

Commercialization dilemmas:

Commercialization dilemma #1 – Being too small

One authority has a big contamination problem that needs to be solved by new technology. But this problem owner alone is too small to be of commercial interest to a private technology developer. Is there anything to gain by exploring common needs with other problem owners? Are there any barriers for doing this? Could they choose to develop the technology in-house instead?

Commercialization dilemma #2 – Who wants to play?

A tech developer or consultant has knowledge of a problem and an idea for a possible technological solution. What are the barriers for finding funding and partners for proof-of-concept testing? And for the next step of bringing a tested prototype to a broader market? Are the barriers and funding channels different for different stages in product development?

Commercialization dilemma #3 – Negotiating conditions

Is there a difference in which conditions are favorable to public and private partners when entering innovation partnerships? E.g. How are Intellectual Property Rights (IPR) shared? Who should hold a patent and how to handle licenses to partners and external

The use of foams, advantageous to treat low accessibility contami-nants has shown true economic and security advantages at the field scale compared to classic ISCO treatment: a better selectivity, less amount of oxidant used, minored risks with low pressure injec-tions and few chemical reactive.

3D Numerical Foam Flow and Transport Modelling in the Porous Media Vadose Zone with the new simulator TMVOC++

Quentin Giraud; Benoit ParisINTERA

Modelling of foam flow and transport in porous media requires the association of two scientific fields: geochemical and computer sciences.

In this study, we present the innovative use of computer sciences in order to model the foam flow and transport in porous media, exclusively in the vadose zone. The aims are, first to have a better understanding of the impact of foam on remediation, secondly to match the simulation data against laboratory studies’ results and finally to generate a predictive model to improve the remediation system elaborated on site.

The 3D simulator TMVOC has been recoded, from the Fortran language into C++, to create a brand-new simulator called TMVOC++. The main idea wasis to build a more robust simulator and to gain some features only available with C++, such as its ability to integrate external numerical modules.

The TMVOC++ simulator has been used to reproduce the labora-tory experiments led by our colleagues from UTINAM, the LGE and REMEA to calibrate our numerical models. Particularly, we modelled the injection of foam in anisotropic layers of sand contaminated by coal tar in a 2D cell.

Finally, we developed a 3D numerical foam flow and transport model in the vadose to improve the design of the in situ scale remediation technology that to be used on site with our colleagues of the MOUSTIC project.

Numerical modelling of foam flow and transport is not an easy task and requires a lot of data from different fields: geology, chemistry, fluid mechanics, biology, biochemistry and computer sciences. Even if several foam simulators do exist, the customisation of TMVOC++, through external modules, allows the user to adapt themselves to new questions.

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The power of bioremediation techniques is therefore the integra-tion of many disciplines that work together towards a common goal: clean-up of contaminated sites. As each discipline advances, finding new harmful compounds and unlocking solutions to old issues, opportunities for new bioremediation systems emerge.

This special sessions wants to highlight the capacity of biological treatments to be employed on the remediation of a wide range of compounds, e.g. 1,4 Dioxane, MTBE, BTEX. Moreover, it focuses on the importance of collaboration among different parties to further improve, or develop, advanced technologies. Finally, an examples of how diverse forms of contracting can drive innovation and cost efficient solutions.

Show-cases are presented by different actors of a project: clients, research institute, consultants and contractors.

Nature based remediation of 1,4 Dioxane at a chemical plant (NL) – phytocontainment and biological source zone treatment

Mr. Paul van Riet¹; John Dijk²¹ Dow Benelux B.V.; ² GreenSoil International B.V.

1,4-Dioxane (dioxane) is an emerging contaminant of concern receiving much attention. At a large chemical production plant in Terneuzen, The Netherlands, historical site activities led to dioxane contaminated groundwater. More than 20 years after the dioxane production has stopped, groundwater in the source zone still contains high concentrations of dioxane, and migration with groundwater is threatening nearby surface water. Pending the implementation of a source zone remediation, as sustainable method for preventing offsite migration of dioxane was developed.

Dow implemented 240 TreeWell® units with hybrid poplars in March/April 2013. Via these adapted TreeWell® units, combined with straws for the deeper aquifer, groundwater is pumped up by the trees and dioxane is treated by degradation under UV (Sunlight) (i.e. phytocontainment). Groundwater measurements show that, in line with the expectations, the dioxane plume is being drawn into the phytoremediation area as a result of the water uptake by the trees. The uptake of dioxane by the trees was significantly less than what was calculated based on uptake rates and dioxane concentra-tions in groundwater, indicating dioxane degradation is occurring before uptake. The 240 TreeWell® unites can treat about 440 m3 groundwater per year.

After years of operation it can be concluded that phytocontain-ment is a feasible option for containing dioxane-contaminated groundwater at active chemical production plants and can be an attractive and sustainable alternative for conventional hydraulic containment

The source zone, however, is still present and several studies have been carried out to investigate the possibility of different (sustain-able) remediation technologies. One of the investigations has been carried out by Greensoil and included stimulated aerobic biological degradation. In cooperation with the Dutch knowledge institute, Deltares, Greensoil R&D conducted a degradation test with contaminated soil and groundwater material from the source zone. The starting concentration in the water phase was 1,270 mg/l and biological activity was measured by means of oxygen consumption and verified by concentration measurements.

Results from the test demonstrated that high concentrations of dioxane could be completely degraded biologically in the presence of oxygen. The addition of nutrients (N and P) stimulated the rate

parties? Which co-financing and cash-back models are preferable? Can differing wishes among the partners halt the partnership, and how can this be solved?

Commercialization dilemma #4 – To validate or not to?

The first full scale test of a new technology showed good results. But are we certain that it works the next time, or under different conditions? We could save money and carbon emissions, but is it worth the risk? When is a new technology regarded as “valid” in the market? Does it require extensive references, third-party validation or just recommendation from another problem owner?

Commercialization dilemma #5 – Public funds in private tech

When public resources are used for development in a Public Private Innovation project, there is a risk of violating state aid rules. How can we avoid this situation? Are there useful tendering rules that can be applied? At what stage should a public partner withdraw from a project and how?

Four inspirational presentations that illustrate the innovation gap challenge

1. Being too small - Can problem owners explore common areas of interest to create a larger volume for new technology? Jarno Laitinen, Senior advisor, Ramboll, Finland

2. A consultant’s thoughts on the challenges in development for the market – as a product or a service. Pros and cons of specializing or staying technology-independent. Per Loll, R&D manager, DMR A/S, Denmark

3. Business development models and how to quantify the return-ofinvestment in tech development. Julian Bosch, CEO, Intrapore GmbH, Germany

4. Examples of cooperation models in technology innovation. Examples of inventions that made it and others that failed. Niels D Overheu, Special consultant, Capital Region of Denmark

4dSps1 | Nature based remediation solutions: Project examples of the power of bioremediation

Nature based remediation solutions

Rogier De WaeleGreenSoil International B.V.

Soil and groundwater contamination are of major global concern, since they extensively damage the biodiversity, threat the public health and cause severe ecological and socioeconomic consequences.

In this framework, biological remediation are particularly appeal-ing as they are environmental sustainable and cost-effective compared to other methods. Particularly, biorememdiation has the potential to restore contaminated environments inexpensively, yet effectively. Indeed, often conventional -physical and -chemical treatments are pricey and inefficient.

Bioremediation is a technology which uses microorganisms and bacteria to degrade contaminants into harmless products, by metabolizing, immobilizing or absorbing them. The main objective is to obtain the right condition in the soil to stimulate the biological activity.

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of degradation significantly. Additional molecular analyses of key enzymes of the known dioxane degradation pathway confirmed the biological degradation together with the strong correlation with the observed oxygen consumption.

The degradation test demonstrated that stimulated biodegrada-tion can be an effective remediation technique to treat soil and groundwater contaminated with high concentrations of dioxane.

Based on the results of both the phytocontainment and the degra-dation test and recent scientific literature, dioxane seems to be more readily biodegradable than expected, enlarging the possibili-ties of biological and sustainable remediation techniques.

Currently Dow is further assessing full scale application of these nature based remediation techniques to be implemented in near future.

Innovative bioremediation of MTBE and organics: in situ bio-sparging and high yield MTBE bioreactor development

Leen Bastiaens¹; Dirk Paulus²; Wouter De Schuyteneer²; Tine Hofkens²; John Dijk³; Jan van den Boogaart³; Rogier De Waele³; Martin Slooijer³¹ VITO NV; ² Tauw Belgium; ³ GreenSoil International B.V.

An industrial site in Belgium, is contaminated with a variety of contaminants. Most of the contamination is difficult to reach in ATEX zones due to the infrastructure and the presence of storage tanks. A field test was conducted to investigate the feasibility of treating the different contaminants in-situ with aerobic bioreme-diation. Due to the mobile character of MTBE and the size of the plume, also a specific MTBE-bioreactor was applied.

The field tests were performed at the site in different areas. Pilot 1 was conducted in an uncontaminated area to test the radius of influence of the biosparging system. Pilot 2 was conducted to test the feasibility of stimulated aerobic biodegradation in a contaminated area. Groundwater was recirculated continuously. In addition, a SVE system was installed in the vadose zone, mainly to prevent emissions due to the biosparging. A bioreactor was used to prove biological MTBE degradation. The MTBE bioreactor was fed from a groundwater extraction well and the effluent was infiltrated in an infiltration well.

In the first months, the redox conditions remained strongly reduced. Additional laboratory and field tests done by GreenSoil and Tauw confirmed that the natural oxygen demand of both soil and groundwater, was extremely high. After slightly adapting the system, the redox conditions improved significantly. Hydrocar-bons and monochlorobenzene were removed with an efficiency of >99%, while the in-situ MTBE removal efficiency was in the range of 56-76%. Despite these start-up issues, the radius of influence of the air infiltration system appeared to be around 6m.

In the first 9 months, the flow of the MTBE bioreactor was limited due to the high COD of the groundwater and the rather low influent concentrations (±. 1000µg/l). It was found that the high COD/BOD was caused by a formerly unknown organic acid. Both MTBE and TBA were degraded with >99% efficiency in the biore-actor to concentrations below detection limit. It was observed that in-situ MTBE degradation was significantly higher (93 %) closer to the infiltration well were the effluent from the MTBE reactor was infiltrated than in the wells further away, indicating the additional effect of bioaugmentation.

The outcomes of these feasibility tests demonstrated the active biological activity in these systems which promoted the strong reduction of contaminants.

VITO is the patent owner of the bioreactor, however GreenSoil has the exclusive license on this technology in Europe, and it is the preferred partner in the rest of the world. The team work of the parties involved allowed a noteworthy development of the application of the biore-actor as part of in-situ and on-site MTBE bioremediation. This feasibility study manifested the importance of collaboration among research institutes, consultants and contractors to further improve existing technologies. The fruitful collaboration results in the client request to develop a full-scale remediation system for this site which is planned to become operational in 2019.

Cyclic bioremediation of a heavily impacted Xylene site in Westerlo (BE) – 100% on site biological treatment of soil, groundwater and soil vapor

Marijke Van Camp¹; Stefan Bangels²; Michela De Camillis²; Rogier De Waele²; Martin Slooijer²¹ RSK Benelux Bvba; ² GreenSoil International B.V.

This session shows how circular bioremediation was applied at a heavily xylene impacted site in Westerlo, Belgium and how lump sum contracting drives innovation and cost efficiency.

A former triacetate production site caused a heavy xylene contami-nation up to 27.850mg/kg in soil and 89.000µg/l in groundwater to a depth of 10 m-bgl resulting in a total mass of 90T of Xylene.

RSK in combination with GreenSoil offered a lump sum contract to the client. Within this lump sum contract, a 100% on site and in situ biological remedial approach was proposed being both more sustainable and economic compared to conventional (off-site) techniques.

The remediation consists of excavation and 100% on-site landfarming for soil (completed) and biosparging for groundwater (ongoing). The excavated soils are placed in biopiles, where dosing of nutrients and bioventing stimulates biodegradation of the contaminants. After soil treatment, the site is levelled and an enhanced in-situ biosparging system is installed below ground level. This in situ system treats residual soil and groundwater contamination.

During the project, innovative techniques like Biopile Air Filtra-tion Technique (BAFT), and Regenerative Bioscrubber (RBS) were successfully developed to reduce costs, especially related to activated carbon consumption.

BAFT. After completion of the soil treatment, biopiles have been redesigned to treat the soil vapors (500-2000 ppm of xylene) origi-nating from new biopiles, as they still contains nutrients and active bacteria called the ‘BAFT technique’.

RBS Soil vapors are also treated by an in house developed bioscrubber (RBS) that can treat both contaminated air and groundwater designed with a continuous regeneration system of carrier material balls.

All 20.500 m3 of heavily impacted soil have been cleaned far below the remedial target values (~400mg/kg) in 1.5 year. Starting from concentration levels up to 10.000 mg/kg, biopiles were reduced within 60-80 days with concentrations levels below 50 mg/kg.to

Both the ‘BAFT process’ and ‘RBS’ reached removal efficiencies between 60-90% in treating highly loaded soil vapors (up to 2000 ppm xylene) originating from other active landfarm depots.

The biological water treatment system worked with high efficien-cies, especially given the high influent concentrations (efficiency rate up to 99-99,9%) and removed the bulk of the incoming

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groundwater mass, leading to a noticeable reduction of activated carbon as well.

Conclusions. The project showed the power of circular biore-mediation in all its aspects and has evidenced that innovation, sustainability and cost can go hand in hand. 99% of the contamina-tion was degraded biologically either in soil, groundwater or air. In addition, 0m3 of soil left the site and cleaned-soil was used as air-treatment. Another remarkable outcome is that the active carbon consumption was reduced with 98% reducing waste.

The main financial costs at risk being (off site) soil treatment, activated carbon consumption and waste processing were managed by the circular bioremediation model allowing to offer a guaranteed outcome by this lump sum contract.

4dSpS2 | Our precious groundwater goes grey… what can we do?

Nanne Hoekstra1; Han Teunissen2; Frank Pels3; Arne Soels; Paul Ver-haagen3

1 Stichting Deltares; 2 Arcadis Nederland B.V; 3 Hannover Milieu- en Veiligheidstechniek BV (HMVT)

Groundwater is a precious natural resource. However, its vulner-ability is often overlooked because in Western-Europe it is easy to use, cheap and abundant. But slowly our groundwater is turning grey: even when soil remediation and groundwater quality standards are formally met, groundwater is gradually impacted by decades of industrial and agricultural activities. Consequently, at numerous water production wells, quality has dropped below acceptable levels, already. This means that additional treatment steps are required before the groundwater can be used for industrial processes or drinking water purposes; with significant -financial- consequences for users. In this session we are zooming in on the origin of the problem, parties confronted with the problem and especially solutions, which are nature-based.

How our groundwater goes greyNanne HoekstraDeltares

Are our water sources sufficiently protected?Han TeunissenArcadis

Constructed Wetlands for cost-effective and energy-efficient remediation of plumes

Frank Pels¹; Nanne Hoekstra²¹ Hannover Milieu- en Veiligheidstechniek BV (HMVT); ² Deltares

In the Netherlands, often only contaminated source locations are remediated, while pollution plumes keep growing as natural condi-tions do not always support natural (bio) degradation. Gradually, large areas will be (lightly) polluted. Traditional approaches of remediating those plumes are very costly and will cause a lot of CO2-emissions. With an alternative nature-based approach, plume remediation can be achieved in a cost-effective and energy-efficient way, by using constructed wetlands. Such biological ‘groundwater treatment plants’ could be situated in green public areas.

In three cases, results and costs of the implementation of con-

structed wetlands will be presented. With these project examples we will show that this application is a promising sustainable way of future plume remediation, which can be incorporated in urban groundwater management and other schemes of sustainable land management and land stewardship.

1) On a chlorinated solvent contaminated site in Amersfoort, a traditional soil remediation with groundwater extraction and purification with a stripping tower was replaced by a windmill to pump groundwater resulting in zero energy consumption and by a constructed wetland to degrade the solvents The system is now fully operational and results are available.

The distribution between chlorinated mother compounds (tetra-chloro-ethene, PER) and degradation products (trichloro-ethene, TRI; cis-dichloro-ethene, CIS; vinylchloride, VC) as well as non-chlo-rinated end products (ethane and ethene) over the constructed wetland shows – even in winter - complete degradation. Lessons learned at this site are used at the other two sites.

2) In the centre area of Zwolle shallow groundwater is polluted with solvents. These pollutions are migrating to the drinking water extraction area ‘Het Engelse Werk’ situated close to the river IJssel. Near the railway station, a groundwater extraction has been installed in order to prevent pollution migration to the drinking water area. The extracted water is first used to heat a building and is then treated in a constructed wetland. This system has been in operation for 5 years already. We showed to the municipality the importance and cost efficiency of purposeful monitoring.

3) In Doorn, a large groundwater chlorinated solvent plume is present, caused by a former chemical laundry. Near ‘House Doorn’, former residence of German emperor Wilhelm II, two-stage purifi-cation (an anaerobic zone and an aerobic zone) is being realized in the moat. Most difficult issue was the historic value of the site, which lead to a complex design process in close consultation with the landscape architect. Underwater, a reactive zone is installed for anaerobic biological degradation of PER to CIS and VC. The rest of the moat will be used for aerobic degradation of CIS and VC. Via a weir the treated water will be discharged to open surface water.

These three examples show that there are low-cost green alterna-tives to treat chlorinated solvent plumes in the available space. The presentation discusses the possibilities for constructed wetlands in urban areas for the treatment of groundwater contaminations.

4dSps3 | Improving the management and reha-bilitation of contaminated soils with low-cost technologies and methods

Irene Jubany; Jose Darrozes

Soils are essential for life; however, they are subject to human actions that sometimes irreversibly degrade them affecting their functions. In particular, in the South West European countries many sites affected by industrial pollution and close to urban sites can be found, affecting not only the soil but also the surface and ground-water, the atmosphere and the human being (through breathing or ingestion). Monitoring and remediation of these sites is needed in order to re-establish the soil properties and reduce the environ-mental impact and health risk associated. However, monitoring and remediation technologies available in the market can be expensive and alternative affordable methodologies are required in order to provide solutions to these sites.

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SOIL TAKE CARE project is an international project co-financed by FEDER (Interreg Sudoe) that aims at improving the manage-ment and rehabilitation of metalloid contaminated soils in the south-west of Europe, comprising regions of Spain, Portugal and France. The project has been conducted in three different industrially contaminated sites close to urban areas: Cartagena-La Unión (Spain), Estarreja (Portugal) and Viviez (France) where different low-cost monitoring and remediation actions have been conducted since 2016. In the context of this project, experimental devices and innovative methodologies to achieve rapid, low-cost diagnostics have been developed, low-cost monitoring tools for air and water pollution have been implemented and different alter-native techniques for remediating soils, such as phytoremediation, have been assessed. Inhalation and ingestion risks have been quantified using the bioaccessibility concept and socio-economic studies have been conducted so to determine the perceived risk by the inhabitants.

In this proposed session, final results and methodologies developed in the SOIL TAKE CARE project will be presented and discussed with the attendants following this proposed structure:

Part 1 (40 min): Introduction. Overview of the project and method-ologies/techniques developed held by the Project manager.

Part 2 (30 min): Poster session. 10 posters showing the main results of the project will be exhibited in the room. Assistants will be able to meet the authors to discuss about the content of the new meth-odologies and the obtained results.

The posters will be on the following topics:

- Low-cost technologies for contamination mapping

- Assessment of the mobilization of the contamination: modelling of transport to groundwater and risk assessment of massive mobilization

- Biomonitoring methods for air control

- Bioaccessibility of metals through inhalation and ingestion. Health risk assessment.

- Low-cost remediation techniques: phytoestabilization

- Socioeconomical cost of pollution

Part 3 (20 min): Round table with main researcher of the project about the benefits and limitations of the proposed methodolo-gies and the possible transferability to other contaminated sites. Discussion with assistants.

Development of a Decision Support System (DSS) in a GIS platform to integrate transport modelling results of soil-surface and groundwater contaminants

Maria Teresa CONDESSO DE MELO; Nuno BARREIRAS; João NASCI-MENTO; Filipe MIGUÉNS; Luís RIBEIRO

Nowadays, the contamination by metals or hydrocarbons is a common issue in many countries that affects the environment and the society and many ways. Efforts have been made in order to respond to those problems but the public environmental authori-ties are facing two major problems: establishing precise inventories of contaminated sites and defining procedures for remediation. The multidisciplinary nature of such problems make the develop-ment of integrated Decision Support Systems (DSS) mandatory and a vital tool for the environmental management of such sites. The case-study herein presented is the Estarreja Chemical Complex Area (NW Portugal), where there is a long history of soil, surface and groundwater contamination related to the past practices (since

1940’s) which often included accumulation of residues at open pits and discharge of non-treated waters that caused serious environ-mental impacts. The ECC area is on top of the Aveiro Quaternary groundwater body, a highly vulnerable multilayer aquifer to point and diffuse contamination. Presently, the groundwater body status is poor (NO3, Cl, SO4, As, Hg and other metals, organic contami-nants) but the population historically relies on groundwater as a source of water supply for domestic and agricultural uses.

The presented methodology includes a transport model for surface water – soil – groundwater processes by integrating different types of models, appropriate to the medium and available data. In order to gather more information on the groundwater status (quantity and quality) several tasks were made in field work. Continuous and automatic measurements of water levels in wells were made, as well as the installation of a weather station for climate parameters, and water and soil sampling to allow the best characterization of the soil and water contamination, both in space and time. The use of drones was an added asset to get more information on the surface conditions, including the application of a new method for instantly measuring water levels in wells and for the identification of potential areas strongly affected by contamination through the assessment of vegetation health. The data and information was used to develop an integrated transport model for surface water – soil – groundwater processes. For the groundwater and transport modelling the GMS 10.3 was used and the simulation and integration of soil-surface water processes was made by using WEAP. The linkage between the groundwater model (GMS 10.3) and soil-surface water (WEAP) was made to allow the integration of both models.

For the best use and integration of results and other products such as vulnerability and risk maps a Decision Support System in a GIS platform was developed.

The hidden socioeconomical costs of pollution. Surveying vulnerabilities and coping tactics in a French industrial town

Pierre Levasseur; Katrin Erlenbruch; Christelle Gramaglia

Pollution is mostly invisible and can have insidious long-term effects on the environment and health. The literature shows that compared to natural catastrophes, it conveys great uncertainties that generate « corrosive effects » on the social fabric (Freudenburg 1997 ; Couch et al. 2007).

Elaborating on data gathered during a qualitative and quantita-tive survey carried out in Viviez (France), a former mining and zinc smelting area, this poster aims at comparing how local residents deal with nuisances and risks on the daily basis. It describes specific vulnerabilities as well as coping tactics that can be developed in the private sphere, complementary to forms of critical expression that are rather voiced in the public space.

How do people manage their life when ordinary practices or hobbies such as gardening, fishing or jogging are impeded or become a possible source of harm? How do they assess their exposure to contaminants? What can they do if they want to protect themselves individually or collectively, and at what (under-estimated socioeconomic costs)? Also, what motivate them to stay? This poster argues that different forms of knowledge and attach-ments should be taken into account when reflecting on adaptation and resilience in polluted areas. It conclude with comparative perspectives on similar cases in Spain and Portugal which were investigated during the SOILTAKECARE project (INTERREG SUDOE 2016-2019).

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soil contamination. Today, one of the many issues of concern is the significant presence of metals and metalloids from mining activities. The issue of environmental and health risks associated with the spread of this contamination appear to be a major public health issue.

In the case of the European project SUDOE -Soil Take Care, this study focused on a highly contaminated tailing (Pb, As, Cd, Zn) located in the mining district of Cartagena/La Union (Sierra Minera), Spain. This work consists in (i) the determination of the soil characteristics and the contaminant speciation, and (ii) their relations with associ-ated health risk assessment.

For this purpose, a physicochemical characterization of the raw material was performed (pH, conductivity, CEC, % CaCO3, particle size distribution) supplemented by a mineralogical/morphological study (XRD, SEM-EDS). Contaminants speciation was determined by sequential BCR extractions and identification of metal(loid)s bearing phases. In vitro methods (UBM and PSF bioaccessibility protocols) have been used to simulate the physiological mecha-nisms of digestion and inhalation to estimate the actual quantity potentially absorbable of metal by the human body and to define the associated health risks.

Several topsoil samples were collected from a representative tailing of the studied area. Selected samples represent various stages of the tailing evolution, with reworked, redeposited materials according to the erosion/weathering/transport processes thus presenting different structure, texture, color... Two separate groups of samples were identified. The first presented relatively stable bearing phases. The contaminants (Pb, As, Cd, Zn) were mainly found in the residual fraction (stable mineralogical phases) of the BCR and had a minimal bioaccessibility inducing a low health risk. The second group had highly labile Zn and Cd-bearing phases with a bioaccessibility reaching up to 85%. Considering the bioacces-sible fraction, the risk calculations (Hazard Quotient and Hazard Index) allow establishing non-acceptable a non-carcinogenic risk for children in the case of lead, zinc and cadmium. In addition, in the case of As, a non-acceptable carcinogenic risk for adults and children has been established. All these results outline the effect of weathering and erosion of tailing leading to a change in the specia-tion of metal(loid)s and thus increasing environmental and health risks.

Copper soil content, soil characterization and plant vigor: what link? Application to a vineyard

Myriam Schmutz; A Baldé; Gregory Dufréchou; Jose Darrozes; Mari-lyne Soubrand¹; Emmanuel Joussein; S Hubbard¹ Marilyne Soubrand

The objective of this study is to define if there is a link between soil metal ions content and soil characteristics and/or plant vigor. We chose to work on a vineyard as these sites have got the specificity to have a significant copper content. This content is explained by copper spreading, content is a mixture called “bouillie bordelaise” used for decades in order to reduce plant diseases.

Various methods had been deployed in the field: spatialized soil geophysical methods (electromagnetic mapping, electrical resis-tivity tomographies, spectral induced polarization tomographies), spatialized optic maps (NDVI index, global hyperspectral range) and punctual samplings (physico-chemical analysis including copper content, and Xray sample analysis).

Couch, Stephen R., and Anne E. Mercuri. “Toxic water and the anthill effect: the development of a subculture of distress in a once contaminated community.” Cultures of Contamination. Emerald Group Publishing Limited, 2007. 117-137.Freudenburg, William R. “Contamination, corrosion and the social order: An overview.” Current Sociology 45.3 (1997): 19-39.

Transfer of heavy metals to agricultural and natural plants and selection of plant species most suitable for phytostabilization trials

Silvia Martínez-Martínez; J.A Acosta; R Zornoza; M Gabarrón; M Soriano-Disla; M.D. Gómez-López; J. Martínez; Angel Faz

With the aim of estimating the rate of accumulation of metal(oid)s from soil to plants (forest and agricultural) two studies were carried out: 1) Study of transfer of metals from soil to plants (Chamaerops humilis, Lavandula multifida, Olea europaea var. sylvestris, Pistacia lentiscus, Rhamnus lycioides) in a natural area near a tailings pond located in La Rambla del Avenque (Cartagena-La Union mining district, Spain) and 2) Study of transfer of metal(oid)s to different varieties of lettuce (“Roman”, “Batavia” and “Lollo rosso”) grown in pot under greenhouse and using three different types of agricul-tural soils representative of the environment of the Mining District. According to the results, it is observed that there is metal(oid)s transfer from the mining area to the natural zone, and considerable differences exist depending on the plant species. The highest risk of transfer of metals to the food chain is recorded in the leaves of Lavandula multifida and in the fruits of Rhamnus lycioides. Results obtained in the varieties of lettuce show that the lowest risk of transfer occurs in the variety of lettuce “Roman”. Regarding the study on the mobility of metal(oid)s in the soil of the natural zone, the order was: Cd> Pb> Zn> As and the following in soil-plant: Cd> Zn> As> Pb, being Zn and Cd the most mobile inside the plant. Thus, plants in this area have defence mechanisms against the existing high concentration of metals. The greater mobility within the plants is observed towards the leaves, being Olea europaea the species that accumulates the highest concentration of metal(oid)s in the aerial parts. In the cultivated plants, the Cd was, by far, the most mobile element in terms of soil-plant transfer, regardless of the type of soil. With regard to the lettuce varieties studied, “Lollo rosso” recorded a higher transfer of As and Pb, and nevertheless, “Batavia” transferred more Cd and Zn from the soil.

Finally, the study on the selection of plant species to be used in the phytostabilization trials that will be carried out in a tailings pond in Cartagena-La Union mining district showed that the most suitable species would be Lygeum spartum and Piptatherum miliaceum due to that these plant species are capable of accumulating heavy metals in the roots, of growing on soils with high salinity values, low content of organic matter and poor soil structure, besides resisting the extreme climatic conditions of temperature and humidity that predominate in the study area.

Investigating the relationship between speciation and oral/lung bioaccessibility of highly contaminated tailings and soils: a technical tool for health risk assessment

Matthias Monneron-Gyurits; Marilyne Soubrand; Emmanuel Jous-sein; Alexandra Courtin-Nomade; Irene Jubany; Sandra Casas

Due to its agricultural, mining and industrial needs, human activi-ties shape the environment and account for the main source of

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In the other hand sensors to control triggering parameters were installed too, as a seismic station and a specially adapted weather station, which can measure intensity of rain with mm per second precision. This is important in weather conditions of investigation site, where torrential rains are common in autumn.

Seismic station, in combination with acceleration signals provide for the National Geographic Institute from Spain, has been used to obtain a damping law adapted to the site of La Unión-Cartagena.

It was also used to define reliable relationships between hori-zontal and vertical components of seismic acceleration vector in the study area. Measurements demonstrate that both (vertical and horizontal) have similar values, refuting the conventional idea that horizontal component is around 50 % of vertical one.

In parallel, boreholes and tests (lab and in situ ones) were made to establish the state of old tails inside dams and their geotechnical properties. They show that moisture levels are still high and shear strengths are quite low, with cohesions around 30 kPa and frictions around 18°.

With all these data, a modeling process has been carried out to evaluate a security factor of monitored dams and its sensibility to changes in triggering parameters.

Preliminary conclusions show that extreme rain falls events could cause severe erosion processes, allowing tails to flow, but not a drastic elevation of piezometric levels (with risk of rotational insta-bility). Earthquakes with similar magnitude to historic ones could cause rotational slides.

Atmospheric dusts characterisation in the mining district of La Unión - Cartagena, Spain: Air quality and health risks assessment

I Blondet; Eva Shreck; J Viers; C. Zouiten; Sandra Casas; Irene Jubany; G Dufrechou; Jose Dazorres; Silvia Martinez; S. Acosta; J Martinez; Angel Faz; Emmanuel Joussein; Marilyne Soubrand; Matthias Mon-neron; C Galy-Lacaux

Air pollution has a major impact on human health and the envi-ronment. The use of owen gauges makes it possible to sample the atmospheric deposition of metals and metalloids coming from an old mining zone (Pb and Zn) in the south-east of Spain. Four sites were monitored: the main mining dump, the urban area of La Unión, the agricultural zone (formerly mining) and the coastal zone.

Firstly, atmospheric fallouts have been characterized from a physico-chemical and mineralogical point of view. The laser particle size reveals a dust particle size around 15 μm, with coarser particles in the city and thinner at the slag heap. XRD analyzes show the presence of quartz, carbonates, sulphides and sulphates. Observations with SEM-EDX confirmed these chemical spectras, and made it possible to classify the particles into well-crystallized minerals and heterogeneous dusts.

Secondly, the quantification of the metallic elements brought by the atmospheric fall-out was carried out by ICP-MS ; the rela-tionship between the elemental contents in atmospheric dusts collected by Owen gauges and the estimated average contents given for the upper Earth’s crust (Taylor and McLennan, 1985) reveals significant enrichments compared to the earth’s crust: ratio between 29 and 444 for Cd, between 49 and 387 for Pb, between 55 and 297 for Sb, between 13 and 218 for Zn, and between 8 and 87 for As. Fluxes (expressed in μg/m2/d) of atmospheric deposition exceed threshold values (OPAIR, 1985, TA LUFT, 2002) for Zn, Pb, As

Tillandsias usneoides for air quality biomonitoring in the mining district of La Unión - Cartagena, Spain: New insights for epiphyte’s uptake mechanims and pollution source tracing by the use of Zn and Pb isotopes

Eva Shreck; I Blondet; J Viers; C. Zouiten; J. Darrozes; G Dufrechou; Y Auda; Silvia Martinez; J.A Acosta; M Gabarrón; Angel Faz; C Galy-Lacaux; R Freydier; R Freydier

The atmospheric pollution has a major impact on the human health and the environment. It then turns out to be necessary to develop good bio-indicators of the air quality - little expensive compared with the traditional collectors of particles - and able to monitor air quality over a wide zone.

In this study, the relevance of the epiphytic plants Tillandsias usneoides is studied to estimate the transfer of metals and metal-loids from a former Zn and Pb mining zone in the Southeast of Spain to the local atmosphere. Five sites were monitored: the main mining area, the rehabilitated mining zone, the urban area of La Unión, the agricultural zone and the coastal zone. An aliquot of plant was collected in every site every two months during 1 year.

The Tillandsias usneoides have been observed with MEB-EDX, and analysed at the GET laboratory to determine major and trace elements concentrations and Zn and Pb isotopes ratios. It appears that atmospheric particles are distributed in an homogeneous manner at the surface of the Tillandsias.

By calculating the enrichment factor of the elementary contents in Tillandsias usneoides with regard to the values of the geochemical background of the region of Murcia (Alcolea, on 2015), we observe a significant enrichment in the epiphytic plants for the following metals or mettaloids : 1.7 for Sb ; 2.4 for As ; 7.9 for Cd, 20.5 for Zn and 33.6 for Pb. This is in agreement with the enrichments obtained in the soils of the mining zone by Alcolea (2015). Tilland-sias usneoides appear to be a good recorder of the atmospheric contamination brought by the mining area.

The statistical analysis of these data suggests also that kinetics of deposition is slower for the urban and coastal sites compared to the mining sites. The similarity of isotopic compositions (Zn and Pb) between Tillandsias usneoides and soils and atmospheric particles suggests also that these plants could be a powerful tool to trace source of matter in the atmosphere.

Reference : Alcolea Rubio, L.A. 2015. Geoavailability of Ni, Cu, Zn, As, Cd and Pb n the Sierra de Cartagena- La Unión (SE Spain). Universidad Politéchnica de Cartagena. Departamento de Ingeni-ería Minera, Geológica y Cartográfica. Tesis doctoral.

Poster presentations:

Evaluation of the risk for contaminants mobilization in a massive way

Inmaculada Álvarez-Fernández

This research develops in the frame of SOIL TAKE CARE SUDOE project. Its approach is establishing a relation between instability events and triggering parameters as earthquakes or raining falls.

Works in GT1 work package include the installation of different sensors in old damns in Cartagena site (Spain) to control on line the answer of parameters as humidity (to control infiltration process), displacements, tilts or block falls. Adapted dataloggers were designed, constructed and installed allowing monitoring in continuous mode and the remote access to data.

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Assessment of the bioaccessibility of metals in soils through inhalation and ingestion pathway for risk assessment

Irene Jubany; Sandra Casas Garriga; Eva Shreck; Jerome Viers; Teresa Condesso de Melo; Nuno Barreiras; Matthias Monneron; Marilyne Soubrand; Emmanuel Joussein

Particle inhalation and ingestion are an important human exposure pathway of heavy metals in contaminated soils. Although health risk assessment associated to these environments is usually based on total metal(loid) content in the particle, using a bioaccessibility approach may be more accurate to quantify real exposure. Bioac-cessibility is defined as the potential of the metal(loid) to mobilise from its soil matrices to the human digestive and respiratory systems.

SOIL TAKE CARE project is an international project co-financed by FEDER (Interreg Sudoe) that aims at improving the management and rehabilitation of contaminated soils in the south of Europe, comprising regions of Spain, Portugal and France. In the context of this project, methodologies for the determination of bioaccessible metal(loids) though inhalation and ingestion pathway have been tested and health risk assessments have been conducted in three different contaminated sites: Cartagena-La Unión (Spain), Estarreja (Portugal) and Viviez (France).

In this work, methodologies for the determination of the bioacces-sibility of metals through inhalation and ingestion are presented and discussed to highlight the advantages and limitations in each case. Inhalation and ingestion bioaccessiblity of the soils and air particles was determined using in vitro models. In vitro models based on human physiology have been developed as simple, cheap, and reproducible tools to investigate bioaccessibility of soil contaminants.

Results obtained within SOILTAKECARE project comparing health risk assessment using total and bioaccessible content are also discussed in this work. Results obtained with this type of tests highlighted the importance of using bioaccessibility for health risk assessment in order to accurately estimate the exposure risks and additionally, to determine the most bioaccessible elements so to be considered in the management and rehabilitation plan of the area.

and Cd in mine tailing area; Zn, Pb, As in urban area and As near coastal zone (beach of Gorguel).

Thirdly, using particles from these Owen gauges, bioaccessible tests and Health risk calculations were performed. Bioaccessible tests were performed on an aggregated sample obtained by mixing several samples from the Owen gauges. We deliver here the prelim-inary results: i) Zn, Cd and Sb were seen the most bioaccesible compounds as presented higher % released in the Phagolysosomal simulant fluid (PSF) solution; ii) Owen Gauge samples presented similar content of metals than the soil samples taken in Cartagena (except for As, which presented higher amounts) ; iii) Risk assess-ment was conducted for Zn, As, Cr, Pb, Cd and Sb. When using total metal concentration, samples presented cancer and non-cancer risk. However, when considering bioaccessible content risk was not observed.Reference : Taylor, S.R., McLennan, S.M., 1985. The continental crust: Its com-position and evolution. Oxford, Blackwell, 312 p.

Application of the GNSS-Reflectometry to map surface properties of mine waste – example of the Cartagena – La Union district (Spain)

Gregory Dufréchou; Jose Darrozes; Minh Cuong Ha; Nolan Varais; Romain Pibouleau; Martin Soriano; Guillaume Ramilien; Inmaculada Álvarez Fernández

The Sierra Minera was affected by underground and surface mining activity for the last 2500 years. Spoils resulting from this open-pit mining activity were extracted and stocked in tailing ponds and more than 40 unconfined tailing ponds are thus present in the Cartagena – La Union district. They are composed of unhealthy soils and are environmental hazards due to their high susceptibility to leaching and erosional processes (e.g. diffusion, flash floods and wind. In such mining areas the presence of wastes and metals in soils remains a source of contamination over long time even when activity has ceased.

In this study we evaluate the potential of an innovative and inex-pensive methods based on remote sensing using a classical Global Navigation Satellite System (GNSS) receiver to map the soils prop-erties (e.g. contamination - heavy metal) of in mining area. The GNSS-Reflectometry is considered as an opportunistic remote sensing technique based on the analysis of the electromagnetic waves continuously emitted by the GNSS constellation (including GPS, GLONASS, Galileo, etc.) that are received by an antenna after reflection on the Earth’s surface so-called multipath (MTP) signals. The effect of multipath reflection clearly affects signal-to-noise ratio data recorded by GNSS receivers on the different frequen-cies (L1, L2, and L5) and can be can be expressed as a function of the heignt of the reflection (Heffective as the height between the ground reflection surface and the antenna), the amplitude (Am) and the phase ( [..submission not completed]

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Pillars of a precautionary policy in the EU to avoid harmful soil and groundwater changes on installations according to IED

Joerg FrauensteinUmweltbundesamt

Activities of industrial and commercial installations might cause serious pollution in soil and groundwater. Due to the experiences with abandoned contaminated sites it is obvious how complex and expensive remediation measures are. Therefore remediation requirements have to be reduced seriously by the strict imple-mentation of precautionary principles for any installations, which are still in operation. The avoidance of any contamination is a much better approach than any sustainable remediation option. The Industrial Emission Directive (IED) took up this approach and considered this by introducing special elements, especially by Baseline Reports, requirements regarding inspections and moni-toring during operation on installations and by obligations to the operator in case of a significant pollution in soil and groundwater.

The baseline report should preserve evidence and should provide references about the initial state related to soil and groundwater.

Periodic Inspection and monitoring of soil and groundwater serves to determine, whether the operation causes significant deteriora-tions through relevant hazardous substances. It is recommended that the operator has to submit a coordinated monitoring plan.

With the final cessation of an installation the competent authority has to decide about the requirement of further obligations caused by significant pollution. If so the operator has to return the site to the baseline situation possibly by proportionate technical interventions.

The IED does not give any methodical advice and tangible criteria to member states, how to implement these regulations into practice. Based on a decision by the conference of environmental Ministers of the Federal Laender in Germany an interdisciplinary working group was mandated to develop guidance documents according to Articles 24, 25 and 26 of IED.

The oral presentation will discuss content and methodology of the available manuals developed in Germany. After the publication of a first edition of the Manual regarding a baseline report it quickly became clear that adequate technical and methodological support can only be provided if the content of the whole process has been taken into consideration.

Consistently followed the development of a Manual about opera-tor’s obligations occurred in case of significant soil and groundwater pollution. The working group decided to launch an open and transparent accompanying stakeholder participation procedure. Ultimately, Germany has introduced a significance factor of 1.5, which triggers obligations to return into the initial state.

To our knowledge, Germany is currently the only member state that has methodically substantiated these obligations occurring from the IED for administrative implementation by competent authorities.

At present the working group is drafting a Manual for the inspection and monitoring of soil and groundwater on sites of installations.

So the IED provides a significant impetus for precautionary envi-ronmental protection. In the future this approach will allow to solve the problem of contaminated sites in a more sustainable way.

Legal 1– 5aSps1 | International developments soil pollution

Legal aspects of the management of contaminated land

Johan Ceenaeme¹; Leo Kerkstoel²; Isabelle Larmuseau³; Bernard Van-heusden⁴; Mark Van Straaten⁵¹ OVAM - Public Waste Agency of Flanders; ² Sertius; ³ LDR Lawyers; ⁴ University Hasselt; ⁵ Witteveen+Bos Belgium

During the legal day we want to work around the four following themes: international developments, waste and soil, emerging contaminants and toxins and ‘ technician meets lawyer ‘.

This gives rise to four sessions. For each session we want to check to what extent other abstracts have been submitted to the proposed themes. It is also possible that presentations of proposed sessions will be joined in this legal day.

1/ International developments Bernard Vanheusden and Johan Ceenaeme

In this session we will focus on a number of developments on the international stage. In addition, this is also an opportunity for comparing the soil legislation in different countries. Possible themes:

- Minamata-convention

- UNEA-3 resolution

- The European perspective

- Comparison of soil legislation in different countries

- Balance between ‘the polluter pays’ principle and the respon-sibilities of the current manager or owner of the contaminated land (the stewardship principle)

2/ Soil and wasteLeo Kerkstoel and Isabelle Larmuseau

What is the boundary between contaminated soil and waste. Are there new developments?

Use of excavated soil. Development of policy and legislation. What are the different options for developing a policy for excavated soil, contaminated or not?

Cases jurisprudence: previous court decisions in applying environ-mental legal principles

3/ Emerging contaminants Johan Ceenaeme and Bernard Vanheusden

Environmental liability What are possible liabilities related to contaminants (of emerging concern)? What is their impact? Is the juridical framework appropriate to deal with old and new emerging contaminants?

4/ Technician meets lawyer Marc Van Straaten

Questions about risk assessment and remediation goals

- Fit for use

- How BA(D)(T) is the BATNEEC-principle?

- Residual contamination

- What legal instruments are available to promote the develop-ment of brownfields?

- How can we incorporate legal instruments that offer guarantees for investigation and remediation of the residual contamina-tion at the moment that the land use changes?

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How to manage heavily impacted sites and complex remediation in fast evolving markets locked by legal and technology constrains.

Shiyuan Peng¹; Steve Leroi¹ Chongqing Jiaotong University

In fast evolving economies across the globe, new environmental legislation for contaminated land requires urbanisation and real estate development to change pace. A succesfull change process requires that governments to envision building full environmental legislative frameworks and technological soil processing capacity. The lagging behind of the environmental framework and techno-logical development can become real constrains. If additionally hazardous landfill capacity is guarded by a ban on landfilling contaminated soils, how do you manage a complex remediation process ?

There are parallels between developments in Europe and Asia. Both good and not so good examples can be highlighted. First some historical developments on policy making in European countries are put forward. These elements are then compared to policy making in Asia. Striking resemblances across societies can be observed.

Finally, two specific cases of a remediation projects are put forward.

In a first cases contaminated land issues are solved at the site by bringing soil processing capacity to the site. In the second case, instead of trying to solve complex remediation uses at the site, the waste flows where brought to existing facility by adapting practices and pro-active openminded approaches.

Both options are viable solutions but require different constrains in terms of timeline, market solutions and the agreement of the local environmental agencies.

Legal 2 – 5aSps2 | International developments policy on soil, land and groundwater

Decision-making on groundwater quality management: perspectives from competent authorities in the Netherlands

Sandra Boekhold, Frank Swartjes, Piet Otte and Arjen WintersenRIVM - National Institute for Public Health and the Environment

The Netherlands is currently reforming its legislation on the protec-tion and utilisation of the physical environment. A number of spatial and environmental laws will be integrated into a new Environment and Planning Act, including the Soil Protection Act. The new Act seeks to modernise, harmonise and simplify current rules on land use planning, environmental protection, nature conservation, construction, water management, urban and rural development and mining, and integrate these rules into one legal framework.

The Environment and Planning Act will support a paradigm shift from protection of the environment using a defensive approach of prohibitions and restrictions, towards a legal framework that supports continuous care of the quality of the environment in the policy cycle, to facilitate economic development and growth.

The associated decentralisation of risk assessment of soil and groundwater contamination, standard setting and soil and groundwater quality assessment will introduce new responsibili-

Management of remediation programs at fuel retail stations in a selection of different European countries: from identification to delivery of remediation works

Francesca Motta¹; Alberto Segatto¹; Michele Camardella²; Alessandro Piva²; Gianmarco Lucchini¹¹ AECOM URS Italia S.p.A.; ² Q8

This paper presents the results of a comparative study carried concerning the application of the environmental legislation in force and the “best practices” used in the environmental remedia-tion procedures for fuel retail stations, in Italy, Belgium, Holland, Denmark, Sweden, Spain.The management of environmental proceedings in the various countries, was analysezed thought the comparison of the following topics: 1) Legislation; 2) Involvement of the authorities; 3) Actions to be undertaken; 4) Main remediation technologies applied and associated costs.

All the analyzed States have environmental laws in force which are enacted by implementing EU directives. In Belgium and Spain, legislation differs in various regions, whilst in the other states a national legislation is in force. In some States (Holland, Belgium, Denmark) the legislations clearly divides the “historical” contamina-tions from the new events, foreseeing different approaches.At the opening of an environmental proceeding, all the applicable laws provide for a notification to the authorities in a period of time that varies from immediate (Spain, Sweden and Denmark), to 24 hours (Italy) to 14 days (Belgium). In all states some immediate response actions should be undertaken when an event occurs that could cause potential contamination. The approach, however, is different between Italy and other states: Italian legislation provides that the emergency actions should be undertaken in order to prevent off-site migration of contamination, even when historical contami-nation is detected. This condition implies, in most cases, the installation of hydraulic barriers on site. The hydraulic barriers often remain in operation on the sites for an average period of 3 years, while waiting for the remediation actions design to be approved. In other states, emergency actions are urgent and immediate after an event that potentially can cause contamination to soil and groundwater, as they are intended to mitigate the spread and consequences of a spill. Subsequently, remediation actions are carried out in the Netherlands and Belgium for recent contamina-tion whilst, in Sweden, Denmark, Italy and Spain, human health risks assessments are carried out to define the need for remedia-tion. The involvement of the authorities/control bodies is different between the Italian approach and those of the analyzed European countries. In fact, the Italian law provides that the Authorities approve the various steps of the remediation procedure (i.e. collec-tion and analyses of split samples, human health risks assessments, remediation design, collection and analyses of split samples for the verification of the remediation goals), within the timing defined in the law. Unlike Italy, the closure of the proceedings in other states occurs with self-certification on data provided by the party and no certification by the Authorities is required.On the basis of the information collected, no substantial differences were found in the technologies more frequently applied to remediation of soil and groundwater at fuel retail stations and unit costs.

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The national soil register (RIT) on the other hand will guarantee transparency and information on soil pollution to citizens and developers. Once a site has been assessed to comply with the law, meaning posing no significant risk to human health, soil ecosystems or groundwater, a soil certificate is issued and will be publically available in the RIT. The certificate will inform for which level of sensitivity of use the site does not pose a significant risk. This will allow prospective buyers or developers to include the soil pollution reality into their decision making.

The government submitted the bill to the parliament in January 2018 and so far the Chamber of Commerce as well as the Chamber of Artisans and the Association of Municipalities have notified it favorably with advice for some minor adaptations. After the soon expected notification of the State Council, the parliamentary work on the text can start.

Barriers limiting the remediation of contaminated sites in italy and possible solutions

Mentore Vaccari¹; Carlo Collivignarelli; Maurizio Tira¹ University of Brescia

The most recent national census indicates that in Italy the potentially contaminated sites are about 15000, whereas the contaminated sites are about 6000 and in 40% of them there is not any remediation action, yet. The Sites of National Interest (SNI) are 39 and they cover a land area of about 145,000 hectares of land and about 135,000 hectares of sea.

It is clear that the remediation of those areas requires huge invest-ments. In the period 2001-2014 the Ministry of the Environment allocated for the reclamation of the SNI over 1800 million euro, to which 988 million euros of allocations of local authorities were added, for a total of almost 2800 million euro. There are not statistics about private investments in remediation intervention, however it was estimated that in the period 2001-2012 around € 1700 million were spent by private sector in the SNI.

The above figures indicate the existence of a considerable potential market in Italy that gravitates around the remediation of contami-nated sites, which, if favored, could help the economic recovery of our Country.

In 2014 a multidisciplinary Working Group was set up at the University of Brescia to define proposals to concretely address the problems that limit the diffusion of remediation activities in Italy. The Working Group includes experts in the legal-administrative, economic-financial and technical-operational fields who met every two month to discuss the critical aspects of the sector and identify possible solutions.

There are numerous legal, administrative and economic-financial obstacles to the development of remediation interventions, such as, for example, the absence of a EU Directive on remediation, unclear legislation, procedural obstacles, the lack of coordination between the public bodies involved in the intervention authoriza-tion, the lack of personnel and specific skills in local authorities, the construction crisis.

The lack of reclamation interventions not only generates a negative impact on the environment and on the population health, but more generally it determines environmental and direct/indirect costs which compromise the development of the community concerned and the area in which they live.

In addition to the problems, the working group has identified few incisive and concrete solutions that could be adopted to facilitate remediation interventions, which will be presented in this article.

ties and tasks for regional and local authorities. At the same time, opportunities arise to introduce tailor made, regional approaches for assessing groundwater quality and fitness for use..

To provide decision support in this new legal context, a state-of-the-art framework for standardisation and instruments for quality assessment of soil and groundwater will be made available during the coming years.

In this contribution, we will present the perspectives of the competent authorities on groundwater quality management in the Netherlands. We will discuss how these perspectives translate into a first draft set-up for a national soil and groundwater quality assessment framework.

Luxembourg’s cumbersome way towards a national soil law

Sophie Capus; Pol TockAdministration de l’environnement Luxembourg

Since the 1990s, the succeeding Luxembourgish governments recognized the necessity to regulate the management of contami-nated sites by law. Certain aspects were thus introduced in the laws about classified installations and defining waste management. These initiatives brought some progress in introducing liability for polluting activities upon cessation of activities and introduced a frame to authorize remediation works. However, the need of a specific law tackling the topic was recognized. In the meantime the discussions around the thematic soil strategy had started at EU-level. The Luxembourgish governments decided therefor to wait for a directive instead of launching a national legislative process. Due to the stagnation of the EU directive, the govern-ment mandated Luxembourg’s Environment Agency in the 2010s to prepare a national bill on soil.

The first step towards the bill was an analysis of the options for the functioning mechanisms of the future law. Questions like the following were raised:

• What should trigger the legal necessity to address potential pollution?

• How can the principles of risk based land management be implemented?

The first draft text resulting from this analysis was ready in 2013. During the following phase we worked in parallel on the consulta-tion of the stakeholders and on the development of the tools to implement the risk based land management on historical sites.

Among the tools, the following two major instruments deserve to be mentioned:

• A coherent set of trigger values with the matching set of risk assessment tools

• The national soil information register (RIT)

The DECLAM (DEcision tools for Contaminted LAnd Management) program was launched to respond to the need for a transversally coherent and transparent system to assess the potential risks posed by a soil pollution. We were faced with the reality that for all existing systems choices had been made in order to find the most appropriate balance between precautionary approach, applica-bility of the results and local specificities. In Luxembourg e.g we face quite high natural soil concentration of As (up to 240 mg/kg) which would inhibit the use of any existing decision system from a region with low natural soil concentrations of As.

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careful economic analysis can reveal both profit and tax incen-tives that will appeal to developers and municipalities alike. Lastly, social benefits, typically relating to better access to the waterfront as well as advancement of other public trust values, will appeal to communities. Thus the cost of cleanup can be allocated to a wider spectrum of interests including industry, commercial devel-opment, municipal or regional government, and the public. This distribution can be justified by evaluating the benefit, as well as liability, present in the specific case.

Using this approach, It may be possible to bring parties together and break at least some of the gridlock currently typical of many European countries.

Waterfront contribution: a new finance paradigm for cleanup of contaminated sediments

Philip Spadaro¹; Larry Rosenthal²¹ TIG Environmental; ² University of California, Berkeley

Contaminated sediments pose significant ecological and human health threats in many areas of the world. Nevertheless, there has been little progress towards cleanup in most countries. Even in the United States, where the Superfund law provides a script for such cleanups, many large sites are facing lengthy delays because of protracted debate over who should pay what share of the cleanup cost. Too often the available financing is insufficient and resources are wasted due to adversarial legalism.

We contend that remedial technologies such as precision dredging, engineered cap placement, and natural attenuation are sufficient to address even the most significant contaminated sediment problems. Where these technologies have been applied in risk-based proportions, there have been significant successes, but far too few given the enormity of the challenge worldwide. Without effective approaches to funding, coordination of cleanup efforts, and waterfront planning, barriers to timely and successful environ-mental actions will remain difficult to overcome.

We analyze the relationship between waterfront redevelopment (sometimes termed “revitalization”), on the one hand, and sediment cleanup, on the other. Using examples from North America, we also evaluate possible changes in the funding paradigm that could better link cleanup with redevelopment, thereby accelerating the pace of overall remediation. We question the efficacy of the 100-percent-polluter-pays model currently employed in cleanups under the Superfund program and state-equivalent models. The polluter-pays model has numerous flaws, including the difficulty of securing relevant polluters’ participation, and the technical chal-lenges of quantitatively attributing sediment contamination to original sources.

Polluters from industries of yesteryear often lack roots in the present-day community. Thus, their sole residual interest is resolving their financial exposure at lowest cost. In stark contrast, entities having longer-term interests on the waterfront – such as local governments, ports, and civil-society organizations – can play a larger role in cleanup finance via responsible planning, sensible development regulation, and uplands remediation. We do not suggest that these entities bear more than their fair share. Rather, we propose a model by which they undertake leadership roles in the process, given their naturally occurring stakes in waterfront revitalization.

This model features new roles for cleanup authorities, new struc-tures in bond-finance, and public-interest capture of inequitable windfalls otherwise benefiting land speculators. Alternative funding methods would provide communities enhanced control over outcomes, scheduling, and long-term performance of the

Legal 3 – 5aSps3 | Soil, sediments and waste

Legal framework for sediment study and remediation of water bodies in Flanders.

Steven DeleersnyderSertius

The flemish soil legislation introduced the obligatory soil study and soil remediation in 1995 for land soils. In 2008, a new chapter was added to the soil decree introducing a sediment study and a sediment remediation for water bodies.

The presentation will explain who is responsible for the sediment study and who can be held responsible for the possible sediment remediation. Specific attention will be paid to the difference between the remediation of diffuse sources of pollution and point sources and to possible exemptions from the obligation to remediate.

A case study will illustrate how these legal principles are put into practice.

Who should pay for sediment cleanup?

Philip SpadaroTIG Environmental

While technology for investigating and remediating contaminated sediment sites has advanced significantly over the past decade, the inventory of such sites in Europe has not been significantly reduced. One repeated obstacle to progress is the question: “who will pay the cost”? The analysis of this question is convoluted and involves primarily legal and technical issues but also social and economic aspects. The typical response to the question has been “the polluter should pay”! And for the most part, this is true but the premise of “polluter pays” reaches practical limits in countries that have experienced repeated cycles of industrial nationaliza-tion and privatization or in countries lacking the aggressive legal framework needed to enforce such an approach. Also limiting this approach are the “time bars” that many national and transnational legislative frameworks impose on polluter liability. The fact that most sediment contamination is derived from discharges asso-ciated with the industrial activity of the mid-twentieth century makes such time bars more or less insurmountable obstacles to the polluter pays principle.

Methods to allocate cleanup cost are being used in alternative dispute resolution format on several sites in the United States. These methods usually involve technical and legal elements. Because legal frameworks vary from country to country, we focus here on the technical issues. The methods used include careful analysis of facts surrounding industrial and municipal discharge points and sediment deposits. The history and current status of these discharge points and associated sediment deposits can be evaluated using several scientific techniques.

This approach could have beneficial application in cases where certain conditions exist. The approach is predicated on the belief that distributing the cost of cleanup beyond a single polluter to a wider group of stakeholders will result in better incentives to proceed with cleanups. More specific, and often more reason-able, cases can be developed to support the relationship between sources and deposits of pollution using modern physical and chemical investigative and forensic techniques. Additionally,

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Legal 4 – 5aSps4 | Technician meets lawyer

Bio-engineering solutions as catalyst for redevelopment of impacted sites

Rogier De WaeleGreenSoil International B.V.

The proposed session would be part of the overall day on legal and economic aspects of contaminated lands. The intention is to highlight show cases where bioengineering and total remediation contracting has unlocked redevelopment issues at (brownfield sites). Often, due to conflicting interests, projects lie in a stand still situation. Identifying and disclosing conflict of interests by finding an overall solution to best overcome the impasse becomes of primary importance.

Every party plays an important role and it is necessary to find potential connections leading to a joint solution among them. In this framework, external consultancy might help to solve intricated aspects providing new and innovative ideas.

The free session is divided into three show case presentations. The show cases are introduced by one of the parties involved who played a decisive part in the operational development of the project. First, the site history characteristics (cause and type of contamination) are described. Then, the presentations focus on the intricated aspects characterizing each specific case and the way they were overcome.

In specific, the talks deal with the following topics:

1) Bioengineering as solution for conflicting site clean-up and windmill constructions.

On a former telecommunication site two source zones with TCA and PCE contamination were encountered. Due to the vertical gradient groundwater is contaminated between 3 and 21 meter depth.

Not only the complex technical remediation was a challenge, also the implementation in the field seemed to be difficult due to the presence of multiple stakeholders on the site and the construction of a windmill on top of one of the source areas.

2) Biological site solution unlocks development potential of cVOC impacted site for client and new owner.

Chlorinated solvents are used for a wide variety of purposes. Reme-diating these contaminations is often a big challenge, especially when there is a limited timeframe and the landowner wants to sell or redevelop the contaminated land plot as soon as possible. Because of the total remediation concept and contract, the site owner was able to sell the property as future ‘green field’ and the redeveloper could buy the site without further limitations or liabilities.

3) Total (bio)remediation contracting unchains blocked brownfield site in Venray (NL).

As a result of the production process of Inalfa, the soil has been contaminated. The new owner had major concerns about the use the site, therefore a tender was open to present plan of approaches to prepare the site to redevelopment after long time of deadlock situation. Timing was crucial and a global solution in a fixed price contract allowed the new owner to redevelop this longlasting brownfield site.

Finally, a panel discussion among the presenters with different areas of expertise and other managing leveled representatives of

cleanup. Additionally, these methods could possibly inhibit current patterns of community displacement occurring as property values rise in response to redevelopment.

Without coordination, financially and otherwise, significant oppor-tunities are lost. Through enlightened practice – perhaps spurred by positive regulation and comprehensive negotiation platforms – greater numbers of effective, impactful cleanups become possible.

How to manage both costs, acceptable risk and stakeholders when excavating material containing asbestos in a context of Big Urban Projects?

Juliette Payet; Julien Matha; Thierry GisbertARCADIS France

As part of the metro station “Gare BVC” project of the incoming line 15 in the Paris area, a public institution “Etablissement Public d’Aménagement” engaged the redevelopment program of about 25 ha in its territory (20 km East of Paris center).

This area includes a mound representing 225 000 m3 of material, which need to be removed and discharged for the project. Subsoil investigations implemented on this mound identified the presence of several types of wastes in soil including asbestos fragments.

In this context, Arcadis has supported its client on managing exca-vating material containing asbestos since the soil investigations phase in 2017. Currently, our project management mission notably consists of:

- Build the operation budgets

- Write the technical specification reports for earthworks/reme-diation companies for the several excavation phases

- Assess the consulted companies’ proposals (technically & finan-cially) and support the client on the final selection

- Follow up on a day-to-day basis and control activities of the selected company

- Certify the good execution of the works

- Assist the client in decision-making and application of the agreement with the contractor

Our role on this mission gradually became essential to our client to safely perform his development program by sorting out the excavated material as much as possible to decrease disposal costs while respecting deadlines.

Through this project, we seized the opportunity to develop a specific approach to manage a large-scale excavation operation including ACM issue by considering the main drivers of our client (tight deadline, budgets securing) in a context of French regulation which is not accomplished for asbestos management in excavating material.

In particular, we engaged a reflection on the waste classification to be considered depending on the way asbestos is identified in the excavated material (Asbestos identified via ACM fragments only, Asbestos identified via ACM fragments but also via fibers detected in the soil matrix), the result of this work could lead to interesting budget economy for our client.

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Ramboll and GreenSoil unlock development potential of a chlorinated solvent impacted land, using enhanced bioremediation techniques

Steven Van Buggenhout¹; Geert De Buysscher²; Rogier De Waele²; Michela De Camillis²; Lennart de Bie²¹ Ramboll; ² GreenSoil International B.V.

Chlorinated solvents are often used for a wide variety of purposes, from cleaning of machinery, clothes and electronic parts to use in chemical manufacturing. However, they have caused a variety of environmental problems, such as contamination of soil and groundwater. Remediating these contaminations is often a big challenge, especially when there is a limited timeframe and the landowner wants to sell or redevelop the contaminated land plot as soon as possible.

In this framework, Ramboll and GreenSoil are working together to address remediation works at a brownfield development site in Mechelen, Belgium. The former metal processing site is heavily contaminated with tetrachloroethene and trichloroethene, to a depth of 16m and over a surface area of more than 5,000m².

Previous undertaken containment measures used hydraulic barrier (10m3/h) combined with a conventional groundwater treatment system. However, the source was not yet identified, and the mass removal was limited. Moreover, migration of groundwater due to P&T barrier led to a strong horizontal and vertical contamination.

In this context, Ramboll and GreenSoil decided it was important to identify the source areas before any additional remediation works were undertaken. This investigation showed the presence of three main source areas.

Following the removal of asbestos-containing buildings and exca-vation of the source areas, an in-situ remediation system, designed to treat residual contamination in groundwater, has been installed entirely below ground level. It was important to the client that rede-velopment of the site for industrial use could continue alongside the groundwater remediation programme, rather than wait for the remediation phase to be completed.

The enhanced bioremediation technique involves the use of an organic substrate, or electron donor (in this case, Dehalo-GS), together with nutrients, trace elements and vitamins, which ferments to stimulate anaerobic biodegradation of the solvents. Careful management of the technique ensures that the electron donor ferments at the right speed, steadily releasing hydrogen to maintain the biodegradation process, while only marginally decreasing the pH of the soil and water.

The remediation system includes 180 extraction and infiltration wells, with the well heads installed at 2m below the ground surface, enabling the development works above-ground to continue.

Concentrations as high as 19.000 µg/l of PCE and 6.400 µg/l of TCE were observed on site. Once the bioremediation started, degrada-tion product concentrations increased with time. Within two years, most of the wells approached/achieved the remediation threshold values set to 500 µg/l for PCE, 500 µg/l for TCE, 1500 µg/l for 1,2-DCE and 500 µg/l for VC.

The active remediation phase will continue for a total of three years with post-remediation groundwater monitoring continuing until 2024.

So far, these results demonstrated the enhanced biological degra-dation capacity on site and the complete dichlorination of the various contaminants. In the meantime, redevelopment works already started as there are no limitations due to the on-going remediation works.

brownfield remediation is set up to discuss dynamically the future of total remediation contracting, contract forms and how the market is expected to evolve the upcoming years.

Bioengineering as solution for conflicting site clean-up and windmill constructions

Karen Van Geert¹; Thomas Van Humbeeck¹; Els Desair²; Rogier De Waele³; Jan van den Boogaart³; Martin Slooijer³¹ ARCADIS; ² Just Business Law; ³ GreenSoil International B.V.

On a former telecommunication site two source zones with 1,1,1-trichloroethane (TCA) and tetrachloroethylene (PCE) contam-ination were encountered, with concentrations up to 200ppb and 100ppb respectively. Due to the vertical gradient groundwater is contaminated between 3 and 21 meter depth. The local litholog-ical constitution, i.e. glauconitic (iron) fine sands with low buffering capacity. In order to select the most efficient remediation strategy for this complex geology and contamination, a multiple step pilot test on enhanced reductive dechlorination (ERD) was carried out in the source zones to decide on the best available technique. Based on this pilot test, bioremediation was selected.

Not only the complex technical remediation was a challenge, also the implementation in the field seemed to be difficult due to the presence of multiple stakeholders on the site. The liable party needs to finance the remediation and has major concerns on cost control. The owner of the site had major concerns about the use, hindrance and redevelopment of his site. The challenge on this site became even bigger as a third party received a permit to build a windmill on the site, in the zones impacted with contamination. This would not only complicate the remediation but also potentially increase the uncertainty in costs and efficiency. As all 3 stakeholders had different and conflicting interests, the project was put on hold and seemed to turn towards a court case rather than remediation case.

Finally an integrated technical and financial solution was proposed, taking into account all concerns of all stakeholders.

On a technical basis, an integrated engineering of the bioremedia-tion and the construction of the wind mill was made. A groundwater recirculation system underneath the windmill was proposed. The groundwater extraction combined with re-injection could be installed together with the construction of the foundation of the windmill and the design of the ground piles for the foundation of the windmill was adapted. Underneath the windmill a recircula-tion system will be operated. A bioaugmentation will be used to limit uncertainties and to increase efficiency of biodegradation is foreseen. The hindrance for the site owner will be limited due to the adapted engineering and the combination with the construc-tion of the windmill. The windmill can be build on the location as permitted.

On a financial basis, the contractor proposed to take over the liability of the client. This action limited the financial uncertainty for the client as well as the extra internal coordination costs (due to multiple stakeholder meetings).

It is clear that in this project cooperation was needed to unblock further progress in remediation of the site. In addition to the technical challenges, it required that multiple stakeholders work together to come to an integrated solution with clear lines of communication and a transparent process. The presentation will give insight in the technical challenges and the integrated approach of the windmill construction and remediation as well as the non-technical challenges and solutions to make this project successful.

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Application of environmental forensic investigations to define the allocation of liabilities in insurance claims

Domenico FracchiollaRamboll Italy S.r.l.

The environmental forensic investigation techniques can be applied to identify the responsible of the environmental contami-nation among different subjects who operated at the site. Ramboll was retained by insurance companies to perform forensic investi-gations to understand who was the responsible for the spill event and how and when it occurred, in order to define the allocation of liabilities in environmental claims and provide a suitable reim-bursement for remediation costs.

In the case study n. 1 Ramboll was asked to define who was the responsible for the heavy groundwater contamination detected at a large petrochemical facility, owned by two different subjects, respectively before and after ‘80s. The Compound Specific Isotope Analysis (CSIA) was used to identify the contribution to contamination due to each of the owners, properly allocating the reimbursement of the estimated remediation costs by the insurance companies.

In the case n. 2 CSIA was applied to assess the migration pathway of chlorinated solvents detected offsite to a large chemical facility, where a hydraulic barrier is operating for containment purpose. The isotopic analysis revealed a different fingerprinting of the contami-nants located offsite with respect to the ones located onsite, demonstrating that they were originated by an external landfill, as source of contamination not related to the insured owner.

The case n. 3 is a logistic site, where the insured tenant detected oil products within unknown underground storage tanks, which contaminated the surrounding soil and groundwater. In this case, the analysis of marker additives and chemicals (e.g. Sulphur), considering the maximum concentrations allowed by the regula-tion in the time, was used to estimate the age of the oil products, demonstrating they were date back before 90’s, when the insured subject was not operating at the site. Moreover, the application of chromatographic fingerprinting in the soil samples provided further evidences to confirm the contaminants origin and the spill age dating.

The case n. 4 is a petrochemical facility located in a coastal area, where aromatic hydrocarbons were detected migrating within the harbor located offsite. The site owner is also operating a hydraulic barrier to prevent contaminated groundwater migration toward the sea. A multiple investigation approach (hydrogeolog-ical modelling, chemical fingerprinting and medicinal chemicals markers) was applied to elaborate a complex conceptual site model, defining the contaminants offsite migration pathway. The investigation revealed the existence of a residual historical contam-ination entrapped within the stagnation zone of the hydraulic barrier migrated offsite before its activation.

These case studies show as a scientific approach can be an effective tool for the insurance companies to solve controversies related to definition of liabilities for contamination events and establish if and how much should be reimbursed to the insured subject within the claim.

Acquisition of liability becomes possible through the use of an integral cyclical design

Martijn van Paassen; Michela De Camillis; Rogier De WaeleGreenSoil International B.V.

As a result of the production process of Inalfa in Venray, the soil has been contaminated. The total surface of the business location is about 8 ha, of which about 5 ha were industrial buildings.

The complex requirements and restrictions present led to a deadlock situation for long time on the site. On one side, the authorities were concerned about neighborhood and contamina-tion migration. On the other side, the liabilities were unknown and the owner had the necessity to redevelop the site. Therefore, many risks were involved in future development of the activities at the site. Amongst all, the contamination source under the building was unknown and the potential remediation had to be combined with demolition works and asbestos removal.

P&T technology, combined with a conventional water treatment system, was used as containment barrier to avoid off site migration of groundwater contamination. Although this control method had been running for years, the mass of contaminant removed was limited as the source was not treated. Moreover, additional migration of groundwater towards the pumping area caused on site further horizontal spreading.

GreenSoil was selected to prepare the site to be redeveloped by offering a lump sum contract and taking over the complete liability. A very short timeframe for commissioning was given. In addition, GreenSoil installed a collaboration with Bodem Beheer Nether-land to continue the monitoring of the plume after 3 years’ time whether the remediation will not be finished yet. The competent authority was thrilled by the inventive approach as the previous technology was no longer efficient.

Local spots of heavy metals spread over the site and two source zones with cVOCs and TPH oil have been found. Following the removal of asbestos-containing buildings, demolition works were then conducted. In addition, the project included excavation and off-site treatment of the source area until 4 m-bgl. However, the interesting aspect of the plan was the installation of the in-situ remediation system which took into account the construction of a new building in the future. In this way, there are no restrictions or risks of damaging the bioremediation system for future works on site.

The so-called combi-filter techniques allowed a fully coverage of the contaminated area in the most efficient and effective way. In addition, to avoid spread of contaminants outside the site boundary, a bio-barrier has been installed. Finally, the site has been prepared for redevelopment, compacted and finished according to requirements.

GreenSoil handed over the site to the client within 5 months. By using the LEAN plan method, together with a good cooperation among the involved parties, all activities proceeded according planning and without conflicts.

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Mass balance of a chlorinated solvent source zone: evaluation of uncertainties to secure remediation contracting terms

Sébastien Kaskassian¹; Solène Coppens²; Thierry Ruffenach¹; Bert Scheffer;. Emile Marnette³¹ Tauw France; ² Tauw France SAS; ³ Tauw bv

At each stage of the assessment and remediation processes, questions concerning evaluation of costs and uncertainties regularly rise. Once the assessment phases conclude in the need for remediation, the contracting process with all stakeholders requires for an accurate estimation of the pollution mass and spatial distri-bution in order to secure the budgets of each party within the remediation scope of work (mass removal, improvement of the health and safety conditions at the site…).

On such a site contaminated with chlorinated solvents, the work owner asked Tauw to assess the risk of exceeding the budget for an in-situ Electrical Resistance Heating remediation project. The contracting terms included a fixed price remediation to reach a target value (maximum residual concentration) with a capped amount of extracted mass assessed to 70 tons by the remediation contractor.

The proposed strategy was to produce a 3D geostatistical model of the contamination in the treatment area and evaluate the uncer-tainties of the mass balance calculation according to:

• The amount and type of data included in the model: 220 soil samples (initial mass estimate undertaken in 2014) vs. 1160 all media samples in 2018 (MIP and PID readings, soil and ground-water concentrations),

• The sampling effect: sampling protocols, grid, sampled media (direct or indirect measurement),

• The computation method: interpolation (nearest neighbor), vs. 3D block kriging vs. statistical simulations,

• The sensitivity of each model (variogram, neighborhood, grid size) and intrinsic uncertainty.

During the contracting period, the initial evaluation based on available data in 2015 and on an simple interpolation method resulted in about 24 tons of chlorinated solvents present at the treatment area. The remediation contractor estimated a potential mass of 71 tons based on the same data and this mass was set as a maximum for the fixed price of the remediation.

With data collected during the installation of the remediation system early 2018, the geostatistical modeling performed by Tauw resulted in a most probable mass between 43 and 61 tons with a sensibility range of ±35%. With this estimation, the work owner was able to secure the remediation contract terms taking into account potential uncertainties.

For comparison purposes, the on-going remediation project allowed the extraction of about 37 tons between May and October 2018.

The presentation will describe the computational methods and limits, discuss the results and the uncertainties for each model (origins and parameters) as well as compare the computed mass to the actual extracted mass at the end of the remediation project (due for February 2019).

From the perspective of the soil-expert: how to stimulate the development of brownfields

Willem Hendriks¹; Geert Rovers²; Annette Haselhoff³; Jan Fokkens⁴¹ Witteveen+Bos; ² Saxion University of Applied Sciences / Antea Group; ³ Tauw bv; ⁴ Uitvoeringsprogramma Bodem & Ondergrond

Despite the various remedial programs over the past decades, there are still lots of (partially) contaminated sites in urban areas, abandoned or waiting to be redeveloped. Still, redevelopment of these so-called brownfields is difficult, especially coming from economic hardship with large impact on urban development. This article presents the results of a project - executed for the Dutch Ministry of infrastructure. In this project we adopted a spatial and governance view on redevelopment of brownfields and translated that to specific perspectives for dealing with contaminated land. By means of case studies and interviews we have looked through the eyes of urban planners, project developers and administra-tors towards the professionals in the field of soil remediation when involved in a redevelopment project. Resulting in a number of points of attention and a strategy to address various types of “brownfield” sites. In our presentation we will focus on improving the role of the environmental experts.

Panel Discussion

Martin Slooijer¹; Karen Van Geert²; Geert De Buysscher³; Vincent Breij⁴; Els Desair⁵¹ GreenSoil International B.V.; ² ARCADIS; ³ Ramboll; ⁴ Bodembeheer Nederland; ⁵ Just Business Law

A panel discussion among the presenters with different areas of expertise and other managing leveled representatives of brown-field remediation is set up to discuss dynamically the future of total remediation contracting, contract forms and how the market is expected to evolve the upcoming years.

Economic 1 – 5aSpS5 | Accounting rules

Chair: Dirk Nuyens (ERM)

Concept:

o Discussion on accounting rules related to environmental liability

o Short discussion

Content: The idea is to give the non-accountant participant a good overview on the accounting framework for estimating, provi-sioning and managing environmental liabilities for publicly traded companies. It will discuss the convergence of the US/International Accounting Rules and give more details on how these liabilities are being estimated and managed within an industrial/real estate portfolio, and what the position/experience is of auditor firms validating the company’s results/value. The impacts of long-term remedial projects, engineering controls, usage restrictions, currency fluctuations, change of company structure, … will also be discussed. The non-financial reporting will also be discussed.

Presenters:

o KPMG: Patouche Van Staay

o Baker & McKenzie : Pascal Malien

o ERM : David Cruickshank

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The following people are involved: OVAM: Johan Ceenaeme, Nathalie Van Trier, Nele Bal, Ann Cuyckens / Consultants: Wouter Gevaerts, Karel Van Nieuwenhove, Pieter Schrooten / Contractors: Siegfried d’Haene, Hans Bailleul, Ellen De Wilde / VITO: Johan Vos, Ilse Van Keer.

5cSps1 – Ports session: Dealing with pollution and land transition in times of the energy transition

Sophie VermootenDeltares

Why this session?

There is more and more attention for dealing with industrial pollution distributed over large areas in ports in light of the energy transition and the related expected shift in economic activities in those areas. This is a major challenge in the coming 10 to 20 years. With this session we want to exchange experience in how ports are dealing with industrial pollution distributed over large area. Relevant experience to share are for instance:

• What approaches are used?

• What tools are used?

• What current solutions can help in remediating the areas?

• Are there ways to accelerate the remediation of locations to make them available for new economic activities?

• What are the gaps in knowledge to solve this challenge?

For whom?

Companies, port authorities, public authorities, consultants and researchers.

Chairs of the session

• Port of Antwerp

• North Sea Port

• Port of Rotterdam/municipality of Rotterdam

• Port of Hamburg

Panel: Chairs and three companies located in ports.

Introduction

In industrial areas like ports, large-scale and complex groundwater contaminations are often found in the subsurface. These contami-nations have spread and mixed for decades. In practice, it proves difficult to effectively tackle areas with large-scale deep subsurface and groundwater contaminations. On the one hand, it is difficult to map the nature and extent of the contamination and the polluter is often not traceable or no longer liable. On the other hand, the (social) costs for complete cleaning up appear to be extremely high and the costs rarely outweigh the benefits.

The energy transition seems to be a new driver of change in the ports. It is expected that within a few decades, industrial activities in ports related to the oil-gas economy will shift to other economic activities.

If these industrial activities leave the port area, how to deal with the remaining contamination? What solutions can help us in dealing

Economic 2 – 5aSpS6 | Due Diligence

Chair: Geert De Buysscher (Ramboll)

Concept:

o 3 Presentations related to due diligence

o Roundtable discussion

Content:

Land contamination is often an important factor in due diligence assessments of (former) industrial facilities. This session will provide insight on how to assess contaminated land liabilities in a transaction process. We will be informed on the benefits and limi-tations of so-called Phase II assessments, so that more informed investment decisions can be taken. We will zoom in on how the total cost of ownership is applied on a complex contaminated site using a case study. And we will be informed about due diligence tools applied on large portfolios of sites. The session will be closed by a panel discussion between the presenters, including interac-tion with the audience.

Participants

o Benefits and limitations of field investigations (Phase II) in an environmental due diligence process

Bertrand Latrobe (Ramboll)

o Total cost of ownership concept applied on a complex site

Wouter Gevaerts (Arcadis)

o Tools for portfolio management

Pieterjan Callewaert (ERM)

Economic 3 – 5aSpS7 | Round table with stakeholders

Chair: Wouter Gevaerts

Concept:

o Discussion related to the practise of environmental liability management: challenges and opportunities

Presentations :

o Each participant explains (5’) how he or she is dealing with financial liability management:

- Point of view of Industry

Signify: Johan De Fraye

Shell : Jonathan Smith

Revive: Alexandre Hughe

Lucia Buve: Umicore

- Point of view of a lawyer

Pascal Mallien (Baker & McKenzie)

- For the panel : Point of view of a regulator

Johan Ceenaeme (OVAM, Flanders)

Common Forum: Dietmar Müller-Grabherr

Flemish Session – 5aSpS8

In the Flemish session we will give an overview of how the soil remediation sector built experience and looks forward to the future, with a focus on the collaboration of the 4 partners govern-ment, consultants, contractors and VITO as a research institute.

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goals are to work together cooperatively on joint initiatives with global organisations with a mutual interest in sustainable land management.

The purpose of this session is to provide a brief global round up of progress, showing how common themes and thoughts are broadening, developing and maturing to more sustainable land management concepts.

The key development in the advancement of sustainable remedia-tion theory and practice since ACS 2017 are:

• The release of a new ISO on sustainable remediation

• Major efforts in wider outreach to educate and promote about sustainable remediation beyond the contaminated land practi-tioner community

• Emerging integration of sustainable remediation in wider land management and sustainability agendas.

This session will showcase some of the newest development areas that SuRFs have been working on. They acknowledge the challenge that they face broadening their discussion of sustain-able land management concepts outside of the technical scientific community and are looking to improve their outreach activities. New aspects that will be shared will be:

• How the ISO 18504 on Sustainable Remediation provides guidance to undertake a sustainability appraisal

• A new animation explaining what sustainable remediation is (SuRF-UK),

• How sustainability has been adopted by the Infrastructure Sustainability Council of Australia (SuRF-ANZ)

• The importance of considering the impact of climate change on contaminated land and remediation (SuRF)

• How broadening the ideas of land stewardship and soil as a natural capital is important (SuRF-NL)

• How sustainability will be used to manage large volumes of contaminated soil in Fukushima over the next 30 years (SuRF-Japan)

Following a series of short presentations, the audience will be asked questions on different themes using a free voting app for real time responses to help shape the discussion for the session. The SuRF community want to continue their collaborative activities and will use the ACS 2019 Special Session to help shape what they see are the next greatest challenges that need addressing to support the wider scientific community.

Presenters will be from a wide number of the different SuRFs, incl.:

SuRF-UK – Hayley Thomas & Jonathan Smith; SuRF – Barbara Maco; SuRF – NL Laurent Bakker; SuRF Japan -Tetsuo Yasutaka and SuRF ANZ

Debunking myths about sustainable remediation

Jonathan SmithShell Global Solutions (UK) Ltd

Sustainable remediation has emerged over the past decade as an evolution of the establish risk-based approach to assessment and management of contaminated soil and groundwater. In this period the contaminated land industry has worked to develop good practice guidance, and most recently international standards. In 2017 an ISO Standard was published.

with those changes? Are their ways to accelerate the transition from one economic activity to another by combining smart reme-diation solutions and policies of transition?

How

We propose to organise a two-hour session with a few presenta-tions followed by a reflection on the stories in a panel discussion with the aim to to exchange practical experiences between the stakeholders. The agenda would be as followed:

- Introduction of the session and who is in the room? (15 minutes)

- Three stories of three ports (45 minutes)

One story will for example be on the “coordinated approach reme-diation of the port of Rotterdam” focusing on financial, legal, organizational and technical aspects of the megasite approach.

Panel discussion (45 minutes): Exchange of practical experience between stakeholders.

How are the approaches different?

What knowledge gaps are present?

What will the port look like in 2050 and what does that mean for the remediation strategies?

Closure whereby each panel member describes in a sentence what the most important learning point is what he / she takes along plus 3 people from the room. (15 minutes)

Coordinated approach remediation of the port of Rotterdam

Jan-Willem Meertens

Short presentation focusing on financial, legal, organizational and technical aspects of the megasite approach in the port of Rotterdam.

What is the current policy and what are the current responsabilities?

How does the coopeartion between all stakeholders work?

What instrument is used to support the megasite approach?

5cSps2 – Progress in sustainable land management worldwide

Nicola Harries¹; Laurent Bakker; Hayley Thomas; Barbara Maco¹ CL:AIRE

Sustainable land management has become an area of develop-ment globally with public and private sector organisations working closely together on projects and developing networks to improve and share knowledge. Initiatives in Europe, North and South America, Australia, New Zealand and Asia are now well established and known collectively as Sustainable Remediation Forums (SuRF). Networks in USA, UK, Australia & New Zealand, Netherlands, Italy, Brasil, Canada, Taiwan, Colombia and Japan are established. These networks meet regularly to share knowledge, work collaboratively and provide support with all information available through www.claire.co.uk/surfinternational. More recently the SuRF initiatives have formed a broader alliance called the International Sustain-able Remediation Alliance (ISRA) www.claire.co.uk/isra. ISRA’s

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5cSpS3 | Nature-based remediation workshop

Geert De Buysscher; Victor Magar; Mark NielsenRamboll

Around the world, cities are expanding while natural areas are gradually shrinking. The UN has set a global objective to stop the decline in biodiversity by 2020. To support this objective, we must integrate nature into all aspects of urban development and utilize natural processes for sustainable site remedies. When we do this, we provide more physical space for wild species and we achieve benefits for people, society, and the environment. New approaches to integrating nature and growing knowledge about ecosystem functions are necessary to develop remediation alternatives that contribute to habitat biodiversity and liveable cities. Nature-based remediation offers an opportunity to create win-win solutions that support the environment and diversity while creating cost-effec-tive and technically effective solutions. There is great potential for nature-based remediation, and costs are often lower compared to traditional remediation and post-remedy habitat planning approaches.

This workshop will discuss nature-based remedy approaches and case studies to manage contaminated media. We will discuss how to evaluate nature-based remedies against conventional alter-natives, and how nature-based remediation can contribute to habitat enhancement. Our appraoch considers the net benefit to the environment and the direct, indirect, and life-cycle impacts of the corrective measures alternatives. Sustainability is primarily evaluated as part of the long-term and short-term effectiveness and protectiveness criterion, but may also affect implementability, cost effectiveness, community acceptance, and land use. We will focus on the following topics and media:

• Nature-based remedies in soil

• Nature-based remedies in sediment

• Leveraging monitoring and maintenance to manage nature-based remedies

The workshop will provide participants with a common under-standing from which to discuss best practices for evaluating and implementing nature-based remedies. Focus will be on case studies where nature-based remedies have been implemented. Three short talk (10–15 minutes) will be given on each of the three elements listed above, followed by a group discussion. The discus-sion will be initiated by a list of questions aimed at discussing best practices and differences in national approaches, and on illumi-nating the expected path forward.

We suggest that knowledge and experiences on the following aspects could be addressed:

• State of the practice. How do we define nature-based remedies and why are they of interest? Do nature-based solutions offer advantages over conventional remediation approaches that often require substantial soil or sediment removal and separate remediation and restoration processes?

• Habitat improvement. How can nature-based remedies be leveraged to improve habitat conditions? Can nature-based solutions be integrated with more conventional remedies to improve habitat while addressing remediation requirements?

• Regulatory requirements and constraints. What are the regu-latory drivers for remediation and how does the regulatory environment support or detract from implementing nature-based solutions?

Practice and application of sustainable remediation has also grown in parallel, but not without some misunderstanding or misinter-pretation in some quarters that has, on occasion, led to reluctance to accept the approach. The reasons for reluctance are frequently based on incorrect understanding of sustainable remediation, or the motivations behinds its development.

This paper will present a series of misconceptions and frequently stated concerns about sustainable remediation, and attempt to debunk the myths that underlie these concerns. The lessons learned by the SuRF-UK steering board since it was established in 2007 are synthesized and presented to help dispel similar concerns in other locations.

Parallels between ISO 14001:2015 and the SuRF UK framework

Hayley Thomas¹; Frank Evans²¹ Shell Global Solutions International B.V.; ² National Grid Property

The UK Sustainable Remediation Forum (SuRF-UK) was estab-lished in 2007 to support the application of sustainability principles for remediation in the UK. SuRF-UK has provided the contaminated land industry in the UK and beyond (through partici-pation in the International Sustainable Remediation Alliance) with a framework for the assessment of the sustainability of remediation strategies and suitable sustainability indicator sets covering envi-ronmental, social and economic factors (https://www.claire.co.uk/projects-and-initiatives/surf-uk).

ISO 14001:2015 is a globally applicable standard which sets out the requirements for an environmental management standard. According to the International Standards Organisation it is one of the worlds most widely used standards and a key business tool for many organisations. More than 300 000 certificates have been issued around the world and it ranks high on the agenda of many organisations worldwide who place importance on their environ-mental impact.

The SuRF-UK framework has received an enthusiastic welcome and is routinely employed by some large consultancies and well-informed landholders. There remains scope however to further embed the approach within the contaminated land/remediation arena. This presentation seeks to identify synergies between the SuRF-UK approach and the ISO 14001:2015 standard. Identification of the commonalities will allow both environmental consultan-cies/remediation practitioners and informed landholders alike to leverage mutually beneficial practices to drive enhanced environ-mental performance whilst contributing to sustainability.

Hayley Thomas works for Shell Global Solutions, based in the Neth-erlands, and is part of a team that provides deep technical support on soil and groundwater risk-management to Shell businesses worldwide. Hayley is SuRF-UK co-chair 2017- present.

Frank Evans is Head of Operations at National Grid Property and is responsible for land regeneration activities across its UK portfolio including soil and groundwater remediation. He was the first chair of SuRF-UK and currently sits on the steering committee.

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6bSps1 | The implementation of soil and land-related Sustainable Development Goals at EU level

Linda Maring (Deltares), Sophie Moinier, Saskia Keesstra (WenR), Melanie Muro (Milieu)….Josiane Masson / Bavo Peeters (DG ENV)Kirstin Marx (UBA) and invited other speakers

In 2015 the United Nations adopted the Sustainable Develop-ment Goals (SDGs); a set of 17 goals aimed to be the roadmap for society to move from exploitation to sustainable use of our planets resources and from inequality, poverty and hunger to a proper education and good life for all. The EU has committed to implement the SDGs both in its internal and external policies.

A robust soil-water system is essential to achieve most of those SDGs. Generally, it is acknowledged that the water-land-soil system plays an important role for SDG 15, especially SDG15.3, “Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss “. Next to SDG 15, there are several other SDGs closely connected to land and soil: SDG 2, 3, 6, 8, 12, 13. Since many claims on land and soils are made at the same time, it is necessary to have more insights in these claims, potential synergies and trade-offs.

In many governance and regulatory documents the necessity to conserve this integrated picture of a healthy, properly functioning soil is not reflected, and therefore not addressed in a sufficient way. Therefore, an analysis of the progress of the implementation of land and soil-related SDG targets in the EU is timely, taking due consid-eration of the 2030 Agenda commitments which date, in terms of the natural system, is fast approaching. Urgent action is needed to implement Sustainable land management to conserve and restore land resources. For this we not only need an analysis of the state of play of the implementation of land and soil-related SDGs in the EU, in particular on the Land Degradation Neutrality target (15.3), we also need a platform that will provide the possibility to exchange ideas and progress on best practices between the MS on the imple-mentation of land and soil-related SDGs.

This session

This session aims at getting an overview of the progress of the implementation of land and soil-related SDG targets in the EU. Which examples and ideas are available?

Presentation: a preliminary overview of the progress of the imple-mentation of land and soil-related SDG targets in the EU from project “Providing support in relation to the implementation of soil and land-related sustainable development goals at EU level” for DG ENV presentation by Linda Maring (Deltares)

Presentation: an/ a few examples in member states.

case study from Germany presentation by Kirstin Marx(UBA)

case study other countries: t.b.c.

Interactive session: attendees are invited to exchange on best practices and ideas between the MS on the implementation of land and soil-related SDGs. This will be done by an interactive and struc-tured set up, where attendees are discussing along a few cases 1) which SDGs are relevant 2) how the SDGs are linked to soils 3) what actions are needed to meet objectives 4) how and to whom this should be communicated.

Applying Working with Nature to Navigation Infrastructure Projects

Victor Magar; Mark NielsenRamboll

The PIANC working group 176 is developing guidance to support ports and other public and commercial maritime interests apply a “Working with Nature” (WwN) paradigm to navigation and infra-structure projects. The guidance document is expected to be released in advance of the 2018 World Congress. The guidance will provide a basis for maximizing opportunities for working with natural processes delivering environmental restoration and enhancement outcomes that go beyond merely avoiding or just compensating environmental impacts. In addition to providing guidance on how to apply the Working with Nature paradigm, the guidance will raise awareness and promote expanded acceptance of Working with Nature as applied to navigation infrastructure projects.

WwN is defined as an integrated approach that involves working to identify and exploit win-win solutions that enhance or protect nature, and are acceptable to project proponents and environ-mental stakeholders (PIANC 2008; 2011). WwN provides an opportunity to:

a. Reduce demands on limited resources by way of using natural processes to maximize project benefits, thus minimizing the environmental footprint of projects while enhancing project benefits.

b. Reduce social friction and resistance by applying science-based collaborative processes to organize and focus interests, stakeholders, and partners.

The guidance draws from existing approaches and best practices worldwide. We will present various case studies that exemplify the WwN philosophy. By focusing on case studies, we hope to provide tangible examples of how WwN can be integrated into standard practice for navigation infrastructure projects. The presentation will discuss:

• The WwN paradigm

• Present Working with Nature as a process of shifting toward more sustainable practices for achieving multiple project benefits (i.e., environmental, social and economic)

• Incorporate adaptive management principles and practices, as appropriate

• WwN case studies

The primary audience in both developed and emerging economies is project engineers, contractors, ecologists, planners, and environ-mental stakeholders who have an influence on the decision-making responsibility pertaining to navigation infrastructure projects.

This paper will provide an overview of the WwN guidance document. Concepts and approaches are illustrated through representative case studies.

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• energy transition

• climate change adaptation and mitigation

• avoiding land and soil degradation

The attendants verify research topics and identify new trends, indi-vidual and national priority research needs related to land use, land management and the use of the soil-water-sediment system.

4. Closing remarks by the moderator on the session results.

SOILveR - Soil and Land Research Funding Platform for Europe

Esther Goidts¹; Frédérique Cadiere²; Nele Bal³; Marije Schouwstra⁴; Yvonne Ohlsson⁵¹ Public Services of Wallonia; ² ADEME; ³ OVAM - Public Waste Agency of Flanders; ⁴ Ministerie van Infrastructuur en Waterstaat; ⁵ Swedish Geotechnical Institute (SGI)

The SOILVER platform is a flexible, self-financed platform of European funders to co-fund and

disseminate research on sustainable management of soil and land. SOILVER is interested in funding activities to implement the INSPI-RATION Strategic Research Agenda (SRA) and SRAs of other

initiatives focusing on soil and land management research.

Transnational collaboration around a common research agenda provides an added-value to the research and its impact within a more coordinated way, a self-financed platform allows to avoid excessive administrative processes and preserve flexibility in research funding coordination, and the involvment of funders which are also end-users ensures that implementable research is produced and that results are uptaken by stakeholders, at all levels from the national to the local.

Besides funding research on soil and land, SOILVER aims at complementing each countries’ expertise through cross-country collaboration and exchanges of experiences between platform members on specific topics around soil and land management in a broad view. SOILveR wants to connect with existing networks depending on specific topics and complement or facilitate them with research funding issues.

SOILVER is preparing its first call on Recognizing and caring for soil and land as an asset. Specific topics are being defined within this overarching thematic. Interested partners are welcome on board of this long-term platform, and can also join the call if they are inter-ested in co-funding proposals covering their priority topics. For any further contact : (mail of Soilver)

During the Aquaconsoil session we will present the aim and working of the SOILveR platform and discuss with interested parties about the platform and the pilot call.

6bSps2 | Towards land stewardship: The INSPIRATION Strategic Research Agenda on soil and land 1 year on...

Stephan Bartke¹; Linda Maring²; Nele Bal; Sandra Boekhold³; Petr Klusáček⁴; Stanislav Martinat⁵; Marie Christine Dictor⁶; Uwe Ferber⁷; Paul Nathanail⁸; Margot de Cleen⁹; Co Molenaar⁹¹ Umweltbundesamt | German Environment Agency; ² Deltares; ³ RIVM; ⁴ Institute of Geonics, Academy of Sciences of the Czech Republic; ⁵ Cardiff University, School of Geography and Planning, Cardiff, Wales, UK; ⁶ BRGM; ⁷ Stadt+Land; ⁸ Land Quality Management; ⁹ RWS

Introduction

The way we manage our soil and land is central to ensuring Europeans transition to a sustainable future based on stewardship principles. Research and knowledge dissemination are funda-mental prerequisites for informed land use and evidence-based spatial planning policies if predictable over exploitation of natural capital is to be avoided. Smarter use of the physical, chemical and biological services provided by the soil-sediment-water system may provide ongoing and new solutions for meeting societal needs without exasperating societal challenges.

With partners from 17 countries across Europe, the INSPIRATION project developed a Strategic Research Agenda (SRA) for spatial planning, managing land and using soil-sediment-water system services across Europe and beyond. The SRA’s topics were identi-fied through a unique bottom-up process of engaging with over 500 key experts from academia, research funders and end-users from industry, policy makers, regulators, municipalities and citizen groups.

This special session focuses on the progress on implementing the SRA 1 year after the INSPIRATION project ended. Contact points in participating countries decided to continue to share information and champion the SRA. 1 year on, it is time to evaluate our outputs and outcomes and plan for the final decade of delivering on the SDGs.

This session will:

• Share information about INSPIRATION’s Strategic Research Agenda (SRA and online platform) for Europe, focusing on research needs demands related to integrated spatial planning, urban and contaminated land management;

• Present follow up activities concerning implementation of the agenda

• Discuss on upcoming trends and research needs 1 year after

• Discuss on possibilities to cooperate

Session outline

1. INSPIRATION Strategic Research Agenda, including identified research topics related to integrated spatial planning, urban and contaminated land management SRA - Stephan Bartke (UBA, DE)

2. Implementation of the SRA: SOILVER network – Nele Bal (OVAM, BE)

3. Facilitated delegate discussions in a world café setting as described below.

In three rounds of 20 minutes, the groups can discuss trends and research needs on their choice of three of the societal challenges / SDGs, such as:

• urbanization and urban planning

• food production

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6dSps | Exploring care, knowledge and agency as levers to Soil+Land stewardship

Bernard Vanheusden¹; Philippe Vandenbroeck; Nele Bal; Ellen Luyten¹ Hasselt University

In this session we would like to discuss what ‘Soil+Land Steward-ship’ means or could/should mean in practice. Soil and land deliver essential services but they are under increasing pressure and have become vulnerable resources. They are in urgent need of care and need to be restored where necessary.

Unfortunately, the role of soil and land often remains insufficiently visible for society. Actors are not always aware of the necessity of good soil management and sustainable land use. There is also an area of tension between the societal services delivered by soil and land and the principle of land ownership. On the one hand, land-owners and users have rights/benefits from their property, but on the other hand also obligations/responsibilities towards society and the planetary ecosystem. In other words, there is a shared responsibility for more care for soil and land. How can we foster the awareness and the shared responsibility?

The principle of Soil+Land Stewardship demands that soil and land users use/relate with their soil and land with due diligence. The principle could be a good instrument to increase soil and land awareness. The innovative and mobilizing power of the stewardship principle lies in the fact that it starts from societal engagement: everyone is connected in their own way to soil and land. The question is whether everyone is also aware of the impor-tance of a healthy soil and resilient land. We aim to strengthen the social commitment and ensure that all citizens, as landowners and land users, “act” upon their soil and land in a careful and sustainable manner. Indigenous peoples have been dealing with their land in this way since ages: “we are not just the users of the land, we belong to it”. It can be a lever to move from ego to eco, to individual interest in balance with collective interest.

The Care-Knowledge-Agency framework, introduced by Enqvist et al (2018) as a means of recognizing plurality, helps to guide future steps to research and practice along productive pathways. Stewardship acts in this framework as the interface beween Care (values-why) – Knowledge (on the soil and land and their management–what) – Agency (how stakeholders bring it into practice–how).

The structure of the session would be as follows. After the introduc-tion to the topic and lessons learnt so far by Bernard Vanheusden and Philippe Vandenbroeck, we would like to have three short presentations (around 10 minutes each) on:

- Social ecological system work – Stockholm resilience center – Maria Tengo OR Jamila Haider

- Soil/land & human rights & legal framework: Prof. dr. Daphina Misiedjan (Universiteit Utrecht) OR Hendrik Schoukens (UGent)

- Stewardship in practice: Slow Food and soil/land OR sustain-able food expert: Marta Messa, director of the Slow Food office in Brussels

Each presentation would be followed be a short intervention (max. 5 minutes each) by two experts from OVAM (Ellen Luyten and Nele Bal). The rest of the session we would like to debate with the audience on the presentations and on what ‘Soil+Land Steward-ship’ means or could/should mean in practice. We want to explore together with participants the Heart – Head – Hands approach.

6cSpS | Water Nexus as a source for innovation in the water security challenge

Participants: Henk Pool, Huub Rijnaarts, Hans van Duijne, Thomas, Repr. Witteveen & Bos, repr. Ministry I&W

Present:

o Huub Rijnaarts (intro project (incl. technology and natural system innovations))

o Henk Pool (interest of the industry)

o Thomas Wagner (system analyses & wetland technologies)

o Representative of the Dutch government Min. of I&W)

o Representative of Witteveen & Bos (moderator and introduc-tion to interactive sessions)

Introduction

* Introduction to Water Nexus (Huub Rijnaarts)

* Which alternative water resources (e.g. wastewater, brackish water) are available and how to connect them to the users? (Thomas Wagner) -

* Challenges from the different stakeholders in the region when using alternative water resources (Henk Pool) -

* Objective and explanation of the session (Witteveen & Bos) -

Interactive

The audience will be split in several groups (5 -6 separate tables) with varying backgrounds. Each group will receive a map with different water users and water resources. In the session, we want to link the water users and water resources through innova-tions. Each group will get a set of ‚post-it‘ of different colors which they can place on the map. Each color represents an innovation category. The categories are technological innovations, natural system innovations, governance innovations and financial innova-tions. The groups are asked to come up with their own innovations to close the regional water cycle. The groups should also highlight with stakeholders are necessary for the innovations.

The main questions which can be used as guideline are:

* How do technology and natural system innovations reach stakeholders?

* Which stakeholders (industry, government, citizens, etc.) are essential?

* Who should talk to whom?

* Which governance and financial innovations are needed to stimulate the connections?

Wrap-up (10 min)

* Each team will give the short wrap up of the outcome of the sessions.

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Innovation for a green future for brownfields

Jean Louis Morel

This presentation will introduce the aim and organization of the session and present the general context of innovative environ-mental technologies for brownfield redevelopment, mainly natural science-based solutions.

Redevelopment of rare-earth mining sites

Rongliang QiuSun Yat-sen University

This talk will present the restoration of former rare-earth mining sites of South China, and the strategy implemented to reduce risks connected to bare mine tailings, and to produce biomass for economic purposes. This strategy includes soil restoration and implementation of biomass to produce energy, fibers and rare-earth based products.

Redevelopment of former coking plant site - the LORVER and TANIA projects

Marie-Odile Simonnot

This presentation will focus on the LORVER project (www.lorver.org) dedicated to the requalification of a former steel-making site in France. Like the previous talk, the presentation will include soil treatment, soil construction and phytomanagement: plants (e.g. hemp, poplar tree) are grown for phytostabilization and to produce biomass which can be used for industrial purposes (e.g. production of energy, fiber and metal-based compounds).

The context of the TANIA Interreg project will also be presented (https://www.interregeurope.eu/tania/). TANIA uses interregional exchange and participation of stakeholders from environmental and innovation fields to address the limitations to the use of inno-vative treatments, especially nanoremediation.

Implementation of ATES & Bioremediation in society by the Living Lab approach

ir. Tim GrotenhuisWageningen University and Research

This talk will address natural science-based aspects, including data showing the accelerated biodegradation of groundwater by using an ATES (Aquifer Thermal Energy Storage) system and process aspects upon the implementation of innovative technologies: ‘how to initiate international cooperation in the implementation of inno-vative technologies in society’.

Panel discussion: which strategies to promote innovation and gain value from abandoned sites?

Marie-Odile Simonnot

Although the innovative technologies presented in the first part of the session cover a wide range of contaminated soils and ground water, they have in common that they are at a stage where they will be worldwide implemented.

As all researchers are aiming at the implementation of their innova-tive technologies, a panel discussion with different societal actors will address specific aspects of the presented technologies about

Introduction to the topic and lessons learnt so far

Bernard Vanheusden¹; Philippe Vandenbroeck¹ Hasselt University

Soil and land deliver essential services to humankind and our ecosystems. However, they are under increasing pressure and have become vulnerable resources. They are in urgent need of care and need to be restored where necessary. The principle of ‘Soil+Land Stewardship’ demands that soil and land users use/relate with their soil and land with due diligence instead of just using it. The principle could be a good instrument to increase soil and land awareness. Stewardship is usually defined as “the responsible use and conser-vation of natural resources taking full and balanced account of the interests of society, future generations and other species, as well as of private needs, and accepts significant accountability to society”.

We will give an introduction to the topic and lessons learnt so far, based amongst others on several workshops organised over the past year.

7aSps | How to implement innovative environ-mental technologies in society to gain value from degraded and polluted sites?

Marie-Odile Simonnot¹; Ir. Tim Grotenhuis²; Jean Louis Morel³; Rongli-ang Qiu⁴¹ Université de Lorraine - CNRS; ² Wageningen University and Research; ³ Université de Lorraine - INRA; ⁴ Sun Yat-sen University

The driving idea of this session is to discuss how to implement envi-ronmental technologies in society to gain value from degraded and polluted sites. The session will be opened by Prof. J.L. MOREL, who will introduce the aim and organization of the session and present the general context of innovative environmental technolo-gies for brownfield redevelopment, mainly natural science-based solutions.

Then, three short talks (15 min + 5 min discussion) will be given. The first two ones will focus on examples of integrated approaches of site restoration.

Prof. R. QIU will present the restoration of former rare-earth mining sites of South China, and the strategy implemented to reduce risks connected to bare mine tailings, and to produce biomass for economic purposes.. Prof. M.O. SIMONNOT will focus on the LORVER project dedicated to the requalification of a former steel-making site in France. Both projects include soil treatment, soil construc-tion and phytomanagement: plants (e.g. hemp, poplar tree) are grown for phytostabilization and to produce biomass which can be used for industrial purposes (e.g. production of energy, fiber and metal-based compounds).

The third presentation, given by Prof. T. GROTENHUIS, will address natural science-based aspects, including data showing the accel-erated biodegradation of groundwater by using an ATES (Aquifer Thermal Energy Storage) system and process aspects upon the implementation of innovative technologies: ‘how to initiate international cooperation in the implementation of innovative technologies in society’.

The chair and co-chair persons are partners in the China’s111 project “Building world class R&D Universities”.

Special Sessions (SpS)

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7bSpS2 | Soil energy as smart low carbon tech-nology for cost-effective climate mitigation

Nanne HoekstraDeltares

Aquifer Thermal Energy Storage (ATES) is a smart way to re-use heat and cold and widely recognized as promising low carbon energy technology. The Climate-KIC E-USE(aq) project (Europe-wide Use of Sustainable Energy from aquifers) shows, through the construction of pilots in 5 different countries, how ATES systems can be imple-mented, thereby starting a flywheel-effect for further proliferation. ATES has a significant climate mitigation impact: realisation of 50.000 systems throughout Europe in the next decade, which should be achievable, could lead to a total annual CO2 emission reduction of 3 million tons CO2.

The E-USE(aq) project shows that ATES systems are cost effective: even payback times of only a few years are possible. Additionally, E-USE(aq) demonstrates that ATES systems are multifunctional and can be efficiently combined with extra services such as remedia-tion of contaminated soils, production of solar power and optimal energy distribution between several users.

E-USE(aq) already contributed to AquaConSoil before. In Copenhagen, we focused on defining the technical, legislative, organisational and socio-economic barriers for Europe-wide implementation of ATES systems. In Lyon at ACS 2017, in a highly-praised session, we presented our pilot demonstrations with some provoking statements on the use of ATES, that triggered vivid discussions between a wide variety of parties in the audience. On ACS 2019 in Antwerp, now the project has come to a conclusion, we can present the outcomes, showing how the identified barriers can be overcome, as proven in 6 full scale pilots. Moreover, we aim to focus on the future in a special session.

In our session we propose to:

1. present project results with short pitches, highlighting achieve-ments, success factors and lessons learned, such as:

o the first application of groundwater remediation by ATES enhanced biodegradation in the field;

o utilization of high resolution underground temperature distri-bution monitoring for system optimization;

o development of a new compact system that can be applied in thin water bearing layers, thus increasing the application possi-bilities of ATES considerably;

o optimization possibilities of permit procedures;

o improvement of business cases and shortening of pay-back times.

2. have a forum discussion with the audience focusing on how to increase the implementation of ATES systems throughout Europe, as a solution for a combination of challenges such as climate-change, energy transition and urbanization. The discussion will be inspired by an international panel consisting of associated consor-tium partners such as (yet to be confirmed):

o John Flyvbjerg, Capital region of Denmark;

o Johan Ceenaeme, Ovam, Belgium;

o Wouter Gevaers, Arcadis ,Belgium;

o Chris vd Meene, Municipality of Utrecht, Netherlands;

o Attilio Raimondi, Emilia-Romagna Region, Italy;

o Salvador Gorriz, Council Town of Nules, Spain;

o Javier Urchueguia Schölzel, Polytechnical University of Valencia, president of European Geothermal panel, Spain.

3. conclude with an interactive wrap up.

their changes and limitations that have to be encountered to come to implementation of innovative technologies.

Therefore, in the second part a panel discussion with the partici-pants of the session will address the following aspects:

• How to connect your innovative idea to societal partners?

• Innovative ideas are ahead of legislation. How to develop new legislation that supports your innovative technologies?

• How to create new business cases in which companies AND societies profit from innovation?

The discussion will involve the chair and co-chair persons, as well as

John Flyvbjerg (Capital Region of Denmark, the main sponsor of the ATES & Bioremediation pilot near Copenhagen)

Jan Frank Mars (Dutch Ministry of Infrastructure and Water, involved in innovative technologies related to groundwater quality)

Patrick Charbonnier (LuxControl, Luxemburg)

A Chinese representative involved in restoration of rare earth mines

7bSps1 | Soil, sediment and groundwater in the circular economy – perspectives and op-portunities

Sophie MoinierDeltares

In this session, we would like to explore the role of soil, sediment and groundwater in the circular economy. These resources differ from regular non-renewable primary resources in the sense that in theory, soil, sediment and groundwater are widely available and renewable. Furthermore, these resources are often used in their natural (eco) system, as opposed to many non-renewable primary resources which are extracted from the environment and processed in factories.

However, the pressure on the water-soil-sediment system increases due to changes (e.g. climate change, population growth) and claims we put on it (e.g. energy transition, urbanisation and food produc-tion). As a consequence, good quality groundwater, soil and sediment recourses are increasingly scarce. Land, soil and groundwater are a finite and shrinking resource, and are being put under further stress through land and soil degradation. This affects their role providing services, including the provision of resources and physical space for nature and human activities. As an economic system that focuses on maximizing the reuse of resources and products and minimizing their depreciation, the circular economy greatly influences and depends on soil, water and sediment management.

This session focuses on examples and strategies where soil, sediment and groundwater resources are managed in a circular way. For each of the examples a short pitch is given.

• Opportunities for urban soil and land (incl landfills) (Deltares)

• Opportunities for (ground)water (VVM)

• Opportunities for circular soil and sediment management (RWS/DEME group)

Then we continue the discussion with the attendees divided in 3 groups. We discuss the issue from different perspectives such as governance/policy, science/techniques, economy/costs and stake-holders. Finally, we add to the examples with existing and new concepts.

The results will be used for an article on opportunities which can be a starting point for new collaboration and research initiatives.

Special Sessions (SpS)

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EcoShape conference, during which we organized knowledge dissemination sessions centered on specific nature-based topics. Nature-based (fine) sediment use solutions was one of the topic which received good attendance and feedback.

We plan:

• Up to 8 short (max 8 minutes, including transition) presenta-tions = 60 minutes;

• Discussion = 30 minutes

All presentations will be presented after each other, with no questions in between. The questions will be typed by the audience into a web-based tool with the cell phone (such as Cahoot). After the presentations, all presenters will be invited to the stage for the informal panel discussion. Some questions will be selected from those submitted by the audience during the presentations and asked to the presenters. Questions will be chosen to stimulate discussion and to involve all presenters.

Presentations:

We propose to include in the session: 1) a EcoShape Living Lab for Mud (overarching EcoShape program that integrates five soft sediment based EcoShape pilots) presentation; 2) the presenta-tion of one EcoShape Pilot (Kleirijperij); 3) the results of the CEDA Working Group on Beneficial Sediment Use. We then propose to fill the session with other appropriate abstracts received by AquaCon-Soil (such to favor broadening the LLM community). If not enough abstracts on this topic are received by AquaConSoil, EcoShape can solicitate abstracts within its internal or external network and/or fill up the session with presentations in line with the session topic.

7cSps | Beneficial and nature-based sediment use as a resource for circular economy

Luca SittoniEcoShape / Deltares

The natural sediment cycle is disrupted and impacted by human interventions world-wide, such as dams in rivers, port develop-ments in estuaries, dredging activities for the maintenance of existing ports and waterways, and pollution from industrial activi-ties. Coasts, shores, lakes and rivers suffer from an imbalance in sediment quantity and poor sediment quality. This impacts human industrial activities (e.g. navigation, logistic and tourism), life and safety (e.g. space for living, flood safety and impact of climate change with loss of coastal areas and more frequent flooding and food security with loss of productivity). While this is generally true for all types of sediment, shortage of sand in many locations of the world brings a special focus on fine and soft sediment, generally considered an unsuitable resource if not a contaminated waste.

The interconnected and partially overlapping concepts of circular economy, beneficial sediment use and nature-based solutions point to sustainable sediment management that connects sediment quantity with quality and demands for no waste.

We invite presentations that share latest developments, technologies and socio-economic considerations related to beneficial, nature-based and circular use of sediments, both clean and contaminated.

Organization:

We propose a dynamic session with short presentations followed by a panel discussion. This approach is based on the June 2017

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surface (ca. 1,000 m2/g). The low requisite doses and dispersed placement have negligible impact on hydraulic conductivity.

Principles of use of the technology, together with corroborating placement and performance validation methodologies, are presented in this talk. The predictive integration of the approach into a wide range of contaminant fate and transport models to aid in concept evaluation, performance-prediction and engineering design is discussed. It is anticipated that this talk will be of interest to environmental engineers, fate and transport modelers / risk assessors, regulators and site environmental managers alike.

Production and use of a biosurfactant for the remediation of soils impacted by Polycyclic Aromatic Hydrocarbons

Mathieu MorlayCOLAS Environnement

Former industrial sites contaminated with Polycyclic Aromatic Hydrocarbons (PAHs) are an environmental and human health concern in Europe. These sites, often former gasworks and coke factories, are close to or are nowadays part of urban areas and are persistent sources of pollution that have to be cleaned. Biore-mediation of PAHs in pore water and soils is possible and had already been achieved but is inhibited by the low solubility of such molecules, which reduces their bioavailability. Surfactants can enhance the apparent solubility of hydrophobic compounds, like PAHs, entrapping them by the formation of micelles. Chemically-produced surfactants, widely used in soil remediation (i.e. soil washing techniques, etc.) are impaired by their low biocompat-ibility. Using biosurfactants, produced by bacteria, can improve this biocompatibility and then enhance PAHs bioavailability.

The objective of this project is to treat an industrial soil impacted by PAH with biosurfactant washing and biodegradation at the same time.

The first step focuses on the biosurfactant production and opti-mization at lab scale. The optimal balance parameters have been selected to improve bacterial growth: carbon sources, mineral nutrients, oxygen supply and temperature. PAHs biodegradation trials were performed with contaminated water and contaminated soil samples. Biosurfactant injection, carbon source injection, and several nutrient injection techniques and balance were achieved. Scale-up from lab scale to bioreactor production of biosurfac-tant had been successful. The extraction and purification of the produced biosurfactant allowed to characterize it.

The second step concentrates on the use of the produced biosurfac-tant for the desorption of PAHs in soil. Tests of injection in columns (constituted of sand and sand + clay) had been made, using the biosurfactant and commercial surfactants to confront them.

From our soil samples, a biosurfactant-producing isolate was selected. This isolate can produce biosurfactant using soluble and insoluble carbon sources, even in rich culture medium. The nutrient balance determines the success of the production of biosurfactant. Biodegradation trials have already proved the high potential of bacterial strains for their ability to produce biosurfactant, which pushes the PAHs up to micellar state. After a first scaling up in

4aCom1 | New advances in the implementa-tion of (bio)remediation additives: a policy perspective

Engineered Retardation Factor Manipulation using Liquid Activated Carbon for Passive Management of Plume Dynamics

Jeremy Birnstingl¹; Craig Sandefur²; Kristen Thoreson²¹ Regenesis Ltd.; ² Regenesis

Monitored Natural Attenuation (MNA) represents a valuable tool in the remediation toolkit. It is typically employed to treat low concentration plumes or to address residual contamination following active remediation. The approach combines pragmatism with science and a detailed understanding of natural processes to provide a methodology able to cost-effectively achieve site goals. However, natural attenuation takes time. This can make MNA impractical. Even when ownership is long-term, advection distances may be too short or groundwater flow too fast to achieve compliance within the required boundaries.

In cases where MNA is thus precluded, active remediation is required instead. This may be through increasing the biological attenuation rate through the use of reagents (Enhanced Natural Attenuation (ENA)), reducing the source and / or plume concentra-tions using physical treatment or in situ chemical oxidation (ISCO), or actively managing advection through groundwater pumping (hydraulic containment / pump & treat). Each approach, whether used alone or in combination, will typically present increased costs and/or disturbance over MNA.

An emerging alternative to active intervention is to effectively ‘splice in’ additional remediation time into shorter distances. This can be achieved by engineering the retardation factor in the subsurface. By definition, this slows the contaminant advection relative to the groundwater velocity. The residence time of the contaminant for (principally biological) attenuation is therefore increased within a given compartment, allowing natural attenua-tion to proceed to target over a far shorter distance.

Source-reduction targets can become more forgiving. If attenuation is compressed into a shorter distance, higher concentrations can degrade before reaching a receptor. The challenge of diminishing returns of source clean-up technologies is mitigated. Securing the stubborn ‘final 10%’ through active treatment may be unnecessary.

The use of colloidal, charge-modified activated carbon suspensions presents a new means of achieving this. The innovation provides a flow-emplaceable method of coating the subsurface flux channels with micron-scale activated carbon particles that strongly adhere. ‘Dialing-in’ the required retardation factor may consequently be achieved through a one-time, injectable intervention – essentially engineering the ‘effective foc‘ of targeted flow-channels.

Retardation factor increases ranging from several hundred percent to multiple orders of magnitude may be readily secured using the approach. The extent of this increase is determined by the interplay of contaminant concentration relative to carbon emplacement, the nature of the contaminants themselves, and the specific / dynamic mix of contaminants and / or competing sorbate species as degra-dation proceeds.

The contaminant migration control can be achieved without impacting groundwater flow. Dispersed carbon placements typically in the range of fcarbon 0.001 to 0.005 are sufficient for the purpose as the material comprises activated carbon rather than native organic matter (foc) and presents an extremely high sorptive

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- The importance of the soil permeability parameter when choosing between injection or soil mixing for an ISCR,

- The radius of influence of a reagent delivered in the ground depending on the technique and the reagent used,

- The effectiveness of a combination of controlled-release solid carbon and ZVI (Daramend® and EHCTM) in comparison with either a sole carbon or a sole ZVI source,

- The maximum reagent concentration that can be delivered by injection or that can be mixed in-situ with the soil.

Performance of a New Activated Carbon Amendment for Bioremediating Petroleum-Impacted Sites

Kris Maerten¹; Paul Erickson²; Steve Sittler³; Dora Taggart⁴; Kristen Thoreson²¹ REGENESIS; ² REGENESIS Inc.; ³ Patriot Engineering; ⁴ Microbial Insights

The treatment of petroleum contamination using injectable activated carbon amendments is increasing in popularity, in part due to the rate with which drops in contaminant concentrations are usually seen after application. Rapid removal of contamina-tion from groundwater by adsorption is attractive, yet in situ biodegradation is often also needed to properly manage higher contamination levels frequently seen in petroleum sites. Here we present a new activated carbon-based amendment that combines micron-sized activated carbon with nitrate (NO3-) and sulfate (SO42-) salts serving as electron acceptors. As a part of develop-ment, the new formulation, PetroFix® Remediation Fluid, was field-tested on a contaminated area downgradient of a former bulk petroleum storage facility in South Bend, IN. Historical remedial efforts included LNAPL recovery and air sparging/soil vapor extrac-tion (AS/SVE), however relatively high concentrations of petroleum hydrocarbons remained in the groundwater, restricting site closure.

PetroFix was injected by low-pressure direct-push methods in an area surrounding a single monitoring well with over 50 ppm total petroleum hydrocarbons in the diesel and gasoline range combined. Groundwater samples were monitored at baseline and at regular intervals post-application for standard chemical and geochemical parameters, as well as by QuantArray® Petro (Microbial Insights) for quantification of the bacterial communi-ties. Baseline microbial analysis indicated a moderate presence of both aerobic and anaerobic petroleum degraders. At both one- and three-months post-injection, contaminant concentrations had fallen by over 90%. At three months, RNA analysis showed Methy-libium petroleiphilum (PM1), a known BTEX degrader, replicating robustly. Another line of evidence for biodegradation was the rapid reduction of NO3- followed by a more gradual loss of SO42-. Dissolved methane initially dipped, before climbing to over twice the pre-application concentration. This is consistent with increased hydrocarbon biodegradation, despite the dramatic removal of contamination from the dissolved phase.

The removal of petroleum from the groundwater by adsorption onto the activated carbon does not appear to have a negative effect on biodegradation. Additionally, the conditions in the treatment area appear to be favorable for long-term biodegrada-tion of the remaining hydrocarbons, as indicated by the increasing methane concentrations when compared to the pre-injection level. The results thus far indicate that PetroFix is a powerful amendment capable of treating sites contaminated with moderate amounts of petroleum hydrocarbons. The placement of activated carbon with electron acceptors under low pressure conditions ensures good amendment coverage in the high flux zones where contami-

biosurfactant production in 6L-biorectors, the column injection tests of the biosurfactant show a high potentiality of the product to be used on a soil washing method by a low sorption in the soil and high desorption capacity of the pollutants.

During the final step of this work, those lab trials will be extended to an in situ pilot treatment on an industrial site.

In-situ solutions using Zero Valent Iron for the remediation of sites contaminated with chlorinated solvents

Marika Sallot des Noyers; Pierre-Yves Klein

Chlorinated solvent contamination is an extensive problem due to its wide use throughout the 20th century in industries such as dry cleaners and metal processing plants.

A number of approaches can be used to address chlorinated solvent contamination in-situ.

Depending on a site’s geology, these techniques may or may not be practicable.

For instance, the performance of In-Situ Chemical Oxidation (ISCO) and In-Situ Chemical Reduction (ISCR) involves a good contact between the reagent and the contamination, which in turn requires enough permeability of the soil if these techniques are performed by injecting the reagent into the ground.

In presence of low permeability soil, different methodologies involving additional means of action (thermal, mechanical,…) have to be used to reach the more impermeable zones where chlo-rinated solvents precisely stay.

REMEA has used in-situ techniques relying on chemical reduction of the chlorinated solvents by Zero Valent Iron (ZVI) on several sites featuring very different geological conditions, which necessitated the adaptation of the ISCR implementation method.

The authors’ experience in reducing chlorinated solvents with ZVI includes:

• 1st case study - A comparative ISCR pilot trial for the remedia-tion of a source area in a saturated zone of low permeability and its plume down to 15mbgs assessing the performances of 2 techniques: the in situ soil mixing with the Springsol® tool (proprietary tool) and the auger impregnation

• 2nd case study - An ISCR full scale implementation involving the remediation of a source area in a saturated zone down to 30m using tube-à-manchette injections (Tamsol® process, proprie-tary technique) and the installation of a PRB for its plume using the in-situ soil mixing technique with the Springsol®

• 3rd case study - An ISCR full scale implementation within a Serviceable Permeable Reactive Barrier (S-PRB®, a proprietary installation) to stop the migration of a plume located in a marl layer

The evolution of the contaminants contents as a function of the site conditions, the technique used and its implementation method, and the area of implementation (source zone or plume) was analysed using the data collected from these projects.

This resulted in a better understanding of the practicability and the effectiveness of these different techniques, in particular:

- The appropriateness of these techniques considering the geology of a site and the remediation objectives,

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Sessions from a business perspective

nants migrate and promotes biodegradation by the microbial community in place.

Successful biostimulation and bioaugmentation treatment of DNAPL and dissolved phase mixed chlorinated solvent contamination under an active commercial site

David Scott¹; Jack Shore²¹ Ramboll; ² REGENESIS

High concentrations, including DNAPL, of mixed chlorinated solvents (TCA and TCE) was present in the groundwater under an active industrial site in Scotland. A DPVE system had been unable to achieve the remediation goal of a 75% reduction in chlorinated solvent mass. Also a supplementary MIP investigation showed that there was further contamination deeper than the maximum treatment depth of the DPVE system (> 6mBGL). Therefore it was determined that an alternative remediation method was required.

A combined biostimulation and bioaugmentation treatment was designed. Using direct push injection, a high volume, micellar electron donor and a microbial consortium specifically designed to degrade both chlorinated ethenes and ethanes, would be co-injected between 3-9mBGL across an area of 1,200m².

However, the MIP investigation found that progression of the rods deeper than 6mBGL was difficult, raising concerns that it would not be possible to reach 9mBGL or inject the substrate. A pilot study was therefore completed across a small area. The trial found that the injection rig could reach 9mBGL and inject the required dose. The test also showed the treatment did not affect site operations.

Using information from the MIP study and pilot test, the full-scale design was tailored to provide the most accurate and cost effective dosage across the site. 60 direct push injection points were completed over 10 nights, with no disturbance to the site operations.

18 months of validation monitoring showed no inhibition of parent compound degradation due to the mixed halogenated compound plume, with 98% and 99% reduction in mean concentration of TCA and TCE respectively. Full reductive dechlorination was achieved with no buildup in daughter products. Analysis of the data suggests that both biotic and abiotic degradation occurred; with the abiotic degradation occurring due to the production of reduced iron species as a result of the low redox conditions created and main-tained by the treatment. Remediation goals were achieved.

Using information and data from the site, this presentation will demonstrate:

• The ability of bioremediation to treat high levels of contamina-tion, suggestive of DNAPL, to very low concentrations

• That no buildup of degradation products occurred, showing full reductive dechlorination was achieved & sustained.

• How bioaugmentation can be used to avoid inhibition of the degradation of chlorinated ethenes or ethanes by ensuring that the microbial consortia contained viable counts of deha-logenating bacteria specialising in either contaminant group.

• The stimulation of abiotic degradation can be achieved through the creation of reduced iron species.

• The value of contaminant delineation and pilot testing to ensure accurate and cost effective treatment.

• How this approach can be used to remediate an active site with no disturbance of the onsite operations.

4cCom1 | Surfactant enhanced remediation as a lead-out for ISCO or ISCR

Glenn HeernaertTerraCorrect

TerraCorrect created a new technology for remediation of highly polluted ground and groundwater with an combined technology of surfactant enhanced remediation(SER) and ISCR or ISCO.

The surfactant is used to wash out bulk concentration of chlori-nated solvents, to approve the groundwaterflow and to adjust the in-situ remediation parametrix. The surfactant is injected in injec-tionwells, and is extracted from outside the area in extractionwell’s in that order that we create a washing effect of the treated area.

We can reduce bulk concentrations of chlorinated solvents with 80 to 90%, within a period of 2 to 3 months.

After soilwashing with surfactants, we can clean up the site with ISCR or ISCO, depending on type and concentration of chlorinated solvent.

With this technology we can approve:

- groundwater flow (5 times faster then normal)

- the remove of bulkconcentration of pollution (3 to 4 times more than with normal pump and treat)

- total cost of the remediation (30% in order to in-situ thermal desportion)

Other profits are:

- less energy consumption

- groundwater can be treated on site

Pilot of this technology is already done with 100% succes. Full scale starts up in april, so first results can be given in the presentation at AquaConsoil 2019. This technque was made a success by the work of IveySol(Canada), Carus Remediation Technology (America) and TerraCorrect (Belgium), so this is a result of combined technology where 1 and 1 ecuals 3.

4cCom2 | Combined treatment technologies and technology trains

Treatment of a large industrial site impacted with chlorinated solvents using a combination of electron-donor substrates and a liquid activated carbon barrier.

Marcello Carboni¹; Paola Goria¹ REGENESIS (Italia)

This talk describes an on-going combined remedies treatment of a 6 hectare disused industrial site in Italy. The site is impacted with chlorinated solvents, including DNAPL in a highly heterogeneous geology. In addition, the site is bounded by a tidal river which peri-odically affects groundwater depth and flow direction.

This project is an example of how thoughtful design using a range of innovative in situ methods can be used to provide cost-effective treatment of large chlorinated solvent sites, remediating high concentrations, to achieve very stringent targets and protect adjacent sensitive receptors.

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An initial remedial approach comprised an integration of multiple techniques including excavation in the source areas and the instal-lation of pump and treat (P&T) system at the site boundary for hydraulic containment, which has operated for over 10 years. This presentation focuses on the treatment of the groundwater plume; the first phase of which employed enhanced reductive dechlorina-tion (ERD).

Prior to application, the site was split into different areas based on hydrogeological conditions and contaminant distribution. A treatment plan was tailored to the requirements of each area by varying the injection depth, spacing, dosage and co-application of up to 4 remedial substrates. Pilot studies were used to verify the efficacy of the approach and create the most accurate full-scale design. The full-scale treatment covered 10,000m2 using approx. 500 injection points to 12m BGL.

18+ months results demonstrate the rapid establishment of the ideal conditions for ERD and reductions in the target contaminants from high starting concentrations with full reductive dechlorina-tion occurring. This has allowed for regulatory site closure for the internal part of the site.

The next phase focuses on the downgradient site boundary, adjacent to which a river presents a sensitive receptor. The proximity of the river and Italian legislative rules, have determined that the site boundary targets are very stringent (< 1 μg/L). Although the previous ERD treatment has reduced the contaminant influx dramatically; for such low targets, biodegradation alone may not reach these low targets.

Therefore, a second phase treatment has been implemented to combine contaminant sorption and biodegradation using an inject-able colloidal activated carbon. A double pilot test of this approach was performed in two areas on site, in order to demonstrate the technology’s efficacy and to design an accurate dose for the full-scale works. The full-scale barrier was implemented in autumn 2018 and has shown initial rapid reductions in groundwater concentrations. The latest monitoring results will be discussed in the presentation. This in situ barrier will replace a costly P&T system and allow the owner to cease all remediation activities with full regulatory site closure.

Surfactant Enhanced Extraction to Expedite Remediation of a Carbon Tetrachloride Source Zone at an Active Grain Elevator Facility

George (Bud) IveyIvey International Inc.

Site is located in Kansas City, Kansas and currently operates as an active grain elevator facility. The site entered into the Voluntary Cleanup and Property Redevelopment Program in 2000 following groundwater and soil detections of grain fumigant constituents of concern (COCs), including carbon tetrachloride, in the vicinity of a former fumigant aboveground storage tank. Following source area investigation and groundwater plume delineation activities, dual-phase vacuum extraction (DPVE) was implemented in 2007 for the removal of COCs in source area soils and groundwater. Groundwater was encountered at the site approximately 2.1 to 2.4 m below ground surface. Lithology within the targeted source zone generally consists of well sorted, loose, silty-sand to depths ranging from approximately 1.19 to 1.58 m, underlain by silty clay.

After 7 years of DPVE operation, resulting in the removal of over 4,091 kg of total VOCs, a subset of source area extraction wells continued to exhibit elevated COC groundwater concentrations.

Additional investigation indicated significant sorbed-phase COC mass, generally limited to the shallow, sandy interval of an area bound by the DPVE wells exhibiting elevated COC concentrations. Light non-aqueous phase liquid (LNAPL) heavily impacted with the site COCs were identified. Surfactant enhanced extraction (SEE) was subsequently identified as the optimal source zone remedial alternative because of the technology’s ability to quickly and effi-ciently remove a concentrated, but relatively isolated and shallow zone of contaminant mass with relatively low surfactant applica-tion concentrations.

A SEE pilot study at the site in April and May 2015 to evaluate the efficacy of the technology under site-specific conditions. The pilot study included single-well “push-pull” tests and multi-well “point-to-point” tests using a solution consisting of 1 to 2 percent Ivey-sol® 106 biodegradable surfactant. In general, the solution was gravity fed into each well to achieve a targeted injection radius, then allowed to remain in the formation for a prescribed residence time period. In 2016 the application was expanded to full-scale.

Based on a comparison of baseline (April-May 2015) and full scale (September 2016), pre to post-SEE groundwater moni-toring results, SEE resulted in carbon tetrachloride groundwater concentration reductions of up to 99 percent. The full-scale SEE targeted remaining COC mass in source zone, and required of additional injection/extraction well installation, and surfactant delivery/extraction methods similar to those employed during the SEE pilot study. The objective of the full-scale SEE application was to achieve source zone COC mass reductions that allow for permanent shutdown of the DPVE system. This remediation goals were achieved in 2017, site entering formal closure phase in 2018.

To share how surfactants can be used to expedite multi-phase extraction to realize soil and groundwater of comingled DNAPL and LNAPL plume more rapidly, with significant cost savings, at challenging sites.

Combined Remedy: Alkaline Activated Persulfate with In Situ Solidification/Stabilization (ISCO-ISS) in a Single Application

Michael Mueller; Brant SmithPeroxyChem Environmental Solutions

In situ chemical oxidation (ISCO) and in situ solidification/stabili-zation (ISS) are two well established remedial technologies that can be applied together in a single event. These technologies use different methods to reduce the risks and hazards posed by various contaminants; ISCO degrades and transforms contaminants signifi-cantly reducing the contaminant mass whereas ISS solidifies, stabilizes and significantly reduces the flux of the contaminant from source zones. In addition, ISS amendments can be varied to help control post application soil characteristics such as hydraulic conductivity and compressive soil strength.

Alkaline activated persulfate, an ISCO technology, share many of the same materials used with ISS, these two technologies can be applied using soil mixing technologies resulting in a significantly reduced mass of contaminant (ISCO) that is stabilized and less mobile (ISS) with control over the critical final soil characteristics needed to render the site ready for redevelopment.

The reagents for ISCO-ISS and contaminated soils were varied and the impact on critical parameters evaluated. After 28 days, evaluated parameters include contaminant concentration, synthetic precipi-tation leaching procedure (SPLP), hydraulic conductivity and the resulting unconfined compression strength (UCS).

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Sessions from a business perspective

and Soil Stabilization approach to treat TPH at a gasoline station in Italy.

Module 4: “Targeted Soils Emplacement into Low Permeability Lithologies.” Case study: Planning and execution of KP injections at a former railway site to treat co-mingled chlorinated hydrocarbons with BTEX and PAHs.

Module 5: “Projecting into the Future: Where does ISCO fit into Remediation in Years Ahead?” Increasing urbanisation, coupled with changes in chemical engineering are resulting in redevelopment of post-industrial brownfield sites. Pressures of climate change and socially unacceptable long distance food miles will encourage meeting such needs from local resources. Some of that resource will be groundwater that is potable apart from the pollution legacy of former industrial activities. Much of this legacy is in the form of halogenated hydrocarbons, which are amenable to oxidation. Taken together, ISCO can contribute to a more economic, socially acceptable and environmentally benign approach to protecting and restoring industrially polluted groundwaters. In the context of ISO 18504:2017, this would be called “sustainable remediation.

The value of bench testing – Lessons learned examining activated persulfate technologies.

Jamie CuttingCE Geochem Ltd

Bench tests and treatability studies are performed to develop site specific design parameters and to confirm oxidant efficacy. Current best practices and methods for scaling up test results to full scale operations will be discussed.

Elements of the outline include:

What is Treatability Testing?

Measurement of Treatment Under “Ideal” Conditions

o Controlled Tests Performed on Water and Soil Samples

o Proof of Concept

o Establish Parameters for Pilot tests

Will target compounds degrade to desired end products under site conditions.

Full-Scale ISCO

Common Objectives

o Determine reactivity of soil

o Select the optimum chemistry

o Evaluate potential adverse reactions

o Develop cost estimates

Benefits of Treatability Testing - Generates Site-Specific Data

Allows Optimization Prior to Full-Scale Implementation

o Refine chemistry

o Incorporate efficiencies

o Cost savings potential

Enhances Pilot Testing / Full-Scale Implementation

o Expected results guide next phase of work

o Simplifies evaluation of field scale results

Limitations of Treatability Testing

o Linear Scale-Up Limitations

o Difficult to simulate heterogeneity in test column

o Small sample volume compared to site

o Well-mixed static system

The data indicate that not only does each technology accomplish their own independent remedial objectives (contaminant destruc-tion for ISCO and contaminant stabilization for ISS), but that several synergies develop between the two technologies. The exact synergies are a function of contaminant concentrations and the blend of reagents applied, but general trends of the synergistic benefits include:

• Alkalinity from ISS reagents used to create alkaline activation conditions for Klozur persulfate saving reagent costs

• Addition of ISCO to ISS resulted achieving remedial goals with less overall reagents applied minimizing the displaced soil requiring disposal and reagent handling. Blends also signifi-cantly reduced leachate concentration results compared to ISS only

• In certain conditions, ISCO-ISS approach resulted in lower hydraulic conductivities than comparable ISS only reactors

• The combined ISCO-ISS reagents allowed better control over post application soil UCS characteristics

5bCom1 | Understanding Best Practices: ISCO with activated persulfates

Michael MuellerPeroxyChem Environmental Solutions

Activated persulfates (sodium / potassium) are among the most common soil and groundwater remediation technologies applied worldwide. Using proper activation methods, persulfate can treat a wide assortment of contaminants, including: i) Petroleum hydro-carbons, ii) Oxidizable chlorinated solvents, iii) Reducible organics, and iv) Emerging contaminants such as 1,4-dioxane, in various lithologies including sands, clays and fractured bedrock. Several years and thousands of applications have resulted in a significant experience set and “lessons learned” regarding best practices for applying persulfates. The overarching lesson is that successful projects are well- planned, designed, executed, and monitored. Successful practitioners understand the nature and extent of contamination, site lithology, means of establishing contact with sufficient oxidant to treat contaminants, and how to properly monitor these applications as more is learned about each site. This session will share real-world insights into ISCO project optimisa-tion, conducted by a broad spectrum of qualified practitioners.

Module 1: “The Value of Bench Testing – Lessons Learned Examining Activated Persulfate Technologies.” Bench tests and treatability studies are performed to develop site specific design parameters and to confirm oxidant efficacy. Current best practices and methods for scaling up test results to full scale operations will be discussed.

Module 2: “Sodium and Potassium Persulfates: Characteristics, Chemistries, and Applications.” Sodium and potassium persulfates have been widely used in ISCO field applications. This section will use bench and field-based data to illustrate the use of activation methods to create oxidative and reductive pathways, differences between SP and KP, and the successful application of these technologies.

Module 3: “Integrated Remediation - Redevelopment of Contami-nated Sites using ISCO-ISS Soil Mixing Technology.” Case study: Planning and execution of an integrated In-Situ Chemical Oxidation

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Sessions from a business perspective

- Decision Making Enhanced

- Site-specific data

- Go / No-go earlier in design process

Lessons LearnedOptimize chemistryDevelop contingencies for concerns

Even “Simple Sites” benefit

Sodium and potassium persulfates: Characteristics, chemistries, and applications

Brant SmithPeroxyChem

Activated persulfate has been implemented for decades to successfully remediating sites with a wide variety of contaminants of concern from around the world. In situ chemical oxidation (ISCO) based on persulfate has been used to remediate petroleum hydrocarbons, chlorinated solvents, pesticides, energetic and many other compounds. The ability to treat different contaminants has been attributed to the activation method and the formation of the sulfate, hydroxyl, and superoxide radicals. These different radicals allow for the treatment of contaminants by both the oxidative (hydroxyl and sulfate radicals) and reductive (superoxide) pathways. It has been shown that the radicals formed are different for each activation method, increasing the importance of selecting the proper activation method for each site including iron chelates, alkalinity, heat, and hydrogen peroxide.

Both sodium and potassium persulfates have been used in ISCO field applications. While both sodium persulfate (SP) and potassium persulfate (KP) release the persulfate anion to generate the same treatment chemistry, they have two primary differences: the salt associated with the persulfate anion and the theoretical solubility of the two compounds with KP having over an order of magnitude lower solubility at typical groundwater temperatures. These differences have resulted in distinctively separate field appli-cations of these two persulfate compounds. Potassium persulfate has typically been applied at sites with limits on sodium, in ISCO permeable reactive barriers, low concentration plumes and where extended persistence is beneficial such as low permeable soils. Sodium persulfate is typically applied to treat highly contaminated source zones, or when ISCO is combined with in situ stabilization (ISS).

This presentation will use bench and field-based data to illus-trate the use of activation methods to create both oxidative and reductive pathways, differences between KP and SP, and the successful application of these technologies.

Integrated remediation - Redevelopment of contaminated sites using ISCO-ISS soil mixing technology

Vito SchifanoLadurner Bonifiche Srl

An in-situ remediation project was completed for a site contami-nated by petroleum hydrocarbons using an innovative technology, based on in-situ chemical oxidation, for the destruction of contami-nants simultaneously with stabilization of the soil using hydraulic binders for the restoration of soil geotechnical characteristics.

Contact and Mixing

o May favorably bias results

o Not possible to evaluate delivery process

Pilot Study usually required

Types of Treatability Tests

Laboratory Tests

o Simple, inexpensive tests

o Incorporate into RI

o SOD, peroxide reactivity

Bench-Scale Study

o Proof of concept

o Basis of design

o Scale-up for pilot test

Pilot Testing

o Provides full-scale design parameters

o Requires extensive monitoring

Stoichiometric Evaluation

o Starting Point for All Treatability Tests

o Establish Baseline for Comparison

o Facilitates Oxidizer Selection

o Mass/volume requirements

o Reaction kinetics

o Catalyst requirements

Soil Oxidant Demand

Measure of Oxidant Depletion Over Time

o Grams of oxidant per kilogram of soil (g/kg)

o Range: 0.1 to 20 g/kg

Standard Methods

o Variables – Soil Related

o Natural organic matter

o Reduced solid species

o Soil structure / mineralogy

Variables – Process Related

o Oxidant

o Oxidant concentration

o Time of measurement

Bench-scale Testing

Establish Basis of Design

o Oxidizer selection

o Dose optimization

o Oxidant/stabilizer concentration

o Catalyst selection

o Secondary considerations

Address Concerns

o Contaminant desorption

o Metals mobilization

o Cr(VI) formation

o pH shift

o By-product formation

Summary – Value of Treatability Studies

- Process optimization

- Cost information

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Sessions from a business perspective

Monitoring results after the emplacement of potassium persul-fate slurry indicated a longevity of oxidant effectiveness for at least 6 months, with a corresponding reduction of contaminant concentrations from over 90 mg/L sum total CVOC + BTEX + PAH by upwards to 90%, and in the case of BTEX to non-detectable concentrations. A full scale remediation of the site is presently being considered by the site owner using the combined approach of TSE and an innovative new ISCO technology for the low perme-ability, bedrock sediments that underlie the site.

Projecting into the future: Where does ISCO fit into remediation in years ahead?

Paul Nathanail, Judith NathanailLand Quality Management, Ltd

Increasing urbanisation, especially in the littoral zone, coupled with changes in chemical engineering are resulting in redevelop-ment of post-industrial brownfield sites across the world. Pressures of climate change and increasingly socially unacceptable long distance food miles will encourage meeting food and water needs from local resources. Some of that resource will be groundwater that is potable apart from the pollution legacy of former industrial activi-ties. Groundwater is stored and to an extent protected and purified at no cost to society. Much of the pollutant legacy is in the form of hydrocarbons and halogenated hydrocarbons, which are amenable to oxidation. As we increase our understanding of, and the value we place on, the subsurface, our appetite for protecting and restoring the form of natural capital we call groundwater will increase. Quite simply investing in groundwater protection and restoration will give a high return on investment (ROI). Making this investment in situ will, likely, result in yields higher than energy intensive ex situ or end of pipe techniques. Such investment in the form of chemical oxidation may potentially also have higher yields than more sophis-ticated, needy in situ bioremediation techniques that require an additional, living, mediator to deliver the desired contaminated degradation or transformation. As groundwater remediation becomes a global enterprise, lower cost and more labour intensive solutions will be needed if they are to be afforded in medium (MIC) let alone low income countries (LIC). Such capacity building will help bring societal benefits to the emerging large and mega cities – most of which will be in MICs. Six new megacities (population >10million) – Luanda, Dar es Salaam, Baghdad, Chennai, Bogota and Chicago – are expected to emerge by 2030, bringing the global total to 39. In situ chemical oxidation (ISCO) will take its part in the armoury of water development in mega and large cities. If the active agents can be manufactured using the principles of green chemistry powered by renewable, carbon-free electricity, then their ability to oxidise conventional, exotic and emerging contami-nants can contribute to a more sustainable urban environment. The health and safety requirements of handling aggressive chemicals will require a step change in training and regulation in many urban centres, thereby contributing to a better educated, skilled and self-supporting population. Taken together, ISCO and, where needed, its in situ chemical reduction (ISCR) cousin can contribute to a more economic, socially acceptable and environmentally benign approach to protecting and restoring coastal, industrially polluted groundwaters. In the context of ISO 18504:2017, this would be called “sustainable remediation”.

Sodium Persulfate was used as a chemical oxidant together with cement to i) activate the oxidation reactions, ii) promote the pozzo-lanic reactions that favor high-pH desorption of hydrocarbons from a solid matrix, iii) immobilize residual contamination, including heavy metals, iv) provide hydraulic isolation of the treatment area, and v) improve the geotechnical properties of the treatment area. This includes increasing the post-treated soils’ strength and bearing capacity, decreasing its compressibility and associated ground permeability, thus ensuring favorable conditions for site reuse.

The reagent formulation was designed by means of a series of laboratory tests, in which the effects of different types and combi-nations of reagents and binders were evaluated. The mechanical distribution of the reagent and of the binder during the execution phase was carried out with the mechanical mixing technology of Bauer Umwelt’s “single column soil mixing” unit.

A reagent-binder slurry was prepared in a batch mixing plant, and injected at the tip of the mixing tool. Soils were mixed in-situ to a depth of 8 meters below ground surface. A design concentration of 5.000 mg/kg of TPH C>12 and 10.000 mg/kg of TPH C

Targeted soils emplacement into low permeability lithologies

M.Eng. Gordon BuresSENSATEC GmbH

In situ remediation and the verification of its effectiveness remains a significant challenge in low permeability geologic formations. “Targeted Solids Emplacement” (TSE®) is an innovative, in situ permeability enhancement and amendment emplacement tech-nology to improve subsurface flow characteristics and provide targeted distribution of treatment amendments in geologically challeng-ing conditions. The TSE approach is a powerful in situ enhancement technology which accelerates and optimizes the remediation of virtually any contaminant present in any phase distribution by:

• Significantly increasing soil/bedrock permeability (up to three orders of magnitude)

• Enabling rapid and targeted emplacement of large quantities of reagents (tonnes/BH)

• Verifying the distribution of treatment amendments in 3D using tiltmeter geophysics

• Treating contaminants to depths of up to100 m biologically, chemically or physically

• Minimizing “rebound effects” from sorbed phase contaminants into groundwater

A case study is presented which illustrates the first application of TSE technology in Germany for demonstrating the effectiveness of treating high concentrations of co-mingled chlorinated hydro-carbons with BTEX and PAH impacts groundwater in bedrock. Contaminant levels were significantly mitigated in the contami-nant source area using TSE in conjunction with novel new in situ chemical oxidation technology designed for treatment longevity, namely activated potassium persulfate, as an extended release oxidant.

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Integrated implementation of the environmental database platform EQuIS and the geostatistical software Kartotrak to perform pollution characterization and to design the remediation of industrial sites

Claire Faucheux¹; Ophélie Lemarchand¹; Yoelma Rodriguez²; Alice Makou²; Thomas Perrier²¹ Geovariances; ² Ramboll France

Building a workflow to gather and handle all available information over a contaminated site, from data acquisition to the optimization of impacted zones to be characterized and remediated.

Simultaneously combining a validated management tool and geostatistical visualization system in a secure workflow providing decision-makers with reliable remedial solutions for industrial sites.

Added-value of this combination comes from the harmonization and validation of all available data along the project lifetime. Litho-logical and piezometric data, organoleptic and visual information, on-site and laboratory measurements from soil, water and soil gas are compiled and integrated in the environmental data manage-ment platform EQuIS that has been adapted and personalized to suit Ramboll needs.

Transferring data to mapping, modelling and visualization tools is also simplified. Kartotrak has been chosen to perform statistical and geostatistical analyses and 3D visualization. It brings concrete results delineating zones to be remediated, better understanding of contamination transfers and estimating impacted volumes together with associated uncertainties.

This methodology guarantees the reliability and quality of data together with an optimization and an increased reliability of char-acterization and remediation costs. Contamination placed into the environmental context also strengthens the overall understanding of customer challenges and communication with partners and authorities becomes easier.

Methodology of this workflow and real case studies will be presented and discussed.

Using spill modelling to better predict environmental risk

Simon GibbonsERM

There is significant value in understanding the detail around potential events, which could occur as a result of a release. Modelling of spills can provide opportunity to optimize response, improve response time and effectiveness and reduce environmental impact.

Oil spill modelling tools have been developed using geospatial and fluid dynamic modelling tools to help companies storing hazardous materials to better evaluate where the liquids might go and to assess their interactions within the environment. Predic-tive simulations on these processes can provide operators with the means to more effectively respond to an incident. Different tools exist to make predictions for overland migration, movement of liquids in surface waters or its fate and transport through the vadose and saturated zones of underlying soils.

The question is will these plans actually assist in a response or will the responders always need to think on their feet and make calls in the field based on limited observations and under challenging conditions?

ThS 1a | Big data, smart data combinations

Statistical modelling of groundwater contamination monitoring data using GWSDAT: A comparison of spatial and spatiotemporal methods

Matthijs Bonte¹; Marnie McLean²; Wayne Jones³; Ludger Evers²; Adrian Bowman²¹ Shell International Petroleum Co. Ltd; ² University of Glasgow; ³ Shell Global Solutions (UK) Ltd

Field monitoring of groundwater contamination plumes is an important component of managing risks for downgradient receptors and remedial strategies that rely on monitored natural attenuation. Collection of groundwater quality data can however take a considerable effort and be associated with high cost. Here, we investigated the relative merits of analyzing groundwater quality data using spatiotemporal statistical modelling as imple-mented in GWSDAT compared to a spatial method (e.g. kriging data for specific time steps)

We assessed the accuracy of both methods and implications for data collection requirements. The aim of this work was to determine whether the quantity of data collected can be reduced, while retaining the same level of estimation accuracy, by analyzing groundwater contamination data using a spatiotemporal model which “borrows strength” across time, rather than a spatial model for individual sampling events.

For the comparison study the predictive performance of a spatio-temporal p-splines model was compared with a spatial p-splines model and a spatial Kriging model. Kriging is currently one of the most popular methods for spatial modelling and interpolation and thus was used in the study as a reference to current practice. Spline-based models allow the complex relationships, often exhibited in spatial and spatiotemporal data, to be estimated in a flexible manner by constructing the estimated function with polynomial pieces.

To capture the variability encountered under field conditions, we used three hypothetical groundwater contamination plumes with increasing complexity developed with MODFLOW/MT3D. The statistical models’ predictive performance was assessed by calcu-lating the mean square prediction error (MSPE) for 200 random well networks consisting of 45 wells. For each simulation, observa-tion data was removed in a step-wise manner, and at each step a statistical model was built. MSPEs were calculated using the ‘true’ concentrations simulated for the three plume types and the data of the well network.

The results shown that when all the data are used the spline models have a slightly superior performance in comparison with Kriging (https://marnie-svst.shinyapps.io/gw-app). As data are removed, the performances of the spatial methods deteriorate markedly in contrast with a much gentler rate of decline with the spatio-temporal model. This demonstrates the benefit of ‘borrowing strength’ across space and time. This particular example involves a substantial number of wells and observations, to allow the relative performances of the spatial and spatiotemporal models to be demonstrated effectively. Clearly, the effectiveness of any model will be considerably reduced when the data become very sparse.

Leveraging the data obtained in this way can result in a reduced need for drilling and sampling of monitoring wells, while better characterizing and managing environmental risks. Freely available tools such as GWSDAT (http://www.api.org/GWSDAT) can facilitate environmental professionals to use spatiotemporal models.

Thematic Session (ThS) – Topic 1 | Soil and water in the digital world

52

tion is calculated based on the data of the mandatory and the selected optional wells.

• In a forth step, the difference between the reference solution and the test solution is calculated (at each node of the grid and summed up).

• In a fifth step, the calculated difference is compared with the previous test solution and based on predefined criteria (that also allow the solution to be slightly worse than the previous solution) the test solution is kept for future optimization steps or discarded. This procedure is called simulated annealing and avoids getting stuck in a local minimum.

• In a sixth step, one well is randomly exchanged and steps four to six are repeated until a predefined stop criterion (e.g. no improvement of solution anymore) is reached.

• In a seventh step, the percentage of optional wells that can be randomly selected is reduced and steps three to six are repeated again. This procedure is continued until the number of optional wells becomes too small to provide data for an interpolation that can reproduce the reference solution with enough accuracy.

• In an eight and last step, the best test solution for each percentage of optional wells is compared with the reference solution. This final comparison is performed visually, like a physician scanning X-ray images for unwanted alterations and leads to the best test solution that can still represent the reference solution with enough accuracy.

Based on our experience it is often possible to reduce the number of sampled wells by a significant percentage when this tool is applied. In one example, for an organic compound it was possible to reduce the number of optional wells by 40 % without significant loss of information.

Making sense of environmental big data: applications for the sustainable management of contaminated soil and groundwater

Gary Wealthall; Gary Wealthall; James Rayner; Cathy Crea; Eryn TorresGeosyntec Consultants

Environmental big data consists of large and complex datasets from multiple data sources, with variable data collection and manage-ment protocols, and end-user applications. The larger and more complex the dataset, the more is onerous it becomes to manage, process, analyse, and interpret using traditional industry methods. Applying big data analytics to environmental site management can improve decision making, reduce costs, and better charac-terize risk. Here we describe methods to address the challenges of managing big data at contaminated soil and groundwater sites. These methods are based on statistical principles, machine learning, and numerical optimization.

The first challenge deals with the quantitative understanding of impacts to soil and groundwater from large datasets, often spanning decades. Complex, large datasets, often spanning decades, are examined by applying multivariate statistical methods such as hierarchical cluster analysis, principal component analysis and non-negative matrix factorization, to identify spatial and temporal patterns and relationships in contaminant mass distribu-tion, mass transfer, and attenuation processes. These data mining methods unlock the value in datasets that would otherwise be inaccessible by conventional techniques, allowing more accurate, evolved conceptual site models to be developed.

This presentation will outline the principles of the modelling approaches and sets out why the availability of high quality input data is now able to support detailed models of the fate of these liquids. To highlight why model outputs used in response plans can be trusted two real world examples from the same operator will be presented. In one instance, an attempted theft led to the contamination of an area of ground, which required remediation. Modelling was used to identify the plausible extent of contami-nation so that an appropriate investigation could be undertaken and the correct area of contaminated soils removed. In the second example, a third party impact on the same buried pipeline led to a release of kerosene into a nearby stream. In this example, responders were equipped with maps presenting model simula-tions, which illustrated the potential extent of the oil in the stream. The responders were able to station recovery systems rapidly and in the right locations.

The operator’s response plans have stood up to two very different incidents and in both cases were supported by output from a range of modelling simulations. The response has undoubtedly saved significant costs by enabling the operator to respond quickly and appropriately to both events. To help in the use of the data generated through the modelling the client also has access to the model outputs via a web-GIS system. This technology allows the office, responders, emergency services and regulators to access all of the relevant information at a location to effectively manage the response.

In addition to these examples a range of spill simulations from operational assets will be presented to highlight the effectiveness of this approach in changing the way operators consider capital investments at site to protect the environment and their manage-ment approach to protecting people and the environment from unplanned releases.

Optimization of a groundwater monitoring network using geostatistics and simulated annealing

David TrudelArcadis Switzerland

Large clean-up sites often have an extensive groundwater moni-toring network with dozens or even hundreds of monitoring wells. These networks normally developed over a longer period of time and contain well locations that are no longer needed due to redundancies in the network. The question arises which wells are redundant and no longer need to be sampled and which wells are still necessary and should be sampled. To answer this question a geostatistical tool using simulated annealing has been developed that can optimize the monitoring campaigns and, thus, leads to reduced sampling and analytical costs with minimal loss of information.

This optimization tool works as follows:

• In a first step, the monitoring wells are divided into mandatory and optional wells. Wells might be mandatory because they are e.g. part of a remediation project or because the authorities do not allow the cessation of sampling.

• In a second step, the original data (all mandatory and all optional wells) are interpolated over a predefined grid using kriging as the geostatistical interpolation method and the resulting interpolation is used as reference solution.

• In a third step, a reduced number of optional wells is randomly selected from the whole set of optional wells and an interpola-

Thematic Session (ThS) – Topic 1 | Soil and water in the digital world

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borehole data and other relevant information (e.g. geophysics from data and/or scanned images).

Groundhog Professional possesses many basic spatial handling features found in GIS. Spatial data can be integrated from multiple sources including WMS, shape files, and scanned images. In the UK, Ordnance Survey open data and links to BGS 1:50 000 geolog-ical mapping are provided as defaults but any data provided via a WMS service can be included. Site based data such as the results of chemistry testing can be added to the database, visualized and interpreted.

We built Groundhog Professional specifically to support devel-opment of CSMs. Borehole data can be integrated with other spatially-referenced information (e.g. historical fuel tanks and chemical data) to help create a CSM in both plan and cross-section views. The CSM data structure allows physical features (objects) to be identified as sources, contaminants, pathways or receptors. These features can be depicted to scale on both plan and cross-section and then used to auto-generate a matrix or network diagram of source-pathway-receptor linkages. Plan and cross-section information is held in separate layers, facilitating organisation of what can often be a large amount of complex 3D material. As the investigation of a site develops, the CSM can be updated dynamically. This can include addition of new data as they become available, redrawing cross-sections and creating multiple interpretations.

Application of machine learning models to predict bioavailability and toxicity of complex chemical mixtures in a lab-based trial

Sabrina Cipullo¹; Boris Snapir¹; George Prpich²; Pablo Campo¹; Frederic Coulon¹¹ Cranfield University; ² University of Virginia

Application of machine learning (ML) to bioremediation is a promising technique to process empirical data to make predic-tions on long-term changes in contaminants bioavailability, and therefore potential toxicity to receptors, in a cost-effective manner.

In this study empirical data from a 6-month mesocosms experiment were used to assess the ability and performance of two machine learning (ML) models, including artificial neural network (NN) and random forest (RF), to predict temporal bioavailability changes of complex chemical mixtures in contaminated soils amended with compost or biochar.

From the predicted bioavailability data, toxicity response for relevant ecological receptors was then forecasted to establish envi-ronmental risk implications and determine acceptable end-point remediation. The dataset corresponds to replicate samples collected over 180 days and analysed for total and bioavailable petroleum hydrocarbons and heavy metals/metalloids content. Further to this, a range of biological indicators including bacteria count, soil respiration, microbial community fingerprint, seeds germination, earthworm’s lethality (expressed as condition index (CI) at 3, 7 and 14 days), and bioluminescent bacteria were evaluated to inform the environmental risk assessment. Parameters such as soil type, amendment (biochar and compost), initial concentration of indi-vidual compounds, and incubation time were used as inputs of the ML models. The relative importance of the input variables was also analysed to better understand the drivers of temporal changes in bioavailability and toxicity. Results obtained showed that both NN and RF were able to model the bioavailability of various contami-nants and RF performed slightly better than NN to predict the

The second challenge explores the benefits of using stochastic modelling techniques, informed by environmental big data, to enable thorough risk assessments and improve decision-making for industrial site management and remediation. Uncertainties in estimated parameters and variability in field data are accounted for by applying probability theory to predict the range of plausible outcomes and their likelihood.

The last challenge deals with optimizing monitoring well networks, requiring the evaluation of large datasets from long-term ground-water monitoring programs. An optimization method was developed to reduce operating and maintenance cost at a variety of monitoring sites with complex monitoring and remediation histories. A novel 3-D spatial (well network) optimization algorithm is combined with a propriety, refined adaptation of the industry-standard Monitoring and Remediation Optimization System (MAROS) software to analyse plume stability and recommend sampling frequencies. Using big data analytics in this context has yielded significant cost savings, due to dramatic reductions in the number of monitoring well locations and sampling frequencies, while maintaining regulatory compliance and stringent monitoring objectives. These methods continue to be applied and evaluated at a variety of new sites.

ThS 1b | Artificial intelligence

Data driven conceptual site models using Groundhog Professional

Darren Beriro¹; Judith Nathanail²; Paul Nathanail²; Tanya Richmond¹¹ British Geological Survey; ² Land Quality Management, Ltd

The brand new BGS/LQM Groundhog™ Professional is game changing geological software tailored for post-industrial brown-field redevelopment projects. The software has been created jointly by the BGS and LQM to facilitate the development of data-driven conceptual site models (CSM). Users can import ground investigation data to produce accurate scaled borehole logs, plans, geological cross-sections and network diagrams that can be combined into CSMs. These outputs link to either a digital terrain model or more rudimentary borehole levels for your development site. Users can import a site boundary along with ground investi-gation data and visualise these in the context of a topographical basemap, geological maps and other environment data. Boreholes logs and cross-sections can be exported directly into technical reports or into 3D geological modelling software, BIM or CAD environments.

Groundhog Professional’s borehole logging functions are built on an underlying AGS Data Format database (a UK initiated, but widely used internationally, format for ground investigation data). Borehole data can be entered within Groundhog Professional or imported in various formats. It provides the means to create or display logs as well as to use the data contained within the logs for modelling ground conditions.

Groundhog Professional has excellent geological cross-section drawing tools. Scaled cross-sections can be drawn and linked to a digital terrain model (ESRI ASCII Grid). Special attention has been given to methods of depicting water tables/piezometric surfaces which can be ground investigation data derived or drawn by users. The interpreted cross-section draws on the linked geological map,

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While field data are collected during the execution, in the past these data were not available to revise and adjust the execution works readily. Digitalization of paper field forms, reorganizing, trans-forming and aggregating the field data with other data sources like laboratory data and eventually creating meaningful graphs and visualizations was a repetitive, time consuming, error prone and, more than often, frustrating task. Timely decisions based on most recent data was practically impossible.

Today, many software tools allow digital workflows and real time decisions. However, often these tools are not suitable, expensive, need additional infrastructure and/or require much time and effort to implement. Arcadis succeeded to use what is today standard software for a 100% digital workflow for the follow up of their envi-ronmental remediation projects.

Interactive dashboards with mapped visuals and trend graphs in combination with real-time analytics, like automated Pearson or Mann-Kendall trend analyses, are now used by specialists and project leaders to consume the data collected in the field in real-time, empowering specialists and project leaders to do what they are paid for: take well founded, timely decisions! Subsequently, this automatic workflow can lead to significant cost savings, while multiple projects can be managed more efficiently at the same time.

Our approach is universal and easily extendable towards most diverse data sources. Today, we can combine and analyze data from multiple sources, e.g.:

- (Digital) field forms,

- Data acquisition and management systems,

- Laboratory data,

- Sensor data,

- GIS data,

- Data from SCADA (Supervisory control and data acquisition) systems,

- Building Information Modelling (BIM) systems, or

- Financial data.

It is also possible to incorporate 3D visualizations like conceptual site models or BIM models and while in the development phase, very soon we will be able to further increase our efficiency with the integration of machine learning and artificial intelligence.

This approach is not limited to new short-term remedial projects. Also, existing and long-term projects can be upgraded. It is even not limited to remediation projects at all.

Before implementation the following steps are always taken to fulfill the specific project and client needs:

- Define client as well as internal needs,

- Develop a suitable data model and define the most appro-priate digital workflow,

- Identify which tools are most suitable for: Data acquisition, Data management, Advanced analytics, Data visualization, Reporting

We will present our approach based on several real case study remediation projects, discuss core issues of the transformation like data management and data discipline and will have an outlook towards future possibilities.

toxicity. Additionally ML models with r^2 >0.7 were successfully used to predict the toxicity at intermediate time step; good predic-tions were obtained for CI 3 days (r^2 =0.95), CI 7 days (r2 =0.83), CI 14 days (r^2 =0.76), mustard germination (r^2 =0.91), ryegrass germination (r^2 =0.95), and soil respiration (r^2 =0.77).

This study suggests that ML models are good candidate tools to support remediation monitoring of multi-contaminated sites, in a cost-effective manner.

Innovative modelling and visualization methods in optimizing is situ remediation of contamination source: Way of working, opportunities and risks

Wouter Gevaerts¹; Marco Petrangeli Papini²; Paolo Ciampi²; Jelle Staverman³; Denny Schanze³; Alessandro Violetti³¹ ARCADIS; ² Sapienza University of Rome, Italy; ³ Arcadis

IoT is also influencing the contaminated land world, resulting in a lot of tools that give us much more detail on the status of the soil and groundwater (time related data, space related data); future focus will be on sensors for measuring concentrations in soil and groundwater. This increase in amount of data will oblige us to work much more with geostatistical tools and later on with several types of visualization tools.

In this presentation we will focus on :

- The IoT evolutions

- Current data acquisition tools : use of tablets in the field, with automised links to eg laboratories

- Manage the data

- Analyse the data, including software like PowerBI

- Reporting of data

- Visualization tools, including virtual reality and augmented virtual reality tools

This will be demonstrated by a step by step explanation of a site investigation (a site with tens of drillings, CPT measurements, MIP measurements and a geophysical investigation), building of the conceptual site model, and presenting several augmented/virtual reality tools. Those tools will be demonstrated on small interfaces (eg mobile phone) as well as on the screen.

On the other side the risks for mistakes are also important. The main issues are:

- how to deal with uncertainties : the density of data will vary between the different parts of the site, creating less and more reliable parts of the CSM

- how to discover mistakes : eg a wrong water level ?

- how to include expertise ?

Remediation Dashboards – Real time remediation follow up and decision making

Denny Schanze¹; Wouter Gevaerts²¹ Arcadis Nederland B.V.; ² Arcadis Belgium nv

To be in control of soil and groundwater remediation activities is a challenging task, especially during execution of short-lived in-situ remediation activities like for example ISCO (in-situ chemical oxidation) or other reagent-injection based technologies.

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ThS 1c | New technological developments

BIM : The Dunkerque refinery cleaned up using an innovative digital tool

Henri MolleronCOLAS SA

Eventually, very large-scale deconstruction and remediation projects have been a challenge for decades. The lack of global and shared vision has always been the main blocking points.

COLAS had been facing similar difficulties regarding to the reme-diation project of the former Dunkerque refinery.

Global simplified overview of the 95 ha refinery site reveals about 35 km of buried pipes, 250 km of pipes, 30.000 tons of steel (equiv-alent of 4 Eiffel towers) and 200 tanks. In parallel, the astronomical amount of data related to the site and the investigations performed lead to deal with more than 60.000 plans, 2.000 digitized plans, 200 environmental drillings and about 6.000 asbestos samples. Last but not least, the site has been through bombardments during the first and second world war.

To deal in full transparency with those challenges, COLAS chose to innovate. A special task force named BIMbyCO has been built to create a digital tool dedicated to the Dunkerque project: The BIM.

The first goal of the BIM is to allow a technical innovation. Through algorithms and extrapolation related to the undergrounds knowledge and sciences, COLAS produces intelligence. Concen-trating site data, nature of soils and nature of the contamination, the BIM generates behavioral models to define the very right global understanding regarding to contamination challenges.

The second purpose of the BIM is to create a deep interactive rela-tionship between all the actors of the project. Sharing in real time the same information with several unrelated teams, the site super-vision and the environmental authorities. Thanks to the BIM, the site supervision monitors the underground models chosen, the treatment options and the cost control of the project.

The BIM is obviously a digital tool allowing transparency for all the actors and especially the project commissioner. COLAS has been awarded with the “BIM d’or” by Le Moniteur for its creative engi-neering digital tool.

Combining geostatistics and data from numerical simulations to improve estimations of pollution plumes in groundwater or soils

Léa Pannecoucke¹; Chantal de Fouquet¹; Xavier Freulon¹; Mathieu Le Coz²¹ MINES ParisTech, PSL University, Centre de géosciences; ² Institut de Radiopro-tection et de Sureté Nucléaire (IRSN), PSE-ENV/SEDRE

Characterization of contaminated groundwater or soil around industrial plants is a major issue of site remediation. A classical approach consists in providing an estimation of the polluted zone extent thanks to observations (pollutant concentration data) and geostatistical tools (e.g. kriging). However, this estimation might turn out to be of poor quality if only little data are available. Besides, flow and contaminant transport simulation is a widely used tool when it comes to assess potential migration paths of solutes through the subsurface. It is efficient even if information from sampling is not available, as long as the input parameters are

Water Management 4.0

Wim Schiettecatte¹; Pieter Quinart²; Rob Van Dun², Inge Genné¹ VITO; ² Calculus bvba

VITO is a Flemish RTO with over 15 years of experience in industrial water audits and launches its new Water Management 4.0 product. Calculus is a Belgian ICT-company offering technical solutions and a flexible online portal for the processing and visualization of industrial production and utility data.

In times of flow meters with data exchange, mini sensors, controlled valves, internet of things,… the definition of water management needs to be revised. A conventional audit consists of a three step approach: inventory phase, scenario analysis towards water- and cost reduction and a technical/economical evaluation of the selected scenario’s.

Now, the new digital era enables the transition from a static to a dynamic approach. In Water Management 4.0 all data are central-ized and real-time processed through the implementation of an online portal. It offers new opportunities and clear advantages such as:

- real-time follow-up of the water balance of your facilities;

- interdisciplinary approach, linking water balance to contami-nants-, energy- and cost-balances;

- fast detection of water related problems as overconsump-tion, leaks, contamination,… and coupled alarm generation (dashboard);

- real-time data processing towards further automated process control, e.g. the control of valves based on sensor information;

- linking water related data to production numbers, e.g. for benchmarking;

- increased awareness and intrinsic motivation of employees through data processing and communication (dashboard);

By matching VITO’s water expertise with Calculus’ technical knowledge, data hardware and its online portal, we can offer the industry a fresh and innovative end-to-end solution towards an improved insight in, and control over, its water networks.

Two Water Management 4.0 reference cases are presented. Both projects are a joined effort of the ICT company Calculus and VITO.

Case 1: WaterVille

This 3-years research & innovation project (2016-2018), supported by the Flemish government, aimed at the implementation of an intelligent water network and the demonstration of innovative ‘residential’ water technologies at the living lab DreamVille, being the camp site of the dance festival Tomorrowland. The main goal is the set-up of a cloud dashboard for the operators for a better control, faster intervention and more optimal buffer level control.

Case 2: Carwash

One of the largest carwash companies of Belgium (up to 2000 cars per day) wanted to move away from the monthly follow-up of flows and chemical consumptions and a time-consuming data processing in Excel, towards a real-time process dashboard and control. VITO drew up the carwash process and water network, defined the important spots to monitor and the relevant indicators (eg. water to car ratio, recovered water to tap water ratio, rainwater to fresh water ratio…) and set the lay-out of the dashboard. In the online portal all data was visualized in indicators, Sankey flow diagrams and historical data graphs.

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consistent with the site under study.

The approach developed in this work consists in combining classical geostatistical tools and simulations of flow and contaminant transport, which easily provide large sets of data. This approach aims at improving the quality of the estimation of the polluted zone extent.

Two methods are proposed, based on the building of an a-priori model of pollutant plume migration, which is sampled to obtain unconditional simulations. For the first method, hundreds of those simulations are combined to compute empirical covariances. These covariances account for the spatial variability of the regionalized variable representing the pollution under study. Hence, we are able to compute non-stationary covariances that reproduce this variability better than a model based on observations only. For the second method, a few simulations well correlated to the obser-vations are used as drift functions in a kriging with external drift, which enables to add information about the variable under study through auxiliary variables.

In order to implement these two methods and assess their perfor-mances, a synthetic model of subsurface is built. This synthetic model is representative of an alluvial soil and includes a vadose zone of a few meters deep in which the flow and contaminant transport is simulated. The synthetic case is composed of a reference simula-tion, which represents a real scenario of pollution due to a tritium source, and for which only some observations are available in order to estimate the polluted zone extent. Then, hundreds of simula-tions are run with input parameters slightly differing from the reference simulation to generate a large set of data.

The extent of the reference polluted zone is then estimated using (i) a classical geostatistical method considered as a benchmark and (ii) the two above-mentioned methods combining geostatistical tools and data from simulations. The results show that the estima-tions are improved when using methods combining geostatistical tools and simulations, even if few observations are available, which underlines the interest of the method.

Finally, the proposed approach could help better estimate volumes of soils to be decontaminated in the context of remediation of industrial sites. It is presented here in the context of a radiological pollution but could be transposed to other types of pollution.

This work is supported by the French National Radioactive Waste Management Agency (Andra) under the “Investments for the Future” Program.

What’s the potential of geophysics for mapping landfills and industrial sites?

Timothy Saey3Dsoil

Despite the complementarity of geophysical prospecting with the more conventional forms of prospection of landfills and indus-trial sites, it was only deployed sporadically, and this despite its non-invasiveness. This could be due to a lack of experience with the potential and possibilities and due to the uncertainty of the contrasts within the soil. Nevertheless, a combined approach with a deliberate employment of geophysics could increase the effi-ciency of different steps within the remediation process.

Using geophysics, different types of underground features can be mapped both laterally and vertically in large detail. It allows to account for both the depth and extent of deviating soil layers,

and structures or objects composed of metal, concrete, brick stone, slag… Moreover, the course and depth of different types of utilities can be mapped in high resolution. Given this informa-tion, underground phenomena can be mapped and accounted for three-dimensionally, which implies that soil augering, trenching and excavation can be directed more effectively. The implementa-tion and integration should however be well-thought-out.

In this presentation, some approaches of the application of geophysics for mapping the subsoil of landfills and industrial sites will be introduced. Moreover, these will be illustrated by examples from researches in Flanders and abroad.

Use of drone as a sustainable solution for surveys

Jasper SchmeitsTauw bv

Nowadays thousands of developers and makers around the world are contributing to the drone technology. The usage of drones makes it possible to open new market potentials and allows marketers to provide new perspectives because of its advantages. The collection of these kind of data can be used in several surveys for soil- and waterprojects.

This global trend occurs which have an impact on the market trends in the consultancy business. Traditional methods are often time-consuming, dangerous and expensive. More attention is given to the these aspects. During the last years Tauw explored the possible applications of drones within their offered products and services. Applications are manifold because drones are able to carry many kinds of sensors. Some examples are optical, multi-spectral, hyper-spectral, heat, LiDAR, Medusa, etc. Possible applications within our business are related to 3D-point cloud models, ecological inven-tories, diverse inspections, detection of soil moisture, and many more. Nowadays we perform several surveys with our own drones, we map different kind of data and we use this data in various products. The overlapping advantage of this technique is that an enormous amount of data is generated with little efforts. This gives a profit relative to conventional survey-techniques. We are continu-ously expanding our perspective on the usage-potential (growing market potential) and technical-potential (new market segments / sensors).

Due to examples of projects is explained how this innovative technique is usable in Smart City concepts, some concepts are proven, other are examined at this moment:

- Mapping an actual digital terrain model by drones gives 3D-pointclouds which can be used in performing an flooding calculation – insight can be used in redevelopment of city-plans

- Detecting heat-differences of houses by drone mapping – insight in insulation-levels provides useful input in the challenge for a more sustainable world

- Environmental sampling/measurements in air or water – possibility to use drones for sampling or measurements were conventional methods have there limitations (for example: in order for safety)

In the presentation these kind of opportunities will be explained in line with technical opportunities, data processing, regulations and new developments.

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his hands free and the need to decipher all, as he calls it, ‘spaghetti’ drawings: with the glasses he can just see the cables and pipes lying in the ground (viewing). Furthermore, with these kind of systems it could be possible to let someone look with you to analyze the environment (transmitting video-signal) and thirdly it could be possible to detect and analyze data (sensing). At this moment pilots are performed to use and combine these kind of techniques.

Due to examples of projects is explained how this innovative technique is usable for soil and water surveys, some concepts are proven, other are examined at this moment:

- Viewing digital information of cables and pipes through Google Glasses – Fieldworker has it’s hands free to has proposed work

- Viewing subsurface characteristics – for example the location of roots of trees based on groundradar data

- Exploration in possibility to use Glasses as sensing-system – mulitspectral / hyperspectral views make it possible to view organic components; heat-measurements gives insight in differences of isolation of houses

Fieldworker of the future - combination of sensing and augmented reality

Jasper SchmeitsTauw bv

The field employee of the future is one who, in addition to a very good foundation of knowledge and experience, will increasingly use technology more widely, and more integrally, making his work easier, more efficient, safer and more fun. We have seen it happen in recent years with the new field computers and smart databases. Now it is time for the next step, namely the use of augmented reality (AR) in our work outside. The developments in the field of hardware and software for augmented reality are so fast that today we can already make the above dream a reality. The challenge is to optimally utilize these developments and to integrate them into our activities. The potential of AR for the work outside is very high.

Imagine: when you arrive at the industrial park, the field employee picks up his tablet. Through an augmented reality glasses, he has

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on-going degradation may be secured using microbial diagnostic tools, but quantitative estimation of rate - critical for performance prediction and monitoring - remains elusive.

A methodology is presented that employs in situ microcosms and isotope analytical tools for estimation of sorbed-phase biodegra-dation rate in activated carbon barriers. Interference from abiotic factors, including on-going sorption or desorption, are differ-entiated from biotic changes using passive flux meters, control microcosms, and compound-specific isotope analysis (CSIA). Addi-tional ‘lines-of-evidence’ context is secured through microbial diagnostic tools. A case study is presented from a chlorinated solvent site in Missouri, USA.

Biodegradation of sorbed-phase VOC mass is indicated through CSIA and microbial diagnostic lines of evidence. This further supports the understanding that biodegradation is not restricted to the dissolved-phase. Sorbed-phase degradation rate estimates and isotopic enrichment factors are contrasted with those of other available sources: the ambient dissolved phase, laboratory estimates, and published values. This relatively simple approach is an important first step in refining conceptual site modeling for sites that employ activated carbon-based treatments. Ideally, the results of this study will be leveraged for use in more predictive analyses in conjunction with plume modelling software. Its full potential therefore rests on an adequate understanding of the limits of confi-dence in the data it provides.

Integrated approach in the management of a jet fuel contaminated site. The Decimomannu Air Base (CA, Sardinia)

Paolo Ciampi; Carlo Esposito; Paolo Rizzetto²; Andrea Chiappa²; Michele Bernabei²; Giorgio Cassiani³; Gian Piero Deidda⁴; Marco Petrangeli Papini¹¹ Sapienza University of Rome; ² Italian Air Force; ³ University of Padova; ⁴ Università di Cagliari

Usually, the design of remediation interventions in polluted sites is carried out based on the characterization data, which are aimed at acquiring the necessary parameters for the Risk Assessment, often utilized for the definition of the remediation targets. These data are often, unfortunately, insufficient to identify the best reme-diation strategy. In particular, the remediation strategy/plan is usually defined based on characterization data collected (many) years before and that do not take into account the natural “aging” of potential secondary sources of contamination. This aspect is particularly relevant in the case of fuel contamination, complex mixtures of hydrocarbons that contain categories of substances with significantly different chemical / physical and biodegradability properties. In the initial phase of the spill, or however when the primary source is active, the most soluble components (i.e. BTEX) are mobilizable in the groundwater flow and aerobic biodegrada-tion processes are active on the more readily degradable fractions (linear hydrocarbons with shorter chain). The progressive aging of the contamination source corresponds to a depletion of the more mobile and degradable fractions, with the accumulation of high molecular weight fractions, less transferable to both aqueous and soil gaseous phase. Therefore, the accurate characterization of the residual phase’s real characteristics allows the definition of the best remediation strategy.

An illustrative case history is here presented concerning the Military Airport of Decimomannu (CA), affected by various aviation fuel (JP8) spills in 2007 (40000 l), in 2009 (5000 l) and in 2010 (5000 l). The creation of a “4D” geographical database (which also considers the

ThS 2a | Advances in sampling, monitoring techniques and methods

A novel active-passive sampling approach for monitoring a broad range of pollutants in water

Elvio Amato¹; Raewyn Town; Adrian Covaci; Jonas Hereijgers; Ben Bellekens; Dragan Subotic; Tom Breugelmans; Maarten Weyn; Freddy Dardenne; Lieven Bervoets; Ronny Blust¹ University of Antwerp

Passive sampling offers several advantages over traditional sampling methods (i.e., discrete spot sampling), however, data interpretation from conventional passive samplers is hampered by difficulties in estimating the thickness of the diffusion layer at the sampler/medium interface (δ), often leading to inaccurate determi-nations of water concentrations. In this study, the performance of a novel active-passive sampling (APS) device was investigated in the laboratory. The device is comprised of a diffusion cell fitted with a pump and a flowmeter. Three receiving phases were incorporated in the diffusion cell and allowed the simultaneous accumulation of cationic metals, polar, and non-polar organic compounds, respec-tively. The flow within the diffusion cell was accurately controlled and monitored, and, combined with diffusion coefficients measure-ments, enabled the average δ to be estimated. Different flow rates and sampler configurations were tested by exposing the APS device to artifiacial freshwater spiked with a mixture of pollutants (e.g., Cd, Cu, Ni, Zn, carbamazepine, diuron, isoproturon, fluoran-thene, PCBs). Strong agreement between APS and time-averaged concentrations measured in discrete water samples was found for most of the substances investigated. These results indicated that the proposed APS approach could be useful for simultaneously monitoring a broad range of legacy and emerging pollutants in water.

Estimation of sorbed-phase biodegradation rate in activated carbon barriers using microbial diagnostics, CSIA and in situ microcosms

Jeremy Birnstingl¹; Samuel Rosolina²; Matthew Burns³¹ Regenesis Ltd.; ² Microbial Insights; ³ WSP

The migration of organic contaminants in groundwater can be mitigated through injection of activated carbon reagents into the subsurface. The approach offers significant design flexibility in strategies ranging from source area containment to barrier config-urations. Contaminant flux retardation within the treatment zone may be supplemented with biodegradation. This can extend the time to breakthrough owing to bioregeneration of the sorption sites on the carbon. The barrier longevity may be extended indefi-nitely if the degradation rate is sufficient. An understanding of the in-barrier degradation rate is therefore important for performance calibration and management.

In situ monitoring of contaminant degradation is typically achieved through groundwater sampling. Ambient rate may be estimated from concentration trends and advection rates (assisted by models) as the system is dominated by dissolved-phase flux. Within barrier zones however, the contaminant mass is predominantly in the sorbed phase. Contaminant concentrations in the dissolved phase may be close to or below detection limits. The consequent challenge of ‘clean’ water in the barriers limits options for performance moni-toring through groundwater sampling. Qualitative indications of

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the borehole to assess the controlled mass flux of organic (TAME) and inorganic (Zn) dissolved species at two different flow rate and two concentrations. Field-scale experiments and modeling were performed at a dedicated pilot site at the French historical Lacq industrial area equipped with several piezometers. Multilevel monitoring tools validated at lab-scale were deployed at field scale to assess groundwater flow and solute transport in high permeable shallow and free aquifer. The results of these characterization tools for groundwater flow and mass flux gave encouraging results for further operating deployment. Indeed, the long-term R&D strategy is targeting in-situ, real-time, remote and cost-effective monitoring solutions for operating industrial sites and facing challenges of heterogeneous geologies, transition areas in streambed, estuarial and shoreline environments.

Rapid assessment of potential inhalation risks due to the vapour intrusion pathway using building pressure cycling and high volume subslab testing

Helen Dawson¹; William Wertz; Todd McAlary; Paul Nicholson; Darius Mali; Theresa Gabris¹ Geosyntec Consultants, Inc

Inhalation risks due to vapour migration of volatile organic compounds (VOCs) from subsurface sources into occupied buildings, referred to as the vapour intrusion (VI) pathway, are chal-lenging to assess using conventional indoor air sampling methods because of temporal and spatial variability in indoor air concen-trations and contributions from background sources. Indoor air concentrations measured over periods of a few hours to a day can exhibit greater than 100-fold variability over time and space. Many background sources of VOCs exist in everyday use and vapour emissions from such sources can lead to a high bias in the estimate of VI-related inhalation exposures. This presentation describes two innovative methods of evaluating potential inhalation risks due to the VI pathway: building pressure cycling (BPC) and high volume subslab sampling (HVS).

BPC offers a means of quickly characterizing building susceptibility to VI as well as determining background (non-VI) contributions to indoor air VOC concentrations. The BPC method involves depres-surizing a building to varying levels, which promotes VI, and subsequently pressurizing it, which hinders VI, while concurrently recording cross-building and cross-slab pressure differentials and sampling indoor air under the various levels of imposed pressure conditions. Building susceptibility to VI and reasonable maximum exposures due to VI can be determined in a one or two days or less, depending on the size and complexity of the building. The results have been found to exhibit sufficiently low temporal vari-ability (generally less than 3-fold) that repeat sampling in different seasons is not needed to support reasonable risk management choices.

HVS offers a means of characterizing the VOC vapour mass loading under the building that could potentially impact indoor air quality through VI and deriving building-specific indoor/subslab attenuation factors. The procedure involves measuring vapour concentrations as a function of the volume of gas extracted and measuring vacuum under steady and transient periods of vapour extraction from below the building foundation. These data are used to calculate the transmissivity of the subslab materials and the leakance of the slab, parameters that can be used to calculate a building specific attenuation factor. These tests also can be conducted in one or two days or less, depending on the size of the building. Multiple HVS tests at large buildings can be used to

timing factor) allows the integrated management, representation and analysis of different data (geological, hydrogeological, hydro-geochemical and geophysical). The data used for the construction of a georeferenced database, have been enriched by field hydraulic tests and detailed speciation, through GC-MS, of supernatant that has been occasionally detected over the years in the piezometric monitoring network. A campaign has been conducted on the site with the UVOST-LIF (Laser Induced Fluorescence) technology, the first performed in our country, which allowed to delimit the volumes of subsoil previously impacted by the primary spills. The labora-tory and field investigations carried out have made it possible to identify the presence of contaminants in the residual phase. Based on the results, an in situ enhanced chemical desorption strategy was implemented to increase the desorption of hydrocarbons adsorbed to saturated soils or at the capillary fringe and to increase the product recoverability in a separate phase. The hydrocarbons are made available in the dissolved phase or in a separate phase with lower viscosity, allowing a subsequent rapid and effective physical recovery. The integration of the large amount of informa-tion has allowed to outline a conceptual model of the site more representative of the current situation and essential for defining the correct intervention strategy.

Innovative characterization solutions for monitoring of groundwater and dissolved contaminants dynamic

Anthony Credoz; Nathalie Nief; Rémy Hédacq; Béatrice Ducastel; Laurent CazesTOTAL S.A.

In the frame of environmental monitoring of industrial sites, groundwater flow parameters, such as direction and magnitude of water velocity, are deduced from indirect measurements between several piezometers. Then, groundwater is generally sampled in the whole column of water inside each borehole to provide one concentration value per piezometer location. These flow and concentration values give a global “static” image of potential evolution of contaminants plume in the shallow aquifer with huge uncertainties in time and space scales and mass discharge dynamic. TOTAL R&D Subsurface Environmental team is challenging this classical approach with an innovative way of characterization of groundwater dynamic in shallow aquifer. The current study aims at optimizing the tools and methodologies for, first, a direct and multilevel measurement of groundwater velocities in each piezom-eter and second, a determination of potential flux of dissolved contaminant in the shallow aquifer. Lab-scale experiments were designed in a 1.5 m length sandbox equipped with a 80 mm diameter borehole and filled with calibrated sand where a range of controlled flow rates were applied. Multiphysics modeling with COMSOL Multiphysics was performed to calibrate the sandbox and simulate some experiments. The modeling study took into account Darcy equation in porous media and Navier-Stockes equation in the borehole. For groundwater flow rate measurements, 4 R&D and commercial tools were deployed and tested at different locations of the sandbox. Point Velocity Probes were buried directly in the porous media. Colloidal borescope, In-Well Point Velocity Probe (IWPVP) and Direct Velocity Tool (DVT) were deployed in the moni-toring borehole. In this unconsolidated porous media, direct-buried tool PVP presented the most relevant results for measurements of direction and magnitude of groundwater flow. Experiments and modeling also showed that the structure and location of measuring tools installed in the borehole increased uncertain-ties of velocity measurement. Then two additional commercial tools Permeable Flux Meters (PFM) and i-FLUX were installed in

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Risk of vapor intrusion to the indoor climate from groundwater contamination

Anne Gammeltoft Hindrichsen¹; Minakshi Dhanda²; Sine Thorling Sørensen²; Cecilie Amtorp²; Mads Georg Møller¹; Preben Bruun³; Kim Haagensen¹¹ Orbicon A/S; ² Capital Region of Denmark; ³ Danish EPA

In Denmark there is a big awareness on the risk for the indoor climate from groundwater contamination with volatile organic compounds. In many cases we need to evaluate this risk for future redeveloped sites for residential use. This risk assessment is often based on fugacity calculations from groundwater concentrations and transport through the vadose zone. This theoretical method often leads to an unacceptable calculated risk, especially for vinyl chloride, but unacceptable concentrations are rarely observed in the indoor climate at actual sites.

The Capital Region of Denmark, the Danish EPA and Orbicon, has therefore carried out a project with the overall target to identify measurable parameters that control the transport of chlorinated solvents through the soil column and hence the risk of vapour intrusion to the indoor climate. These parameters are subsequently measured at field sites. The project aims at highlighting the factors that control transport along the soil column, and hence strengthen the basis for the calculation. The project is funded bythe Capital Region and the Danish EPA.

We have performed field investigations at two sites (Blokken 25 and Gydevang 1) where there is a groundwater contaminant with chlo-rinated solvents (PCE and TCE) overlaid by clay till. At each location there is installed a sampling nest for sampling of groundwater and soil gas in a vertical profile. Sampling of groundwater and soil gas has been carried out summer, autumn and winter in order to inves-tigate the seasonal variations in the vertical concentration profile. At present time, the summer and autumn samples have been taken, and the final sampling will be carried out in December 2018. During the whole period, local weather stations have been installed on the two sites to measure temperature, pressure, wind and precipita-tion. During installation of the sampling points soil samples were taken in order to measure contamination, water content, loss on ignition, and grain size analysis of the clay till (determined by laser diffractometry atAarhus University). Data loggers are also installed in the borings for logging of pressure levels in unsaturated zone and water table changes in the saturated zone.

The first results indicate that grain size and water content are important factors that should be taken more in to consideration when evaluating the future risk, and that the theoretical calcula-tions overestimate the contribution of groundwater contamination to the soil gas and hence to the indoor climate. In these calcula-tions, it is assumed that all transport occurs in the unsaturated zone. In many cases this assumption does not apply since the soil layers above the groundwater table consist of both saturated and unsaturated zones. Transportation in the saturated zones is controlled by diffusion in water, which is around 4 times lower than in air. Hence, the diffusion in the saturated zone will be the limiting factor for the transportation and thereby the flux to the unsatu-rated zone. Furthermore, the fugacity-approach does not include mass transport, and therefore it assumes an infinite source with the measured concentration in the groundwater.

distinguish areas of high potential mass loading from areas that don’t pose a VI risk and to design an efficient and effective mitiga-tion system to mitigate or remediate any VI threat.

These methods were intensively studied under the United States Department of Defense (USDoD) Environmental Security Tech-nology Certification Program (ESTCP), which is the USDoD’s environmental technology demonstration and validation program. This talk presents results from these studies as well as studies conducted at other buildings, and presents protocols for using these methods to inform risk management decisions about the potential for VI to impact buildings.

Advanced monitoring tools for in situ remediation measures - Conclusions from 233 contaminated site investigations

Heinrich Eisenmann; Anko FischerIsodetect GmbH

Bioremediation concepts as well as monitoring tools have advanced to complex practice within the last 20 years. As the development and control of treatment train strategies requires a valid charac-terization of biodegradation processes, practical expertise in the application of monitoring techniques is necessary.

For this purpose we present an overview on advanced monitoring tools that were applied for the investigation of 233 contaminated field sites throughout Europe within the last 12 years. Various methods were used to characterize natural attenuation processes (80% of cases) or success control of stimulated biodegradation (8%) sometimes in combination with forensic objectives (12%). Compound-specific isotope analysis (13C/12C-CSIA, 2H/1H-CSIA, 37Cl/35Cl-CSIA) of pollutants evolved as the key method to prove and quantify degradation of chlorinated ethenes (CE), BTEX or MTBE (in 221 monitoring campaigns), while in situ microcosms (24x) and metabolite analysis (28x) were the major tools to demon-strate PAH degradation. Further methods such as qPCR analysis of gene markers (19x), CSIA analysis of redox compounds (20x), GC/MS screening (10x) or enantiomer analysis (2x) were used for more detailed and specific objectives (e.g. environmental forensics or proof of pesticide degradation). When natural attenuation is accepted as a relevant option for remediation, detailed studies on stimulation of degradation processes and plume develop-ment are mandatory. In some cases, laboratory experiments (7x) were applied to evaluate efficient stimulation of degradation by specific reagent mixtures. At 111 sites, multiple-line-of-evidence approaches provided independent and differentiated information on the microbial elimination of contaminants. The combination of methods depended mainly on dominant pollutants and - possibly combined - in situ treatment strategies. As a case study, we describe that CSIA, qPCR and laboratory microcosms are feasible tools for successful application of cost-efficient biostimulation at a chlorinated ethenes contaminated site.

Concisely, in situ remediation measures will only be viable by understanding biological, chemical and hydrogeological processes within a contaminated site. Adequate monitoring tools are available to fulfil this challenge and they are still considerably improved by research efforts. As recent and future remediation strategies are highly complex, they will be facilitated by process-oriented investigations.

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LNAPL baildown tests and hydrographs are used to understand the LNAPL mobility and provide important information about soil conditions. While baildown tests themselves are conceptually simple - a stress is applied to the LNAPL body and the response is measured – accurate measurement of fluid levels is not always straightforward. Notably, measuring two dynamic interfaces is difficult in practice and the well may take some time to return to the initial condition, leaving gaps in recorded data as personnel may not be continuously present on site to monitor the test. LNAPL wells can also be in areas that pose significant hazards to site personnel. Furthermore, factors such as groundwater fluctua-tion and inter-operator variation can cause inconsistencies in the collection of the data.

Understanding of the site is also reliant on longer term monitoring of the LNAPL. Hydrographs are created from periodic monitoring of boreholes but cannot provide a true picture of the groundwater movement-LNAPL relationship within a practical time frame.

Ecologia has developed a safer, more reliable and accurate measurement technique LNAPL monitoring for both baildown tests and hydrographs.

The approach comprised the use of a guided wire radar sensor. A series of laboratory trials provided robust data and we established that the sensor was able to track movements of LNAPL with a high degree of accuracy and precision. Studies then progressed to field trials where the LNAPL interface data collected could be interrogated and verified, and engineered controls developed to allow the sensor to work on site, allowing recording of the LNAPL and water levels in boreholes to a resolution of 2 mm, with a high degree of repeatability.

The field trials demonstrated that system power requirement is very low, enabling a sensor to operate for long periods on a small battery. The ability of the set-up to provide prolonged monitoring meant that hydrographs of very high resolution were created. The hydrographs showed groundwater-LNAPL interactions over the course of several days and provided information that would not be possible to acquire through the use of periodic measurements using an interface probe.

The system was also used to carry out baildown tests at the start of and throughout an LNAPL recovery project, providing vital data on the change of mobility with LNAPL recovery.

The use of the system avoids problems often faced when employing a baildown test. The quality of the data is better than would be obtained by following the current ASTM standard. The set-up can be used to create hydrographs of far greater utility than can be currently made. The accuracy and precision of the set-up are also greater than an interface probe. In addition, the system removes the need for a continuous site operator presence, freeing up site personnel for other work, and more importantly, minimising any health and safety concerns associated with monitoring LNAPL-extraction or monitoring wells.

Field scale comparison of four passive sampling techniques for monitoring contaminant flux in groundwater CVOC plumes

Jarno Laitinen¹; Heidi Ahkola²; Reija Kalajo³¹ Ramboll Finland Oy; ² Finnish Environment Institute; ³ Finnish Defence Administration

Sustainable risk based contaminated land management is based on a balanced analysis of the long-term risks imposed by contami-nation. Traditional approach for evaluating and monitoring these

High resolution site characterization: The basis of your conceptual site model

Jos Gompelman¹; Pieter Dijkshoorn¹; Daniel Wijkhuise²; Ruurd Peppel²¹ ERM BeNe; ² Nouryon

Conventional soil and groundwater investigations on a large indus-trial site located in a former river delta showed the presence of soil and groundwater impacts with mainly chlorinated volatile organic carbons (CVOCs). Following the investigation efforts a ground-water abstraction system was put into place in 1989 to contain groundwater plumes from migrating off-site. The groundwater abstraction system remained operational since then and proved to be successful in containing the groundwater plumes on site.

Although results showed a positive effect on the site’s subsurface quality (estimated mass removal of 520 tons of CVOCs) the residual concentrations in soil and groundwater remained high, indi-cating that the strategy would not result in a sustainable soil and groundwater quality in the near future. To find a more sustainable approach in managing the soil and groundwater impacts, addi-tional investigations were conducted to develop a more robust conceptual site model.

Since 2010 soil and groundwater investigations were conducted using a variety of high resolution site characterization techniques allowing for the development of a more rigorous conceptual site model. Amongst others:

• Passive soil gas samplers were deployed for source zone identi-fication and characterization;

• Membrane interface probes (MIPs) were advanced in order to obtain a more detailed understanding of geology and vertical distribution of contaminant mass in source and plume areas; and

• Discrete groundwater sampling (BAT sampling) was conducted.

The detailed site characterization showed that the site’s geology was much more complex than initially understood and better understanding the geology was key in explaining on-site contami-nant behavior. Besides, the characterization resulted in more precise determination of locations of original source zones, identification of more previously unidentified source zones, a more complete characterization of the plume architecture, a better quantification of the contaminant mass, a better understanding of the migration behavior of the chlorinated solvents and a better quantification of the potential risks for human health and/or environment. Overall, the conceptual site model was further completed. The updated conceptual site model will result a revised remedial strategy.

This presentation will cover the high resolution site characteriza-tion techniques used in this particular investigation and how the findings were used to further understand the complex Site geology and to refine the conceptual site model. This more rigorous concep-tual site model will ultimately be the basis for a more sustainable remedial strategy.

Advances in in-situ automatous LNAPL and water level monitoring by guided wire radar: Detailed analysis of LNAPL behaviour and improved site understanding

David HolmesEcologia Environmental

Recovery of hydrocarbons that are present as Light Non-Aqueous Phase Liquids (LNAPL) in soils is an established remedial process and its success lies on a sound understanding of LNAPL behaviour.

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Nowadays, Laser Induced Fluorescence (LIF) methods are recog-nized as rapid, low-invasive and cost-efficient site characterization methods. Applied by Cone Penetration Testing techniques, those methods deliver amazing efficiencies (up to more than 100m per day), at the same time preserving their vertical high-resolution capabilities.

A Dual LIF site characterization system was developed by combining a UVOST and a TarGOST system under a single Dual LIF probe coupled afterwards to a CPT cone. The combined system was deployed at a Swedish site in Malmö. The site main contaminants are oil-related with reports over coal-tar specific type of NAPL. A no. of 45 UVOST-TarGOST-CPT profiles down to around 10m bgl were carried out indoor and outdoor of site facilities. They revealed the type, spread and intensity of site contamination. For calibration and validation aims, several soil samples were recovered by depth oriented MacroCore sampling.

As a high-resolution site characterization method, LIF displays significant advantages over the traditional characterization techniques. Especially for NAPL detection and delineation, a LIF deployment followed by complementary target-oriented soil sampling delivers the key to reliable site models. A combined use of UVOST and TarGOST under a CPT environment proved to potentiate the high-resolution methodology by enforcing valida-tion resp. resolution capabilities in terms of contaminants (heavy vs light contaminant classes, different saturation degrees, vertical differentiation of NAPLs) and geotechnical parameters (lithology, soil density and consistency).

This combined UVOST-TarGOST-CPT methodology applied for the first time in Europe illustrates the need for site specific screening methods able to provide reliable images of the site under cost efficiency requirements. Moreover, reliable site models open the perspective of successful remediation strategies and scenarios.

Contaminant mass flux measurement in groundwater with passive samplers coupled with flowmeter measurements

Julien Michel¹; Goedele Verreydt²; Fabrice Richez¹; Hélène Demougeot-Renard³¹ INERIS; ² iFLUX; ³ eOde Sàrl

Contaminant mass flux measurement in groundwater can be of great interest for contaminated site management since it can better define pollution sources and plumes and improve site characteriza-tion and remediation. In Switzerland, contaminant mass flux is one of the criteria used to evaluate the objectives and the urgency of a remediation plan. But contaminant mass fluxes are calculated from concentrations measured in snapshot groundwater samples and generic Darcy velocities and do not account for concentration and groundwater flux variations over time and space. Passive samplers for contaminant mass flux can be an interesting alternative to improve contaminant mass flux determination in groundwater.

This work aimed at evaluating passive flux meters (PFMs) and iFLUX samplers to measure contaminant mass flux in groundwater at two sites contaminated with chlorinated solvents (HVOC). The first site was a former landfill and HVOC concentrations in groundwater were below 100 µg/L. On site, 6 monitoring wells were equipped with PFMs at different depths and 3 sampling campaigns were carried out. The second site was a former watchmaking factory and iFLUX samplers were installed in two monitoring wells during one exposure phase. HVOC concentrations in groundwater were up to 100 mg/L. Prior and after passive sampler exposition, ground-

risks is based on concentration comparisons at specific points of control. Variations present in concentration measurements at varying time series have been addressed by the introduction of passive samplers, that allow measuring longer time and/or volume based average concentrations. In the recent years evaluations have also begun to include contaminant mass discharge and flux esti-mations, which instead of concentrations aim to express the mass flux through a well-defined control plane(s) or plane(s) of compli-ance. Combining the passive sampling with the flux analysis to monitor the strength of a source or plume improves evaluation of the risks and also serves to help design more sustainable remedia-tion approaches.

In 2018 the PASSIIVI –project (use of passive sampling in ground-water evaluation and monitoring) was established to investigate the practical applicability of passive sampling and mass flux analysis as tools for groundwater monitoring on contaminated sites. Three active remediation sites with groundwater contaminated by chlo-rinated solvents were selected as project sites due to the extensive background information available. The aim of the PASSIIVI project is to compare different techniques developed for passive- and mass flux sampling, namely iFlux, SorbiCell and TIGER, with traditional groundwater sampling and modelling. The comparison includes the application and use of the samplers, resource needs, costs, interpretation of results, and the use of the results for regulatory compliance reporting.

The project is implemented by multiple partners and managed by the Finnish Environment Institute. The duration of the project is from March 2018 to June 2019 and expected final report due date is May 2019.

The results thus far (2018) have shown that the practical application and use off passive samplers and flux measurement tools requires significant changes to existing working methods, potentially increases resource and labor needs, is not necessarily cost-effective and requires more training for the interpretation of results. The tested methods also provide results in a non-comparable form due to the differences in approach towards average weighting. Due to these limitations the use of the results for regulatory compliance reporting seems limited.

The presentation will include a short description of the project and the test sites, having the focus in comparing the results for passive and traditional sampling methods in terms of understanding contaminant flux conditions. The presentation will also address the issues to be noted in the practical use of passive samplers by comparing the resource needs, economic perspectives and the use of average concentrations and contaminant fluxes in risk evalua-tions and regulatory reporting. As a conclusion the presentation will present practical guidelines that practitioners and politicians should take in account when planning to apply and use passive sampling and flux estimations.

Reliable and cost-effective site characterization using a Dual LIF (simultaneous UVOST-TarGOST)-CPT approach

Eugen Martac¹; Randy St. Germain²; Lars Davidsson³¹ Fugro Germany Land GmbH; ² Dakota Technologies Inc.; ³ WSP Sverige AB

Conventional site investigations based on soil and groundwater sampling may involve significant uncertainties due to insufficient sampling density under limited budgets. NAPL extension might be highly affected by traditional sampling schemes which often may happen to miss the contaminant bodies. Applying a denser sampling grid may not be feasible due to time and cost constraints (large sites, accessibility issues, depth specific problems).

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water was sampled with a pump after purging the well and HVOC concentrations were measured in these samples. Heat Pulse Flowmeter (HPF) measurements were carried out in each well to evaluate production zones under pumping conditions.

Passive sampler evaluation consisted in comparing:

• concentration A: average HVOC concentration in ground-water, calculated from groundwater samples obtained before and after sampler installation. These concentrations are point-in-time measurements and average concentrations all along the screened interval of the well, weighted by the contaminant flux coming from the different production zones,

• concentrations B: sum of HVOC concentrations given by PFMs and iFLUX samplers exposed at each depth in a well (average concentrations over the exposure time) weighted by groundwater flux at these different depths given by HPF measurements.

Concentrations A and B were of the same order of magnitude or comparable in most of the wells, showing a reliable concentration measurement with these samplers, meaning a reliable contami-nant mass and groundwater velocity measurement. In the wells where differences were observed between concentrations A and B, this could be explained thanks to the exposure strategy of the samplers since some of them were voluntarily not exposed in front of production zones. PFMs and iFLUX samplers showed a vertical distribution of the contamination in some wells and signifi-cantly higher concentrations could be measured at some depths, comparing to groundwater sample concentration. Therefore, concentrations could be underestimated in groundwater samples, leading to an underestimation of the risk for human health and the Environment. Passive samplers for contaminant mass flux measure-ments seem very promising for contaminated site characterization and remediation improvement.

The use of in situ biosensors to monitor a biostimulation pilot at a chlorinated solvents plume

Jean-Michel Monier¹; Sébastien Kaskassian²; Adeline Galmiche²; Olivier Sibourg¹¹ ENOVEO; ² Tauw France

In situ remediation techniques require to strengthen monitoring strategies in terms of parameters, frequency, and spatial locations in order to better describe processes at stake in real life environments. Data collection is of special scrutiny when applying chemical or biological processes. This past decade has seen the development of biomolecular tools (ADEME, 2016) as well as connected technolo-gies in the field of environmental remediation. The site under study is contaminated by chlorinated solvents (chlorinated ethenes). The groundwater plume originates from at least two source locations that cannot be easily accessed due to the presence of building on site and is reaching privately owned extraction well outside the site limits. It has been decided to evaluate the feasibility and efficiency of enhanced anaerobic biodegradation in order to stop the plume progression towards the receptors. The field pilot is designed as follows: a substrate injection line of 10m width and 6 well locations (up- and down-stream from the injection) over a 40  m length along the flow with multiple depth screened wells. Since the aquifer shows strong vertical stratification for both contaminant concentrations and groundwater velocity, the selected substrate (vegetable oil-based emulsion) was injected every 50cm in depth over the 10m wide x 5m deep vertical plane of injection.The moni-toring strategy included classical groundwater sampling at various time intervals in all screens of each well over a 9 months period and

analyses ofphysico-chemical parameters (TOC, ORP, pH, dissolved oxygen, Cl-VOCs and non-toxic metabolites, inorganic electrons acceptors and donors) as well as molecular biomarkers (qPCR and RT-qPCR on 16S, Dhc, pceA, tceA, bvcA, vcrA). In situ NODE biosen-sors developed by ENOVEO were also deployed in the aquifer at a downgradient location from the injection plane in order to evaluate the presence and duration of the substrate at 3 different depths:

- Dissolved Organic Carbon monitoring using NODE biosensors where the in situ biofilm (indigenous microbial popu-lations) growth reflects the groundwater quality and induces a corresponding electrical signal,

- pH, Temperature, ORP and Dissolved Oxygen moni-toring using in situ physico-chemical probes.The use of remotely connected sensors allowed to closely monitor the equivalent TOC release into the aquifer in real time and thus to:

1) optimize the sampling events over the monitoring period,

2) evaluate the dynamics of the TOC release over time and the heterogeneous diffusion with depth,

3) validate the need for a second injection phase.

Correlations between biosensor signals and lab analysis of TOC groundwater were satisfying.The pilot achieved a 99 % reduction in Tetrachloroethylene and Trichloroethylene concentrations with the accumulation of cis-dichloroethylene. This bottleneck was confirmed by the absence of corresponding biomarkers in ground-water (both DNA and RNA) and the duration of the best suited pH - ORP conditions. A second substrate injection has started and on-line sensors should demonstrate the benefit of the new substrate formulation.

Innovative, multi technique investigation for residual NAPL presence in order to assess bedrock remediation at a site in Sweden

Patrik Nilsson¹; Jonas Bruzell¹; Rogier De Waele²; Michela De Camillis²; Martin Slooijer²¹ Projektengagemang AB; ² GreenSoil International B.V.

GreenSoil BV and Projektengagemang (PE) have undertaken several field studies to identify potential residual chlorinated solvents in fractured bedrock below a 27,500 m2 metal manufacturing site in southern Sweden. Historic site operations included degreasing of metals and spray painting. A faulty solvent pipe resulted in a 1,4 km long diffuse plume of TCE. The volume of lost product is unknown, but in excess of 200 kg was recovered from soil in the source area between 2012 -2018.

The site is located on permeable, glacio-fluvial deposits, above a significant groundwater protection zone. Depth to bedrock, which is composed of granitic gneiss, ranges from 5 to approximately 16 m.

Fracture zones can be significant migration pathways for rapid contaminants transport. The locations of down-gradient, plume hot spots show a strong correlation with such structures. It was therefore proposed that residual NAPL may not only occur in, but also have migrated extensively downwards, with dissolved phase migrating laterally in the bedrock fracture zones.

In order to determine the potential presence of residual NAPL in bedrock, which likely constitutes a secondary source area feeding the plume, an investigation was proposed using a combination of bedrock investigation techniques.

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Geological mapping, focused on fractures in outcropping bedrock near the site, was used to develop a geophysical resistivity study of the subsurface geology surrounding the site. Three 400 metre long lines, aligned to intersect the detected fracture sets, were laid out in optimal directions along and down-gradient of the site to intercept likely target sets. Interpreted profiles from the lines indicated a major, 100m wide fracture zone directly underneath the source area which projected extension aligns with the shape of the plume. The source zone was subsequently targeted through drilling of three 40m deep bedrock borings, in which a combina-tion of NAPL FLUTe™ and FACT™ liners were inserted. These liners will show a stain where a product-bearing fracture intersects the borehole liner. The activated carbon liners collect and trap any dissolved phase product migrating in intersected fractures. The carbon is then analysed to show the relative concentration variation of contaminants down the length of the borehole. Thus, the reactive liners allow determination if, and to what depth, free phase product occurs along the intersected fractures in the boring, whereas the FACT allows determination of the depth of impacted groundwater in that location. Boreholes where staining or dissolved phase TCE occurs are scanned using an acoustic tele-viewer to identify the strike and dip of impacted fractures. The flow in fractures is measured using loggers while seasonal groundwater level fluctua-tions are monitored using Divers.This iformation is used to predict the impacted areas, and will direct additional bedrock boreholes to delineate the size and depth of the source zone.

This session describes the results of the multiple technique investi-gations and how this new conceptual model is used to design and improve product recovery from the site.

Why the US EPA is promoting the collection of time-integrated, passive indoor air samples for vapor intrusion risk assessments

Harry O’NeillBeacon Environmental Services

When determining potential health risks from the vapor intrusion (VI) of organic compounds into buildings above contaminated groundwater, indoor air samples are typically collected over 24-hour periods or less; however, research completed by Dr. Paul Johnson (Colorado School of Mines), as well as others, have determined that the temporal variability of indoor air contaminant concentrations from VI can vary by orders of magnitude over time and that 24-hour samples are likely to produce results that are not representative of actual health risks. However, using sorbent samplers to passively sample air over days or weeks provides long-duration average concentrations that overcome the uncertainty from temporal vari-ability and episodic occurrences of vapor intrusion.

An ongoing sampling program involves the collection of indoor air samples at over 600 homes during the winter seasons and employs passive sorbent samplers collecting samples over 26-day periods. The passive samplers have uptake rates that were verified to be linear out to 26 days by a robust study completed by an inde-pendent third party. This sampling approach replaced the prior sampling program that used stainless steel evacuated canisters to collect only discrete, 24-hour measurements. The ability to collect an air sample over 26 days provided a time-weighted average concentration that represents with one sample more than 25% of the entire winter season, when VI is more likely to occur at this site. By collecting long-duration samples, greater confidence was achieved that the health risks were properly assessed. Collected samples were submitted to the accredited laboratory for analysis

following EPA Method TO-17 to target a range of chlorinated compounds, as well as BTEX compounds. Results were provided within five (5) business days for each of the sampling events. Blind duplicates were submitted and a correlation coefficient (r2) of 0.994 was found between the sample pairs.

The temporal variability of indoor air contaminant concentrations from vapor intrusion can differ by orders of magnitude over time. Short duration samples collected over 24 hours are likely to produce results that are not representative of health risks and do not provide sufficient data to properly assess whether building occupants are exposed to unacceptable contaminant concentrations. The prior decade of sampling in support of this indoor air monitoring program using evacuated canisters did not alleviate the concerns that VI may be occurring even though homes consistently reported non-detects over 24-hour sampling periods. However, after three (3) seasons of employing passive samplers to collect samples over 26-day periods, the regulators are confident that homes with non-detects do not pose an unacceptable risk from VI and are being removed from the ongoing sampling program. This level of confi-dence in the data generated from long duration, time-integrated measurements will allow funds to be better appropriated to focus on buildings that do present VI risks to occupants and to fund the installation of mitigation systems where needed.

Multiple lines of evidence approach to assess chlorinated ethenes degradation during treatment with liquid activated carbon and bioamendments

Cecilie Ottosen¹; Poul Bjerg; Dorte Harrekilde; Nina Tuxen; Daniel Hunkeler; Jeremy Zimmermann; Gareth Leonard; Mette Broholm¹ Technical University of Denmark

Application of activated carbon together with biological amend-ments is an emerging technology to remediate groundwater contamination with e.g. chlorinated ethenes. These amendments are injected into the subsurface where the activated carbon sorbs the contaminants and decrease the concentration in the aqueous phase. The sorption further concentrates contaminants and bacteria together and is thereby intended to enhance the degrada-tion. Previous field investigations have documented fast reduction in dissolved contaminant concentrations in monitoring wells post injection. Though promising, this limits the possibility of differenti-ating sorption and degradation with aqueous samples.

A developing method to characterize and quantify degradation is a multiple lines of evidence approach, including novel techniques such as molecular biology tools (MBT) and compound specific isotope analysis (CSIA). Further investigations are required to assess the applicability and compatibility of these tools in the presence of activated carbon, which is complicated by the expected low aqueous concentrations.

Therefore, a research & development project was carried out at field scale applying these special techniques (MBT and CSIA) along with typical measures to assess their applicability to evaluate degra-dation of chlorinated ethenes after the application of activated carbon and bioremediation. The AC-based product applied was PlumeStop® that consist of suspended (1-2 µm) activated carbon. PlumeStop® was injected together with a culture of Dehalococ-coides and other dechlorinating bacteria (BDI Plus) and organic electron donors (HRC), as an intended barrier (12 injection wells) perpendicular to a chlorinated ethenes plume. An extensive monitoring program was carried out prior and post injection in down-gradient (54 screens) and up-gradient (26 screens) moni-toring wells.

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A laboratory treatability experiment was additionally carried out with the same monitoring parameters for process understanding in a closed system to support the assessment of the field results. The experiment revealed that equilibrium between the phases and PlumeStop is necessary before CSIA results could be used to char-acterize and quantify the degradation of TCE.

The preliminary results from the groundwater monitoring at field scale suggested effects of and interaction between transport, sorption and dechlorination. The CSIA results demonstrated that it is of high importance to understand the transport of injectates and contaminants to assess the transformation caused by the injection. Microbial analysis indicated that bacteria known to degrade the less chlorinated intermediates were not active/thriving, clarifying why the dechlorination appears to stall at cis-DCE. The multiple lines of evidence approach was necessary to evaluate the remedial action providing information the typical measures would have been unable to. The identified challenges and possibilities related to the tools and analyses will further be of use when transferred to cases with stronger sorption.

Biosensors for measuring the bioavailability of heavy metals in the remediation of biochar-amended soil

Bastian Saputra; Stephen Rolfe; Steven ThorntonThe University of Sheffield

The application of biochar to soil can reduce the bioavailability of heavy metals (HM) towards microorganisms. Adsorption of HMs to biochar can potentially decrease their toxicity, thus increasing soil function and productivity. To assess biochar performance as a soil amendment, we have developed bacterial biosensors to measure heavy metal bioavailability at the cellular level. In contrast to sequential extraction and chemical analysis, which measures HM concentrations in different soil phases, biosensors measure directly the impact of HMs on cell physiology.

The aim of this research is to develop and apply biosensors to monitor the bioavailability of HM in the remediation of biochar-amended contaminated soil. FRET (Förster Resonance Energy Transfer) is an attractive approach to report HM concentrations within living cells. The biosensor consists of a metallothionein protein (which binds Cd, Zn and Pb), placed between cyan (eCFP) and yellow (Venus) fluorescent proteins expressed in bacteria. Changes in the ratio of fluorescence emission results from binding of HMs to metallothionein and allows the quantification of HMs inside the living host cell. The FRET-MT sensor has been constructed in a bacterial plasmid and verified by sequencing. This sensor has been expressed in E.coli host cell for in vitro and in vivo characterisation. The in vitro results showed that the emission ratio increases in response to Cd (concentration range 1-5000 μM) and Zn (1-1000 μM). Preliminary in vivo tests also showed the emission ratio of the host cells changes in response to Cd and Zn and can be observed after 120 minutes exposure. However, the sensor does not respond to Pb. Future work will express the biosensor inside a host cell suitable for soil analysis e.g Pseudomonas putida, which is considered a robust host cell typically found in contaminated soil.

Following biosensor development and testing, they will be used as monitoring tools to measure the change of bioavailable HMs following biochar amendment of contaminated soil. The biosensor measurement will be integrated with an analysis of soil microbial activity and plant-bioavailable heavy metal concentrations to assess remediation performance. These measurements are expected to provide information on conditions that can enhance soil microbial activity and plant growth after biochar amendment, thus improving land quality for alternative uses.

Quantification of PCE from contaminated building materials to indoor air – Tools and NxtGen conceptual understanding

Trine Skov Jepsen¹; Per Loll¹; Martin Flyhn¹; Maria Hag²; Sine Thorling Sørensen²; Niels Døssing Overheu²¹ Dansk Miljoeraadgivning A/S (DMR A/S); ² The Capital Region of Denmark

At a test facility owned by the Capital Region of Denmark, a former dry-cleaning site heavily contaminated with tetrachloroethylene (PCE), high indoor air concentrations have been sought mitigated via (i) internal air purification and (ii) sub-slab depressurization. These measures were not sufficient and explanatory hypotheses were proposed. This presentation concerns studies associated with the hypothesis that PCE evaporation from contaminated building materials significantly impacts the indoor air.

The study purpose is to determine the importance of PCE evapo-ration from building materials to the indoor air including to see if there is a correlation between PCE content in drilling dust/concrete samples and the flux of PCE from the concrete to the indoor air. In addition, the sampling activities will contribute to elucidating the non-commonly and innovative methods: Sampling of drilling dust and foil-cover measurements.

From drilling dust sampled from the concrete slab (46 points, two depths), the walls and the foundation (10 point, two/three heights) it can be concluded that:

- No contamination is detected in walls or foundation.

- PCE is detected above 0.1 mg/kg in 12 of 48 samples from the upper part of the concrete slab. The highest detected conc. is 9.3 mg/kg.

- PCE is detected above 0.1 mg/kg in 16 of 48 samples from the lower part of the concrete slab. The highest detected conc. is 4.8 mg/kg.

- PCE extent and content in the upper and lower concrete samples is different.

From five foil-cover measurements (one over non-contaminated concrete, one over heavily contaminated concrete, two over less contaminated concrete and one over a crack) emission fluxes can be calculated and it can be concluded that:

- Mass discharge from the crack is orders of magnitude higher than the flux from contaminated concrete.

- The higher the content of PCE in the concrete the higher flux.

- From the non-contaminated concrete, the magnitude of diffusive contribution can be estimated.

- There is a good (logarithmic) fit between the concrete concen-tration and the flux.

It can be estimated that contaminated concrete contributes (in the range of 5-10 µg/m3) to the PCE-content in the indoor air. PCE evaporation from contaminated building materials is part of the reason that former actions to secure the indoor climate did not solve the problem.

Perspective and lessons learned: Sampling of drilling dust is an easy and cost-effective method to assess a possible contribution of contaminants to the indoor air. Foil-cover measurements can be performed on concrete slabs resulting in good determination of fluxes.

In a broader perspective the study shows that contaminated building materials may contribute significantly to the indoor air concentration, enlarging our conceptual understanding to next generation (NxtGen). The influence can be quantified using rela-tively simple methods.

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Thematic Session (ThS) – Topic 2 | Advances in assessment of risk and monitoring of soil, sediment and water qualityIt is expected that a general model for the correlation between concentration in concrete and flux can be developed based on further data, thus the contribution from contaminated concrete to indoor climate may be estimated based on only samples of drilling dust.

Direct distribution of soil gas in an older industrial building

Sine Thorling Sørensen¹; Maria Hag¹; Niels Døssing Overheu¹; Trine Skov Jepsen²; Per Loll²¹ Capital Region of Denmark; ² DMR A/S

At a former dry-cleaning site, heavily contaminated with tetra-chloroethylene (PCE) high indoor air concentrations have been detected. Today is it a test site is owned by The Capital Region. The indoor climate in the building has been sought remediated using (i) internal air purification and (ii) sub-slab depressurization. These measures were not sufficient. This presentation studies the distri-bution of contaminated soil gas via cavity walls and sewers as an explanatory hypothesis.

The aim is to illuminate the uncertainties in the conceptual under-standing of the various partial contributions to the indoor climate of a typical older industrial building on a polluted site, including the contribution from direct dispersal of soil gas. In addition, the study assesses whether a vacuum solution under the building can cut off the pollution contribution from direct dispersal of soil gas from sewers/downpipes and cavity walls.

The pressure gradient over the floor is primarily upward under normal circumstances(baseline). When establishing suction beneath the floor, an effect is seen in form of a negative pressure under the floor(downward gradient). Ventilation is also seen to have an effect in relation to the pressure gradient in downpipe behind the toilet, but not in other sewer installations. The pressure level in the cavity walls is not affected.

Despite increased cons. in the direct dispersion pathways which indicate penetration of contaminated soil gas from the underlying contamination, no effect on the differential pressure in the cavity walls has been detected when the negative pressure is established.

Based on tracer tests, contact between the downpipe behind the toilet and various cracks and joints in the bathroom is observed. The tracer gas is also detected in broken tiles and ventilation across the wall.

The neg. pressure solution can reduce the possible contamina-tion contribution. Current investigations do not indicate contact between soil gas and cavity walls, thus the detected PCE content is assessed to originate from either 1) impact of cavity wall with PCE from the indoor air, 2) a very limited, but prolonged air transport from the soil air resulting in an accumulation of PCE. PCE content has been demonstrated in sewers and cavity walls, and trans-ports from leaky sewers to the indoor climate is detected, but not considered to be significant, nor is the impact of the cavity wall. In general, a high concentration does not necessarily equal an active dispersal pathway.

It can be difficult to pinpoint the exact pathways of contaminated soil gas into the indoor climate. An understanding that is very important to ensure a robust solution when changing the use of existing buildings from industrial to residence purpose.

Establishing a vacuum under the floor together with logging of the differential pressure, is a cost-effective survey technique for the conceptual understanding of the soil gas contribution to the indoor climate. Combined with a tracer gas survey, a very strong study is obtained, which can be applied in both old and new buildings when conducting indoor climate risk analysis.

Pollution flux measurements as part of risk assessment for the spreading of groundwater pollution

Bert Van Goidsenhoven¹; Kurt Bouckenooghe²; Karel Biesemans³; Isabelle T›Seyen⁴¹ OVAM - Public Waste Agency of Flanders; ² Antea Group; ³ Arcadis; ⁴ Witteveen+Bos Belgium NV

Carrying out a thorough characterization of a contamination together with a well-founded risk assessment forms the basis of risk-based management of groundwater contamination.

Soil contamination poses a risk of spreading when receptors are negatively affected or when there is a risk that receptors may be adversely affected in the future. Receptors of groundwater pollution can be wells, surface water, water extraction areas or groundwater dependent ecosystems.

The characterization of the pollutant flux that is released from the total waste load and that threatens a receptor is a very relevant criterion in the context of risk assessment, remediation evalua-tion and follow-up. In the standard procedures for descriptive soil research as they exist today, no explicit attention is paid to the pollutant flux.

An evaluation based on only pollutant concentrations that were determined with active sampling has the important shortcoming that the resulting pollutant fluxes often do not correspond with the actual pollutant fluxes. Concentrations measured with active samples are after all a snapshot of one specific moment in time. For certain pollutants such as chlorinated solvents, samples sometimes show strong fluctuations in measured concentrations. Passive sampling techniques for groundwater allow samples to be taken over a long period of time. In this way a time-averaged picture of the concentrations can be obtained. In combination with a direct or indirect determination of the groundwater flux, the pollutant flux can be derived.

After a standard procedure for passive sampling techniques for groundwater was established, OVAM launched a call for soil experts to present pilot projects on the use of flux measurements. The goal of these pilot projects was to collect knowledge and experiences on the use pollutant fluxes in soil investigation.

The three pilot projects treated diverse types of pollution in different geological conditions. The results of flux measurements were compared with results of conventional sampling, keeping in mind that these different techniques measure different aspects.

The pilot projects demonstrated that flux measurements are a valuable addition in soil investigation in specific situations. Careful attention is required though in the setup and the interpretation of the results.

The presentation will give insight in the concept of pollutant fluxes, the results of the pilot projects and conclusions on the use of fluxes in risk assessment.

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Applications of the new Geoprobe® OIP systems for NAPL and tracer detection

Anders Georg ChristensenNIRAS A/S Denmark

A new class of probes (OIP-Optical Imaging Probes) from Geoprobe® are using in-situ fluorescence to identify the presence of several types of non-chlorinated residual phase NAPLs. The probes can use either excitation by LEDs with UV light or Green light depending on the type of NAPLs that are investigated. Additionally the probes can also be used for photo logging of the soil using a secondary visible light source also built into the system, as well as measure the soil resistivity using the standard EC-dipole used with most Geoprobe® direct imaging systems. The latest version of these probes combines the OIP probes capabilities with the existing HPT-system (Hydraulic Profiling Tool) and are named OIHPT probes. The system is thus now capable of simultaneously detecting the discrete depths with LNAPL and the vertical variability of the hydraulic conductivity – and this enables a very fast and efficient process for building informed and meaningful conceptual site models.

The use of various probes will be highlighted by several case studies that exhibits some of the key capabilities of the various systems.

The first case includes a very large scale delineation effort of a creosote DNAPL where the NAPL distribution is very closely linked to the interbedded sand and silt facies found in a braided flood plain. More than 70 individual OIP-logs to approx. 20 m were produced and a new and much more realistic 3D conceptual site model was build.

The second case is data from a gasoline retail station where many investigations have been completed over more than a decade. The geology is a glacially disturbed sequence of till and meltwater deposits. The OIP-UV data illustrates how the presence of the residual NAPL (gasoline) is typically not correct interpreted when using the standard auger methods for collecting soil samples and measuring the position and amount of residual and mobile NAPL phases. At this particular site the existing conceptual site model grossly overestimated the presence of the residual NAPL phase over depth, and hence also the total volume of NAPL.

The third case relates to the use of the newest OIHPT-G probe for the detection of fluorescence of a injected fluorescent tracer (Eosin) during a remediation pilot test. The simultaneously collected data from the HPT-subsystem shows a vertical hydraulic conductivity profile. The aim here was to determine how the injected water was travelling away from the injection point by detecting the dissolved tracer with cm scale vertical resolution at various directions and distances from the injection point. The results showed a very hetero-geneous distribution of the tracer that was clearly linked to the hydraulic properties – and allowed a very rapid evaluation of the potential and limitations for an injection-based remedy at the site.

Comprehensive target and non-target analyses of Hg-As compounds and organic contaminants of mining, metallurgy and demolition waste in a brownfield

José Luis R. Gallego; Luis M. Lara; Begoña Fernández; Nerea García-González; Julia Ayala; Juan María Menéndez AguadoUniversity of Oviedo

Mining and metallurgy facilities often impact the environmental compartments, especially when the closure of the productive activities is followed by a long-term abandonment. In this context,

ThS 2b | Advances in in-situ measurement and analytical techniques

Application of EnISSA-MIP at coal tar or creosote contaminated sites: Individual GCMS detection of (s)VOC’s can tackle differences in trip time in the MIP system

Pieter Buffel¹; Samuel Van Herreweghe¹; Herman Brangers²¹ EnISSA; ² Witteveen+Bos Belgium NV

A detailed and solid conceptual site model (CSM) is the key for successful site investigations and (cost)-effective remediation designs. A good understanding of the hydrogeology and contami-nant situation is essential to propose the most effective solutions and to decrease the failure risk of the remediation project. Many incomplete characterizations, especially at DNAPL contaminated sites, have resulted in serious underestimation of contaminant loads, ineffective remedial actions, exploding, never-ending costs and missed deadlines.A growing number of consultants have embraced the High Resolution Site Characterisation (HRSC) approach to increase data density and decrease uncertainties and data gaps in the CSM’s. The membrane interface probe (MIP) is an interesting tool to provide high resolution data (more detail with depth) and to create 3D image of contaminations. It can be combined with the Hydraulic Profiling Tool (HPT) or Cone Pene-trometer Test (CPT) to generate more complete conceptualization of the local geohydrology and the understanding of the storage or transport zones for the contaminants. The application of MIP in site investigation projects is limited by the detector set-up generally used by service providers. Standard systems are equipped with PID, DELCD or XSD and FID and suffer from high detection limits and sum-signals that cannot differentiate between individual chemical compounds. To increase sensitivity and selectivity of the conven-tional MIP system, the EnISSA-MIP approach has been developed. This enhanced MIP system presented at different conferences earlier, uses a modified GCMS system which is connected to the MIP system. The advantages of using a GCMS detector, are the low intrinsic detection limits of the detector and the capabilities to measure individual compounds, hence bringing the lab into the field. The high sensitivity allows the application of MIP also for plume delineation reducing both sampling costs and time in investigation projects.The present work describes the application of the EnISSA MIP system at coal tar or creosote contaminated sites located in The Netherlands, Belgium and Sweden. At this type of contaminated sites LIF techniques (UVOST,TarGost) or the recent Optical Image Profiler (OIP) can be used to deliver HRSC data in source zones. Those systems are able to detect the presence and extent of PAH contamination in soil but cannot detect concen-trations below around 100 mg/kg or the solved contaminants in groundwater. Common groundwater contaminants at MGP sites are off course BTEX and Napthalene, but also more heavy PAH’s are likely detected. Detection with a MIP system of this type of contaminant cocktails is hindered by the different ‘trip times ‘ of each compound in the trunkline resulting in elevated sum-detector signals over a stretched depth interval and misinterpretation of the MIP results. Since the EnISSA MIP approach with GCMS detection can detect each compound individually, interference of the heavier compounds can be excluded and by determination of individual trip time correction factors for the detected compounds a more accurate view of the contaminated groundwater can be delivered.

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way, but results must be waited at least for days and typically weeks.

In the present study, novel multimetal analysis method for metal concentrations of water samples was developed. The method is based on nanotechnology enhanced x-ray detection of metals. The core of the technology is a metal collecting filter build from a specific hybrid nanomaterial. The filter has a size of slightly smaller than ten euro sent coin. A water sample is pumped through the filter, which collects metal ions from the solution. The metals are concentrated to 1000 – 10000 higher ratio in the filter compared to the original water sample. The metals can be then measured straight from the filter with fast and affordable X-ray fluorescence technique (XRF) and original metal concentration of water can be calculated.

The metal collecting filters were prepared by attaching developed hybrid nanomaterial particles on a filter support to form about 200 µm permeable layer. Lake water from Kuopio Savilahti bay was pre-filtrated through 0.45 µm filter. After this, lake water was spiked with several different concentration of one selected metal between 50 ppb – 10 ppm and pH was set to about neutral. 10 ml of metal spiked lake water sample was filtrated through metal collector filter with flow rate of 1 ml / min. The metal content of the filters were measured with handheld XRF straight after the filtration from the wet filters. The experiment was repeated three times for each metal concentration and altogether for six different metals including Cu, Zn, Ni, Pb, U and Mn. The metal concentrations of different spiked samples were measured with ICP-MS before the filtration.

The XRF results measured from the wet filters correlate linearly (R2 > 0.97) with the real metal concentrations of the water samples. The results indicate that the developed method is capable of measuring broad metal concentrations ranges between 10 ppb to 10 ppm with reasonable reliability in field conditions in less than 15 min per sample. This statement was further proved by building a field portable prototype system that used the above mentioned measurements as a calibration dataset. The results from the field measurements with this prototype were comparable to laboratory ICP-MS.

Screening for 21 perfluorinated organic compounds in Czech wastewater treatment plants

Jaroslav Semerad; Nicolette Hatasova; Tomas CajthamlInstitute of Microbiology of the Czech Academy of Sciences

Nowadays, a large group of perfluorinated organic compounds (PFCs), widely found in both terrestrial and aquatic environment, are classified as emergent and often characterized as persistent pollutants. High global production of PFCs, very slow breakdown and high mobility are the main reasons why these compounds are detected worldwide more frequently. Despite low toxicity, the half-life of elimination shows the potential of PFCs to bioaccumu-late in living species. Due to this, there is a big need to monitor the potential way of introduction of these compounds to the environ-ment, as well as to monitor their subsequent fate. According to the current knowledge, some of the PFCs are also able to accumulate in sludge. However, the situation in the Czech Republic has not been monitored and evaluated yet.

The presented study deals with monitoring of the occurrence of 21 PFCs in wastewater treatment plants (WWTPs) in the Czech Republic using a newly developed and validated LC-MS method. A series of 10 WWTPs from small towns to large cities were sampled. The water (influent, effluent) and solids (sludge) were extracted (SPE and ASE), purified and proceeded to analysis.

La Soterraña site (abandoned in the 1970s) can be considered one of the most severely polluted sites in Southern Europe. It was included in one of the main Hg-mining districts in the world (Asturias, Northern Spain) and it has been deeply studied in what respects to the high Hg and As pollution found in soil, water and vegetation in its surroundings. Nevertheless, neither detailed studies of pollution sources (different types of waste) nor any description of the abandoned buildings (partially demolished) has been carried out. Therefore, a novel multi-purpose approach has been followed in order to evaluate the behavior of the different waste accumulated, and to identify unexpected contaminants by means of non-target analysis. Notably, this included not only the mining-metallurgy waste found but the construction and demoli-tion (C&D) waste as a repository of hazardous pollutants.

The brownfield area was divided in several sub-areas in coherence with the former activities that were developed within them. Forty samples of waste of different characteristics were taken, including mining, metallurgical and C&D waste of the ruined buildings in the area. These samples were subjected, in accordance with the histor-ical and environmental data previously reported and the in-situ observations, to different analytical procedures. This included target analysis such as total concentration of heavy metal(loid)s, FRX characterization, leaching/availability potential, and, for organics, quantification of PAHs, PCBs, PCDD and PCDF. Addition-ally, non-target analysis (GC-MS and Pyrolysis-GC-MS) were also carried out.

Hg (up to 16%) and As (up to 44%) extremely high concentrations were found in some of the metallurgical waste, very high levels (above 3% for As and close to 1% for Hg) were also found in the mining waste whereas C&D materials also presented significant concentrations specially in the old chimneys and in demolition waste. In all cases As showed higher availability and leachability than Hg. Regarding organics, PAHs and PCBs were found in levels above threshold limits in some types of waste. Overall, non-target analyses offered also very remarkable information, such as the presence of highly toxic and unexpected Hg organo-compounds (phenylmercury derivatives), the identification of arsenic oxides (Arsenolite) and the pyrogenic origin of the PAHs.

This work suggests that not only mining or metallurgical waste stock-piles but also C&D waste should be analyzed to manage hazards in long-term abandoned brownfields. It is also pertinent to conduct multi-characterization of inorganic residues, followed by a screening for organic contaminants. We recommend such an approach for the reexamination of these sites as a prelude to accurate risk assessment studies and the implementation of clean-up approaches.

On-site analysis of metal concentrations of natural waters

Tuomo NissinenUniversity of Eastern Finland

On-site and real-time monitoring of low metal concentrations from waters is still problematic. The laboratory devices remain to be the primary techniques utilized for this purpose. The measurement includes sampling on-site, delivery of the samples to laboratory, preparation of the samples and measurement with inductively coupled plasma mass spectrometer or optical emission spec-trometer (ICP-MS or ICP-OES). These measurements are expensive, because of various steps, valuable devices and working hours of educated personnel required. Moreover, real-time information from the metal concentrations of waters cannot be obtained this

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elevation were only a few centimeters. Sediments at the site were shown to be relatively stable over time, with little net sedi-mentation or erosion, although there is likely periodic small-scale sediment movement and elevation changes.

ThS 2c | Soil-sediment-water interaction and system dynamics

Transport, fate and risk assessment of groundwater contaminants discharging to a stream: Novel approaches and current understanding

Poul L. Bjerg¹; Vinni Rønde¹; Nicola Balbarini¹; Majken Frederiksen¹; Anne T. Sonne¹; Mackenzie Cremeans²; John Frederick Devlin²; Michael D. Annable³; Philip J. Binning¹; Ursula S. McKnight¹¹ Technical University of Denmark; ² University of Kansas; ³ University of Florida

Contaminants such as chlorinated solvents, pharmaceuticals and pesticides, as well as emerging micropollutants are released to streams from multiple point and diffuse sources. Sustainable management of water resources requires assessment of multiple contamination sources within a watershed in order to assess their direct impact on water quality. Determination of flow paths and groundwater fluxes are essential for evaluating the transport, fate and potential impact of contamination discharging to streams. This implies that investigators have the tools to evaluate the governing parameters, including an appreciation of the scale of variability, as well as conceptual and numerical models that incorporate the various mechanisms affecting flow, transport and fate. A major multidisciplinary field-scale investigation of the Grindsted stream area was carried out in 2012-2018 to develop the scientific basis for conducting risk assessments for contaminated sites impacting groundwater and stream water. The contamination originating from a former pharmaceutical industry discharges into a multilay-ered aquifer system and a downgradient stream. The groundwater plume contains high concentrations of pharmaceutical compounds, chlorinated ethenes and benzene. The contamination in the source area has been depleted and today the main challenge is related with the complex plume discharging into the stream. The main impact zone is located within a mixed land-use stream system, comprising urban areas and agricultural production, with multiple chemical stressors impacting the stream corridor.Our overall aim of the field investigations was to (i) advance our understanding of transport and fate of chlorinated ethenes and pharmaceutical compounds in a multilayered aquifer-stream system; (ii) test the applicability of different methods for mapping groundwater flow and pollution as it enters a stream at a complex site; (iii) perform a risk assessment of the stream using the contaminant mass discharge approach; and (IV) assess the stream’s chemical and ecological status in a multiple stressor context.The study included development of geological and hydrogeological models, geophys-ical measurements, numerical modeling of the flow and transport, mapping of the contaminant plume at various scales, and detailed field investigations at the main entry point of the plume into the stream. We quantified the flow, contaminant mass discharge and attenuation of the plume at the groundwater-surface interface using different approaches and innovative tools. The transport and fate of pharmaceutical compounds in the plume were addi-tionally assessed by statistical methods, analyzing the historical development and the current state of the plume and a literature review. Finally, the stream system was risk assessed by chemical

The results showed that 10 perfluorinated carboxylic acids (PFCAs) in the concentration of 2–101 ng/g, perfluorooctane sulphonate (PFOS) and other sulphonates in concentrations of 2–38 ng/g even in the sludge from small-town WWTP were found. Some of the compounds were detected in influents in concentrations several times lower than in the respective sludge samples which supports a theory of sorption on sludge. However, some of the sulphonates and PFCAs were also detected in the effluent from WWTP which indicates an insufficient treatment process. The results of this first screening of PFCs in the Czech Republic emphasize the need for deeper and more extensive monitoring and identification of potential sources of their origin.

Use of a fiber optic temperature sensor system to evaluate EMNR/MNR at a sediment remediation site

Thomas Van Hoestenberghe¹; Philip Spadaro; Jessica Winter-Stoltzman²; Roel Vanthillo¹¹ Fluves NV; ² TIG Environmental

The site is a shallow tidal inlet channel located in San Francisco, CA, that has been filled with construction debris and other materials leaving a narrow channel. Investigations identified polychlorinated biphenyls (PCBs) and lead as contaminants of concern (COCs) in sediments at the site. The Environmental Protection Agency-approved remedy allows enhanced monitored natural recovery (EMNR) or monitored natural recovery (MNR) to be employed, in lieu of dredging and capping, in areas where COC concentrations in surface sediments are marginally above remedial goals and technical studies can demonstrate short- and long-term effective-ness. A reliable assessment of the stability of the surface sediment layer and current site-specific sedimentation rate was needed to evaluate the potential for EMNR/MNR to be successfully employed at the site. Field data collection required measuring sedimentation rates of approximately 1 cm/yr. Traditional methods (such as time-series bathymetric surveys or sedimentation pins) do not meet the accuracy required for this project within the time frame, and the results of radioisotope methods are not deemed reliable because historical fill placement has disturbed the stratigraphy. TIG Environ-mental employed a novel fiber optic temperature sensor system at the site to evaluate sedimentation and erosion in combination with sedimentation pins and a marker horizon layer.

The fiber optic temperature sensor system consisted of a fiber optic cable laid in the sediment that measured temperature changes to determine whether the cable was surrounded by sediment or water. The cable was wrapped around a pole to enable measurement at different elevations. The vertical accuracy of the measurements was 4 mm. This approach allowed detection of changes in sediment elevation over time at multiple points along the length of cable. This method has been employed at several sites in Europe to evaluate sedimentation associated with mainte-nance of rivers and offshore wind farms, and at a site in the United States to evaluate groundwater leakage through capping layers. Informal research shows this method has not been utilized as part of a sediment remediation project. As part of this study, more than 2,000 m of cable were installed in a loop from the upland power source through five poles at various in-water locations. Measure-ments were taken twice daily (at high and low tide) for a six-month period. Sedimentation pins and the marker horizon layer method were also used to collect information on sedimentation rates at co-located points.

Measurements showed a slow increase in sediment elevation at three of the five locations, and a slow decrease in sediment elevation at two of the locations. Overall, changes in sediment

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Turnover of organic matter in river sediments - The BIOMUD project

Julia Gebert; Florian ZanderDelft University of Technology, Faculty of Civil Engineering & Geosciences

Turnover of sediment organic matter under reducing conditions leads to the formation of methane, carbon dioxide and others gases. Gas bubbles in sediments obstruct sonic depth finding and impede sedimentation and consolidation, reducing the efficiency of maintenance dredging. Disposal and beneficial use of dredged sediments are affected by the evolution of gas, e.g. through reduction in sediment density, viscosity and shear strength and thereby increased susceptibility of subaquatic constructions or backfills towards erosion. On land, depletion in organic matter causes mass loss and possibly undesired subsidence. Further, methane is a potent contributor to global warming. Release of methane from subaquatic or land-based disposal sites enhances anthropogenic greenhouse gas emissions, poses a threat to human safety and, in the case of landfills, requires collection and treatment of the landfill gas.

Magnitude and rate of gas generation are a function of the content and degradability of sediment organic matter and are therefore subject to spatial and temporal variation on different scales. The project BIOMUD (www. MUDNET.eu) aims to quantify differ-ently degradable organic carbon pools in port sediments, to link organic matter turnover to sediment rheological properties and to predict organic matter degradation from sediment properties that can be more easily analytically determined. Hereby, fundamental questions are directly linked to applied dredging practice as carried out in all major ports worldwide.

The presentation shall highlight the results from one full year of investigating the spatial and temporal variability of sediment properties and organic matter degradation, carried out in a down-stream-upstream transect in one of Europe’s largest ports, the Port of Hamburg.

How influence metal concentrations in soils and in river beds the metal accumulation in a reservoir?

Christian Opp¹; Jens Hahn; Raphael Ganzenmüller; Anntke Ewert¹ Philipps-Universität Marburg

Reservoir sediments frequently act as sinks for arsenic and heavy metals. The fluvial heavy metal input into a reservoir is a result both of erosion and transport of soils in the catchment and the re-mobi-lization from floodplain sediments. To study these relationships, a field survey of soil and sediment samples has been carried out in the catchment of the Klingenberg reservoir in the German Ore Mountains.

All samples were air-dried, homogenized in a porcelain mortar and sieved (< 2 mm) before analyses. Soil and sediment acidity was analyzed by stirring the samples in distilled water and adding KCL according to DIN (2005). After a reaction time of two hours, the pH value was determined with a glass electrode. For the grain size analysis the organic components were removed by heating the samples in H2O2 for two hours. After the substrates were converted to suspensions, Na4P2O7 was added to reduce the cohesion effects of the fine particles. The proportions of the sand fractions were calculated by wet sieving (DIN 2002), the particle fractions < 63 µm were determined by x-ray sedimentation analysis (Micromer-itics, SediGraph 5100, Aachen/Germany). The soil samples were

and ecological methods in relation to other potential sources impacting the streams.Our current understanding of the attenua-tion processes for key contaminants in the aquifer, the hyporheic zone and stream, the value of the innovative field methods applied, and the benefit of the contaminant mass discharge for risk assess-ment will be discussed in the presentation.

Lower metal fluxes from fiberbank deposits than expected

Paul Frogner-Kockum¹; Anna Apler; Sarah Josefsson²; Ian Snowball¹ Swedish Geotechnical Institute; ² The Geological Survey of Sweden (SGU)

Environmental legacies of pulp and paper industry are of global concern and include deposits of contaminated fibrous materials that exist in waterbodies and alter aquatic ecosystems. Historical industrial activities led to parts of the Swedish northern coastal zone to be covered by deposits of so called fiberbanks or fiber rich sediments. This study contributes to an initiative to expedite remediation of contaminated sediments, specifically to develop methods that may be useful in site characterization and environ-mental risk assessment. Previous surveys of fiberbanks and fiber rich sediments found concentrations of hazardous substances, such as PCB, DDT and toxic metals such as Pb, Hg and Cr, that are above national background levels and contravene environmental quality objectives. We report the outcome of novel in-situ benthic flux chamber measurements that were carried out at two pilot sites, Sandviken and Väja (in the estuary of Ångermanälven at the Baltic Sea, Sweden) to determine fluxes of metals from fiberbank deposits and fiber rich sediments.

We obtained fluxes for Co, Mo, Ni and Zn and were able to compare fluxes with model predicted ones and to metal concentrations in fiberbanks. Eventhough Pb, Hg and Cr occur in relative high concentrations in fiberbanks compared to national background levels, no fluxes of Pb, Hg and Cr were detected. It may partly be explained by lack of quantifiable Pb and Hg levels in porewaters of fiberbanks at Sandviken and Väja (Apler et. al., 2018). It may also be explained by estimated sediment-water distribution coefficients (KD) for metals that shows on a high sorption for Pb to solid phases in the Sandviken fiberbank and on a high sorption for Cr to the solid phases in the Väja fiberbank (Apler et. al., 2018). It should be mentioned that Pb sorption to the solid phases always was higher than for other metals at all sites where it was quantifiable (Apler et. al., 2018). The lack of quantifiable Hg in porewaters may also be explained by Me-Hg formation as a concequence of prevailing reduced conditions in fiberbanks. It is thus likely that Pb and Cr are transported particle bound from eroding fiberbanks while Me-Hg likely is transported from fiberbanks via bacteria and then further through plankton, invertebrates to vegetative fish and predatory fish. (Wiener et al., 2003). Consequently, a lower metal flux then expected was found from fiberbanks especially with respect to toxic metals, and significant differences between observed metal fluxes and model predictions. We thus demonstrate that it is appropriate for risk assessment of contaminated sediments to complement metal content in fiberbanks with in situ flux measurements.

Apler A., Snowball, I., Frogner-Kockum, P., Josefsson, S., Distribution and dispesal of metals in contaminated fibrous sediments o findustrial origin, Chemosphere 2015: 470-481.Wiener J.G., Krabbenhoft D.P., Heinz G.H., and Scheuhammer A.M., 2003, “Eco-toxicology of mercury,” Chapter 16 in Hoffman D.J., B.A. Rattner G.A. Burton Jr., and J. Cairns Jr., eds., Handbook of Ecotoxicology, 2nd edition.: Boca Raton, Florida, CRC Press, p. 409-463.

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Within the research program Applicera, we have developed a Triad based framework for site specific ERA where a multi-criteria analysis tool, SF-Box, is used to assess the potential soil quality at each individual sample location. This information allows us to cate-gorize the soils into five different soil quality classes. Results from ecological and toxicological measurements made at contaminated sample locations are compared with results from “clean” locations within the same soil class. Indicators for assessing the potential soil quality involves soil texture, content of coarse material, organic carbon content, available water, C/N, pH and available phosphate.

The combined Triad/SF Box framework for ERA was applied on a former industrial site severely contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals (Cu, Zn, Pb). In order to account for bioavailability we analyzed pore water concen-trations of PAH (Arp et al. 2014, Env. Sci. Tech. 48, 11187−11195), which were compared with water based critical limit values (Verbruggen, 2012, RIVM report 607711007). Bioavailability-corrected critical limit values for metals were obtained with the Soil PNEC calculator (www.arche-consulting.be). Toxic pressure values, corrected for bioavailability, were calculated for each sample location. A suite of ecological and toxicological measurements, including soil fauna characterization, DNA-based characterization of key enzymes involved in the nitrogen cycle, multi-substrate induced respiration and the Microtox bioassay were made on a total of 50 sampling plots.

An ERA based on a comparison of total concentrations with generic SQS indicated a severe risk for the soil ecosystem over the whole investigated area. In contrast, when applying the Triad/SF Box framework, the area with a potential risk was reduced to a small fraction (< 5%) of the total area. Limited bioavailability of bulk contamination was the major explanatory factor for the reduction in assessed ecological risk. The proposed framework seems to be robust with small differences between the three lines of evidences.

Linking bioavailability of complex chemical mixtures to toxicity changes to assess recovery of multi-contaminated soils

Sabrina Cipullo¹; Ilaria Negrin¹; Leila Claveau¹; Boris Snapir¹; Stacie Tar-dif²; Coren Pulleyblank³; George Prpich⁴; Pablo Campo¹; Frederic Coulon¹¹ Cranfield University; ² University of Copenhagen; ³ Dublin City University; ⁴ University of Virginia

A six-month laboratory scale study was carried out to compare biochar and compost techniques for the remediation of soil contaminated with tar. Soil samples were collected from two brownfields (Soil 1 and Soil 2) occupied by former gasworks sites in UK, and amended with 15% w/w commercial compost (C), 5% w/w biochar (B), or left with no amendment. Total and bioavailable concentrations of hydrocarbons and heavy metals were monitored throughout a 180-day incubation period. To define remedia-tion endpoint and to link bioavailability to toxicity changes, a different range of biological indicators for hazard assessment have been taken into account such as bacteria count, soil respiration, microbial biomass, microbial community fingerprint, seeds germi-nation (Mustard (B. alba), rye grass (L. perenne), pea (P. sativum)), earthworms lethality (E. fetida), and bioluminescent bacteria (Vibrio fischeri) with Microtox® assay.

Compost amendment enhanced the degradation of both the aliphatic and aromatic fractions in the two soils, while biochar contributed to lock the hydrocarbons in the contaminated soils. Specifically, total petroleum hydrocarbon concentration decreased by 46% and 30% in Soil 1 and Soil 2 amended with compost. These

examined for ammonium-nitrate and aqua-regia-extractable concentrations of arsenic (As), cadmium (Cd), chrome (Cr), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn). The concen-trations of the diluted aqua regia and ammonium-nitrate extracts were determined by ICP-mass spectrometry (X-Series 2, Thermo Fisher, Dreieich/Germany). Element concentrations were calculated as the mean value of three repeated measurements per sample. The results were rejected if the mean concentration exceeded the standard deviation of 10 %.

The metal concentrations of the soils have been compared to concentrations in local riverbed sediments and in the Klingen-berg reservoir sediments. The catchment’s soils were slightly enriched by Cd, Pb, and Zn, while the other elements showed normal concentrations. Cd and Zn in particular were characterized by high mobilized fractions. The mean heavy metal concentra-tions in riverbed sediments were higher than in catchment soils, while reservoir sediments stored the highest amounts of the analyzed elements. Comparing the metal concentrations of the soils, riverbed sediments, and reservoir sediments, small differ-ences were detected for Cr, Fe, Mn, and Ni, while As, Cd, Pb, and Zn showed strong differences. For Cd and Zn, which are comparatively enriched mostly in riverbed and reservoir sediments, a signifi-cant release from acidic catchment soils by leaching processes can be concluded. The accumulation of As and Pb in the reservoir sediments was probably influenced by soil erosion and by anthro-pogenic or chalcogen sources in the catchment. Vertical variations of the element concentrations in the reservoir sediments indicate a gradual regression of the input of most of the studied elements in the recent past.

ThS 2d | Human health and environmental risk assessment

A Triad based framework for ecological risk assessment (ERA) that accounts for inherent soil quality effects

Dan Berggren Kleja¹; Anja Enell¹; Charlotta Tiberg¹; Pär-Erik Back¹; Sara Hallin²; Christopher Jones²; Astrid Taylor²; Anke Herrmann²; Jana Weiss²; Karin Wiberg²; Maria Viketoft; Maria Larsson³; Lars Rosén⁴; Yevheniya Volchko⁴¹ Swedish Geotechnical Institute; ² Swedish University of Agricultural Sciences; ³ Örebro University; ⁴ Chalmers University of Technology Gothenburg

Soil quality standards (SQS) based on total contaminant concen-trations are frequently used to assess ecological risk. However, these values are generally conservative by nature and may over-estimate risk when applied to specific sites. Accordingly, there is a great need to develop robust, applicable frameworks for site-specific ecological risk assessment (ERA). During the last decades, there has been a growing interest in the Triad approach, which recently was adopted as an ISO standard (ISO 19204:2017). Triad is an optimized weight-of-evidence approach, where the results of chemical analyses, toxicity testing and ecological measure-ments are combined into a single risk value. Two major challenges with the Triad method are 1) accounting for the bioavailability of contaminants, and 2) how to find appropriate reference conditions for ecological and toxicological measurements. The latter is crucial for being able to differentiate between the contaminants’ effect on soil biota and the soil quality effects (other than those related to the contaminants).

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Thematic Session (ThS) – Topic 2 | Advances in assessment of risk and monitoring of soil, sediment and water qualitydecreases were accompanied by a reduction of 78% (Soil 1) and 6 % (Soil 2) of the bioavailable hydrocarbons and the most signifi-cant decrease was observed for the medium to long chain aliphatic compounds (EC16-35) and medium molecular weight aromatic compounds (EC16-21). Neither compost nor biochar affected the distribution and behaviour of the heavy metals and metalloids, suggesting that the co-presence of these elements posed a low risk.

Soil 1 (C) and Soil 2 (C) displayed the most significant reduction in toxicity to both microbial indicators (increase in soil respiration rate along with a more stable microbial fingerprint) and ecotoxicolog-ical assays (increase in germination rate, as well as a net decrease in toxicity for the bioluminescent bacteria).

Ultimately, strong negative correlations were observed between the organic and inorganic contaminants bioavailability and the responses in the microbial and ecotoxicological assays; suggesting that when bioavailable concentrations decreased, the toxicity also decreased. This study reinforces the idea that an integrated approach can provide multiple lines of evidence to support the risk characterisation and assess the remediation end-point.

Polluted sites. French methodology,example of a best practice

Charline Darracq; Aurélie BlusseauARCADIS France

In France, the management of polluted sites is guided by the meth-odology dated February 2007, updated April 2017. The priority is to treat concentrated pollution (hot spots), wherever technically and economically feasible, rather than doing risk calculations for human health in order to demonstrate that this pollution can remain in place. This methodology is different from that used in most other European countries. The goal of this presentation is to explain the methodology and illustrate it using a case study.

To anticipate and reinforce the management of the residual impacts of pollution after remediation, collaboration with the different stakeholders helps to ensure that the development project will be compatible with the residual pollution on site (from a human heath perspective).

This methodology will be illustrated by a case study regarding the construction of a school in Grenoble. This redevelopment of a polluted site has been accomplished thanks to the cooperation of the various stakeholders. Between 2011 and 2013, environ-mental investigations and HHRA (human health risk assessment) concluded that the redevelopment into a school was possible with the known environmental quality. In 2014, construction plans were modified: buildings were moved to an area where no construc-tion was initially planned and no investigation was performed. Complementary investigations were performed and disclosed the presence of chlorinated solvents in soils and soil gas.

In accordance with the French methodology, concentrated pollution areas were identified by a variety of tools (complemen-tary investigations, statistical analysis, mass balance analysis, iso-concentration maps). Based on these results, first threshold values (not based on HHRA) and remediation areas were proposed in soil and soil gas for PCE to guide the remediation works, in terms of mass removal. Given the sensitive context of the development project, collaboration between the French Administrations (called DREAL and ARS), the Mayor Office as well as the developer and the architect, has enabled the improvement of the project (crawl space, ventilation ...)

Furthermore, a HHRA was performed to verify if the remedia-tion works, after the mass removal, would need to be driven by health criteria. This study concluded that in the western part of the building, the remediation works had to be driven by health criteria. Therefore, a Maximal Admissible Concentration (MAC) was proposed in soil gas.

Based on the mass removal threshold values and the MAC, a final remediation area was proposed in soil and soil gas for PCE to guide the remediation works. A cost-benefit analysis and treatment trials concluded that regarding the planning of construction of the school, the best option for remediation was the excavation and the treatment of the impacted soil in a ventilated biopile.

After remediation works, soil gas concentrations were below MAC. In addition, ambient air within the crawl space of the building conformed to threshold values. Ambient air monitoring inside the school was performed by the Mayor Office to ensure that the air quality was in accordance to threshold values.

Mercury transfer through the food web of the three-spined stickleback (Gasterosteus aculeatus)

Vyshal Delahaut¹; Ines Silva Casinhas; Lieven Bervoets; Federico Calboli; Filip Volckaert; Gudrun De Boeck¹ University of Antwerp

Mercury is considered as one of the top priority chemicals by the WHO and is a pollutant of global concern due to its capacity to travel long distances through the atmosphere. Nowadays, point sources of mercury pollution in Flanders are rare but certain regions are still contaminated as consequence of historical pollution. Microbes can convert inorganic mercury to a methylated form which is biomagnified through the food chain and has strong neurotoxic properties. The actual risk of transfer of environmental mercury to biota is highly dependent on physicochemical proper-ties of the water and sediment since they influence methylation processes and bioavailability. Profound knowledge on the matter of bioavailability remains scarce due to the complexity of mercury speciation and sensitivity of mercury analysis. This study was setup to gain a better understanding of mercury bioavailability and the transfer through the food chain of the three-spined stickleback (Gasterosteus aculeatus). During a preliminary field study within the Scheldt and Maas basin of Flanders, 8 stickleback populations characterized by both high and low muscle mercury content were identified. Subsequently, water-, sediment-, macroinvertebrate- and fish samples were collected and analyzed for total mercury concentration and additional physicochemical properties (water and sediment). Biota-sediment magnification factors (BSMFs) were calculated as a proxy for mercury bioavailability for benthic macroinvertebrates. Differences between populations in terms of bioaccumulation as a consequence of dietary mercury exposure was evaluated via estimated biomagnification factors (BMFs). The total mercury load within one specific river was positively corre-lated with organic matter content (R= 0.77) and smaller grain sizes (R=0.52), while samples with a higher percentage of sand had less mercury (R = 0.80). Organic matter content (R=0.67), a larger clay (R=0.62) and silt (R =0.57) fraction and higher acid volatile sulfide concentration (R=0.79) in the sediment did decrease the overall bioavailability of mercury for sediment dwelling invertebrates. The BMFs of the low-contaminated populations were close to or even below 1. On the contrary the biomagnification factors of highly polluted populations ranged from 2-4. The observed differences in mercury biomagnification between distinct populations of the same species is an interesting finding and possible explanations are currently being explored.

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Thematic Session (ThS) – Topic 2 | Advances in assessment of risk and monitoring of soil, sediment and water qualityTo use or not to use: Handling sewer overflow sludge

Kim Dieleman¹; Marc Bethlehem²; Marloes Luitwieler¹¹ Bioclear earth; ² Waterschap Noorderzijlvest

Sewer overflow sludge is sludge removed from ditches and canals in close proximity to a sewage overflow. In case of heavy rainfall, the sewage system overflows, exposing the environment to possibly contaminated water. In the Netherlands, it is assumed that sewer overflow sludge is contaminated with pathogenic microorganisms or pollutants. Therefore, it cannot be used for the same purposes as normal sludge. It must be disposing of it in landfill sites. However, water board Noorderzijlvest thinks some overflow sludge is clean enough to be used sustainably. In early 2017, they published the Waterbodembeleidsplan 2017-2027, making it possible to use this overflow sludge.

To test this hypothesis, a pilot was conducted to investigate whether there are risks to applying overflow sludge on land. Two depots were set up in October 2017, one containing clean (reference) sludge and one containing overflow sludge. During 1 year the effects of drying on pathogenic microorganisms and drug residues was tested. If there are no additional risks when using overflow sludge versus clean sludge, the water board plans on using overflow sludge in dikes, on industrial sites or under roads.

Both the depot with clean and overflow sludge were monitored over the course of one year. During this period, samples were taken at four time points and analysed on the following parameters:

• Broad screening for drug residues in sludge and drain water.

• Pathogenic microorganisms, based on culturing of sludge and drain water.

• Relevant pathogenic microorganisms, based on viable-PCR. Next Generation Sequencing was carried out, mapping the complete microbiological population of the sludge, defining relevant microorganisms.

• Antibiotic resistance, based on ESBL-culturing of sludge.

• Hormonal disruption, based on ER-Calux to determine the estrogenic activity in sludge and drain water.

Several drug residues and other biologically active compounds origi-nating from personal care products were found in both the clean and overflow sludge, like clozapine, salicylic acid and gentisic acid, dipyridamole, metoprolol and propranolol and triclocarban. The concentrations of these compounds were found to be similar in both depots after 12 months. No residues were measured in drain water.

The microorganisms Clostridium perfringens, Enterobacteriaceae, E. Coli, and Turicibacter sanquinis were found in similar numbers in both depots. There was no indication of antibiotic resistance in both depots based on ESBL-culturing. No pathogenic microor-ganism or drug residues were found in the drain water from the overflow depot. In the overflow sludge, low hormonal activity was measured at six months, being lower than the proposed standard for drinking water and slightly above the proposed standard for ecology.

Based on results, reuse of overflow sludge may be increased instead of disposing of it in landfill sites. At AquaConsoil we will present the results of the pilot project, discussing the choices made, setup of the depots and the results of the analyses and the implications of the results on the use of sewer overflow sludge.

How to deal with a “cocktail” of contaminants - Risk assessment as a key tool for effective remedial strategy implementation in the new regulatory framework

Glauco Giordano; Jacek WojciechowskiARCADIS Sp. z o.o.

Since 1952, the production of organic and inorganic raw materials, chemical agents and solvents at a chemical Site located in Silesia Province, in Southern Poland, has resulted in significant soil and groundwater contamination.

The heavy environmental legacy of the communist era includes a wide range of heavy metals (mainly Mercury and Cadmium) and Chlorinated Hydrocarbons (mainly Chloromethanes), but also BTEX, Cyanides, Chlorobenzene, Bromobenzene and PAH locally occur.

Through multiple site investigation phases, including GPR Survey, borehole drillings coupled with soil, groundwater and soil gas sampling as well as using high-resolution characterization tools like the Membrane Interface Probe (MIP) (which is rarely used in Poland), the “cocktail” of contaminants has been assessed and delineated within a complex geological framework. Below a 1m thick layer of made ground, the subsurface consists of glacial deposits, i.e. sandy and silty clays interbedded with silty sand soils. Two separate water-bearing horizons occur respectively in the sandy layers and underneath in permeable lenses within the silty-clayey material up to about 20 m below ground level.

A robust Risk Assessment model has been implemented by RBCA Tool Kit and US EPA Vapor Intrusion modules, representing an inno-vative challenge in Poland, since a risk-based approach was only introduced in 2014 and is not yet supported by any methodolog-ical guidance.

The model, targeted at assessing human health and environmental impacts, was built up based on multiple scenarios, in order to comprehensively address the distribution of contamination in the various source areas and in the different geological layers. Indoor air and groundwater exposure pathways were found to be the most critical pathways for the identified receptors, but also potential direct exposure by dermal contact, dust inhalation or accidental ingestion of contaminated surface soil cannot be excluded.

Mercury and Cadmium are the key contaminants of concern for the direct routes of exposure, while Mercury, Trichloromethane and Tetrachloromethane pose potential hazards for vapor intrusion. As concerns the groundwater plume, mainly Trichloromethane and Tetrachloromethane have been highlighted as potentially posing risk to off-site human and environmental receptors.

Based on RBCA Tool Kit backward-mode, site-specific target levels for each contaminant have been calculated, to be thereafter used as cleanup levels for the further remedial actions.

Human health and environmental risk assessment was confirmed to be an indispensable tool for a quantitative, comprehensive approach to environmental issues, capable of highlighting the key contaminants of concern effectively posing risk for receptors in a complex geology, assessing the areas and maximum depths where remediation is needed and providing final remedial goals for soil and groundwater.

Key model outcomes represent an action platform capable of supporting the stakeholders in the development of the most suitable environmental Site exit strategy and to help the authority in a complex decision-making process within a local regulatory framework still under strong development.

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Thematic Session (ThS) – Topic 2 | Advances in assessment of risk and monitoring of soil, sediment and water qualityIndustrial scale destruction of old chemical ammunition of the Great War on the western front the hundred-year-old forgotten contaminations

Daniel HubéBRGM

During the Great War, ammunition had been used on an unprec-edented scale. When hostilities ceased, huge ammunition dumps remained. Unexplosed ordnances were collected on former battle-fields too. There was an urgent need to dispose 2.5 to 3 million tons of hazardous ammunition during the interwar period. New methods for safely breaking down chemical shells were then developed by civilian companies when the army demobilized. This also offered the possibility of recovering valuable materials, and was a source of profit. After defusing, the rounds were emptied by perfora-tion when the toxic contents were liquid, by steam or hot-water washing-out for TNT explosive shells and by open-burning for both chemical and explosive shells. These processes caused severe top soil contaminations especially on former burning-grounds of chemical shell. Recent research has been conducted on 9 burning-grounds in France and Belgium. To this day, no vegetation grows at some locations due to extreme high grade of heavy metal (Zn, Pb, Cd,…), ranging for Zn from 10 to 100 g/kg DM, chlorinated and /or brominated dioxin & furan (1 000 to 4 000 000 ng/kg DM), and arsenic (2 to 110 g/kg DM) when arsenical “Blue Cross” shells loaded with the sternutators diphenylchlorarsine (CLARK 1) and diphen-ylcyanoarsine (CLARK 2) were open-burned. Inorganic arsenical compounds are associated with organic by-products produced by the oxidation (diphenylarsinic acid) or thermal decomposi-tion (triphenylarsine, As-PAH like phenylarsafluoren) of CLARKs. Brominated dioxin, energetic compounds (TNT, nitronaphtalin) and thianes (impurities of yperit) have been measured too. High resolution geomagnetic measurements had been conducted on a site where 1,5 million old chemical shells have been destroyed during the interwar period in Spincourt, near Verdun, leading to severe top-soil contamination, the contamination of the barley that try to grow on the spot, crops and meat destructions and the sequestration of the ground. Open-detonation pits and systems of burning trenches have been recognized and carefully probed using a backhoe under high security constrains. To this end, food products of plant and animal origin were sampled in 2015-2016 and contaminant analyses were conducted. Human exposure was assessed using a tiered approach. Exposure to site-specific contam-inants through the consumption of foodstuffs produced locally on the considered site was unlikely to be a health concern. However, as for inorganic arsenic, given the presence of highly contami-nated zones, it was suggested that cereals should not be grown on certain plots. Two sites will be decontaminated because of the up-take of pollutants by crops (barley) or fresh water pollution caused by run-off. Spincourt is an example of the ignorance of soil contamination left behind by WWI in land-use planning. Further research is needed to assess these forgotten contaminations and sites and theirs related environmental risks.

Mixture exposure to PFAS: A relative potency factor approach

Johannes Lijzen¹; Marco Zeilmaker¹; Eric Verbruggen¹; Bas Bokkers¹; Ellen Brand¹; Hans Slenders²; Tessa Pancras²¹ National Institute for Public Health and the Environment (RIVM); ² Arcadis Netherlands

PFASs comprises a large group of poly- and perfluoroalkyl compounds. They have a dirt-repellent effect and are therefore used, for example, in finishing clothing. Their use is very versatile, they are being used in many industrial and household applica-tions. The two best known PFAS; PFOA and PFOS, have been studied intensively and much information is available, including the threshold for the quantity of PFOS and PFOA that people may be exposed to without causing negative effects on health.

In 2016, RIVM derived such a quantity for PFOA. However, much less is known about most of the other compounds in this group of substances. PFASs often occur together as contamination in soil, groundwater or drinking water. To be able to better assess the risks of this type of contamination, the RIVM has investigated the extent to which it is possible to express the harmfulness of a number of PFASs in relation to PFOA. It was concluded that this can be done by using so-called Relative Potency Factors (RPFs). A method is presented to assess the total toxicity of PFAS for mammals and humans based on a Relative Potency Factor of individual compounds compared to PFOA. The exposure to a PFAS-mixture is expressed as a compa-rable amount of PFOA. The use of the RPF method does, however, have an important condition, namely that a (limited) set of compa-rable toxicity data for individual PFAS compounds is available. For the relevant health effect (on the liver of test animals), such infor-mation was available for 11 PFAS compounds. The liver reacts most sensitively to PFOA in humans and laboratory animals. The effect is an enlargement of the liver (hypertrophy), which is an unwanted effect. Because kinetic characteristics of PFAS in animals generally are paralleled in man, as a first tier, it is concluded that the derived RPFs hold for humans as well. Based on liver toxicity data RPFs have been derived for 8 PFCAs (PFBA, PFHxA, PFNA, PFUnDA, PFDoA, PFTeA, PFHxDA, PFODA) and 3 PFSAs (PFBS, PFHxS, PFOS).

The RPF-method can be used for dealing with pollution with PFASs in the environment, e.g. in cases involving contamination in soil, groundwater or drinking water. Measured PFAS quantities are simply expressed in PFOA units, so that they can be compared with PFOA standards for soil or (drinking) water.

Vapor intrusion study in a densely populated residential area (Mechelen, Belgium) impacted by a soil and groundwater pollution of turpentine and chlorinated ethenes beneath private homes

Kurt Bouckenooghe¹; Sylvie Seurinck¹; Tim Caers²¹ ANTEA Belgium; ² OVAM - Flemish Waste Agency

A vapor intrusion study is currently ongoing in a residential area in the city center of Mechelen (Belgium). Soil and groundwater are polluted with turpentine and chlorinated ethenes. LNAPL is also present. The pollution originates from a former dry cleaner and is situated beneath streets and houses without gardens, therefore very challenging to remediate. The former dry cleaning site is owned by the Flemish Waste Agency (OVAM).

From February 2013 until January 2017 the pollution was treated by means of soil vapor extraction and multiphase extraction. A high mass of pollution was already removed but the removal rates

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Developing a Flemish risk assessment tool for contaminated sediments

Stien Van Gestel¹; Stien Van Gestel²; Katrien Van de Wiele³; Ward De Cooman⁴¹ AECOM Belgium BVBA; ² AECOM; ³ OVAM - Public Waste Agency of Flanders; ⁴ VMM (Vlaamse Milieumaatschappij - Flemish Environmental Agency)

Contaminated sediments in a water body have the potential to pose ecological and human health risks. The focus on contami-nated sediment has emerged in Flanders over recent years and several field studies targeting potential hotspot locations have been carried out. A sampling procedure has been developed and in 2019 the strategy will be imbedded in the existing regulatory guidance document regarding Phase I investigations. As a first step the contaminant concentrations will be compared with trigger values. This result will determine the need for a further evaluation of the quality of the sediment. The outcome of the previous studies performed in Flanders revealed the need for a consensus on the risk evaluation of contaminated sediments resulting in sustainable management of these sediments.

The risk assessment of contaminated sediments is complex, and highly site-specific, resulting in different chemical and biological lines of evidence. The degree of toxicity cannot be solely based on measured chemical concentrations, but is also determined by sediment chemistry, bioavailability, system hydraulics and sediment transport… Remediation of sediments also has the potential of exacerbating the problem. These factors are driving the need for a Flemish framework.

AECOM was commissioned by OVAM to start with the develop-ment of a risk assessment tool. As a first step a literature study will be performed, comparing existing risk assessment tools that are currently being applied in a variety of countries and evalu-ating the potential of introducing these tools, or certain aspects of them, in a framework specific for Flanders. AECOM’s sediment team in the US, comprising together over 100 years of experience, will be supporting the Belgian team with the literature study and a steering committee of stakeholders will be consulted during the process. Based on the results of the literature study a first ‘Flemish approach’ will be defined. As a second step the tools, gathered in the first step, will be implemented to assess different sites in Flanders with a known sediment quality issue. The project started in November 2018. The results of the first phase will be available in March 2019.

In a next step the risk assessment tool will be fine-tuned, taking into account the specific Flemish conditions resulting in a final risk assessment framework for contaminated sediments.

were declining. Although a large quantity of contamination is still present beneath the private homes, active remediation was no longer considered to be BATNEEC. The question arose whether the remediation was sufficient to remove human health risks. Therefore the vapor intrusion impact associated with the remaining pollution is being investigated using a multiple-lines-of-evidence approach consisting of soil, groundwater, soil-gas and indoor air sampling and use of a vapor intrusion model (S-Risk).

In the first phase, the former dry cleaning site, the adjacent streets and 7 townhouses situated directly above the source zone are included in the study. Before the vapor intrusion sampling a building survey with the homeowners was conducted. During this survey indoor household solvents that could potentially hinder a vapor intrusion investigation were identified and information about the building structure and use of the rooms was collected. All houses have basements with different use (e.g. work shop, church, wine cellar, storage room) and therefore different potential for human exposure.

Indoor air was sampled for 24h in the basements of three houses. An outdoor air sample was collected in the street. Subsequently, soil borings with hand auger were performed and undisturbed soil samples were taken. Additionally VOCs were measured by a PID field instrument. The soil samples were analyzed for BTEX, TPH split, HHO and chlorinated VOCs. In 4 of the 6 houses a smear zone was detected about 0,5 m underneath the basement floor. In these houses a sub slab vapor sampling device was installed. In the remaining study area permanent soil-gas wells were installed with a depth interval of 2,3-2,8 m-bgl. Vertical profiling of soil-gas was also examined at different points by installing additional soil-gas wells at other depths. In total, 9 soil-gas wells and 5 sub slab sampling points were installed across the source zone.

Air samples were actively sampled on charcoal sorbent tubes (2 x 400/200 mg in serie). Sampling flow rate was set at 200 mL.min-1. Sampling duration and therefore soil-gas volume was adapted depending on the expected level of contamination. Temperature and pressure were also monitored during air sampling. All air samples were analyzed for BTEX, TPH split and chlorinated VOCs.

The conceptual site model of the site will be presented. The results will be evaluated against the applicable regulatory standards. The modelling results of the vapor intrusion model S-Risk will also be discussed as well as possible mitigation measures.

Thematic Session (ThS) – Topic 2 | Advances in assessment of risk and monitoring of soil, sediment and water quality

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Thematic Session (ThS) – Topic 3 | Diffuse and emerging contaminants

The mass flux conducted on these projects offers examples of how mass flux estimation provides advancement in our understanding of site-related impacts:

• within complex co-mingled groundwater plumes;

• on off-site environments with wide-spread PFAS impacts;

• for prioritising remedial planning; and

• for stakeholder advocacy of PFAS management strategy.

Evaluation of sources and sinks for chiral pesticides in groundwater – a case study

Kevin Kuntze¹; Katerina Tsitonaki²; Sandra Roost²; Stella Dalby Agger³; Nanette Levanius Schouw Christiansen³; Anko Fischer¹¹ Isodetect GmbH; ² Orbicon A/S; ³ The Region of Zealand

Due to the increasing scarcity of drinking water resources caused by emerging contaminants, e.g. pesticides, the fate assessment of such contaminants in the water cycle has a high priority in the future. The evaluation of pesticide sources and sinks in water bodies is challenging, because appropriate methods are lacking (1). For chiral pesticides, two innovative methods are available for source identification and evaluation of degradation processes: i) analysis of enantiomeric ratios (2) and ii) enantioselective stable isotope analysis – ESIA (3).

Our study highlights the application of a combination of both methods at two field sites contaminated by the pesticides Dichlor-prop, Mecoprop and 4-CPP. Primary and secondary pollutant sources could be identified based on different stable isotope ratios of up to 4.6 ‰. Significant shifts in enantiomeric ratios and stable isotope ratios of the enantiomers provided evidence of biodegra-dation for the pesticides. Shifts of up to +2.4 ‰ to more positive isotope values of (R)-4-CPP along groundwater flow path indi-cating a biodegradation of the R-enantiomer of 4-CPP. This finding was confirmed by the decrease of the respective enantiomer in the potential groundwater effluent of the source area.

Based on the results of our study, we discuss the requirements, potential limitations and promising perspectives of both methods. They are applicable for all chiral pollutants such as pesticides (e.g. Phenoxy acids, alpha-Hexachlorocyclohexane, Heptachlor, Bromacil) and pharmaceuticals (e.g. Ibuprofen, Naproxen, Meto-prolol, Venlafaxin, Salbutamol).

(1) Fenner, K.; Canonica, S.; Wackett, L. P.; Elsner, M. (2013). Evaluating pesti-cide degradation in the environment: Blind spots and emerging opportunities. Science 341, 752-758.(2) Hühnerfuss, H.; Raza Shahb, M. (2009). Enantioselective chromatography - A powerful tool for the discrimination of biotic and abiotic transformation processes of chiral environmental pollutants. Journal of Chromatography A 1216, 481-502.(3) Badea, S.-L.; Danet, A.-F. (2015). Enantioselective stable isotope analysis (ESIA) - A new concept to evaluate the environmental fate of chiral organic contaminants. Science of the Total Environment 514, 459-466.

Mapping PFAS contamination in the Netherlands

Tessa Pancras¹; Elisabeth van Bentum¹; Ko Hage²; Remco Vis³; Hans Slenders¹¹ Arcadis Netherlands; ² TTE Consultants; ³ Witteveen+Bos

Up to a few years ago little was known about the occurrence of PFAS in soil and groundwater in the Netherlands. Even though it was known that PFAS exist, there was still the question; are they also an issue in the Netherlands? Or are they just a local problem?

ThS 3a | Transport processes of emerging contaminants

Using groundwater mass flux tools for evaluating complex issues associated with PFAS – lessons learnt at multiple PFAS impacted sites

Ken Kiefer; Wijnand Gemson; Gavin Powell; Stephen MulliganERM Australia

Measuring mass flux in groundwater is a recognised approach internationally in contaminant land projects with growing accep-tance in the industry (CRC CARE, 2016). Mass flux estimation can be conducted following a variety of methods and used in several facets of contaminated site management, including enhancing the conceptual site model; development of remedial criteria; remedial design; and long-term performance and risk reduction monitoring.

The use of mass-flux for per- and poly-fluoroalkyl substances (PFAS) impacted sites provides an approach for evaluating complex issues associated with PFAS, including:

• Differentiating contribution of multiple on-site and/or off-site sources to comingled groundwater plumes; and

• Developing enhanced understanding of site-related PFAS mass contribution to off-site environments with wide-spread impacts from multiple sources.

This paper describes the lessons learnt from the use of mass-flux tools at multiple PFAS impacted sites and the influence of the mass-flux results on the design of the site management strategies.

The mass flux estimates were conducted using the transect method as detailed in the guidance document “Use and Measurement of Mass Flux and Mass Discharge” (Interstate Technology and Regula-tory Council, 2010). Mass flux calculations were undertaken with the GSI Environmental Mass Flux Toolkit.

This approach used existing site data augmented with on-site slug testing to derive required hydraulic conductivity values. Hydraulic gradients were calculated from available groundwater level gauging data and the available groundwater monitoring datasets were used. Total mass flux estimates were calculated for plume transects across the sites perpendicular to the direction of ground-water flow.

The mass flux characterization conducted on these projects provides an example of how mass flux estimation can be used to:

• Demonstrate that site contribution to the flux of PFAS in groundwater across a site was negligible relative to up-gradient off-site sources. The results supported that remediation of PFAS in site soils was not warranted;

• Provide a line of evidence that site contribution of PFAS to an off-site urban surface water system with multiple PFAS source industry was minimal and likely would be un-detectable in down-gradient surface water system. The results, supported by a third-party regulatory representative, underscored that requests for conducting off-site sampling programs would be confounded by off-site sources;

• Demonstrate the ability to differentiate contribution of multiple known and unknown source areas of PFAS to co-mingled groundwater migrating to a site boundary. The results identi-fied one primary on-site source area contributing to the off-site migration of PFAS.

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Thematic Session (ThS) – Topic 3 | Diffuse and emerging contaminants

Transport of selected neonicotinoids in groundwater: column experiment

Damian Pietrzak; Jarosław Kania; Ewa Kmiecik; Katarzyna WątorAGH University of Science and Technology

Neonicotinoids have been increasingly used worldwide in the last decades because of their systemic activity and selective effective-ness against insects. Although these insecticides help growers control the pests, their residual occurrence in environmental may cause unintended adverse ecological consequences to non-target species. Because less than 20% of the active ingredient is absorbed by the plant, most of them are spread in the environment and enters the soil and water after planting. Many factors can affect the mobility of pesticides in soil and water, including soil charac-teristics (texture, organic matter and clay content, permeability), physicochemical properties (e.g. solubility in water), as well as the timing of application. Migration of neonicotinoids has not been sufficiently examined so far, hence there is a necessity for farther investigations. For this purpose, the column experiment can be applied. Soil columns have been used for many years to evaluate transport models and to monitor the fate and mobility of contami-nants in soil, including pesticides.

The present paper aims to study the mobility of selected neonicotinoids, mentioned in European Union first Watch List, in an aquifer with different properties to provide important transport parameters. Miscible displacement experiments were conducted, using soil columns under soil water-saturated conditions and constant flow velocity. The aquifer materials medium to fine sands came from the representative profile of the agricultural fields (south-east Poland). The extent of neonicotinoids mobility was measured by quantifying the concentration in the effluent solution versus time. Chlorides were used as a conservative tracer, while neonicotinoids served as reactive tracers. The chlorides input concentration was of 500 mg/L, while the initial concentrations of neonicotinoids were selected based on their average and maximum values observed in groundwater in Poland. Neonicotinoids concentrations were measured using liquid chromatography triple quadrupole mass spectrometry LC-MS/MS. Breakthrough curves were next simulated using STANMOD software. Analyses of neonicotinoids breakthrough curves enable to determine neonicotinoids transport parameters, such as retardation factor (R), sorption parameters (Kd, Kf, Koc, sorption isotherm) and degradation parameters (DT50), which in turn affect the distance of neonicotinoids’ migration and their amount.

To raise awareness, analytical field data were collected and across large areas elevated background levels were found.

In 2016, the Dutch Expertise Centre on PFAS started an in-depth program (Handelingskader PFAS) which comprised investigations into the presence of PFAS at 29 potentially contaminated sites and collecting, analyzing and displaying existing PFAS data at unsus-pected sites (surface water, groundwater, soil).

Furthermore, the program also included a knowledge document, toxicological evaluation and a policy evaluation, summarized in an action framework document. The project has been finished in 2018, and the results are available online (https://www.expertise-centrumpfas.nl/). This abstract focusses at the field data collected during the project, the other items of the project are discussed in another abstract.

PFAS data has been collected from:

- 29 potentially contaminated sites (new investigations)

- Surface waters, ground water and (raw) drinking water (existing data from different sources)

- Soil samples (existing and new data from different sources)

The field studies at potentially contaminated sites and at the unsuspected sites confirmed that PFAS are widely present in the environment in the Netherlands. As expected, they are detected at suspected sites, but also at unsuspected sites. And moreover, although PFAS are man-made chemicals that should not show a natural background concentration, elevated background levels were measured for both PFOS and PFOA, especially in urban areas.

Different footprints for PFOS, PFOA and other PFAS have been measured. PFOA is clearly present in elevated concentrations related to the fluorochemical plant in Dordrecht. Increased levels of PFOS were mainly measured at AFFF (Aqueous Film Forming Foam) related sites and chrome plating industries. In the urban areas, the concentrations of PFOS and PFOA were quite similar.

The results of the different sub-projects show that PFAS is ubiqui-tously present in the environment in the Netherlands, and likely at similar levels in other countries. The widespread presence of PFAS has a lot of consequences, although the concentrations do not really point at significant risks for human health or the environ-ment, the main problem that arises is a question of soil handling and reuse. There is a stand still principle in the Netherlands which is to not increase the contaminant level at a site in case of soil transfers. With emerging contaminants present at levels above the detection level this causes a major disruption for redevelopment of sites, since it is not allowed to transport contaminated soil to another site with lower contaminant levels. The field data gathered in this project were used to set frameworks for soil handling, both a guidance at a national level, and regulation in the Dordrecht region.

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Sediments as a source of PFAS in biota – Two case studies from Norway

Hege Mentzoni Grønning; Gøril Aasen Slinde; Sarah Hale; Åse Høise-ter; Gijsbert D. Breedveld; Håkon Austad LangbergNorwegian Geotechnical Institute (NGI)

Two case studies from Norway will be introduced, both in which sediment may be an important contributor to PFAS accumulation in biota. The study sites represent different aquatic environments and ecosystems, which will provide information about the ecological significance of PFAS-polluted sediments in different environmental conditions. The presented studies included sampling of sediments, water and biota at several trophic levels, including the benthic ecosystem.

Tyrifjorden – inland lake: Tyrifjorden is Norway’s fifth largest inland lake. In 2015, perch was sampled and high concentrations of PFOS were found in liver (Miljødirektoratet, 2016). There were no known sources of PFAS-contamination to the Tyrifjorden-area. In 2017, NGI did a survey to track the sources of PFAS in the area.

Saltenfjorden – Norwegian coast: Saltenfjorden is a 40 km long fjord leading to the municipalities of Bodø and Gildeskål in Nordland county, Norway. Saltenfjorden has, caused by Saltstraumen, the world’s largest maelstrom, located approx. 11 km from Bodø Airport, were PFAS-containing AFFF has historically been used over large areas.

The investigations of the case study sites has been carried out during numerous field campaigns, collecting samples of sediments, water, pore water, passive samplers and biota at several trophic levels.

At both study sites, sources of PFAS has been identified, and could be connected to elevated concentrations in sediments and/or biota. For instance, in Tyrifjorden the largest sources of PFAS were the sediments outside a closed paper factory and in connection to the local fire station at Hønefoss. The sediments in Tyrifjorden itself were also found to have quite high concentrations, possibly leading to the increased levels in perch confirmed during the sampling in 2017. In Saltenfjorden, PFAS was found in high concen-trations in discharge water just outside the fire-fighting training facility at the airport. Investigations of PFAS-concentrations in fish (Atlantic cod (Gadus morhua and Pleuronectes platessa), a sea snail (Patella vulgata) and crabs (Carcinus maenas and Hyas araneus), showed elevated concentrations in some individuals, and generally the concentrations were higher in biota sampled near the airport compared to the reference station. Analyses of passive samplers and sediments in Saltenfjorden on the other hand, showed low concentrations, probably due to the frequent exchange of large amounts of water in the fjord caused by Saltstraumen.

Follow-up studies at Tyrifjorden are on-going during 2018. The results will give important knowledge that will allow to assess the ecological significance of PFAS-polluted sediments, and possibly the differences between the various aquatic systems.

Prioritization model for risk management of groundwater bodies with poor chemical status in Finland – A new approach

Liisa Koivulehto¹; Jarno Laitinen¹; Kimmo Järvinen¹; Esa Rouvinen²¹ Ramboll Finland Oy; ² South Savo Regional Centre for Economic Develop-ment, Transport and the Environment

In Finland there are 95 groundwater bodies with poor chemical status from which 87 are important for water supply. One of the

ThS 3b | Risk management of diffuse and emerging contamination

Exploring the pesticide biodegradation potential in aquifers used for drinking water production

Andrea Aldas Vargas; Nora B. Sutton; Siavash Atashgahi; Hauke Smidt; Huub H.M. RijnaartsWageningen University

In the Netherlands, the preferred source for drinking water produc-tion is groundwater. However, the presence of pesticides at very low concentration (ug L-1) threatens groundwater quality and therefore drinking water production. Bioremediation is a non-invasive and cost-effective method for in situ remediation of groundwater. This technique relies on microorganisms which are capable of transforming contaminants through metabolic or co-metabolic processes.

Microorganisms in groundwater systems have to overcome several challenges, such as low organic carbon substrate concentrations representing an oligotrophic environment and spatially varying anoxic redox conditions. These bottlenecks result in low biomass concentration in aquifers. Moreover, very little is known about microbial biodegradation capacity towards pesticides under the above mentioned conditions. The study of the microbial commu-nities in the field can provide information about the pesticide biodegradation capacity of the indigenous microbes and therefore an impression about natural attenuation potential and feasi-bility for application in pollution management. To determine the potential for pesticides biodegradation, microbiology studies need to be conducted and combined with geochemical data from actual field locations.

As part of this study, three monitoring drinking water wells located in the East of the Netherlands were sampled, each one at six different depths from 13 to 65 m deep. A stable redox zonation that changes with depth from nitrate to iron and sulphate reducing condition was found. The presence of some pesticides was also found at typical micropollutants concentrations of 0.01 – 1 ug L-1. DNA of the groundwater filtrates was extracted and used for 16s rRNA gene sequencing, quantification of bacteria and archaea (using qPCR) and metagenomic analysis. The 16sRNA copy of bacteria and archaea was 106 to 107 and 104 to 105 mL-1 of groundwater, respectively. A stable microbial community in groundwater systems over time was observed along the years from 2015 until now, and through 16s sequencing some candidate divisions were identified at high taxonomic ranks (i.e. class). Therefore, at lower taxonomic ranks such as genus, the phylogenetic information obtained was quite limited. In the aim of studying potential biodegradation capacity, metagenomics studies were also done in these samples and data analysis is ongoing.

The information generated is used to determine the current microbial community composition in the field and how this relates to groundwater chemistry and concentration of natural organics. We demonstrated that the use of microbiological tools have potential to evaluate the natural attenuation of pesticides in the sampled groundwater locations. Moreover, in the future, we aim to enhance the natural attenuation in the field by the application of bioremediation techniques.

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concern and its overall aim is the analysis of the potential risk to human health, in terms of food security, and to ecosystems, asso-ciated with the indirect reuse of surface water strongly impacted by WWTP effluents. With this perspective during the first year of the project, the research aimed to evaluate the transfer of selected pharmaceuticals, their corresponding transformation products (TPs), trace metals (TMs) and metalloids from the source (WWTP effluents) to the receptor (agricultural soils and crops), considering the propagation through the irrigation ditch. The study site consti-tutes an excellent scenario to carry out such a research. Indeed, it is an extensive agricultural land (75 km2) downstream the city of Madrid (Spain) where a flood-based farming is used to cultivate mainly corn crops. The surface water for irrigation belongs to two rivers, that prior to be retained by a dam, flow throughout the urban settlement.

Sampling campaigns were conducted to collect WWTP effluent, surface water, sediments, irrigation water (from the ditch), soils and corn grains. Beside standard physico-chemical analyses, all samples were analyzed for the detection of a group of 50 pharmaceuticals (analgesics, anti-inflammatories, antibiotics, cardiovascular, bron-chodilators, lipid regulators, antidiabetics, antiulcer, hormones, and psychiatric drugs and life style compounds), including several TPs, eight TMs and metalloids (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn). Specific analytical methods based on mass spectrometry were developed and validated for the quantification of pharmaceuticals and TPs in the various environmental matrices (water, soil, sediments and corn grains).

Results demonstrate the ubiquitous presence of several phar-maceuticals and TMs. Some compounds are being transformed, as shown by the appearance of their more persistent TPs whose effects in the environment are still largely unknown. Concentra-tions of pharmaceuticals, TPs, TMs and metalloids in the selected WWTP effluent are usually lower than concentrations in the surface water. This suggests the presence of uncontrolled wastewater discharges that decrease the water quality along the flow path. Some of target compounds show affinity to soil whereas others are partly absorbed by the crops and bioaccumulated in the corn grains. However, measured concentrations in the three environ-mental matrices suggest that attenuation processes are occurring to a certain extent. Potential dietary uptake of these compounds by humans was predicted to be low.

The management of diffuse lead contaminated soil in Flanders and The Netherlands. A literature study for the development of effective strategies for the management of diffuse soil pollution in Flanders and The Netherlands

Kaat Touchant¹; Ellen Brand²; Mirja Van Holderbeke¹; Ton Schouten²; Lieve Geerts¹; Johan Bierkens¹; Ilse Van Keer¹; Griet Van Gestel³; Marco Zeilmaker²; Piet Otte²¹ VITO; ² RIVM; ³ OVAM

Both in the Netherlands and in Flanders (Belgium) soil remediation policy has mainly been focused on contaminated sites with known pollution sources. However, the presence of large areas of diffuse lead contamination in soil is still an issue. The remediation is compli-cated and costly by the large size of the polluted areas and the often complex infrastructure. In addition, lead can be very heteroge-neously distributed within the diffusely contaminated area.

Although diffuse lead in soil has been recognized in both countries for decades (Eylenbosch et al., 1984; Walraven et al., 2014, Otte et al., 2016), an effective approach has not yet been established.

objectives in the EU Water Framework Directive 2000/60/EC (WFD) is that all groundwater bodies will have to achieve good quantita-tive and chemical status by 2015 with possible deadline extensions until 2027. According to an estimation of the Finnish ELY centre experts, approximately 30 % of those nearly 100 groundwater bodies will not achieve a good chemical status by 2027.

The “poor” or “not good” chemical status of a groundwater body is proposed when a threshold value from a list of compounds in groundwater is exceeded and its risks to water supply, surface water bodies and the ecosystem have been assessed to be possible or significant. In Finland a groundwater body’s chemical status is usually deteriorated due to contaminated land, salinification or nutrients from agriculture. Groundwater remediation has high costs since it is technically challenging and time consuming. Currently all point source emissions in a groundwater body are assessed separately and isolated from each other - instead of looking at the whole picture in a more comprehensive way. Therefore, prioritizing risk management procedures is also challenging.

To address these challenges and to develop a more comprehensive risk-based approach for prioritizing risk management for ground-water bodies with poor chemical status, a development project with a multidisciplinary consortium of government research and administration institutes, waterworks companies and consultants was launched. The approach for prioritizing risk management is currently being composed and tested with tools such as sensi-tivity analysis (DRASTIC index), numerical groundwater modelling (MODFLOW), fate and transport modeling and co-creation workshops with different stakeholders and experts. The aim of the project is to produce an approach using open access data so that numerical modelling would not necessarily be needed. Ideally the final approach can be used in prioritizing risk management tasks and utilized in land use planning. It also will provide tools for the national and regional regulators to assess the chemical status of a groundwater bodies in a more comprehensive way.

The presentation will discuss the status of WFD objectives in Finland and describe the multi-stakeholder process of composing a new, comprehensive risk management approach for groundwater bodies in risk of not achieving the objectives. The presentation will also present the outcomes of the project, the developed prioritiza-tion model for risk management and the different applications of the model eg. in advancing land stewardship, urban planning and emergency services. The presentation will provide valuable new insights and tools for anyone working with risk assessment and prioritization of diffuse contamination and provide new perspec-tives to working within the WFD framework.

Pharmaceuticals, trace metals and metalloids in the surface water used for crop irrigation: Natural attenuation or risk to health?

Raffaella Meffe¹; Ana de Santiago Martín¹; Gloria Teijón Ávila¹; Virtudes Martínez Hernández¹; Jorge Hernández Martín¹; María Isabel López Heras¹; Covadonga Alonso Alonso¹; Irene de Bustamante²¹ IMDEA Water Institute; ² Universidad de Alcalá (UAH)

The use of surface water impacted by wastewater treatment plant (WWTP) effluents for crop irrigation is a form of indirect water reuse. Natural attenuation processes occurring mainly in the unsat-urated zone can buffer contamination spreading. However, this practice can suppose the transfer to the crops and to the under-lying aquifer of the most persistent contaminants, such as some emerging compounds and trace metals, posing a risk to human health and ecosystems. The project FatePharM arises from this

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were found 8 kms from the factory (downwind, in the prevailing wind direction) and PFOA was still found in soil 20 kms downwind from the factory.

Since 2012, PFOA has been replaced by GenX in Teflon produc-tion. GenX was found in lower concentrations and only close to the factory in Dordrecht. However, in 2017, a Dutch waterboard found GenX in surface water and sewers in the vicinity of Helmond, a city 80 kms away from Dordrecht. An investigation by the water-board showed that the GenX came from a facility in Helmond that processed GenX for the plant in Dordrecht. A study of the produc-tion process showed that GenX (and in the past PFOA) was mainly discharged via the chimney. An investigation into soil, ground-water and surface water showed similar results as in Dordrecht, with the highest concentrations of GenX and PFOA in the direct vicinity of the factory. The further away from the plant - the lower the concentrations. The plant in Helmond no longer processes PFOA or GenX which is already reflected in a decrease in concentra-tions in (flowing) river water. In stagnant water, the concentrations remained fairly constant over time.

At both locations, concentrations in the plume do not exceed the current guidance values and thus do not point to significant risks for human health or the environment, but some exposure pathways need close monitoring and the impact is much more widespread than anticipated. Also the relatively small and very well organised plant in Helmond would normally not have been regarded as a possible source of widespread contamination.

PFOA and GenX have been found in surface water, in swimming water and even in raw drinking water in one of the areas. Highest PFOA concentrations were detected in a polder system with low permeable soils and upward groundwater flow. Most critical are impacted grazing areas and vegetable gardens. The Dutch Food and Product Safety Authority is currently studying PFAS in food from both areas. Economically, the largest impact was perhaps the disruption in site redevelopments, when projects were put on hold because of uncertainties about soil handling and reuse of soil containing low concentrations of PFOA.

Our experience with PFOA and GenX in Dordrecht and Helmond shows that atmospheric deposition of emerging contaminants might be often overlooked and has a large impact even at relatively low concentrations.

Improving decision making for contaminated land management using environmental risk levels

John van Tol; Annelies VoogtTauw bv

With the current myriad of chemicals being produced and used, it is easy to get lost in terms of risks for human health and the envi-ronment. For emerging contaminants and substances of concern (ZZS in Dutch legislation) there is an urgent need for prioritiza-tion of management measures when these substances are used or have been spilled into soil and/or groundwater. Site owners and authorities need guidelines on how to deal with all sorts of chemicals, especially toxic chemicals. For a selection of substances widely used or present environmental risk levels (usually generic screening levels based on human health and ecology, for instance Dutch Intervention values) have been provided by regulatory authorities. However, for a wide array of other chemicals these environmental risk levels are not available. When such levels are not available authorities tend to use background levels or analyt-

Lead affects children’s brain development and is associated with a reduced intelligence quotient score. The European Food Safety Authority (EFSA, 2013) concluded that there is no evidence for a threshold for critical lead-induced effects. Lead pollution in soil particularly causes a health risk to young children, through ingestion of soil particles while playing in- and outdoors. In the Netherlands and Flanders competent authorities started to develop a pragmatic approach. With respect to the assessment of risks and the management of diffuse soil lead contamination a literature review has been carried out by RIVM and VITO.

The literature study directs on the causes, effects and management options of lead pollution in soil from measuring environmental health indicators towards risk assessment and management options. Topics addressed are sampling strategy & soil analysis, external & internal exposure, usage restrictions & public informa-tion campaign and, toxicity & health effects.

To achieve an adequate risk assessment a detailed characterization of the pollution is necessary, including not only the determination of total lead concentrations in the contact zone, but also speciation analyses to identify individual parameters. Component-specific isotope analyses to distinguish the sources of the contamina-tion can be valuable. Subsequently, the oral bioavailability can be evaluated in order to take into account the actual (internal) exposure level instead of the total soil concentration, and to decide about the most appropriate measures.

The most important goal, the reduction of exposure to the lowest possible level, can be achieved by taking various mitigation measures. Which combination of measures is most effective can only be determined at local level.

ReferencesEFSA (2013) Scientific Opinion on Lead in Food. EFSA Panel on Contamination in the Food Chain (CONTAM). Published on 22 March 2013, replaces the earlier version published on 20 April 2010. EFSA Journal, 8.Eylenbosch W.J., van Sprundel M.P. & Clara R.R. (1984) Lead pollution in Ant-werpen, Belgium. Ann Acad Med Singapore, 13(2), 224-30.Otte P.F., Bakker M.I., Lijzen J.P.A., Versluijs C.W., Zeilmaker M.J., (2016) Non-point source lead contaminated soils. National Instituate for public Helath and the Environment, Bilthoven the Netherlands. Reportnr. 2015-0204 (in Dutch)Walraven N. (2014) Lead in rural and urban soils and sediments in The Neth-erlands: background, pollution, sources and mobility. PhD Vrije Universiteit Amsterdam.

Atmospheric deposition of PFOA and GenX around fluorochemical processing plants in Dordrecht and Helmond in the Netherlands

Elisabeth Van Bentum¹; Tessa Pancras¹; Hans Slenders¹; Patrick Meuken²; Frans van der Ham³¹ Arcadis, The Netherlands; ² Municipality Helmond; ³ Regional Environment Authority Zuid Holland Zuid

A fluorochemical plant in Dordrecht has been using PFAS to produce fluoropolymers since the 1960s. In 2016, modelled air emissions from the plant showed elevated PFOA levels in air and PFOA was found in in the blood of employees and residents in the area. The Municipality then decided to investigate whether atmo-spheric deposition could have led to the contamination of soil and groundwater in the vicinity of the plant. It was the start of phased research showing the impact over tens of kilometres.

The first results showed a remarkable resemblance to air emission contours modelled by the RIVM, with highest PFOA concentrations close to and downwind from the plant. Further studies confirmed this, but surprisingly high PFOA concentrations (max 320 µg/kg)

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ical reporting (detection) limits as management tools. A more risk based approach would improve the decision making power of stakeholders in the management of contaminated land. Present-day wide societal concerns on the environmental risks of widely used PFAS substances, urged the Dutch RIVM for example to make haste with deriving environmental risk levels. Apart from PFAS, other emerging substances and substances of concern need this attention as well. Research institutes like Dutch RIVM and regula-tory authorities however are not accommodated to derive risk levels for this vast amount of chemicals which are often region-ally distributed or even site specific. For a large amount of clients (mostly private site owners and industrial companies) over the last decades we derived over 100 indicative environmental risk levels for soil, groundwater, surface water and/or fresh water sediment. The derived levels vary from generic screening levels to site specific target levels for monitoring or remediation. The methodology used was based on guidelines/policy from regulatory authori-ties and institutes like Dutch RIVM. These levels were used by the clients and regulatory authorities in the decision making for the management of the contamination. Having (indicative) risk levels for exotic substances which are related to current/future site use of the contaminated site and the surroundings facilitated the stakeholders in detailed decision making and setting priorities in dealing with contamination.

In our presentation we will give a short overview of the various methods available for deriving risk levels and share our lessons learned. We will address for instance how we deal with the limi-tations of risk models (human health and ecological exposure modelling), limited (scientific) data on (chronic) human health toxicity and/or ecotoxicity, multiple data sources with sometimes contradicting information and limited physical/chemical informa-tion. We will include a few interesting and illustrative case studies.

We strongly believe involving all stakeholders in using (site specific) environmental risk levels will improve and support the decision making for dealing with contaminated land.

Screening values for polyfluoroalkyl substances (PFAS) PFOS and PFOA in soil and groundwater

Arjen Wintersen¹; Piet Otte¹; Marije Schouwstra²; Paul Römkens³; Ellen Brand¹; Eric Verbruggen¹; Marino Marinkovic¹; Frank Swartjes¹¹ RIVM - National Institute for Public Health and the Environment; ² Ministery of infrastructure and Water Management; ³ Wageningen Environmental Research

The Netherlands, the PFAS compounds, PFOS and PFOA, are frequently found in soil and groundwater. In some cases, the source of PFAS can be traced back to former emissions, e.g. spills of firefighting foams. In other cases the source is unknown, but here levels encountered in soil are relatively low, ranging from 1 to 4 µg/kg.

In order to assess the risks of soil and groundwater contamina-tion and to manage the reuse of soil and sediment, environmental screening values have been derived. Existing values were updated based on the latest data on human toxicity, ecotoxicity and fate and behavior of these substances in soil, groundwater and crops, and for some endpoints new values were calculated.

In order to derive human health based risk limits, the exposure model CSOIL was adapted to take into account fate and transport of dissociating organic substances. Experimental data on partitioning was used when available. Bioconcentration factors (BCF’s) for the calculation of accumulation in crops were re-evaluated based on

field data from literature searches. Toxicological endpoints were chosen and tolerable intake values were selected, based on the latest evaluations by EFSA and RIVM.

A re-evaluation of ecotoxicity data was performed with specific attention for the bioaccumulation and biomagnification potential of perfluorinated substances. Environmental risk limits for secondary poisoning were derived using an updated methodology that accounts for the amount of substance per unit of energy that an animal needs per day. This method is versatile in the source of food that can be considered for secondary poisoning (earthworm, plants). Further, predators eating birds and mammals are also taken into account by adding a biomagnification step to the terrestrial food chain, which is relevant for these perfluorinated substances.

The fate and toxicological mechanisms of PFAS differ significantly from other substances for which environmental standards have been derived in The Netherlands. When deriving national envi-ronmental standards for PFAS, these specific issues need to be addressed. In our presentation we will address these issues, among which:

• Risk of leaching of PFAS to groundwater;

• Accumulation in organisms and the food chain;

• Multi compound exposure;

• Food safety issues related to agricultural use of soil.

Developing MNA and remedial strategies for norbornene flame retardants and insecticides

Jim Wragg¹; Leah MacKinnon¹ Geosyntec Consultants Ltd

Norbornene (or cyclodiene) insecticides (aldrin, dieldrin, chlordane, etc.) often degrade in the environment to a structurally similar compound, chlorendic acid (CA), which is potentially recal-citrant to further degradation. This chemical is also involved in the synthesis of flame retardants, resins, coating agents, corrosion resistant plastics and lubricants. The unique chemical properties of CA make it resistant to many common remedial technologies. With a complex ring structure, six chlorines and two carboxylic acid groups, it’s behavior in groundwater can be similar to hydro-phobic organic species under some geochemical conditions, and inorganic species under others.

The viability of a monitored natural attenuation (MNA) remedy has been evaluated for a site where CA is present in groundwater. Addi-tionally, for MNA to be accepted by the regulators as the primary off-site remedy, a contingent remedy for active treatment in the off-site plume has been identified and designed.

Our work sought to identify potential remedial technologies for CA, and to identify potential reaction processes that occur under natural attenuation conditions, a series of treatability studies were completed. As there is limited documentation of demonstrated CA treatment processes, this has included a wide array of technolo-gies including aerobic and anaerobic bioremediation, chemical oxidation, hydrolysis, precipitation, sorption and chemical reduction via zero valent iron.

In parallel, groundwater modeling and assessment of the geochem-ical conditions within the plume has been used to support the MNA evaluation. Synthesis of the model results, geochemical data, plume distribution and treatability results has confirmed that

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processes observed at the laboratory scale are reflected at the field scale, allowing prediction of the future fate of CA at the site and further insights in to the CSM to be gathered.

This case study demonstrates some of the key challenges we face in developing remedial strategies for relatively novel and poten-tially recalcitrant contaminants. Ultimately these tests, combined with a detailed evaluation of the plume dynamics, confirmed the chemical processes by which natural attenuation is on-going. Additionally, potential technologies for in situ treatment have been identified and conceptual design of the preferred contingent remedial approach developed.

The results of this study yielded both surprises and disappoint-ments - confirming that, as with all remediation, that chemistry rules. The results from this study also reflect on potential remedia-tion and attenuation processes for structurally similar compounds such as cyclodiene insecticides.

ThS 3d | Policy strategies of environmental concerns of emerging contaminations

PFAS: a stress test for sustainable soil management in the Netherlands

Michiel Gadella¹; Co Molenaar¹; Dik Welkers²¹ Rijkswaterstaat; ² Ministery of infrastructure and the Environment

The Dutch society is familiar with sustainable soil management. A hundred Million tons of soil/year are applied of which 50 % is lightly contaminated. Soil reuse is necessary in order to meet societal chal-lenges on circular economy, climate adaptation and urbanization. The location of the Netherlands in the estuary of the rivers Rhine and Meuse and the fact that the western part of the Netherlands is placed below the see level, results in an large demand for dredging of sediments and soil and sediment application to compensate for soil subsidence and for elevating dikes. Furthermore the Nether-lands has seen a spectacular growth in terms of inhabitants in the last century and therefore in urbanization and the necessary infra-structure. This results in a large demand for building materials and application of soils. Given these circumstances it is logical that the Dutch have implemented legislation on the sustainable reuse of lightly contaminated soils (Dutch Soil Quality Decree, 2008) . The legislation is based upon the principles of stand-still and fit for use. The competent authorities are 380 municipalities for the applica-tion of soil on land and 24 water authorities for the application of soil in water. Through guided implementation of this legislation every municipality has made a choice between the national soil policy or a tailor made local soil policy. A system of private quality assurance and public environmental guarding is installed in order to stimulate a level playing field and public trust in the quality of soils that are applied. These circumstances, policy, legislation, daily practice and environmental guarding results in a fine balance between the protection of soil and the need to recycle. Dutch society is proud of this system of sustainable soil management

The recent discovery of diffuse concentrations of PFAS poses a stress test for sustainable soil management. The challenge is to fit the diffuse contamination with PFAS within the existing system.

The Soil Quality Decree contains soil standards for a limited number of contaminants such as heavy metals, mineral oil and

PAH’s. All other contaminants (such as PFAS) cannot be reused until the municipality adjusts its local soil policy with soil standards for this specific contamination. The municipality of Dordrecht in close collaboration with the ministry of infrastructure and environment have made a guideline for dealing with PFAS. A few municipali-ties have installed local reuse standards in order to meet the need to recycle excavated soils within their municipality. These same municipalities call upon the Dutch government to install national soil standards to enhance the exchange of PFAS contaminated soils between different municipalities. At present these national reuse standards are being developed by the RIVM.

The full article will address the governance on diffuse soil contami-nation with PFAS. What can we do about prevention? What are the advised soil standards on PFAS by the RIVM? What is the task of the competent authorities? What actions are being taken by the ministry of infrastructure and environment? What do we learn from PFAS for other upcoming contaminants?

How compounds become identified as emerging/new contaminants, and the implications for stakeholders

Nanda Hermes¹; Jennifer Byrd¹; Paulo Valle²¹ ERM; ² ERM BeNe

Emerging contaminants can be defined as synthetic or naturally occurring chemicals that are not commonly monitored in the envi-ronment but which have the potential to enter the environment and cause known or suspected adverse ecological and (or) human health effects. With new chemical compounds constantly being developed and science continuously improving its understanding of current and past contaminants, developing effective regulations and guidance for emerging contaminants has presented chal-lenges in many countries.

In the European Union (EU) and the United States (US) various ways have been developed for screening compounds and prioritizing its potential hazards. In the United States, the Safe Drinking Water Act (SDWA) requires the Environmental Protection Agency (EPA) to issue a Contaminant Candidate List (CCL) containing contami-nants that are not currently subject to drinking water regulations, but are known or anticipated to occur in public water systems. In addition, the Toxic Substances Control Act (TSCA) provides EPA with authority to require reporting and impose restrictions relating to the production, importation, use, and disposal of chemical substances.

In the EU the NORMAN network, which is a collaboration between reference laboratories, research centers and related organizations for the monitoring and biomonitoring of emerging environmental substances, has identified a list of the currently most frequently discussed emerging substances and pollutants. A similar effort is underway in the Netherlands, where the RIVM (National Institute for Public Health and the Environment) has compiled a list of what is called ‘Zeer zorgwekkende stoffen’ (Substances of High Concern) to guide Dutch policies focused on prevention or minimizing emissions of such substances to the environment. And recently Germany has started compiling a list of substances that are persis-tent in the environment, mobile in the aquatic environment and toxic may be critical for the quality of raw waters.

The presentation will focus in discussing the different ways to handle identification of emerging contaminants and describes the regulatory and technical challenges that may surface during the process. We will conclude with lessons learned and its potential implications to regulatory agencies, consulting companies and industries.

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Towards a less stringent groundwater body objective? Feedback from a French heavily industrial and urban study area

Corinne Merly¹; M. Grémont²; P. Vigouroux²; M. Bouzit²; B. Clozel³; L. Cadilhac⁴; C. Schlosser⁴¹ BRGM (French Geological Survey); ² BRGM, D3E, NRE; ³ BRGM; ⁴ Agence de l’Eau Rhône Méditerranée Corse

Groundwater Directive 2006/118/EC (Daughter to Water Framework Directive 2000/60/EC) establishes specific measures in order to prevent and control groundwater pollution. It specifically requires to assess plumes originating from punctual sources such as those due to industrial activities, in order to check if they do not spread and degrade the chemical state of the groundwater bodies. In 2012-2013, BRGM (French Geological Survey) supported by the AERMC (Water Agency on the Mediterranean Rhone River basin) carried out a study to assess the impact of industrial activities on the quality of groundwater bodies in the Rhône river basin. It enables to identify 10 groundwater bodies which were at risk of not reaching the groundwater environmental quality target set by the French application of the Groundwater Framework Directive. Some of these groundwater bodies impacted by persistent and widely spread contaminants such as chlorinated solvents are very unlikely to recover groundwater quality standard by 2027. In this context, AERMC and the BRGM initiated an innovative project in order to define a methodological framework to justify for an exemption of the current groundwater quality objectives and the possibility to propose a less stringent groundwater objective.

The methodology was developed for a French groundwater body severely impacted by anthropogenic contaminants (chlorinated solvents and pesticides) where urban and industrial pressures are significant. The study included four phases:

1) Detailed description of the quantitative and qualitative hydro-geology of the study area; This step enabled to a) make the inventory of substances concerned by GWFD and for which an exemption case can be developed, b) describe the under-standing of the hydrogeological functioning of the zone (flow direction, interface groundwater and surface waters), c) identify the substances for which a significant impact on groundwater quality was observed, d) identify and describe sources zones and finally e) give recommendation on groundwater monitoring.

2) Inventory of remedial actions (including costs) and defini tion of scenario; This steps aimed at a) making an inventory of current remedial actions, b) suggesting other potential remedial actions for development of scenario and c) develop-ment of scenario aiming at analyzing the situation from various perspectives and on which assessment methods were applied.

3) Application of assessment tools for the justifications for exemption; Notably, two main methods were applied here: a) Assessment of actors payment capacity and b) cost-benefits analyse (including a full inventory of benefits originating from the current and a good status groundwater body).

4) Definition of a less stringent groundwater quality objectives; this steps is planned in near-future.

This project gives great methodological feedback on technical, regulatory and governance aspects. Regarding technical aspects, among others, data availability and study boundaries were discussed. As for regulation, the stand points differences between contaminated land management and French declination of the groundwater directive requirements were tackled. At last but not least, the governance of the project involved many types of stakeholders with whom a common vision was attempted to be developed throughout the running of the project.

Towards a remedial action plan for PFAS in soil and groundwater at an industrial site in Antwerp: results on research for treatment and reuse of soil and discharge of groundwater

Bart Meyns¹; Jeffrey Casier¹; Karel Van Nieuwenhove²; Annemie Boden²; Youri Mertens³; Joris Vanderhallen⁴¹ Sertius; ² Antea Group; ³ OVAM - Public Waste Agency of Flanders; ⁴ Port of Antwerp

On a site managed by the Port of Antwerp (PA) a contamination with PFAS (poly-fluorinated alkyl compounds) in soil and ground-water was detected.

Reason for specific research on PFAS was a calamity during the dismantling of a storage tank for fire-fighting foam. Results of this investigation however revealed that the contamination was more extensive than could be explained by only the calamity. The contamination with PFAS probably was caused by industrial activi-ties of the former operator by spills or tests on the fire-fighting foam. The owner of the site PA was exempted and further soil inves-tigation and delineation of the contamination was commissioned by OVAM to Antea Group.

Previously another historical contamination with (mainly) mineral oil and volatile aromatics in both soil and groundwater was detected in the same area. This contamination already was the subject of a remedial action plan in which biological treatment was foreseen. Due to the presence of the additional contamination with PFAS the remediation of this contamination was put on hold. An additional consideration of the possibilities to achieve clean up values and reuse of soil is needed while focusing on a combined approach for both contaminations.

PFAS are considered as one of the so-called ‘emerging contami-nants’. There is at present no single approved approach regarding this contamination and there is uncertainty on the risks. Due to their properties, PFAS are persistent, bioaccumulative and toxic substances. A risk to man or the environment can already occur at very low concentrations (order of magnitude µg/kg.dm and ng/l).

Their specific properties make PFAS difficult to remove from the environment. Currently there is little practical experience and it is unclear what clean up values can be achieved when applying conventional processing or cleaning and purification techniques.

For this reason, specific research on soil treatment techniques and groundwater purification methods for PFAS was instructed by OVAM. This research aims to achieve insight in the processing and treatment of soil and groundwater as well as in the reuse of treated soil (linked to leaching). Also a better view (technical and financial) on the feasibility and possible discharge standards for PFAS is intended.

This is the first research of this scale that is realized in Flanders on treatment possibilities of PFAS.

In consultation between PA and the OVAM 3 Parties were appointed to perform this research (Mourik (in collaboration with VITO), Envisan and Greensoil (in collaboration with Aertssen).

The research on soil include:

- Physico-chemical processing (laboratory scale and full scale)

- Thermal processing (up to 600 °C and 1200 °C)

- Chemical oxidation

- In-situ immobilization

On groundwater tests are conducted with:

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- Adsorption resources (activated carbon, resin)

- Ultrasonic waves

- Chemical oxidation

- UV technology

The tests are in progress and the results are expected in January 2019. The general follow-up of the tests and the overall review and report of the results is entrusted to Sertius.

The presentation will include the site-specific problems and the overall research results.

Geochemical baseline of urban soils with undedicated datasets: Link between methodology and environmental policies

Baptiste Sauvaget¹; Chantal de Fouquet²; Cécile Le Guern³; Hélène Roussel⁴¹ BRGM/Mines ParisTech PSL; ² MINES ParisTech, PSL University, Centre de géosciences; ³ BRGM; ⁴ ADEME

Optimized management of excavated soils in urban areas involves setting up channels for the reuse of unpolluted or slightly polluted soils, to limit landfill. In this frame, the French environmental policy proposes a methodology to verify the compatibility of these materials with the receiving site, as it is mentioned in the French guide on the management of excavated materials. This includes the geochemical background of soils. The usual algorithms used to calculate a geochemical baseline are adapted in case of dedicated datasets. However, France does not acquire such dedicated data in a systematic manner, as compared to other countries. Because the usual statistical approach shows important limits in case of undedi-cated datasets, we explore the potential of a spatial approach, and more particularly the potential of geostatistics.

The available data coming mainly from pollution diagnostics, many values correspond to point source contamination. Because these data do not correspond to the geochemical background, there is a need to first separate the corresponding geochemical “anomalies” from the “background” values. These latter correspond to natural geochemistry of materials in place plus diffuse contamination due to human activities. To achieve this separation, we tested the potential of a filtering based on a factorial kriging. The geochem-ical data associate land use as well as geological descriptors. In this frame, we developed a R program. We examine its application at two different scales (a site and a district) and compare the results to previous statistical calculations.

The results demonstrate that the factorial kriging can separate the geochemical anomalies based on their spatial variability, even with undedicated datasets. The comparison with the statistical threshold values shows that the range of values obtained with filtering better reflects the pedo-geochemical background by being certain not to take into account anomalies, even in cases of high propor-tions of these anomalies. It can be used at different scales. Such a geostatistical approach shows to be a good alternative to statistical algorithms for the calculation of the pedo-geochemical baseline. It allows also a spatial representation of the geochemical background and facilitates comparison between producing and receiving sites.

This methodological work, carried out as part of a thesis funded by the French environmental Agency (Ademe) and BRGM, contrib-utes to the reflection on the implementation of local geochemical quality standards for urban soils in France linked to the current French environmental policy.

Multi-national perspectives and remedial considerations for 1,4–Dioxane as co-contaminant at chlorinated solvent sites

Paulo Valle; Olga Vounaki; Ken Kiefer; Wijnand GermsERM

There is an increasing awareness of the potential presence of 1,4-Dioxane (Dioxane) as a co-contaminant associated with chlori-nated solvents in groundwater, driven largely by work undertaken in the USA. Dioxane is a water soluble compound classified as a likely human carcinogen and it’s co-occurrence with chlorinated solvents has primarily been associated with its use as a stabilizer for 1,1,1-Trichloroethane (TCA). Patent documents further suggest that Dioxane may have been used as a stabilizer for some formula-tions of Trichloroethene (TCE).

A large scale study in the USA (assessing data from > 2 000 sites) showed that where Dioxane had been analyzed and detected, it co-occurred with TCA 76% of the time (Adamson et al, 2014). In a study undertaken for US Naval sites approximately 64% of Dioxane detections were associated with TCE independently (Anderson et al, 2012). In comparison to the work undertaken in the USA, there is still a paucity of Dioxane data in relation to TCA groundwater impacts in other parts of the world. Recent studies performed in Belgium at sites with known TCA impact identified Dioxane above the WHO drinking water guideline of 50 µg/L in 13 out of 16 sites. Test work undertaken at a known TCA affected site in Australia returned Dioxane concentrations above the laboratory limit of reporting in all 15 groundwater samples tested, with reported concentrations ranging between 49.4 µg/L and 86 600 µg/L. While the data from Australia and Belgium are still relatively limited, it does suggest the likely widespread co-occurrence of Dioxane with TCA.

The presentation will provide a summary of knowledge gained from the review of relevant literature on the co-occurrence of Dioxane with chlorinated solvents, and will outline learnings from the analysis of pooled data from sites in Australia and Belgium that the authors have access to. Remedial considerations will be discussed, along with the importance of identifying the presence of Dioxane early in the project given the differing chemical properties of Dioxane and chlorinated solvents. The latter will be demon-strated through case studies entailing groundwater treatment facilities treating chlorinated solvent plumes from multiple sites. The treatment plants utilized air stripping technology (prior to identifying the presence of Dioxane), which while effective for the chlorinated solvents targeted, led to post-treatment Dioxane impacted water being re-injected into the environment. For a case in Australia, this created a large scale dilute Dioxane plume leading to the shutdown of municipal and several private drinking water wells. Such occurrences can be avoided with early identification of Dioxane impact allowing for the timely incorporation of appro-priate mitigation measures.

Policy on diffuse soil contamination and emerging contaminants: New sounds from Flanders

Griet Van Gestel; Dirk Dedecker; Johan CeenaemeOVAM - Public Waste Agency of Flanders

Diffuse soil contamination and emerging contaminants are major challenges for current policies on soil protection, in Flanders and elsewhere. Until recently, the soil policy in Flanders focussed on contamination related to known risk-entailing activities.

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A framework for dealing with PFAS in the Netherlands

Martijn van Houten¹; Hans Slenders²; Arne Alphenaar³; Willem Hendriks¹; Tessa Pancras²; Ko Hage³¹ Witteveen+Bos; ² Arcadis Netherlands; ³ TTE Consultants

For the past 30 years the emphasis of soil policy has been on tackling regular contaminations, however new substances are discovered and produced continuously. The risks associated with these new substances were often unknown. An example is PFAS, a substance group that includes both known and new pollutants. In 2015 two cases of pollution with PFAS caused social and political unrest in the Netherlands and led to political discussions. This caused a call for a framework for dealing with such substances. A lack of knowledge led to unacceptable risks as well as the imple-mentation of unnecessary (precautionary) measures. Therefore, the challenges of dealing with PFAS in the Netherlands were not only technical but also regulatory.

Since 2015 the Centre of Expertise on PFAS (Arcadis, TTE Consul-tants and Witteveen+Bos) have worked together with the National Institute for Public Health and the Environment (RIVM) and 19 government authorities (municipalities, waterboards, provinces) to obtain knowledge and to develop an operational framework for soil management with regard to PFAS. This project was commissioned by the municipality of Dordrecht, with support of the Ministry of Infrastructure and Water.

In June 2018 the Dutch Centre of Expertise on PFAS released a framework document which describes how to deal with PFAS contaminated soil and groundwater in the Netherlands. This document was intended as a practical and implementation-oriented framework that helps with strategic policy development, initiation of field-investigations, interpretation of chemical data and determining the next/follow-up steps.

Besides the framework document a few other documents were published. These documents were made with the support of the 19 local and regional authorities who support this project with pilot cases, data, field measurements and their knowledge. The results were published in an additional document which provides:

- information on the behaviour of the PFAS contaminants and why these substances require attention;

- the Relative Potency Factors (RPFs) of 11 PFAS and GenX in relation to PFOA;

- an analyses off soil and groundwater data close to possible sources/hot spots for PFAS;

- operational perspectives for dealing with PFAS in soil and (ground)water;

- information on practical aspects of working with PFAS contaminated soil and groundwater, such as safety measures, remediation solutions etc.

The framework will be implemented by local and regional authori-ties for the reuse and remediation of soil and groundwater. In order to draw up this framework detailed information on PFAS was required, for which five lines of research were formulated. In our presentation we will outline the process that led to the operational framework. We will focus on the major problem in the Netherlands with PFAS, namely the impact of the impossibility to reuse soil that is (lightly) contaminated with PFAS. Furthermore we will briefly present the overall results of this project, for example regarding the RPFs that were derived by the RIVM.

Also, only well-known substances are analyzed in the common practice. However, the growing concern on these matters urges that emerging contaminants and diffuse soil contamination are included as well, in order to protect human health and soil ecosystems.

In Flanders diffuse soil contamination is defined as soil contamina-tion that cannot be directly linked to a known source, or is caused by dispersed sources. E.g. soil contamination that is due to all kinds of small-scale artisanal activities in the past of which no record has been kept; or soil contamination caused by atmospheric deposi-tion from an unknown source, agricultural inputs, flood events, … Also soil contamination covering large areas and difficult to delineate, is considered as diffuse soil contamination.

To include emerging contaminants in the regulations on soil contamination, OVAM followed a stepwise approach, with priority given to substances of the highest risks. In order to estimate the overall risks for Flanders, exploratory measuring campaings were organized for substances such as 1,4-dioxane and PFAS. The implementation of these emerging contaminants in regulations and guidelines, revealed questions regarding liability and obliga-tions defined in the Soil Decree. Some emerging contaminants are related to known risk activities, but many others, e.g. pesticides, perfluors, brominated flame retardants, … are present as diffuse soil pollution, and enhance the urgency to develop an adequate policy on diffuse soil contamination.

As authority, we are facing following challenges:

1) Taking decisions with missing or fast-evolving knowledge, e.g. on critical levels of new substances in soil. Especially, policy decisions on excavated soils cannot be postponed. The precau-tionary principle needs to be balanced with practical feasibility and principles of circular economy.

2) It is clear that the ‘polluter pays’-principle alone will not be suffi-cient to solve the problem. We need to look at other principles as a basis for legislation, e.g. the responsibility of land owners or producers.

As a basis for future policy, OVAM started an inventory study of all data on diffuse soil contamination in Flanders. The aim is to have an idea of the scale and characteristics of the problem, and to find out if these data can be incorporated in the OVAM database. Data to include are e.g. technical reports on excavated soil, large scale monitoring studies, data on discharges in surface waters, on fertil-izer and pesticide use, … . A global risk analysis will be done, in order to prioritize the different kinds of diffuse soil pollution. Gaps in information will be indicated, where monitoring may be appro-priate. Also juridical consequences will be considered.

In the presentation, the inventory study will be discussed, as well as other relevant policy actions. Practical examples will be given, and the need for international collaboration will be stressed.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologies

Enhanced in-situ bioremediation (EISB) combined with in-situ chemical reduction (ISCR) for the remediation of a heavy contaminated chlorinated solvents source zone in an industrial site in South of Italy

Firoozeh Arjmand; Irene Bona; Marialuisa Cremonesi; Leandro MorettiJACOBS

The present site comprises an urban development site where a historical Chlorinated Compounds-CHC (Tetrachloroethylene-PCE) contamination has been released in aquifer before eighties. Inves-tigation and safety measures started at the end of nineties. The contamination was present in shallow aquifer (CHC concentration up to 10 mg/L), characterized by diverse and complex geology, and decreases vertically. The traditional site characterization has been integrated with an MIP investigation for finalizing the remediation project. This identified the specific shape of the plume. The plume has been addressed into four areas of interest, to be addressed step by step, from upgradient to the end of the plume.

The strategy of the remediation was focused on a short term schedule. A combination of EISB and ISCR was selected as a means of securing dissolved phase contaminant removal due to biodeg-radation, potentially approaching the electron donors for the target solvent and the common point of bioremediation stall. This combination allows to create rapidly a reducing ambient due to producing hydrogen in both chemical reaction of ZVI and substrate fermentation stimulating the microorganisms to degrade the PCE into the less chlorinated compounds and at the end to ethylene.

The first injection applied in a pilot scale to better calibrate the in-situ technology for the site-specific conditions. Based on the successful results of this phase, the full-scale planned for phase two and applied in three steps. First step covered the northern part of the plume (area A) in the upgradient area (where the groundwater moves towards the source zone) and the main secondary source zone (area B) which was the most contaminated part of the site. After almost a year, the injection took place in area C near to the site boundary and in area D in downgradient of the site were the contamination where observed. Finally, in July 2018 last Step took place to complete the previous steps. PCE bioremediation arose in by-products (in small amounts) production: trichloroethylene (TCE), 1,2-dichloroethylene (1,2-DCE) and vinyl chloride (VC).

During the enhanced reductive dechlorination we have observed methane production because of methanogenesis reaction, even with the injection of methane inhibitors; methane accumulated below paved areas while in proximity of the green zones it mineral-ized. A specific SVE system, with biofiltration plant was installed to prevent migration. The challenge of the treatment of this complex geology has been solved by using fixed injection points incorpo-rating a series of non-return valves corresponding to the depth of treatment in each aquifer. This allowed for accurate and tailored dosage application of the product into the aquifer without any risk of cross-contamination. The PCE, has shown reduction of three orders of magnitude and in some points, we reached the target limit, without by-products accumulation. The whole efficiency of the remediation activities is currently of about 99.9%, having removed more than 300 Kg of dissolved PCE.

ThS 4a Bio-, nano-, and chemical remediation

Comparative evaluation of the polyhydroxylalkanoates (PHAs) fermentability from different sources for bioremediation applications

Neda Amanat; Marta M. Rossi; Berardino Barbati; Laura Lorini; Laura Chronopoulou; Marco Zeppilli; Mauro Majone; Marco Pertrangeli PapiniUniversity of Rome “La Sapienza”

Nowadays bioremediation technologies are receiving growing attention as cost-effective and in-situ applicable strategies for contaminated site. Moreover, in soil and groundwater naturally occurring microorganisms can effectively reduce chlorinated compounds, by the so-called Biological Reductive Dechlorination (BRD). They consist of several stages to convert a toxic organic contaminant (high chlorinated ethane/ethene) to less toxic compo-nents (until ethene). Nevertheless, the lack of electron donors is usually recognized as a limiting factor in BRD. To overcome the problem, the in-situ bioremediation of chlorinated solvents has been used based on the injection of electron donors to speed up the reductive dechlorination natural processes. In this context, the use of biopolymers known as polyhydroxybutyrates (PHBs), which are completely biodegradable polyesters, have been advanta-geously used as electron donors source for sustaining in-situ BRD (Matturro et al., 2018). These biopolymers are produced in very strictly conditions which cause high-cost of production. In recent years, more interest has been dedicated to polyhydroxylalkanates (PHAs) obtained by selected mixed microbial cultures (MMC) which reduce the total costs by combing the wastewater treatment with bioplastic production (Valentino et al., 2017).

This work is aimed to investigate, by monitoring of Volatile Fatty Acids (VFAs) production in microcosms, the anaerobic ferment-ability of three laboratory-made PHA / PHB (as obtained by MMC), in comparison with three commercial PHB. The laboratory-made materials were: (i) raw biomass after PHA accumulation step, (ii) purified PHA extracted from the (i) ( (i) and (ii) were from Trev-iso-Italy wastewater full-scale plant) and (iii) PHB blending with zero-valent iron particles to combine consolidated chemically reactive media with a slow-releasing carbon source (prepared at the University of Rome “La Sapienza”) (Chronopoulou et al., 2016). The tests were set up by adding the different materials in serum bottles with anaerobic mineral medium and inoculated with an anaerobic activated sludge. After some latency period, the VFAs production increased for both commercial and lab-made products, although the differences are the way that they arrive at the maximum quantity of production. These differences can be attributed to the granulometry of the materials since they have been studied in powder and pellets formats which determines various surface areas and, therefore, different kinetics, and as expected the VFAs increase more rapidly for the powder ones. Moreover, the behavior observed for the raw PHA is very interesting due to its immediate fermentation with quantity of VFAs comparable to commercial ones; in addition, due to its possible environmental application, the cost of production is much lower as it has not been subjected of extraction and purification phase. Also, the PHB-ZVI composite material showed a rapid fermentation with high quantity of VFAs production; the advantage that this material could offer in the field of remediation resides in the synergistic effect is coupling of biotic and abiotic reductive dechlorination processes.

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and ecosystems. In this sense, the use of nanoparticles to immo-bilize metal(oid)s in contaminated water and soil samples has resulted effective. Concretely, As is a prolific metalloid in polluted soils, which has been started to study at laboratory scale using zero valent iron (ZVI) nanoparticles. Therefore, this work aims to evaluate three types of commercial iron nanoparticles to immobi-lize As in a polluted sandy soil, and also to examine qualitative and quantitative effects on hydrocarbons.

Samples from a former industrial area located in southern Spain were characterized, revealing As and hydrocarbons affection exceeding soil screening levels. Arsenic and PAHs (total 16 priority from EPA) mean concentrations were 1,300 and 1,115 mg/kg respectively. Subsamples were treated with three types of nanoparticles at different doses based on previous studies and homogeneous in what regards to iron content. The evolution in As availability was evaluated according to the TCLP test and the two initial fractions of a sequential extraction procedure (Tessier). Total As contents were obtained by GF-AAS, and arsenic speciation was analyzed by HPLC-ICP-MS. In addition, a germination test was carried out to determine nanoparticles phytotoxicity. Regarding hydrocarbons, quantitative data (PAHs) and qualitative ratios were obtained by GC-MS.

The nanoparticles addition decreased the As availability in the three cases after 3 days of treatment. The best immobilization results were obtained for goethite nanoparticles, that promoted a severe decrease of As availability using both low (83% reduction) and high doses (close to 100%); however, soil phytotoxicity was increased using these nanoparticles at higher doses as a consequence of a notable increase of electrical conductivity. On the contrary, ZVI and magnetite diminished soil phytotoxicity. According to Tessier extraction, in the three cases, the increase of nanoparticles doses implied the increase of residual fraction and the decrease of the other fractions. In addition, goethite decreased slightly the pH whereas an increase was observed for magnetite and ZVI nanoparticles. Arsenic speciation was not affected, (>95% of As(V) in all cases). Regarding organics, magnetite nanoparticles favoured a reduction of PAHs concentration to 865 mg/kg, this mechanism might be due to their crystalline structure (magnetic spinel), although the effect of the organic coating should be also considered. Conversely, ZVI did not modify organics content while nano-goethite increased PAHs concentration as a probable effect of an increase of availability. These results show the effectiveness of the evaluated nanoparticles depends on the pollutant concentra-tion and characteristics and the applied dose.

Acknowledgments: REHABILITA CTM2016-78222-C2-1-R and NANOBIOWASH CTM2016-75894-P (AEI/FEDER,UE)

Cathodic autotrophic microbial communities able to stimulate hexavalent chromium reduction

Gabriele Beretta¹; Anna Espinoza²; Giorgio Ferrari¹; Andrea Franzetti²; Andrea Mastorgio¹; Lisa Pedrali¹; Sabrina Saponaro¹; Elena Sezenna¹¹ Politecnico di Milano; ² Università degli studi di Milano – Bicocca

Groundwater is the environmental compartment most frequently affected by anthropogenic hexavalent chromium. Because of its cancerogenicity, Cr(VI) must be removed, hopefully using envi-ronmental-friendly and sustainable remediation technologies. BioElectrochemical Systems (BESs) applied to bioremediation offer a sustainable alternative to traditional bioremediation tech-niques, with minimum disturbances to the natural groundwater conditions. Some bacterial families are capable of oxidizing and/

Innovative solution for difficult to treat a large TEX contamination: Stimulation of the anaerobic bioremediation

Hans Baillieul¹; Jeroen Vandenbruwane¹; Fleur Verfaillie²; Geert Boucneau²¹ Sodecon; ² Universoil

On an industrial site near Brussels, the presence of 40 underground solvent storage tanks have led to a large TEX contamination. A total surface of 4.000 m² has been contaminated and the contamination has reached a depth of 18 m-bgs. Concentrations of up to 90 mg/L total TEX are present in groundwater.

The first step of the remediation consisted in removal of the under-ground storage tanks and excavation and on-site treatment of the soils to a depth of 5 m. Treatment of the deeper part is difficult mainly because of the silty texture of the soils resulting in a limited permeability between 5 and 13 m-bgs. As a consequence, tradi-tional technologies like groundwater extraction and biosparging cannot be used to treat the contamination.

Sodecon was asked to develop a robust solution for the deeper contamination. After a first evaluation, it was proposed to add sulfate as an alternative electron acceptor instead of oxygen to degrade the contamination. As the solubility of sulfate is more than 1000 x higher than oxygen, the oxidative power per volume of water that can be added to the subsurface is significantly higher than with an airsparging system. This is a huge advantage for treatment of the low permeability soils on the site since it is difficult to inject large volumes.

In order to test this innovative remedial approach, a pilot test was performed with injection of a sulfate solution. As injection in soils with low permeability is challenging, two different injection technologies were tested. Testing has revealed that one injection technology caused superior distribution of the injection solution. It was also discovered that – in contrast to the visual observations during drilling - there was a large degree of heterogeneity in soil that needs to be taken into account. After the successful pilot injection, sulfate was still present in all monitoring wells 8 months after injection causing large reductions in TEX concentrations: toluene: 99%, xylene: 80%; ethylbenzene: 59%. Degradation is still in progress as sufficient sulfate is still present. A full scale remedia-tion plan has been made to treat the whole site.

Anaerobic processes are well known for chlorinated solvents but are not common for treatment of BTEX contamination as these processes are generally thought to be too slow. However, this pilot test demonstrates that it is possible to achieve rapid degradation of TEX compounds in difficult geologic settings in case of a well-designed injection strategy.

Comparing zero valent iron, magnetite and goethite nanoparticles to remediate concurrent inorganic and organic pollution in brownfield soil

D. Baragaño¹; J.R. Gallego¹; M.C. Lobo²; J. Alonso²; E. Rodríguez-Valdés¹; M. Gil-Díaz²¹ University of Oviedo; ² IMIDRA

Anthropogenic activities, as mining or manufacturing, are sources of concurrent pollution. In case of organic contaminants, their degradation can be performed by means of bioremediation tech-niques, however, it is not possible to degrade metal(oid)s but reducing their mobility is a viable strategy to avoid risk for humans

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40÷50°C for 12 days to attribute PAH removal only to biological treatment. PAH concentrations, PAH bioavailability and biogas production were monitored. TD, testing different temperatures in 1 hour of experimentation, was carried out with aluminum capsules containing 10 g of soil each and introduced in a muffle furnace at 150, 300 and 450°C. PAH concentrations were measured at 1, 2, 5, 15, 30 and 60 minutes. The removal efficiency of the most bioavailable PAHs, i.e. phenanthrene and fluoranthene, was 10% higher than that obtained with anthracene and pyrene (i.e. 15%), with the process performance increasing by 20% when the nutrient solution was used. No PAHs were detected in the activated carbon after the vola-tilization test, indicating that the main PAH removal mechanism was biodegradation. In regard to TD, low molecular weight PAHs were removed faster than high molecular weight. Indeed, phenanthrene and anthracene were completely removed at 150°C. In contrast, the removal of fluoranthene and pyrene reached 60%. Increasing the temperature to 300 and 450°C, all PAHs were completely removed from sediments in 5 minutes and 1 minute, respectively.

Enhanced anaerobic bioremediation of a site contaminated with chlorinated ethenes: From lab studies to full-scale implementation

Natàlia Blázquez-Pallí¹; Mònica Rosell²; Albert Soler²; Teresa Vicent³; Ernest Marco-Urrea³; Marçal Bosch¹; Joan Varias¹¹ Litoclean; ² Universitat de Barcelona; ³ Universitat Autònoma de Barcelona

An industrial site in Barcelona (Spain) was contaminated with perchloroethylene (PCE) after its use as a degreasing agent. The initial investigation of the site revealed that, besides PCE, trichlo-roethylene (TCE), cis-dichloroethylene (cis-DCE) and traces of vinyl chloride (VC) were also found in groundwater. Monitoring of concentrations and carbon stable isotopes (δ13C) of these pollut-ants together with molecular analyses in microcosm experiments suggested that biostimulation with sodium lactate was a feasible strategy to transform PCE to innocuous ethene (Blázquez-Pallí et al., 2019). These results were further supported by a single-lactate-injection in situ pilot test performed in one of the impacted boreholes. The monitoring of the pilot test showed that lactate injection promoted a significant decrease in the redox potential, which was accompanied by an enrichment in the heavier isotopes of the chlorinated ethenes, and that ethene was the main product detected after 200 days. Based on these observations, a full-scale biostimulation with sodium lactate was designed and implemented starting on August 2017. Three injection campaigns were initially planned over a year, one every four months, approximately. Lactate was strategically injected in several boreholes that were spread across the site, aiming to cover the maximum area of the contami-nation plume. The most relevant parameters (redox potential and metabolites’ concentrations) were monitored periodically after two and a half months of each injection. The first monitoring campaign revealed that, after biostimulation, redox potentials rapidly decreased across the site and that PCE was globally dechlorinating to its degraded forms (TCE, cis-DCE and VC). However, it was also detected that redox potentials were recovering (to more positive values) faster than expected; therefore, periodicity of lactate injec-tions was increased to once every three months, approximately. To confirm biodegradation and to fully evaluate the success of the biostimulation treatment, a monitoring campaign was carried out on September 13th, 2018, focused in concentrations and δ13C of the remaining contaminants. Results show that after, approxi-mately, one year of lactate injections into the aquifer, the total concentration of chlorinated ethenes has greatly decreased, PCE and TCE are almost eliminated from the plume, cis-DCE is still

or reducing, respectively, solid electron donors or acceptors. On the bio-cathodes, bacteria act as a biocatalyst, using the electrons provided from the electrode to reduce oxidizing compounds present in the cathodic solution.

In the present study, we have assessed the possibility to stimulate bio-reduction of Cr(VI) in a biocathodic compartment of a dual-chamber Microbial Electrolysis Cell (2C-MEC), with the cathode as the sole electron donor. To develop an electro-active microbial community, three clean graphite electrodes were initially inserted into the anodic compartment of a dual-chamber Microbial Fuel Cell inoculated with sludge from an anaerobic digester. After a period of acclimation, two electrodes were used as the cathode into two identical potentiostatically controlled BESs, set at -300 mV and 700 mV (vs. SHE) respectively, and the third one in the open-circuit control. The three systems were spiked with Cr(VI) to an initial concentration of 1000 µg Cr(VI) l-1, and operated in parallel. Cr(VI) dissolved concentration was periodically checked during and at the end of the tests by spectrophotometric method. At the beginning and at the end of the experiments, the microbial characterization of the communities enriched on the bio-cathode and in the cathodic solution was performed by sequencing the 16S rRNA gene.

“Cr(VI)-reducing BES” with the bio-cathode set at -300 mV showed the highest Cr(VI) removal efficiency (93%), with higher reduction rate than the other systems. The different operative condi-tions (cathode potential or open circuit) affected the microbial community structure, thus changing the overall efficiency of the process and Cr(VI) reduction rate.

Removal of polycyclic aromatic hydrocarbons from contaminated marine sediments by biostimulation and thermal desorption

Francesco Bianco¹; Marco Race¹; Stefano Papirio²; Giovanni Esposito²¹ University of Cassino and Southern Lazio; ² University of Napoli Federico II

Polycyclic aromatic hydrocarbons (PAHs) are a group of total petroleum hydrocarbons known to be carcinogenic and mutagenic. These organic pollutants are released into the environment due to petrogenic and pyrogenic causes, and highly accumulate in soils and sediments due to their hydrophobicity. Many studies have reported and quantified PAH accumulation in marine sediments worldwide, such as 16.20 mg·kg-1 (as ∑PAHs/dry soil) in Kaohsiung Harbour (RC), 23.32  mg·kg-1 in Chesapeake Bay (USA) and 90.44  mg·kg-1 in Montevideo Harbour (UY). In particular, concentrations of 2807 mg·kg-1 exceeding the acceptable PAH limits imposed by the Italian legislation (i.e. 100 mg·kg-1 ∑PAHs/dry soil for an industrial use of the remediated soil) have been found in the Bagnoli Harbour, in the area of Napoli. In this study, a comparison between bioremediation (BR) and thermal desorption (TD) was performed for the removal of PAHs from an artificially spiked marine sediment. The selected PAHs were phenanthrene, anthracene, fluoranthene and pyrene, added each with an initial concentration of 300 mg·kg-1 dry soil to simulate the contamination values found in previous studies. BR was operated through biostimulation (BS) under strict anaerobic conditions, using digestate and organic fraction of municipal solid waste as inocula and sources of extra organics. The addition of a nutrient solution to the soil was used to stimulate PAH biodegradation. The experiments were conducted using 80 mL bottles, with each bottle containing 10 g of dry soil mixed with inoculum at a ratio of 1.0:0.1 (w/w), and a moisture content of 60% to ensure microbiological activity. The bottles were closed and incubated in a water bath at 37±1 °C for 90 days at 130 rpm. A volatilization system, using activated carbon as sorbent, was tried out in a temperature-controlled chamber at

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VITO is the patent owner of the bioreactor, however GreenSoil has the exclusive license on this technology in Europe, and it is the preferred partner in the rest of the world. The team work of the parties involved allowed a noteworthy development of the application of the biore-actor as part of in-situ and on-site MTBE bioremediation. This feasibility study manifested the importance of collaboration among research institutes, consultants and contractors to further improve existing technologies. The fruitful collaboration results in the client request to develop a full-scale remediation system for this site which is planned to become operational in 2019.

A review of chemical treatment methods for soil and groundwater containing arsenic and chromium

Philippe Denecheau; Alan Seech; Alberto LeombruniPeroxyChem Environmental Solutions

Treatment of soil and groundwater contaminated with a mixture of heavy metals can be challenging because the mechanisms operative in adsorption, precipitation, and co-precipitation of these target compounds are complex and vary widely. For example, an alkaline reduction treatment that effectively removes soluble chromium may simultaneously increase the solubility of arsenic. The mechanisms involved in treatment of heavy metals using reagents based on (a) alkalinity, (b) sulfide, and (c) iron will be reviewed from the perspective of metals present and site conditions. Performance data from both bench-scale testing and field-scale treatment using these three approaches will be presented and discussed. The objective is to review, compare, and contrast various treatment approaches for specific site condi-tions using both target compound geochemistry and data from published field-scale applications.

The mechanisms involved in conversion of common heavy metals from their soluble forms to insoluble forms during treatment with alkaline, sulfide, and iron based reagents will be reviewed with emphasis on the solubility, pH range stability, mineralogy, and other characteristics of the products formed (i.e., heavy metal hydrox-ides, sulfides, iron sulfides, iron oxyhydroxides, carbonates). The findings of both academic and applied research will be discussed from an environmental remediation perspective. The influence of soil/groundwater variables such as native concentrations of iron and sulfate as well as pH and redox status. Regulatory issues and the potential impact of future land use will also be considered.

Treatment approaches for heavy metals should be selected on the basis of several factors including the chemistry of the metals to be treated, the geochemistry and biochemistry of the environment in which the metals reside, the regulatory framework that must be satisfied, and potential changes in land use.

Evaluation of potassium persulfate as an ISCO based permeable reactive barrier for treatment of comingled contaminated plumes

Brianna Desjardins; Brant SmithPeroxyChem Environmental Solutions

In situ chemical oxidation (ISCO) using activated persulfate has been widely applied to treat recalcitrant environmental contaminants of concern (COCs). Much of this history for activated persulfate was based on highly soluble sodium persulfate activated by heat, alka-linity, hydrogen peroxide or chelated iron used to primarily treat highly contaminated source areas. Potassium persulfate is a lower

detected in some boreholes, and VC is the only remaining contami-nant in considerable concentrations. Furthermore, an enrichment in the heavier isotopes of the chlorinated ethenes has been observed, which confirms that biodegradation is occurring. Since the dechlorination reaction of cis-DCE to VC to ethene by native organohalide-respiring bacteria is still active, the following moni-toring campaigns will determine whether further lactate injections are needed. Final analytical results which are expected to show a more advanced decontamination of the plume will be presented at the conference, together with a plan for future monitored natural attenuation that will be designed according to results.

Blázquez-Pallí et al., 2019. Environ. Pollut. 244, 165–173. DOI: 10.1016/j.envpol.2018.10.013

Innovative bioremediation of MTBE and organics: in situ bio-sparging and high yield MTBE bioreactor development

Rogier De Waele¹; Michela De Camillis¹; John Dijk¹; Jan van den Boogaart¹; Martin Slooijer¹; Dirk Paulus²; Wouter De Schuyteneer²; Tine Hofkens²; Leen Bastiaens³; Leen Bastiaens³¹ GreenSoil International B.V.; ² Tauw Belgium; ³ VITO NV

An industrial site in Belgium, is contaminated with a variety of contaminants. Most of the contamination is difficult to reach in ATEX zones due to the infrastructure and the presence of storage tanks. A field test was conducted to investigate the feasibility of treating the different contaminants in-situ with aerobic bioreme-diation. Due to the mobile character of MTBE and the size of the plume, also a specific MTBE-bioreactor was applied.

The field tests were performed at the site in different areas. Pilot 1 was conducted in an uncontaminated area to test the radius of influence of the biosparging system. Pilot 2 was conducted to test the feasibility of stimulated aerobic biodegradation in a contaminated area. Groundwater was recirculated continuously. In addition, a SVE system was installed in the vadose zone, mainly to prevent emissions due to the biosparging. A bioreactor was used to prove biological MTBE degradation. The MTBE bioreactor was fed from a groundwater extraction well and the effluent was infiltrated in an infiltration well.

In the first months, the redox conditions remained strongly reduced. Additional laboratory and field tests done by GreenSoil and Tauw confirmed that the natural oxygen demand of both soil and groundwater, was extremely high. After slightly adapting the system, the redox conditions improved significantly. Hydrocar-bons and monochlorobenzene were removed with an efficiency of >99%, while the in-situ MTBE removal efficiency was in the range of 56-76%. Despite these start-up issues, the radius of influence of the air infiltration system appeared to be around 6m.

In the first 9 months, the flow of the MTBE bioreactor was limited due to the high COD of the groundwater and the rather low influent concentrations (±. 1000µg/l). It was found that the high COD/BOD was caused by a formerly unknown organic acid. Both MTBE and TBA were degraded with >99% efficiency in the biore-actor to concentrations below detection limit. It was observed that in-situ MTBE degradation was significantly higher (93 %) closer to the infiltration well were the effluent from the MTBE reactor was infiltrated than in the wells further away, indicating the additional effect of bioaugmentation.

The outcomes of these feasibility tests demonstrated the active biological activity in these systems which promoted the strong reduction of contaminants.

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(carboxymethyl cellulose, CMC: 0 - 10 g/L). The column experiments (diameter: 1 cm, length: 16.2 cm) were run horizontally inside an anaerobic chamber to minimize particle oxidation. Breakthrough curves were derived by comparison of the particle in- and outlet concentrations over time via optical turbidity measurements with a flow-through cell. The porosity (0.3) and dispersivity (0.0027 m) of the column were determined by fitting the breakthrough curves of a conservative tracer (20 mM nitrate solution) using the MNM software.

In the absence of CMC, sZVI particles quickly agglomerated inside the column with no particles being detected at the outlet. Upon addition of CMC, sZVI breakthrough (BT) substantially increased, with the total BT yield increasing with increasing CMC concentra-tion. However, to yield the same BT with a 10-fold higher particle loading, the CMC amount needed to be increased accordingly, but more than 10-fold. These initial results highlight that like ZVI, sZVI suspensions also need to be amended with a polymer solution to ensure a high radius of influence (ROI) during potential field scale (i.e. aquifers) application. We further observed that pre-condi-tioning of the column with a pure CMC solution is needed to ensure optimum breakthrough. Overall, this study provides very promising results in terms of sZVI transportability, although the parameters controlling the sZVI mobility are not yet fully elucidated.

Acknowledgements: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 675219

Complete dechlorination of chlorinated ethenes and chloroform in a brackish environment

John Dijk¹; Michela De Camillis²; Martin Slooijer²¹ Greensoil Group; ² GreenSoil International B.V.

An industrial site in the port of Tarragona (Spain) is contaminated with mainly chlorinated ethenes, chlorinated methanes and chlo-rinated ethanes. The contamination was caused by leakages of the sewer system in the past. High concentrations (DNAPL) of mainly tetrachloroethene (PCE) and chloroform are present as well as degra-dation products. The remediation goals are 37 µg/l and 6.5 mg/kg for PCE in groundwater and soil, respectively and 440 µg/l and 87 µg/l for Chloroform and Vinylchloride (VC), respectively.

Given the nature of the contamination and aquifer, anaerobic reductive dichlorination was identified as the most promising in-situ bioremedation solution. To test the feasibility of enhanced reductive dechlorination (ERD) to remediate the site both labora-tory tests and a field test were conducted in the past. Based on the successful results of these tests, a full scale remediation is being carried out. Since the site is situated close to the sea, the ground-water is brackish to salt with an electrical conductivity (EC) up to 25,000 µS/cm and sulphate concentrations up to 1600 mg/l.

The remediation consists of circulation of groundwater via extrac-tion and infiltration wells, and adding an electron donor to stimulate the process of ERD. DNAPL was removed from the extracted water above ground. By circulating groundwater the electron donor and dechlorinating microorganisms will be distributed and the contam-ination will be mobilized as well. Besides regular monitoring of geochemical parameters and the concentrations of contaminants also molecular analyses (qPCR and sequencing) were performed to have a better understanding of the microorganisms and degrada-tion pathways involved under these specific conditions.

Concentrations as high as 100,000 µg/l of PCE, 41,000 µg/l of VC and 340,000 µg/l of Chloroform were found on site. After about six

solubility alternative that is being used to extend the period of active treatment for an activated persulfate application to better treat low permeability soils or in permeable reactive barriers.

Potassium persulfate was used to evaluate three separate sites. Two of the sites were contaminated with a mixture of 1,4-dioxane, chlorinated ethenes, and chlorinated ethanes. The third site was contaminated with a mixture of petroleum hydrocarbons and pentachlorophenol. An evaluation of the contaminant mixtures at each site indicated that both oxidative and reductive pathways resulting from activated persulfate reactions would be necessary for complete treatment. All three sites were evaluated in a series of column reactors where site groundwater was then run through the columns until the potassium persulfate had been consumed. Two of the sites were subsequently field pilot tested with one of the sites having potassium persulfate applied on the full scale.

This presentation will provide the results from each site and highlight key conclusions in terms of the effectiveness of the oxidative and reductive pathways and comparative benefits of two activation schemes for potassium persulfate. The data indicated:

• Sites 1 & 2: Hydrated lime induced alkaline-activated potassium persulfate reduced 1,4-dioxane, chlorinated ethenes, and the chlorinated ethanes concentrations to below the detection limit. ZVI-activated persulfate resulted in treatment to non-detect of 1,4-dioxane and chlorinated ethenes while reducing chlorinated ethanes by 20 to 60 percent.

• Site 3: Pentachlorophenol was reduced by three orders of magnitude at the third location tested.

Field data not only evaluated treatment effectiveness but also the persistence of potassium persulfate compared to the sites ground-water velocity. Field data indicates the potassium persulfate was persisting as expected based on the observed groundwater velocities.

Transport of sulfidized zerovalent iron particles in porous media: Need for a particle stabilizer

Flavia Digiacomo¹; Marco Mangayayam²; Dominique Jeanette Tobler²; Thomas Neumann³; Thomas Held¹¹ Arcadis Germany GmbH; ² University of Copenhagen, Denmark; ³ Technical University of Berlin

The use of zerovalent iron (ZVI) for in situ remediation of contami-nated aquifers (e.g., chlorinated solvents, pesticides and heavy metals) is well established. However, there are some major drawbacks to the use of ZVI. Upon injection into the subsurface, ZVI reactivity is often rapidly passivated due to reaction with water. Moreover, it is challenging to get ZVI well distributed due to their rapid agglomeration and settling behaviour. To increase ZVI distri-bution, polymers such as guar gum and xanthan gum can be added to ZVI to create more stable suspensions. However, this treatment does not prevent rapid surface passivation by water. Recently, it has been shown that sulfidized ZVI (sZVI) retard passivation and show even higher trichlorethylene (TCE) reduction rates compared to ZVI. While these sZVI particles have gained rapid interest as potential new in situ reactants, no study has investigated the mobility of these modified ZVI particles so far.

Hence, we investigated the transport behavior of sZVI in packed sand columns (quartz grain sizes:

0.1 – 0.3 mm) as a function of particle inflow concentration (0.1 vs 1 g/L), Darcy flow velocity (69 m/day) and polymer stabilizer

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesmonths, degradation products had increased in concentrations significantly and after about 12 months, ethene increased dramati-cally from below detection limit up to 26,000 µg/l. Molecular analyses of groundwater from several wells were performed and confirmed that there is a strong increase in the amount of bacteria and enzymes involved in dichlorination. For example the VC reductive dehalogenase vcrA increased up to 3.8E+11 copies/l. Dehalobacter, Geobacter and Dehalococcoides were all present in high numbers and increased in time, with the exception of Geobacter in some wells. Also the gene encoding for chloroform reductive dehalogenase (cfrA) increased dramatically from below detection limit up to 8.9E+7 copies/l. The DNA from the well with the highest number of both vcrA and etnE was partially sequenced (ORVIdecode). It appeared that the dominant genus of the bacterial community consisted of Dehalococcoides (27%) of which 70% was closely related to Dehalococcoides mccartyi.

These results so far demonstrated the enhanced biological degra-dation capacity on site and the complete dichlorination of the various contaminants, despite the high concentrations of chloro-form and the brackish to salt environment.

Full-scale in situ remediation of chlorinated solvents in clay till by microscale ZVI emplaced by direct push jet injection: Results after 4 years

Neal Durant¹; Chapman Ross²; Dylan Eberle²; Torben Jørgensen³; Morten Dreyer³; William Slack⁴; Drew Baird⁴; Peder Johansen¹ Geosyntec; ² Geosyntec Consultants Inc.; ³ COWI A/S; ⁴ FRX Inc.

The near-surface geology in northern European countries is commonly comprised of glacial clay till. In situ remediation of chlorinated solvents in clay till can be costly and time-intensive due to diffusion of chlorinated solvents and the low-permeability of the matrix. While excavation and in situ thermal remediation are sometimes feasible, both options are expensive and require a high energy demand / carbon footprint. The Capital Region of Denmark commissioned a project to develop and demonstrate a novel approach to remediating chlorinated solvents in clay till in situ using microscale zerovalent iron (mZVI) emplaced by direct push technology jet injection (DPT-JI). DPT-JI combines high pressure jetting (700 bar) and hydraulic fracturing for controlled delivery of amendments into geologic matrices where contaminants are trapped and back diffusion limits the rate of remediation.

The demonstration was performed at a site in Nivå, Denmark (the Site) impacted with chlorinated volatile organic compounds (CVOCs) in clay till over an area of approximately 750 m2 between depths of 6 to 12 meters (m) below ground surface (bgs). Trichlo-roethene (TCE) was the primary contaminant of concern, with baseline (pre-treatment) soil concentrations as high as 83 mg/kg. In November 2014, DPT-JI was used to inject 49 tonnes of mZVI in a guar/sand slurry into the target treatment zone (TTZ) to address CVOC impacts at the Site. mZVI was injected at 21 boring locations, at 1-m injection intervals between 6 and 12 m bgs, with a design radius of influence (ROI) of 4 m. A combination of colored sands, dye-tracers, and magnetic susceptibility were used to document injection performance in 80 soil core locations across the TTZ. A 6-year performance monitoring program was then initiated to evaluate CVOC destruction over time. Groundwater sampling events have included analyses for CVOCs, degradation products (e.g., ethane, ethene), specific dechlorinating bacteria (e.g., Deha-lococcoides-vcrA), and CSIA of 13C/12C and 37Cl/35Cl enrichment factors for TCE, cis-1,2-dichloroethene, vinyl chloride, ethene, and ethane.

After 44 months, the estimated mass of TCE in TTZ soils decreased by approximately 92% from 29 kg to 2.3 kg, and total CVOC mass in soil decreased by 82%. Groundwater data from 44 months post-injection indicate that the total CVOC mass discharge from the TTZ has decreased by over 94%, and the total estimated mass of ethene and ethane in TTZ groundwater was found to be higher than the remaining total CVOC mass (up to 6.5 mg/L of ethane was detected in groundwater). Results of temporal and spatial assessment of the CVOC/ethene+ethane mass balance within the TTZ indicate that abiotic dechlorination is the predominant CVOC degradation mechanism. 13C/12C and 37Cl/35Cl isotopic ratios indicate that both abiotic and biotic degradation processes are active within the TTZ. Strongly reducing conditions have been observed within the TTZ throughout four years of groundwater sampling events. Results to date indicate that the mZVI emplaced by DPT-JI can achieve a one order of magnitude reduction in CVOC mass in clay till within 5 years.

Sustainable activated carbon for the remediation of insensitive high explosive contaminated water

William Fawcett-Hirst; Tracy Temple; Frederic CoulonUniversity of Cranfield

Activated carbon has successfully been used as an absorbent to remediate contaminated water, removing explosives such as 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and 2,4,6- trinitro-toluene (TNT). However, the introduction of Insensitive High Explosives (IHE) such as 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4-dinitrotoluene (DNT) have different physiochemical chemical properties making them more soluble in water. Due to the high solubility of IHE constituents they quickly exhaust commercial granular activated carbon systems making them less economi-cally viable. Commercially available carbons are usually made from non-renewable bituminous sources such as coal. The use of these non-renewable materials has a high carbon footprint that is asso-ciated with mining and processing. The environmental impact of mining can include soil erosion, loss of biodiversity and contami-nation to groundwater. Therefore, changing to a more sustainable source of carbon would help to alleviate many of these issues.

The aim of this research was to compare the effectiveness of commercially available carbons against sorbents derived from waste materials, such as orange peelings and almond shells to remediate IHE contaminated water. The waste materials were characterised and down selected for their successful sorbtion of materials with similarities to IHE such as the antibiotic metro-nidazole. The ability to use sorbent materials that are renewable and locally available, which avoids intrusive processing is a much more sustainable approach with minimal carbon footprint. The experimental phase involved testing a variety of carbons in both bottle point tests and dynamic tests with an affordability assess-ment to ensure economic feasibility. These tests produced a series of essential isotherms and time/sorption graphs to show the rate of sorption of explosives on to the activated carbons. Further analysis enabled determination of the type of sorption taking place. It was expected that sorbent materials made from waste products could be used to treat contaminated water however they would be less efficient than commercially available carbons. Therefore, the cost benefit analysis is essential to determine the viability of waste carbons as a replacement for commercial activated carbons. Next research steps include the investigation of regeneration methods for carbon, which includes reuse as fertilisers to grow the next generation of crops which can then be used as a sorbent material.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesIn-situ remediation of atrazine- and bromacil-contaminated groundwater: Application screening for two iron-containing reactive particles at the lab-scale

Alina Gawel; Katrin Mackenzie; Sarah Sühnholz; Frank-Dieter Kopinke; Bettina Seiwert; Mechthild Schmitt-JansenHelmholtz Centre for Environmental Research – UFZ

Prior to any application of reactive particles in nanoremedia-tion approaches, the detailed examination of the materials, incl. contaminant degradation, particle fate, formation of transforma-tion products and toxicological assessments are essential.

Two types of particles were studied at the laboratory scale for their suitability for in-situ treatment of water contaminated by the herbicides atrazine and bromacil. Objective of the study was a recommendation to end-users about the most suitable choice of particles in terms of degradation and detoxification performance.

The first particle type is the ISCR material Carbo-Iron®, a composite material consisting of zero valent iron-nanoclusters (ZVI) embedded in an activated carbon (AC)-matrix, which was already successfully applied for contaminations with chlorinated solvents. A strong enrichment of both atrazine and bromacil in the AC particles was found. Both herbicides were chemically converted in the presence of Carbo-Iron®, but only bromacil could be quantitatively reduced. For atrazine, only trace amounts of reduction product were found, as well as for both herbicides in the presence of bare zero valent iron-nanoparticles. Hydrolysis to hydroxyatrazine was the dominant transformation pathway when using Cabo-Iron®.

The second particle type is a Trap-Ox® Fe-zeolite – a sorption-active Fenton-like catalyst. The sorption-active ISCO material offers the possibility to generate stationary permeable oxidation barriers. After an adsorption phase, contaminant degradation and adsorber regeneration is performed by flushing with diluted hydrogen peroxide solution. The adsorption capacity of the examined zeolite towards atrazine and bromacil was below that of Carbo-Iron®, but still in a suitable range for retention in the treatment zone. Both herbicides were degraded with half-life periods below 1 h with 10 g/L catalyst and 30 mg/L atrazine, respectively 50 mg/L bromacil concentrations in 3 wt.% hydrogen peroxide solution. By means of time-resolved analysis of transformation products using UPLC-ESI-TOF-MS, the reaction pathways of the underlying Fenton reaction could be identified.

It is known that ISCO processes can generate partially oxidized transformation products from halogenated compounds which show higher toxicity than the parent compounds. Therefore, green algae toxicological assays were used to examine the ecotoxicolog-ical effects of the treatment process. For both approaches – using the reducing and oxidizing particles – the products showed signifi-cantly decreased phytotoxicity.

For a bromacil-contaminated site, Carbo-Iron® can be recom-mended for further studies in order to prepare a nanoremediation procedure. The same applies to the Trap-Ox® Fe-zeolite regarding both sites contaminated with the herbicides atrazine and bromacil.

Combination of in situ injection of nanoparticles to fix heavy metals, with in situ thermal desorption to address the organics

Jan Haemers Haemers Technologies

Development of a sustainable soil mixing technique using energy efficient binders and iron based reductive dechlorination

Katerina Hantzi¹; Anna Toft¹; Wilhelm Rankka²; Erik Bergstedt³; Klas Arnerdal³; Annika Sidelmann Fjordbøge⁴¹ Capital Region of Denmark; ² Swedish Geotechnical Institute; ³ The Geological Survey of Sweden (SGU); ⁴ Technical University of Denmark

Soil mixing is a delivery technique for reactants in connection with in-situ remediation of contaminant sources e.g. remediation of chlorinated organic solvents by addition of zero valent iron (ZVI). However, in this connection the mixed soil strength is reduced due to amendment with a bentonite slurry. Possible site use alterna-tives after treatment are therefore limited. In 2017, an innovation project called “Sustainable Soil Mixing” was launched, in a collab-oration between the Capital Region of Denmark, the Swedish Geotechnical Institute and the Geological Survey of Sweden. The project is co-funded by Interreg Öresund-Kattegat-Skagerrak (2017-2020). The scope of the project is to further develop the soil mixing technique regarding chlorinated solvents, improving the geotechnical and energy efficiency performance and to demon-strate the new functions in-situ. This is done in:

- a laboratory phase where the project builds new knowledge on how different binder combinations affect the chemical degradation efficiency of TCE in clay till and glacial clay and the development of strength in the treated soil

- a pilot phase where the improved technique is tested on two field sites.

The final aim is to produce a technical guideline for stakeholders (consultants, problem owners, authorities) and to facilitate accep-tance and implementation of the technique in Sweden and Denmark, thereby making it a go to technique, equivalent to exca-vation and thermal remediation.

We will present results from the laboratory phase, which is designed to find an optimal combination of binder components (i.e. cement, slag and/or lime) and reactant(s) (Fe(II)-salts). The combinations are tested for chemical degradation and development of strength. We aim to present binder recipes. We will address several experi-mental challenges and the laboratory methods developed to resolve these. Some challenges are related to expected binder-contaminant interactions: chemical degradation of TCE with ZVI has previously been seen to be inhibited by high pH (>9). Cement is commonly used to improve the soil strength, but the addition of cement raises pH to >11. If ZVI is substituted with Fe(II), the high pH is beneficial for degradation, but perhaps the overall TCE degrada-tion efficiency of the Fe(II)-cement system is reduced compared to the ZVI-bentonite system. The combination of binder components will affect the energy efficiency of the technique, which is a point for consideration, when soil mixing is seen competing with the current state of the art remediation techniques.

We expect the laboratory phase to support conclusions related to the following questions:

- is it possible to combine binder components and Fe-additives to reach acceptable strength in soil and chemical degradation of TCE?

- which binder combinations should be used and how can they be optimized to increase the energy efficiency?

- how can geotechnical and environmental laboratory methods be used to support optimization in preplanning phases?

- how does recommendations for optimization differ between different soil types?

We also expect to gain experience regarding transregional collaborations.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesInvestigation of electrochemistry as a remedy for tetrachloroethylene plumes

Bente Højlund Hyldegaard¹; Akram Alshawabkeh²; Eline Begtrup Weeth¹; Rasmus Jakobsen³; Niels Døssing Overheu⁴; David Gent⁵; Lisbeth Ottosen⁶¹ COWI A/S; ² Northeastern University; ³ GEUS; ⁴ Capital Region of Denmark; ⁵ US Army Corps of Engineers; ⁶ Technical University of Denmark

Chlorinated ethene contamination of the subsurface is extensive and harmful. Effort has been put into remediation of the low-permeable zones, where electrokinetics in combination with more traditional remedies have shown to overcome some of the chal-lenges experienced. With a more frequent detection of chlorinated ethenes above the regulatory levels in groundwater aquifers, attempts are now being made to adapt the promising mecha-nisms of electrokinetics towards remediation of high-permeable zones. Electrochemical remediation is one alternative for in-situ degradation of chlorinated ethene plumes, where i) fast electro-chemical reduction of chlorinated ethenes near the electrodes can be obtained [1] and ii) reactants can be generated, which can subsequently reduce or oxidize the chlorinated ethenes [2]. Focus has been on electrochemical degradation of trichloroethylene in simplified laboratory set-ups. Hence, it is necessary to assess the potential of electrochemical remediation of tetrachloroethylene (PCE) to cover the full range of chlorinated ethenes detected at contaminated sites, and to incorporate field-site characteristics in the assessment. This study aims at filling in some of the knowledge gaps that exist on application of electrokinetics for remediation of high-permeability zones at chlorinated ethene contaminated sites.

The performance of electrochemical remediation of PCE is evaluated using a flow-through column reactor with a three-elec-trode configuration. The significance of electrode configuration and spacing, current intensity and catalyst concentration is assessed. In addition, the influence of a porous matrix, flow rate and orientation of the reactor is examined to simulate field conditions and field-realistic designs. The two-dimensional distribution of the electric field in a sandy geology and the influence of the current intensity on this distribution is assessed in a box set-up. The column and box set-ups are furthermore used for investigation of changes in hydro-geochemistry prompted by the electric field applied.

In the initial screening of electrochemical remediation of PCE in a flow-through reactor, 86% removal was obtained. The results showed, that a 50% increase in catalyst concentration on the cathode improved the removal with 36%-point, while a 60% increase in electrode spacing enhanced the removal with 13%-point due to extension of the redox zones. An inert porous matrix was found to enhance PCE removal with 24%-point compared to a fully water-filled reactor and the horizontal orien-tation accounted for another 9-16% increase in removal. The observed trends are promising when considering the installation and cost of field-implementations. [1] Wang, J., Farrell, J. (2003). Investigating the Role of Atomic Hydrogen on Chloroethene Reactions with Iron Using Tafel Analysis and Electrochemical Impedance Spectroscopy, Environ. Sci. Technol. 37, 3891-3896.[2] Yuan, S., Mao, X., Alshawabkeh, A.N. (2012). Efficient Degradation of TCE in Groundwater Using Pd and Electro-generated H2 and O₂: A Shift in Pathway from Hydrodechlorination to Oxidation in the Presence of Ferrous Ions, Envi-ron. Sci. Technol. 46, 3398-3405.

Biodegradation of crude oil by microbial consortia from Nigerian soils

Paul Iturbe-Espinoza¹; David Brown²; Matthijs Bonte³; John Parsons⁴; Martin Braster¹; Rob van Spanning¹¹ Faculty of Science, Vrije Universiteit Amsterdam; ² Daresbury Laboratories; ³ Shell Global Solutions International B.V.; ⁴ Faculty of Science, University of Amsterdam

The Niger Delta (Nigeria) is a region with a long history of oil and gas extraction. Oil spills have occurred in the region because of sabotage, crude oil theft, operational spills, and artisanal refining. Spilled crude oil is a complex mixture consisting of both hydro-carbons, molecules containing only hydrogen and carbon (large arrays of linear, branched, cyclic and aromatic components) and non-hydrocarbon fractions (asphaltenes and resins such as carba-zoles, thiophenes, and oxygenated hydrocarbons). This complex chemical nature of crude gives rise to a similarly complex persis-tence behavior. To assess the long-term fate of crude spilled into the environment, we carried out biodegradation experiments combined with molecular fingerprinting. The study aimed at investigating how pre-adaptation of microbial communities from contaminated soils relative to those of pristine soils impacts biodegradation rates. We also investigated how different compo-nents present in crude oil degrade relative to each other.

Two different carbon substrates were used as a carbon source: an artificial crude oil and a natural crude oil. The artificial crude oil was composed of a commercially available mix of hydrocarbons including the sixteen priority PAH according to the US-Environ-ment Protection Agency (EPA). The natural crude oil (Bonny Light) was spiked with the sixteen priority PAH. One milligram of soil was inoculated in glass bottles containing mineral salt media and each one of the two carbon substrates. The bottles were closed with Teflon caps and incubated at 30°C. The hydrocarbon concentra-tion was measured by GC-FID. Biomass was measured by qPCR while 16S amplicon sequencing (Illumina) allowed us to link the community structure to their degradation capacity.

Biodegradation of high molecular weight hydrocarbons was observed in both contaminated (pre-adapted) and non-contam-inated soils while loses of the more volatile molecules are attributed to volatilization. In the pre-adapted soil, all the alkanes were degraded after one month, whereas in uncontaminated soil, biodegradation rates showed a much larger heterogeneity for different components. The data confirm earlier findings that individual components of the oil are degraded at different rates, with the highest rates observed in alkanes, followed by low weight aromatics and ending with the more complex PAH. These results indicate that the degradation capacity of the contaminated soil is higher than that of uncontaminated soil. This may well be the result of the adaptation of the bacterial community towards degradation of the spilled oil molecules.

Ultimately this knowledge may contribute to a better under-standing of oil degradation and assist in the improvement of bioremediation efforts.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesOxidation of PAHs and their by-products (polar PACs) in the saturated zone of DNAPL-contaminated sub-soils batch and column experiments

Clotilde Johansson¹; Philippe Bataillard²; Antoine JOUBERT¹; Coralie Biache³; Catherine Lorgeoux⁴; Stéfan Colombano²; Thierry Pigot⁵; Pierre Faure³¹ SERPOL; ² BRGM (French Geological Survey); ³ CNRS, Université de Lorraine, UMR7360 - LIEC; ⁴ CNRS, Université de Lorraine, CREGU, UMR7359 - GeoRes-sources; ⁵ Université de Pau et des Pays de l›Adour, UMR5254 – IPREM

The remediation of former industrial sites is, for many reasons (health and environmental impact, land use…) of great concern. Soils encountered at former coking plants are often impacted by PAHs inherited from coal-tar storage and dissemination. The present work focuses on improving the effectiveness of in situ chemical oxidation (ISCO) to reduce DNAPL (Dense Non-Aqueous Phase Liquids) remaining after pumping in the saturated zone of the impacted soil. The study is part of the BIOXYVAL project, dedicated to the remediation of contaminated sites by coordi-nating various innovative techniques on a former coking plant in the north east of France.

The efficiency of seven different chemical oxidants was compared through batch experiments. PAH degradation and formation/elimination of polar Polycyclic Aromatic Compounds (PACs) were monitored. Polar PACs including oxygen/nitrogen/sulfur-containing PACs, known to be oxidation by-products, have greater mobility in groundwater compared to PAHs and can be more toxic. Conventional oxidants including potassium permanganate, heat-activated persulfate, Fenton-like (activated with magnetite) and Fenton reactions were compared to an innovative and very promising oxidant: potassium ferrates (FeVI). Their reaction products consist of iron hydroxides (FeIII), they have also coagulant properties and are expected to be less harmful to the environment than other end-products (sulfuric acid, manganese salts). Addition-ally, ferrates were used as a Fenton-like catalyst under acidic or neutral conditions.

Oxidations were performed on a reference matrix (Fontainebleau sand) spiked with DNAPL sampled at the studied site, at three reaction times (3 h, 1 day and 1 week). Oxidants were applied at one stoichiometric oxidant demand (SOD) deduced from the elemental composition of the DNAPL.

Magnetite Fenton-like oxidation applied on spiked sand was not very effective (28.5% degradation of 16-US EPA PAH). The ferrates managed to reach 77.9% degradation of PAH after one week even if the protocol was not optimized. The best oxidants were KMnO4 and heat-activated persulfate, which decreased up to 98% PAH and 96.1% PAH, respectively. Similar results were obtained on the extractable organic matter, representing the whole DNAPL pollution. Good degradation rates were also obtained with classical Fenton reaction and Ferrates/Fenton at pH 3: 93.9% and 89.8% PAH removal respectively. Some O-PACs were formed as degradation by-products in different proportions depending on the oxidants and conditions.

Some oxidants are currently optimized in laboratory column tests in order to select the one that will, eventually, be applied at pilot scale. The first step consists in spiking glass beads or soil with DNAPL by drainage/imbibition, followed by water flushing to mimic the removal of the DNAPL fraction by pumping. This will give a residual saturation (Srn) of tar similar to the one obtained on field. Then Ferrates or KMnO4 are flushed through the column. The water quality is monitored throughout the experiment and the PACs remaining in the matrix after treatments are quantified.

Developing zero-valent iron nanoparticles (nZVI) suspensions from plant extracts and assessing their reactivity to hexavalent chromium

Mihalis Karavasilis; Christos TsakiroglouFoundation for Research and Technology, Hellas

In the present work, plant extracts were used to synthesize zero valent iron nanoparticles (nZVI) for in situ groundwater remedia-tion studies. With thermal treatment, the extracts of Camelia synesis (Green Tea) and Punica Granatum (Pomegranate) were produced, and their total concentration in polyphenols (as equivalent concen-tration of Gallic acid) was measured by using the Folin-Ciocalteu method. nZVI suspensions were synthesized in semi-batch reactors by injecting, at constant influx rate of 4 mL/min, a pre-specified volume of plant extract in an aqueous solution of FeSO4 7H20. During the mixing of solutions, the generated black-colored liquor was attributed to the production of zero valent iron particles. The pH and redox potential (Eh) of the solution were recorded continu-ously as functions of time, with the aid of a data acquisition card. A dynamic mathematical model of the nZVI synthesis process was developed by accounting for the kinetics of all reactions included, the numerical solution of which allowed the calculation of the transient responses of pH and Eh. The numerical predictions of the model were fitted to the experimental datasets by a non-linear estimation algorithm (Athena Visual Studio) to estimate the kinetic parameters of reactions.

A variety of techniques were used to characterize the produced iron nano-colloids: Dynamic Light Scattering (DLS) to measure the particle size distribution; ζ-potential to quantify the stability of iron nano-colloids; XPS to identify the oxidation state of iron particles surface; ATR-FTIR to understand the interactions of iron cations with polyphenols and other substances leading to the iron reduction and capping; SEM and TEM to confirm visually the sizes and morphology of nanoparticles and any other aggregates created.

To assess the reactivity of nZVIs, the kinetics of hexavalent chromium Cr (VI) reduction in aqueous phase was measured. Aqueous solutions of Cr (VI) prepared from potassium dichromate were mixed with nZVI suspensions, and the transient variation of their concentration was determined by using 7196A method.

The morphological and physicochemical characteristics of nZVI suspensions were correlated with the nZVI reactivity and the kinetics of synthesis procedure, and guidelines for the preparation of the most efficient nano-colloids were provided

ACKNOWLEDGMENTS

We acknowledge support of this work by the project “Innovative Actions in Environmental Research and Development (PErAn)” (MIS 5002358) which is implemented under the “Action for the Strategic Development on the Research and Technological Sector”, funded by the Operational Program “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund).

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Thematic Session (ThS) – Topic 4 Advances in remediation technologies

The effects of hydraulic/pneumatic fracturing enhanced remediation (FRAC IN) at a site contaminated by chlorinated ethenes

Ondřej Lhotský¹; Jan Slunský; Jan Kukačka; Kristýna Marková; Tomáš Cajthaml¹ DEKONTA, a.s.

A technology for direct push injection of remediation agents combined with hydraulic/pneumatic fracturing (Frac In) has been tested at a site with chlorinated ethenes contamination and complicated geology.

The site is characterised by heterogeneous geological conditions with the contamination fixed to low-permeable sandy clays in both the saturated and unsaturated zones. The aquifer at the site shows low permeability (in the range from 10-5 to 10-6 m/s) with prefer-ential flow paths.

ISCR combined with BRD was utilised as the remediation technology within the pilot test. Thanks to the fracturing (both pneumatic and hydraulic), it was possible to inject 5.5 m3 of suspension that contained 832 kg of sand; 832 kg of milled iron; and 35 kg of sulfidated nanoscale zerovalent iron particles both to the saturated and unsaturated zones. In addition, 5.5 m3 of solution containing 300 kg of dry whey and 11 kg of NaOH was injected as a carbon source for BRD. In total, injections were successfully performed in 9 injection points, with 45 successful injection horizons.

The effects of the performed injections were monitored using several different approaches.

Monitoring wells logging during the actual injections showed the expected ROI was between 2 and 6 m.

The tracer tests confirmed that the injection resulted in signifi-cant increase of the pore volume of the preferential pathways in the aquifer while the general permeability of the aquifer did not increase.

Long-term groundwater monitoring was performed in 8 wells prior and after the injection. It showed the injection triggered the contaminant breakdown processes, as the mean tetrachloroethene concentration dropped from 10 mg/L to 1 mg/L within 5 months after the injection. The processes responsible were of both abiotic (confirmed by elevated acetylene concentrations) and biotic nature (confirmed by increase in bacterial biomass and specific degrada-tion genes monitored by qPCR).

5 months after the injection, a part of the locality was excavated in order to obtain information on the fracture distribution in the unsaturated zone. The fractures were rather narrow and were developed mainly in the pre-existing disruption zones both in the vertical and horizontal directions.

An integrated biogeochemical/electrochemical method for remediation of contaminated groundwater

Raphi Mandelbaum¹; Elie Elgressy²; Gal Mandelbaum¹; Jim Mueller³; Gil Elgressy²¹ LDD ADVANCED TECHNOLOGIES; ² E. Elgressy; ³ Provectus Environmental

New technologies are desired for safe, cost-effective reme-diation of groundwater impacted by a wide variety of organic contaminants, including (rapidly) emerging contaminants such as perflourinated compounds, Ideally, the in situ technology can be effectively employed in deep aquifers and mixed litholo-gies to easily manage large, dilute plumes often in remote areas.

Impact of the soil mineralogy on the contamination and the microbial communities during lab-scale bioremediation of petroleum-contaminated soil

Axel Lebreton¹; Coralie Biache¹; Catherine Lorgeoux²; Aurélie Cébron¹; Thierry Beguiristain¹; Manuel Pelletier¹; Pierre Faure¹ LIEC - CNRS/Université de Lorraine; ² CNRS, Université de Lorraine, CREGU, UMR7359 – GeoRessources

Nearly one quarter of the sites requiring a monitoring, invento-ried in the French database BASOL, are impacted by petroleum contamination. During natural attenuation, these organic contami-nations evolve through abiotic and biotic processes as they are known to be sensitive to microbial degradation. In parallel to mineralization, the contamination transformation can cause an accumulation of refractory residual by-products (high molecular weight compounds, polar polyaromatic compounds) through time. Moreover, soil minerals can interact with the contamination and impact degradation processes. They have a role in the sorption of organic molecules, hence affecting their availability towards biota, especially microorganisms. They can (i) catalyze condensation reaction of some molecules, particularly during abiotic oxidation, and (ii) influence the selection of microbial consortia.

The aim of this study is to clarify the interactions between the petroleum contamination, the soil minerals and the microorgan-isms. This work focuses especially on (i) elucidating to what extent the selection of microorganism is control by the nature of pollution and/or mineral in soil, and (ii) understanding the impact of mineral phases on petroleum contamination and on soil microorganism evolutions.

To achieve this goal, a forest soil impacted by petroleum seepage since several centuries was sampled in the forest of Haguenau (Alsace, France). A batch microbial incubation was carried out in the laboratory according to several modalities: the soil, a mixture of soil and goethite (10%wt), a mixture of soil and Fontainebleau sand (20%wt), a mixture of soil and bentonite (20%wt). Addition-ally, these four modalities were also spiked with 5% wt of crude oil sampled on site.

The initial and incubated samples were characterized in term of (i) mineralogy and surface properties, (ii) microbial abundance and structure, and (iii) petroleum composition through molecular and spectroscopic analyses. Additionally the CO2 production was monitored throughout the incubation and enzymatic activities (phosphatase, arylsulfatase...) were determined initially and for three intermediate sampling times.

The first results reveal that the mineral phases and the petroleum spiking impacted the CO2 production. Molecular analyses showed that the petroleum spiked soil and soil mixed with sand reached a higher degradation level than the soil mixed with goethite and bentonite. For the latter, the degradation was very limited suggesting either a strong sorption of the hydrocarbons on the bentonite surface leading to lower contaminant availability, or a negative impact of the bentonite on the petroleum degrading microbial communities. In term of microbiology, a first screening showed only slight impact of the incubation on the microbial abundance whatever the modality.

Additional data concerning the three studied compartments (mineral, petroleum and microorganisms) that are currently being acquired, will implement these first results.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologies

The second method used was the disaggregation by ultrasonica-tion, which allowed obtaining sample OF-U.

Scanning Electron Microscopy was used for the characteriza-tion of the size and morphology of the original material and the two produced materials showing similar morphology for OF-U and OF-G. Laser Diffraction Spectrometry showed a final size in the range 100-200 nm for OF-M and Dynamic Light Scattering showed sizes around 1 micron for OF-U sample,. Comparison of the BET area for the three materials showed decreasing values with the decreasing in size (51% loss for OF-M and 20 % loss for OF-U compared with initial OF-G) attributed to the destruction of internal porous.

Equilibrium batch tests were performed by maintaining in contact dissolutions of arsenic (V) (£4 mg/l) and phosphate (£150 mg/l) with the three materials for 120 h at ambient temperature, constant stirring of 8 rpm and darkness.

Langmuir and Freundlich isotherms for the three materials showed very good correlation, with properties of OF-G were slightly better than OF-M. The % of variation of adsorption capacity (qmax) of reduced materialsvs OF-G showed general moderate losses of equilibrium values.

The kinetic behaviour of the three materials in batch studies was also tested. In the case of arsenic (V). 75 mg of materials where put in contact with 5 mg/l arsenic (V) and in the case of phosphates 100 mg of materials where put in contact with 30 mg/l phosphate. A pseudo second-order kinetics was successfully fitted for all the contaminants and materials. Establishing the kinetic constant (K2) of OF-G as a reference, the K2 increased 4.2 times for As and 1.9 times for phosphate in the case of OF-M and 9.7 times for As and 3.9 for phosphate in the case of OF-U.

As a conclusion, the size reduction allowed similar equilibrium and an increase of 1.9 to 9.9 fold the adsorption rates values, despite the decreasing of the BET values.

The financial support of the present research work has been funded by the project NANOREMOV (CGL2017-87216-C4-3-R) from Spanish Ministry of Science, Innovation and Universities and AEI/FEDER,UE.

References: [1] Ribas, D., Černik, M., Martí, V., & Benito, J. A. “Improvements in nanoscale zero-valent iron production by milling through the addition of alumina”. Journal of nanoparticle Research, 18(7):1-11 (2016). [2] Ribas, D., Černík, M., Benito, J., Filip, J. & Marti, V. Activation process of air stable nanoscale zero-valent iron particles. Chemical Engineering Journal, 320: 290-299 (2017)

Enhanced anaerobic dechlorination of TCE via recirculation and batch injection pilot systems near São Paulo, Brazil

Mark Mejac¹; Gustavo Dorota Carreiro De Mello; Guilherme Borges; Yvonne Sutter; Mathias Stein¹ Ramboll

At a manufacturing site in the State of São Paulo, Brazil, ground-water is impacted with trichloroethene (TCE) at concentrations as high as 30,000 micrograms per liter (µg/L), with lesser concentra-tions of other chloroethenes and chloroethanes. The impacted groundwater is present within a diabase saprolite at depths up to 18 meters below ground surface over an approximate 2 hectare area, including an off-site manufacturing facility. Bench and pilot testing were implemented in late 2017 and early 2018 to evaluate the effectiveness of enhanced anaerobic dechlorination (EAD) for

One such method involves integrated electro-chemical reactions under controlled conditions. Direct oxidation at semiconductor films coupled with enhanced Electro-Fenton oxidation is achieved electro-chemically and controlled remotely. Secondary effects include enhanced contaminant desorption and stimulated biogeo-chemical destruction. Rapid oxidation of chlorinated solvents and petroleum hydrocarbons has been observed at pilot and full scales. future applications could address perflourinated compounds, 1,4-dioxane, pharmaceuticals and other challenging contaminants.

The EBR® (US 9,975,156 B2) system is comprised of subsurface electrodes with high catalytic activity for O2 generation which is constantly reduced to form H2O2. An additional electrode is used as constant source of Fe cations via forced corrosion and effective Fe 2+ formation from Fe3+. The system radius of influence is increased by imposing an effective constant flux across the well interface due to boundary conditions effects and high chemical potential, in addition to the existing natural dispersion and advection forces. Furthermore, electro-osmosis induces groundwater flow between coupled wellbores yielding a more complete approach to aquifer remediation, especially in fine-grained, low-permeability materials that typically harbor sorbed residuals because electro-kinetics enhances the mobilization and therefore the availability of the contaminants. In terms of secondary processes to help manage contaminant rebound, the co-mobilization of nutrients and the oxidative nature of the method supports accelerated aerobic bioremediation.

Successful implementation of the EBR® technology at several sites has resulted in rapid site closure. The method was inspected by the water authority of Israel and its use is widely approved. For example, a study conducted by the Israeli Geological Survey and the Israeli Water Authority it was found that the electrolysis system induced rapid change in the biochemical conditions on the site (ORP levels are remotely monitored and regulated by the system). Anaerobic (low redox) wells rapidly turned aerobic. As a result, from this change, a significant decrease in the concentrations of MTBE from 68 mg/L to “< 0.04” mg/L was associated with a change in its isotopic composition. Assuming that the isotopic enrichment constant in the process of groundwater MTBE breakdown equals the enrichment, constant obtained from microbial experiments in the laboratory (ε = -0.7‰), then > 96% of the MTBE underwent oxidative destruction. Lastly, we present the idea of non-uniform electro-kinetics via a polarity exchange technique to intermit-tently reverse electric currents to prevent significant pH changes and discuss potential applications for other contaminants under various site conditions.

Comparative adsorption of groundwater contaminants onto differents sizes of particles obtained by two top-down approaches

Vicenç Martí¹; Irene Jubany²; David Ribas²; José Antonio Benito¹; Berta Ferrer¹; Ada Ginesta¹¹ Technical University of Catalonia (UPC); ² Fundació CTM, Centre Tecnològic

This study shows a comparison of arsenic (V) and phosphate removal at lab scale by using granular ferric hydroxide (OF-G) reduced at different sizes by top to down methods in order to increase the reac-tivity and improve the groundwater treatment efficiency.

A first method used for reduction was wet milling without disper-sant. This approach has been successfully used previously by our group to decrease the size close to nanoparticle range and improve the reactivity of Zero Valent Iron [1,2]. The sample OF-M was obtained by using this method.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesin-situ treatment of the chlorinated organics in site groundwater, for possible full-scale remediation.

Maintenance of near-neutral groundwater pH is required for EAD systems, as acidic or alkaline conditions inhibit microbial activity. Based on the likely presence of acidic soil at the site, bench-scale pH buffer capacity testing was conducted to determine the quantity of alkaline buffer needed to maintain near-neutral groundwater pH as part of electron donor injection. In order to retain flexibility with regard to future full-scale electron donor delivery approaches, two EAD pilot tests were conducted. One (on-site) pilot test included groundwater recirculation of rapid-release electron donor (sodium lactate) and sodium bicarbonate for pH control through two extraction wells and two upgradient recirculation wells. The other (off-site) pilot test included batch injection of slow-release electron donor (emulsified vegetable oil) and sodium bicarbonate through three injection wells. These two electron donors were selected in part because acid production caused by fermentation of these electron donors is low when compared with other applicable electron donors.

The effectiveness of the two pilot tests was evaluated based on geochemical and chlorinated ethene molar concentration data from monitoring wells located within the pilot test treatment zones. TCE concentrations within the recirculation pilot test treatment zone decreased by 83 percent (from 2,375 to 406 µg/L) between October 2017 and March 2018, with generation of biodegradation daughter product cis-1,2-dichlorethene (cDCE). TCE concen-trations within the batch injection pilot test treatment zone decreased by 97 percent (from 2,354 to 59 µg/L) between October 2017 and March 2018, with generation of biodegradation daughter products cDCE and vinyl chloride. The generation of vinyl chloride is consistent with development of Dehalococcoides dechlorinating bacteria. The favorable results of the pilot tests were used to design full-scale EAD systems, using groundwater capture zone analyses. The on-site full-scale EAD system will include six extraction wells and ten recirculation wells. The off-site full-scale EAD systems will include ten batch injection wells, five extraction wells, and seven recirculation wells. The rationales for the design of these electron donor delivery approaches will be discussed. The full-scale EAD systems will commence operations in January 2019, and available full-scale performance data will be presented.

Removal of heavy metal contamination from groundwater using iron-oxide nanoparticles: A field application

Sadjad Mohammadian; Beate Krok; Rainer MeckenstockUniversity of Duisburg-Essen

Due to their strong toxicity even at low concentrations, elimination of heavy metal ions from groundwater is important to protect public health and the environment. The current technology for removal of heavy metals from groundwater is Pump & Treat, which requires installation of large-scale facilities on the site and investments in the Million-Euro range, which is a limiting factor in remediation efforts. In many cases, an in-depth remediation is economically not feasible for e.g. low-concentrations of contaminants, in urban areas, sealed areas, or with limited financial resources.

A recently developed practical approach to mitigate spreading of heavy metal contamination is to install an in-situ permeable adsorp-tive barrier using nanoparticles. Colloidal iron oxide nanoparticles can be introduced into aquifers through injection wells, where due to their minute size, nanoparticles pervade in the subsurface and then coat the surface of aquifer matrix. Nanoparticles offer

larger surface areas in comparison to bulk materials, which in turn increases the adsorption sites for heavy metals.

In this work we introduce an iron-oxide nanoparticle (ColFerroX®) for groundwater remediation. Iron oxides are natural, they have low toxicity, and impose no danger to the environment or to the personnel. Unlike nZVI, ColFerroX® nanoparticles remain as stable suspension and do not clog pores due to coagulation. Hence, the can be injected over longer distances making them suitable for application for groundwater remediation at field-scale. Once in the aquifer, particles precipitate and cover the aquifer matrix where they adsorb As, Zn, Pb, Cu, etc. from contaminated water.

The current work presents the first field-scale application of iron-oxide nanoparticles for removal of heavy metals from contaminated groundwater. Optimized ColFerroX® particles were injected into two heavily contaminated sites in Portugal and Spain. At each site, a permeable barrier of ca. 22 x 9 meter was installed by injection of >100 cubic meters of stable ColFerroX® particles into nine injection wells. Intensive monitoring revealed that the injected ColFerroX® particles were distributed homogenously around injection points inside intended radius of influence of 2.5 meters, and that the installed barrier was stable, i.e. the particle did not travel away with groundwater flow after precipitation.

Analysis of groundwater samples showed that mobile heavy metals have been successfully removed from groundwater. The groundwater contamination levels were reduced to less than 50% of pre-injection values. The reduction was even observed in a low-pH zone (pH~4) of the site in Spain. ColFerroX® particles are therefore a promising, efficient product that can be used to remove contamination from groundwater aquifers.

Cheese whey injection in groundwater: Use of an economically and eco-friendly substrate for in-situ bioremediation of chlorinated solvents

Antonio Molinari; Luca Sacilotto; Bartolomeo Bosio; Giada Di Marco; Michele LecceseRamboll Italy S.r.l.

Remediation of chlorinated solvents represents a continuous challenge in the framework of contaminated sites restoration with specific regards to the possibility to apply solutions able to reduce resident concentrations of contaminants with low cost solutions in shorter times than conventional methodologies. The possibility to take advantage of the microbial activity of microor-ganisms naturally occurring in groundwater, by the addition of a soluble organic substrate, can represent a new and promising way to obtain a cost-effective remediation approach.

The present study illustrates the results of a groundwater reme-diation project associated with an industrial site located in the Northern Italy. The site is contaminated by chlorinated solvents (mainly PCE and TCE) and the employed approach involves the stimulation of endogenous dechlorinating microorganisms by the addition of economic soluble organic substrates able to trigger the achievement of suitable conditions under which chlorinated solvents can be depleted through a stepwise set of biologically mediated reductive reactions, leading to the formation of ethylene as the final, harmless, metabolite. This process, which can be referred to as Reductive Anaerobic Dechlorination (RAD), was firstly tested at the field scale (pilot test) on a small portion (30x30m) of the contaminant plume, then extended to treat the existing plume, spreading off-site for 1 km length from the industrial site, impacting also private wells located downgradient the facility.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesDuring the pilot testing, two types of possible low cost and eco-friendly alternative substrates were tested: molasses (i.e. a sugar-water solution) and cheese whey. The substrates were added to the aquifer under natural gradient conditions and distributed by spontaneous advection/dispersion phenomena.

After about four years of plant operation for the plume treatment, we injected about 2700 m3 of cheese whey into the aquifer using 60 injection wells located along the plume. During this timeframe, the RAD process was effectively activated, and we observed signifi-cant reduction of PCE (-99%) and TCE (-98%) concentrations along the contaminated plume.

Between the two tested substrates, cheese whey was selected as the best organic substrate since it is much cheaper than sugar and it represents a necessary by-product of many local cheese factories, which, if not reused, needs to be disposed of as waste. Further-more, it showed TOC values approximately ten times larger than the sugar with high nutritional value in terms of carbohydrates, fats, proteins and vitamins which enhance the development of microbial microorganisms.

Replacing pump and treat system with sustainable in situ bioremediation strategy for chlorinated solvent plume

Kevin Morris¹; James Vondracek²; Derek Ross¹; Piero Mori³; Giorgio Barozza³¹ ERM NA; ² Ashland; ³ ERM Italy

An operating chemical facility in an industrial district of Northern Italy experienced releases of chlorinated ethenes, primarily tetra-chloroethene (PCE) and trichloroethene (TCE) in the 1980’s. Site characterization, including groundwater monitoring and plume modeling, had indicated the potential for off-site migration of the dissolved phase PCE/TCE plumes south of the facility boundary. The Italian regulators required remediation to mitigate the potential for off-site migration, therefore a pump and treat system was installed in 2006 that included multiple pumping wells. A review of the pump and treat system concluded that it would have to continue operating indefinitely due to low permeability soils and slow contaminant mass flux. The responsible party requested a review of more sustainable remedial strategies that would be as effective as pump and treat, however, use less energy, require less O&M, reduce the overall project lifecycle, reduce waste manage-ment and cost. A semi-quantitative sustainability review identified phased in situ bioremediation via anaerobic reductive dechlorina-tion as the most sustainable remediation strategy to replace the pump and treat system.

A 2017 microbial survey indicated limited colonies of chlorinated ethene degrading microbes, thus requiring bioaugmentation to accelerate the anaerobic reductive dechlorination process. The first phase of bioremediation included the installation of a series of shallow and intermediate (A and B zones) injection points at ten locations perpendicular to groundwater flow as an injection biobar-rier to replace the pump and treat system. Approximately 2,500 liters of a 10% emulsified vegetable oil (EVO)/fresh water solution, one liter of a microbial consortium (that included Dehalococcoides sp.) were injected into the points to generate the biobarrier in October 2017. The second phase included shallow and interme-diate injection points installed at six locations upgradient of the biobarrier in a TCE source area that had been delineated during previous investigations. A shallow injection point was also installed at a thirty-five degree angle to target a source under a building footer inside a chemical storage building. The same volume of

EVO/water/microbes substrate was injected into the source area injection points in March 2018.

The injections of EVO/water/microbes in both the biobarrier and the source area have generated anaerobic reducing treatment zones that are stimulating the bioremediation of PCE and TCE to ethene and ethane in both the A and B water zones. Comparing the July 2018 sampling data with the September 2017 data (prior to substrate injections) significant reductions in the parent compounds PCE and TCE are observed. Only a few months after injections, TCE and PCE have been reduced in the source area from 2,400 to 87 µg/L and 170 to 6.4 µg/L, respectively. Monitoring wells downgradient of the biobarrier have also shown reduced PCE/TCE and presence of innocuous end products ethene and ethane. Monitoring will continue for the next two years to continue evalu-ating the reductive dechlorination process.

Penicillium sp. removes pharmaceutical compounds from hospital wastewater and outcompetes native bacterial and fungal community in fluidized batch bioreactors

Darío Rafael Olicón Hernández¹; Cinta Gómez Silván²; Clementina Pozo¹; Gary Andersen²; Jesús González López¹; Elisabet Aranda¹¹ University of Granada (ESQ1818002F); ² University of California, Berkeley -Lawrence Berkeley National Laboratory

Pharmaceutical active compounds (PAhCs) represent an increasing problem of human concern in the wastewater around the world. The PAhCs arrive to the wastewater treatment plants mainly from the pharmaceutical industry, poultry and livestock farms, and urban wastewater, which include wastewater from hospitals. PAhCs encompass a variety of aromatic compounds considered emerging contaminant, since they are not regulated by the current legisla-tion. Traces of these compounds are frequently found in water sources, starting to cause long term effects on aquatic organisms and the acquisition of antibiotic bacterial resistances, which could have serious implications for public health. In this study we use a batch bioreactor inoculated with the xenobiophile ascomycete fungus Penicillium sp., isolated from a hydrocarbon polluted place. Penicillium sp. possesses interesting features to resist highly hydro-carbons polluted environments and to remove a broad spectrum of PAhCs. In this bioreactor, the capacity of removal of different non-steroidal anti-inflammatory compounds from a non-sterile real wastewater from a hospital was monitored by UPLC/MS-MS. The microbial community shifts over time was analyzed using two high-throughput molecular approaches, Illumina MiSeq sequencing platform and PhyloChip, a phylogenetic microarray that allows better detection of minority populations. The results showed Penicillium ability to remove the majority of the analyzed PAhCs, including diclofenac, paracetamol, ketoprofen or mephenamic acid, in 24 hours. Also in the first 24 h, Penicillium outcompeted all the native fungal populations present in the wastewater, including several fungal human pathogens species such as Mycosphaer-ella, Drechslera or Cyphellophora. Bacterial community diversity decreased too along the treatment, with the displacement of some bacterial human pathogens belonging to Clostridiaceae and Brucellaceae families. Groups of bacteria which include important degraders such as Pseudomonadaceae remained in the system, which could involve a possible natural consortium formed during the degradation. These results indicate the possibility to use this system for the removal of PAhCs under real conditions.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesSynthesis, characterization and reactivity of hydroxyapatite coatings deposited on calcium carbonate micro- and nano-particles for the removal of heavy metals from contaminated water

Gibert Oriol; Vicenç Martí; Àlex Marín; César Valderrama; María Mar-tínez; Rosa Maria DarbraTechnical University of Catalonia (UPC)

Contamination of groundwater by acidic metal-rich streams is an environmental problem worldwide. Because ex-situ treatment of groundwater is often cost prohibitive and sometimes techni-cally impractical at depth, in-situ remediation in the aquifer itself has become a matter of active research. One emerging approach for in-situ remediation that is gaining increasing attention of researchers is the application of nanoparticles (NPs) in the subsoil able to immobilize, neutralize or decompose the contaminants present in groundwater. For heavy metals, NPs based on hydroxy-apatite (Ca10 (PO4)6(OH)2, hereafter referred to as HAP) have been acknowledged as one the most suitable reactants thanks to the high sorption capacity of HAP for heavy metals and its resistance to acidic conditions.

Within this context, the objective of this bench-scale study was to coat calcium carbonate micron- and nano-sized particles (MPs and NPs, respectively) with a layer of HAP for the removal of heavy metal ions (Cu2+ and Zn2+) from contaminated water.

The work was conducted in two stages. First, the synthesis of HAP by conventional precipitation of Ca2+ and PO43- on calcium carbonate MPs was systematically studied by varying pH, the type of PO43--compound and concentration of PO43-. The effect of conducting two successive precipitation steps was also considered. All synthesized HAP coatings were characterized using multiple techniques, including scanning electron microscopy coupled to energy-dispersive spectrometry (SEM-EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), electrophoretic light scattering coupled to laser Doppler velocimetry (ELS-LDV) for zeta potential measurements and BET for specific surface areas determinations. Resistance of all coatings to acid attack was also assessed. Once the synthesis path leading to the top performing coating was identified, it was replicated for the coating of calcium carbonate NPs.

Second, the prepared HAP-coated MPs and NPs were tested to evaluate their sorption capacity toward Cu2+ and Zn2+. Sorption isotherms and kinetics were determined in batch tests with synthetic solutions containing the ions separately and simul-taneously as well as with a real water sample. Results allowed identification of the most favourable conditions to synthesize a layer of HAP on the surface of calcium carbonate MPs and NPs with the ability to remove heavy metal ions from contaminated water. From a broader perspective, and given the scarce data within this field, results contribute to a better understanding of the synthesis and reactivity of HAP coatings on calcium carbonate particles for their application in in-situ remediation of groundwater.

The financial support of the present research work has been funded by the project NANOREMOV (CGL2017-87216-C4-3-R) from the Spanish Ministry of Science, Innovation and Universities and AEI/FEDER, UE.

Mechanisms involved in the remediation of PAH-polluted soil using a slurry bioreactor

Douglas Pino Herrera¹; Yannick Fayolle²; Stefano Papirio³; David Huguenot⁴; Giovanni Esposito⁵; Eric D. van Hullebusch⁶; Mehmet A. Oturan⁴; Yoan Pechaud⁴¹ Université Paris-Est Marne la Vallée; ² Irstea; ³ Università degli Studi di Napoli «Federico II»; ⁴ Université Paris-Est Marne-la-Vallée; ⁵ Università di Cassino; ⁶ Université Paris Diderot

Soil slurry bioreactor technology has emerged as an effective and feasible technique with a high remediation potential for the fine soil fractions, which often contain high levels of recalcitrant pollutants and are hard to treat with conventional approaches. However, the mechanisms involved in the pollutant removal in the bioreactor are still not completely understood. In addition to the biological processes, important mass transfer mechanisms need to be considered (gas-liquid oxygen mass transfer, sorption-desorp-tion, volatilization, etc.). For this study, a mechanistic approach was developed, in which the bioslurry process was deconstructed using a model system, each part was isolated and analyzed individually. Then, the global process was studied and the results of the analysis of the individual parts were used to understand the global biore-mediation treatment.

The experiments were performed in a 4.2-l glass reactor, mechani-cally agitated using a marine propeller and aerated through a porous-glass sparger located on the bottom. A mixture of clay and Sphagnum peat was used as model soil and PAHs were used as model molecules. The effect of different operational parameters and physicochemical properties of the pollutants on the mass transfer and biodegradation mechanisms were tested. A model of the individual mechanisms was developped and used to obtain the key paramaters of each process.

Among the results obtained, the next can be highlighted: i) clay presence in soils can strongly affect oxygen transfer in slurry systems by modifying the hydrodynamic conditions in the reactor; ii) the pollutant bioavailability was limited by the desorption process, particularly when organic matter was present in the soil; iii) volatilization can be the major removal process during the lag phase period in biodegradation; and iv) the conditions during the development of enriched microbial cultures determines their behavior towards the pollutants. The results of this research work can be extrapolated to the study of real contaminated soil remediation. The mechanistic approach can be used as a generic method to investigate the slurry bioreactor treatment for any type of soil, different pollutants and microbial communities, and other operating conditions.

Comparison of ZVI-products for combined abiotic and biotic treatment of chlorinated solvents

Kirsten Rügge¹; Torben Højbjerg Jørgensen¹; Dimin Fan²; James Wang²; Neal Durant²; Maria Tropp Hag³; Nina Tuxen³¹ COWI A/S; ² Geosyntec; ³ The Capital Region of Denmark

The synergy between zerovalent iron (ZVI) and biological reductive dechlorination has long been recognized and applied as an effective remediation strategy at chlorinated solvent sites. By scavenging natural oxidants (i.e., oxygen, nitrate, sulfate) in the subsurface, the reactions facilitated by ZVI create strongly reducing condi-tions—together with the hydrogen produced by ZVI reacting with water—that support biological reductive dechlorination. Recent research has led to a new type of ZVI, sulfidated ZVI (S-ZVI), with which the corrosion reaction with water is significantly inhibited.

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The behavior of VOC in soil requires a specialized investigation & remediation approach. So, VLABOTEX and their partner soil reme-diation experts are using more innovative clean-up technologies to remediate as cost-efficient as possible.

The main remediation goal is source zone treatment(mass reduction) resulting in sufficient risk reduction (distribution risk, exposure risk) and a stable or shrinking plume.

The typical remediation targets for PER are around 5 mg/kg for the soil and 4.000 µg/l for the groundwater

Today, in Flanders, only 12 ISCO treated sites are known with only 3 sites remediated up to a no further action state. There is still an urgent need for more know how and expertise in the field of soil remediation.

Because the fact that remediation is a “contact sport”, in-situ chemical oxidation based on injection of gas is a clean-up tech-nology with high potential. Ozone is injected with compressed air by a combined remediation technology (volatizing and oxidation)resulting in a larger vertical and horizontal ROI compared to liquid injection. An additional benefit is that gas injection is less influenced by the permeability of the soil. Furthermore is the remediation process a continuous process whereby the injection process can be adjusted at any time and monitoring is easily achieved. Also stimulated biological anaerobe remediation is still possible as aftertreatment.

Being a contact sport, fully understanding where the pollution is situated is a must. In 2 of the 3 cases, the descriptive soil survey did not succeed in identifying the whole source zone with a negative effect on the remedial efficiency.

In residential areas, safety of the residents is an important factor to be taken into account. In 1 case intrusion of pollution in the indoor air was observed beyond the theoretical ROI of the remediation.

On a practical level, there are also some issues to be considered : for instance the clogging of the filters., the cost of cooling of and energy. Also, because vertical migration is an important distribu-tion factor, the technique is sensitive to less permeable horizontal layers.

Interactions of sulfidized nano-zero-valent-iron with microbes

Adrian Schiefler¹; DominiqueJeanette Tobler²; Nina Tuxen³¹ Capital Region of Denmark/University of Copenhagen; ² University of Copen-hagen; ³ Capital Region of Denmark

Sulfidised zero-valent iron (sZVI) shows great promise for subsur-face remediation of chlorinated solvents due to its enhanced reactivity towards trichloroethene (TCE) and its longevity (i.e., reduced interaction with water). However, while sZVI performs well in simple batch experiments, its performance and fate under field conditions is still poorly constrained. In particular, little is known about how sZVI injection will impact on indigenous microbial communities and biotic degradation processes, that are often stimulated to work in conjunction with abiotic treatment. For non-sulfidised ZVI (nZVI), several studies have shown that nZVI induces the formation of reactive oxygen species (ROS) which damages the microbial cell wall, i.e., kills the cells. However, adverse effects seem even more pronounced under anaerobic conditions. Seeing that sZVI are even more effective at generating ROS compared to nZVI, sZVI may have even more adverse effects towards microbial communities. However, this also depends on whether sZVI are in direct contact with microbial cells (their affinities towards each

This leads to enhanced efficiency of S-ZVI for abiotic dechlorination that tends to produce significantly less reductive dechlorination intermediates (cis-DCE, VC). However, the interactions between abiotic dechlorination and biological reductive dechlorination both facilitated by S-ZVI remain largely unknown. This bench scale treatability study compares the treatment performance for TCE dechlorination between two ZVI-organic carbon composites and three novel S-ZVI products in combination with bioaugmentation. The objective is to identify the optimal ZVI-product for creating a permeable reactive barrier (PRB) at a former industrial site in The Capital Region of Denmark who is funding this project.

Microcosm reactors have been prepared using site groundwater and aquifer materials under anaerobic conditions. For each ZVI product, treatment includes ZVI alone, and ZVI + KB-1® (a dechlo-rination culture). For the test, TCE and cis-DCE have been spiked to each reactor up to an initial concentration of 6 mg/L (sum). Samples have been collected periodically over the course of two months to analyze chlorinated compounds, dissolved gases, as well as geochemistry parameters. Multiple respikes have been performed for all ZVI-products given the anticipated fast dechlo-rination kinetics to evaluate the sustainability of S-ZVI reactivity in comparison with the two ZVI-organic carbon composites. The degradation kinetics, product distribution, together with consider-ations of injection approach and field hydrogeology, will be used to select one product for a subsequent column test. Column test will be constructed using 1% ZVI to sediment ratio and conducted at a linear velocity of 0.45 m/day for about two months. Porewater will be sampled from several ports along the column to obtain the first-order degradation rate and desired residence time for the field PRB.

Preliminary results show that S-ZVI products are far more reactive that the ZVI-organic carbon composites. Adding KB-1® culture does not appear to enhance the degradation in the batches containing S-ZVI products i.e. no apparent biotic processes are ongoing. After the first respike, the strong abiotic reactivity of S-ZVI has been sustained. Additional respikes will determine the sustainability of the products. Preliminary data also suggest the effects of different types of ZVI on methanogenesis, which may compete with dechlo-rination for electron donors. The current tests will be completed in December 2018.

The use of in-situ chemical oxidation (ISCO) : the application of ozone in combination with hydrogen peroxide

Filip Sanders¹; Bert Opgenhaffen²; Sam Fonteyne³; Filip De Naeyer³; Samuel Van Herreweghe⁴¹ Witteveen+Bos Belgium NV; ² Vlabotex; ³ OVAM; ⁴ EnISSA

Witteveen + Bos Belgium coordinated and supervised 3 soil reme-diation sites of VLABOTEX, where ISCO was applied (combination of ozone and hydrogen peroxide).

The soil legislation in Flanders provides for a regulation for the establishment and accreditation of soil remediation funds. As specialized organisations they take the burden of soil research and remediation from the hands of the individual companies from the sectors concerned. For the government, soil remediation organiza-tions are an effective policy instrument to activate large numbers of soil dossiers.

VLABOTEX npo is a Flemish soil remediation fund for drycleaning sites (founded in 2007). Their mission is the remediation of 200 dry cleaning facilities in the Flemish Region (North Belgium).

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ISCO with fracturing: Challenges of full-scale application at an operative site

Laura Simone; Greet Schrauwen; Thomas HeldArcadis Germany GmbH

Most of the challenges in the planning or optimization of ground-water remediation are often encountered during the pilot phase and must be evaluated to effectively implement the full-scale application. Remediation of contamination at developed proper-ties with logistical constraints and low permeability soils poses even more challenges.

A site in Germany exhibiting these features will be described. Contamination is located mostly beneath operative warehouses and the site is characterized by a perched aquifer, underlain by clayey layers, followed by weathered bedrock (groundwater aquifer). During the former industrial use of the site, soil, soil vapor, and groundwater were contaminated with chlorinated volatile organic compounds (CVOCs). After approximately 17 years of soil vapor and groundwater extraction and treatment, the contamina-tion in the perched aquifer has been removed, but impacts are still present in the groundwater aquifer, for which remedial targets have never been set. Hence, source remediation is required to increase the efficiency of contaminant removal and reduce the remediation time. A combination of hydraulic fracturing with injection of in situ chemical oxidation (ISCO) reagents (permanganate) was identified as the most feasible remedial option.

A pilot test performed in 2017 confirmed the feasibility and suit-ability of this method. Soil and groundwater investigations showed that the planned radius of influence could be reached, the expected permanganate vertical diffusion from the fractures in the adjacent soil took place and a significant CVOC concentration reduction was achieved with no rebound after one year.

The pilot test showed some challenges to be addressed in the full-scale planning, including the oxidant demand of the thickener used for the fracturing fluid. The guar gum derivative used as thickener showed a high oxidant demand, resulting in increased permanganate consumption. To reduce the overall oxidant dosage, a different thickener with a lower permanganate demand, but still ecologically safe will be applied during the full-scale remediation, significantly reducing the remedial costs.

The effects of the injections on the warehouse were also investi-gated in the pilot test, showing no damages to the structure. To exclude any risks for the stability and integrity of the buildings during full-scale remediation, the maximum permissible ground surface elevations are calculated considering the planned full-scale injection locations. Potential elevations of structural components inside the building will be continuously monitored by means of water level devices. If the predefined permissible changes are exceeded, injections shall be stopped immediately.

Instead of solely focusing on the optimization of the remedial technology, Arcadis also proposed and obtained approval for site specific, mass flux based remedial targets for the groundwater contamination based on a guideline by the regional authority.

The newly set remedial goals are expected to be reached with the selected technology in a relatively short timeframe. Thus, Arcadis is proceeding with the full-scale design and implementation of the remediation measures.

other), as well as on geochemical variables. Overall, it is therefore critical we assess the interaction of sZVI with soil microbes, to allow planning of combined abiotic/biotic treatments of contaminated sites, as well as to ensure environmental safety.

We developed an ATP-luminescence based assay to test bacterial cell viability in the presence of sZVI particles, as a function of exposure time, sZVI particle loading and sZVI type (two different sulfidation treatments). We perform these tests for two different bacterial strains (Shewanella oneidensis, Desulfitobacterium PCE-S). Initial results indicate that the sulfidized particles are more toxic than classical nZVI under aerobic conditions, and we see little difference between the differently synthesized sZVI (i.e., post-sulfidization of ZVI with NaS or dithionite). As expected, we see a clear decrease in cell viability with increasing particle loading and exposure time, although most cell viability (>95%) is gone within 1 h. Electron microscopy images show that the particles are closely associated with the bacterial cells. Preliminary results of cellular oxidative stress response show little difference between ZVIs, implying a possible relevance of other mechanisms.

In a second step we will apply the assay to an enriched anaerobic groundwater community and analyze for shifts in community structure to investigate the impact on both soil functioning and natural biotic attenuation. In a third step we plan to investigate the interaction with a reductively dechlorinating consortium under controlled laboratory conditions (early 2019) and follow the time course of TCE dechlorination, as this is of particular interest for combined remediation approaches.

The power of power: effects of electric fields on bacterial deposition and transport in porous media

Yongping Shan; Hauke Harms; Lukas Y WickHelmholtz Centre for Environmental Research – UFZ

Deposition and transport of bacteria are key to many biotechno-logical applications in environmental engineering and chemical production. Microbial deposition promotes the formation of beneficial biofilms (e.g. in waste water treatment) or give rise to unwanted effects (biofouling, bio-corrosion). There is, hence, strong interest in measures to control microbial deposition to surfaces as the first step in the formation of biofilms. We here tested whether electrokinetic forces (electroosmotic shear force, electro-phoretic drag force) acting on bacteria may be used to control bacterial deposition during transport in laboratory percolation columns exposed to external direct current (DC) electric fields. For different bacteria, yet similar experimental conditions we observed that DC fields either enhanced or reduced bacterial deposition effi-ciencies relative to DC-free controls. By calculating the DLVO force of colloidal interactions, the electrokinetic and the hydraulic shear forces acting on single cells at a collector surface we found that DC-induced changes of the deposition efficiency depended on the ratio of the electroosmotic shear force to the electrophoretic drag force. This finding allows for prediction and application of DC electric fields to influence microbial deposition and transport in porous media and, hence, microbial ecosystems services such as the degradation of unwanted chemicals.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesApplication of the novel sulfidated iron nanoparticles (S-nZVI) on a site heavily polluted by trichloroethene (TCE)

Jan Slunsky¹; Ondřej Lhotský²; Anke Wiener³; Jana Oborna⁴; Petra Skacelova⁵¹ LAC, s.r.o.; ² DEKONTA, a.s.; ³ Institute for Modelling Hydraulic and Environ-mental Systems, University of Stuttgart; ⁴ Regional Centre of Advanced Tech-nologies and Materials, Palacký University Olomouc; ⁵ NANO IRON, s.r.o.

Removal of contaminants using nanoscale-zero valent iron (nZVI) particles is elaborately studied by many research groups over the world and plenty of literature sources dealing with this topic are published every year. However, in-situ application of this material is still a challenging task requiring a complete insight into hydro-geological conditions at the locality. The final efficiency of nZVI depends on numerous variables (e.g. chemical composition of the groundwater, its flow velocity, contamination level, etc.). For the planning and implementation of successful in-situ groundwater remediation using S-nZVI, not only preliminary tests to characterise the reaction agent to be used are important.

The aim of this pilot study was to verify the efficiency of S-nZVI in reductive dehalogenation of highly chlorinated ethenes (primarily TCE) in the field conditions. As its research has shown, S-nZVI has earned a reputation as a promising material due to its high reactivity towards some pollutants, its increased mobility, and its longevity caused due to suppressed corrosion. The chosen pilot site is located in the area of the pharmaceutical company in the Czech Republic. The soil and groundwater are characterized by a high concentra-tion of chlorinated hydrocarbons (CHCs), namely TCE reaching up to 400 000 µg/L. CSM at this site involved preliminary mapping of groundwater and soil contamination using MIP probe and drilling. Batch experiments testing reactivity and migration ability of S-nZVI in comparison to non-modified nZVI were conducted prior to the in-situ application. Elaborately performed conceptual site model (CSM) ensured the subsequent application of S-nZVI into the most contaminated zone. The site was remediated using 150 kg of S-nZVI (NANOFER 25DS from NANO IRON) which was applied in August 2018. The material was injected in form of an aqueous suspension (concentration approx. 3 g/L) employing the pressure injection into permanent wells.

The groundwater and soil were periodically sampled before and after the remediation event. In-situ and ex-situ measurements of physical-chemical parameters, contamination levels, nZVI migration and changes in biota were performed by employing of the field-ready laboratory equipment as well as the advanced analytical techniques. Monitoring of the subsurface has proved the decrease in average concentration of CHCs and chlorine number, especially in the highly contaminated deeper horizons. Application of S-nZVI resulted in increasing pH, decreasing redox potential and evolution of gaseous products of CHCs degradation (ethane, ethene, acetylene). To our knowledge, this is the first application of S-nZVI accompanied by complex detailed pre- and post-injection monitoring.

Acknowledgement: This work was supported by a grant from the Technology Agency of the Czech Republic “Competence Centers” (project No. TE01020218).

Biochar properties influence heavy metal immobilization on polluted soils and plant growth

Rosa Soria; Stephen Rolfe; Steven F. ThorntonThe University of Sheffield

Biochar is a black carbon produced by pyrolysis of residual biomass. It typically possesses high specific surface area and is rich in oxygen-ated functional groups. Due to these properties it can be useful for

the treatment of heavy metals (HM) in contaminated soils; it can immobilize pollutants by different chemical and physical mecha-nisms, reducing metal toxicity towards plants, which may then enable land to be brought back into productive use.

This project aims to determine how the mechanistic properties of biochar influence its application in the remediation of heavy metal polluted soils. The objectives are to 1) select biochar materials and characterize their properties related to heavy metal immobiliza-tion, 2) identify the immobilization mechanisms for Zn, Pb and Cd triggered by the selected biochars, and 3) determine the effect of biochar amendments on the reduction of bioavailable HM in artifi-cially polluted soils and plant growth.

Biochars produced from oil seeds, soft wood, wheat straw and Miscanthus pellets were characterized for their cation exchange capacity (CEC), specific surface area (BET), pH and surface morphology by scanning electron microscopy (SEM). Batch sorption tests with soil pore water were done to deduce metal sorption kinetics, the effect of pH, the effect of adsorbent dose and single adsorption isotherms. The kinetics demonstrated that equilibrium was reached within 24 hours. The sorption process followed a pseudo-second order model, indicating a fast sorption phase (chemisorption) followed by a slow diffusion (physical sorption). The kinetic constant k2 of the biochars indicated that adsorption occurred in the following order from rapid to slow Pb>Cd>Zn. The study of pH effects on the soil pore water solution indicated that biochars can immobilize Cd and Zn at pH between 6 to 8, while for Pb the adsorption capacity decreased above pH 5. Biochars with similar CEC had high immobilization capacity for Cd and Zn suggesting that CEC is the main sorption mechanism for these metals; in the case of Pb the main mechanism seems to be precipitation caused by changes in the pH. Greenhouse soil incu-bations were amended with biochar at application rates of 1, 3 and 5 % (w/w). Arabidopsis thaliana seeds were planted on the experi-mental pots to evaluate the effect of biochar on reducing plant HM toxicity. Plant response was monitored by a chlorophyll fluores-cence imaging scanner. RGB and chlorophyll fluorescence images were taken daily to determine growth rate and plant health state by monitoring the functioning of photosystem II (Fv/Fm). Plant tissue and bioavailable soil concentrations of HM have been deter-mined. Biochar had a different effect on plant growth depending on the application rate, biochar type and the metal present in the soil. Overall 1% (w/w) application rate protected plants against the toxic effects of HM, while 5 % (w/w) resulted in growth inhibition, which is being investigated. Complementary analyses are required to determine the sorption mechanisms involved and the effect of biochar on the bioavailable HM fraction in the studied soil.

Electro-kinetically enhanced nZVI: Experiences from France and Switzerland

Vojtech Stejskal; Petr Kvapil¹; Jaroslav Nosek²; Pierre Matz³; Antoine Joubert⁴; Cédric Palmier⁵; Jaroslav Hrabal⁶¹ Photon Water Technology s.r.o.; ² Technical University of Liberec; ³ SOLVAY S.A.; ⁴ SERPOL; ⁵ Ford Aquitane Industries; ⁶ Mega a.s.

The use of nZVI for contaminated groundwater remediation is nowadays one of standard methods for in-situ treatment or stabi-lization of chlorinated hydrocarbons, selected inorganic anions, heavy metals and others. The effectiveness of this method depends on the geological and hydrogeological conditions which affect both the reactivity of nanoparticles with contaminants and their spreading in the subsurface. In the case of low permeability envi-ronment, the migration of nanoparticles is very limited and the efficiency of the method might be therefore reduced. The applica-

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiestion of nanoparticles supported by direct current (DC) electric field of certain field intensity leads to a significant increase of lifetime and total efficiency of this combined remediation technique.

Combination of nZVI and electrical field was successfully tested in laboratory and afterwards on several sites in the Czech Republic. With successful references we went abroad – first to France in May 2017, and then to Switzerland (November 2017). French site lies in Bordeaux area, with the following characteristics’: unconfined aquifer (mainly silty gravel and sand), contamination of chlori-nated ethenes (PCE, DCE, VC) exceeding concentration levels of 200 mg/l in total and very low permeability due to embedded silty layers. On our French site we performed two identical pilot tests – the only difference between them was that in one pilot there was DC applied and on the other one it wasn’t. This field test was performed aiming to define DC potential in real conditions. In both cases 41 kg of nZVI (NANOFER STAR DC, fabricated by Nanoiron, CZ) has been injected using 4 direct-push injection probes. Electrodes for DC application were hammered into the soil. For the evaluation groundwater samples were collected during 9 months. Swiss site is characteristic by deep aquifer with bottom in 16-17 meters of depth and 3-4 m of thickness. It is contaminated by chlorinated ethenes in concentrations from 12 to 70 mg/l in total, (especially PCE and TCE). In Switzerland we injected the same material as in France – NANOFER STAR DC, a product design for application with DC. In total there was injected via packer system 25 m3 of 10 g/l nZVI into 5 wells creating a permeable reactive barrier. A system of electrodes was installed directly into the monitoring wells due to very deep groundwater level. 9 months long monitoring was held on our Swiss site including a tracer test confirming direction of groundwater passing through the barrier.

DC application has a positive impact on efficiency and longevity of used nZVI particles. This result has been confirmed on the French site, where the pilot with DC enhancement proved more reductive conditions (ORP), 33-58% more CHC degraded and 8 times higher production of ethene compared to the pilot without DC application. PRB in Switzerland was able to degrade inflowing CHC concentration in range of 20 to 69 mg/l with efficiency 92-98 % for first 7 months since nZVI application and up to 9 months with efficiency 74 %. These results showed a significant improvement of efficiency of this method compared to the conventional use of nZVI.

Superoxide radical as a green reagent and an ultimate solution for soil and water contamination

Uri Stoin¹; Yoel Sasson²¹ Alpha Cleantec; ² The Hebrew University of Jerusalem

The contamination of soil and water by organic chemicals remains a significant worldwide problem, even after decades of research. The most common soil pollutants are polychlorinated hydrocarbons (PCHs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorinated solvents, petroleum products, and pharmaceutical leftovers. The contamination of soils and water by persistent organic pollutants (POPs) is an environmental concern because of their high chronic toxicity to both animals and humans, and their long-lasting sorption by soils and sediments.

During the past decades, several new and innovative solutions for efficient contaminant removal from soils and water have been developed and investigated. The methods include excavation and landfilling (for contaminated soil), thermal desorption, incinera-tion, washing, biological remediation, vacuum extraction, chemical extraction, chemical oxidation (AOP’s), photocatalysis and electro-chemical treatment.

Advanced oxidation processes (AOPs) provides an effective means of rapidly treating bio-refractory compounds with efficient process control. Chemical oxidation is a promising process for degrading an extensive variety of hazardous compounds in water and soil remediation. Nevertheless, the biggest challenge of soil remedia-tion industry is the non- homogeneous of the soil, emulsion in water, contact between the pollution and oxidizing agent and the sensitivity of the process.

Superoxide ion is one of the most extensively studied radical species due to its critical role in a wide range of chemical and biochemical processes. However, production and stabilization of superoxide compounds is still a substantial challenge. The high price of manufacturing and required high concentration exclude superoxide radical as economically reasonable advanced oxidation processes. Currently, there is now available methodology for efficient and cost-effective preparation and exploitation of super-oxide radical as soil and water remediation procedures.

In recent years, we developed two different processes (AFA and SOA) for straightforward, efficient and economical superoxide prepara-tion and applying as strong oxidizing agent, under NTP conditions. Under these conditions, superoxide radicals reveal properties of a super nucleophile and super-oxidizing agent which rapidly reacts with a wide range of soil pollutants on concertation up to 100,000 ppm and responsible for the rapid treatment and swiftly mineralization of absorbed and NAPL contaminants. While AFA is based on advanced Fenton and Haber-Weiss reactions activated for superoxide production. SOA is a unique process of alkali super-oxide production from standard and stable shelf products. Both of our patented methodologies applicable for in situ and on-site treatment approaches. The laboratory development phase with dozens of different types of contaminated substances has been accomplished. The technology stability and efficiency have been approved by independent laboratories and first pilot test for PCB and dioxin decontamination have been held. The conversion rate of 65% - 90% was achieved after only two hours of reaction.

Iron minerals as catalytic activators for persulfate: performance and mechanistic studies

Sarah Suehnholz¹; Katrin Mackenzie; Frank-Dieter Kopinke¹ Helmholtz-Zentrum für Umweltforschung GmbH – UFZ

Recently, advanced oxidation processes (AOPs), like Fenton-like systems or such based on the substances peroxydisulfate (PS) and peroxymonosulfate (PMS), received increasing attention for the remediation of persistent pollutants in surface, ground or waste waters. Particularly regarding in-situ remediation strategies for aquifers contaminated with perfluorinated compounds (PFCs), the main focus of attention lies on the heterogeneous activation of PS or PMS for sulfate radical generation. In contrast to hydroxyl radicals, sulfate radicals are reported to be able to degrade perfluorinated compounds (PFCs). Our search for heterogeneous environmentally compatible PS activators led us to iron minerals.

In the present study, the ability of various iron minerals to activate PS was investigated. The performance of the eligible PS activators was evaluated in the oxidation of trichloroethylene (TCE) as a fast responding model contaminant. From the set of iron minerals, iron sulfide (FeS) proved to be the activator with the highest perfor-mance qualities among the tested minerals.

The screening studies with TCE as model led to optimized reaction systems which were successfully tested for their suitability to decompose PFCs. The fact that sulfate radicals degrade PFCs in

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesan iron-containing system is remarkable. The presentation will discuss system requirements and parameter optimization for PFC degradation.

Mechanistic investigations regarding the activation process of PS with FeS will be presented. Studies on the activation process, its activation energy, radical yield and long-term performance not only propose a new mechanism of the activation of PS with FeS but also lead to the assumption that FeS acts as a catalyst with a high lifetime.

By insight into the mechanistic activation of PS via heterogeneous activation, this work breaks new ground for novel remediation approaches using PS for in-situ and ex-situ remediation.

In-situ remediation of pesticides in groundwater used for drinking water production: The potential of DOM

Nora Sutton; Yujia Luo; Siavash Atashgahi; Huub Rijnaarts; Rob ComansWageningen University

Groundwater, as essential freshwater source for drinking water production, is threatened by the presence of pesticides due to their continuous worldwide use, and their persistent nature. Currently, pesticides are found in groundwater near approximately one quarter of Dutch drinking water production locations. However, we have neither the knowledge to predict the environmental fate of pesticides, nor in-situ technologies to remove these contaminants from groundwater systems. Both are crucial towards developing natural and engineered groundwater treatments.

Pesticide biodegradation is governed to a large extent by ground-water geochemistry, especially the availability of electron acceptors (redox condition) and dissolved organic matter (DOM) concentra-tion and quality. Both are crucial to support biological activity in the oligotrophic groundwater systems used for drinking water production.

In this work, we studied the influence of electron acceptor avail-ability and DOM on pesticide (2,4-dichlorophenoxyacetic acid, 2,4-D) biodegradation in batch and column experiments. Batch experiments were first conducted to test the influence of two different DOM types on 2,4-D biodegradation, and to select an appropriate DOM source for biostimulation. Subsequently, bios-timulation was performed in column experiments simulating groundwater systems with various redox conditions i.e. nitrate-reducing, iron-reducing, sulfate-reducing and methanogenic conditions. Pesticide degradation, functional genes related to each redox condition and those involved in 2,4-D biodegradation, and changes in DOM quantity and fractions was conducted.

The results of batch experiments clearly show that DOM extracted from compost better supported 2,4-D biodegradation than DOM collected and concentrated from groundwater. The differences in respiration rates indicated that the DOM from compost was a more biodegradable carbon source. Thus, DOM extracted from compost was used in column experiments, where minimal pesticide biodeg-radation was observed in any redox conditions in the absence of DOM. Interestingly, in the presence of DOM, 2,4-D biodegradation was considerably enhanced from 23.5±10.2% to 82.3±11.6% under nitrate-reducing conditions, and from 6.3±12.6% to 31.1±36.3% in a column mimicking iron-reducing conditions. Characteriza-tion of changes in humic and hydrophilic DOM fractions showed a reduction of the fulvic acids (FA) pool in these two columns over time, and an increase in microbial biomass and functional genes after DOM addition in all columns. These results are a proof-of-

principle that natural DOM can support 2,4-D biodegradation. DOM-functionality was found to be determined by specific (humic) properties that require further identification to enable selection of effective DOM sources. Future research focuses on translating this into in-situ technologies to treat pesticides in groundwater and thus safeguard drinking water quality.

Nanoparticles in remediation of heterogeneous aquifers: laboratory tests and numerical simulations

Fabio Tatti; Marco Petrangeli Papini; Paolo ViottiSapienza University of Rome

Removal of contaminants stocked inside low permeability zones of aquifers is one of the most important challenge of groundwater remediation process today. As Non-Aqueous Phase Liquids (NAPLs), polluted low permeability layers can be considered secondary long-lasting sources of contamination representing a real limita-tion for a complete and effective groundwater restoration. When dissolved plume encounters low permeability layers, concentra-tion gradient between low and high-permeability zones of aquifers determines storage of dissolved pollutants into the lower perme-ability layers by molecular diffusion (Forward-Diffusion). After the end of the plume passage, an inversion of the gradient direction occurs leading to a slow re-distribution of contaminants from the lower permeability zones to the higher permeability zones (Back-Diffusion). This process causes long plume tails that hamper remediation efforts (Tatti et al., 2016). Recent studies demonstrate the low efficiency of traditional remediation technologies due to the long depletion time of the Back-Diffusion process and to diffi-culties to locate contaminated low permeability zones (Tatti et al., 2018). These observations strongly suggest that remediation processes based on “bulk” approach can be considered the best solution to restore heterogeneous aquifers.

The proposed research aims to investigate nanoparticles transport in heterogeneous porous media by laboratory tests and numerical simulations in order to evaluate their suitability to be used as alter-native remediation strategy for contaminated low permeability zones of aquifers.

To reach the goal, an aquifer was reconstructed inside a tank and groundwater flow was reproduced by means two peristaltic pumps. Fluorescent nanoparticles were injected into the aquifer and images of the box model were acquired by a camera. To define the distribution of nanoparticles in the porous media, the image analysis technique was used.

Experimental results were utilized to validate a numerical model developed to simulate the transport of nanoparticles in saturated porous media and to investigate their distribution inside aquifers using different injection technologies. In particular, numerical simulations were performed to compare nanoparticles distribution obtained injected them using a traditional well and an innovative groundwater circulation system (Groundwater Circulation Well).

ReferencesTatti, F., Petrangeli Papini, M., Raboni, M., Viotti, P., 2016. Image analysis proce-dure for studying Back-Diffusion phenomena from low-permeability layers in laboratory tests. Sci. Rep. 6, 30400; doi: 10.1038/srep30400.Tatti, F., Petrangeli Papini, M., Sappa, G., Raboni, M., Arjmand, F., Viotti, P., 2018. Contaminant back-diffusion from low-permeability layers as affected by groundwater velocity: A laboratory investigation by box model and image analysis. Science of the Total Environment 622–623, 164–171.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesHexavalent chromium remediation by green rust sulfate: How µm-scale structure of reaction byproducts can be used to evaluate stability

Andrew Thomas¹; Elisabeth Eiche¹; Jörg Göttlicher¹; Ralph Steininger¹; Liane Benning²; Helen Freeman³; Dominique Tobler⁴; Thomas Neumann⁵¹ Karlsruhe Institute of Technology (KIT); ² GFZ German Research Centre for Geosciences; ³ University of Leeds; ⁴ University of Copenhagen; ⁵ Technical University of Berlin

Chromium speciation in soils is intimately linked to the iron and manganese redox cycles, and aqueous and structural Fe (II) can therefore be used to remediate the toxic chromate (CrO42-) anion by reducing it to Cr (III) and removing it from solution. However, as this reaction is reversible in the presence of Mn (IV) oxides if dissolved Cr (III) is released into solution, heterogeneous reactants such as green rust sulfate with multiple reaction sites and possible mechanisms can be tailored to produce less soluble and therefore more stable Cr-bearing reaction products. In this experiment, synthetic green rust sulfates, (naturally occurring mixed-valence Fe (II, III) oxides), isomorphically substituted with Zn, Mg and Al, were reacted with solutions of chromate at concentrations typical of groundwater contaminant plumes. The solid byproducts were then characterized using X-ray diffraction, transmission electron microscopy, pair distribution function analysis, and Fe and Cr K-edge extended -ray absorption fine structure spectroscopy to determine the structure and Fe- and Cr- elemental speciation of the reacted products. In addition, the product suspensions were treated with synthetic pyrolusite (δ-MnO2), and the resulting release of chromate into solution was measured to quantify the stability of the products. We found that substitution of Al and Mg into the green rust reactant favored the formation of mixed Fe  (III)/Cr  (III) oxyhydroxides and increased the stability of the product, while Zn substitution had the opposite effect. The results also suggest that the use of these modified green rusts for remediation is optimized by adding a large amount of green rust in excess of the amount needed to reduce the chromium, as this would allow for the precipitation of Cr (III)-bearing goethite as a product of Ostwald refinement.

Reduction of aqueous mercury in contaminated sediment by activated carbon/clay-based active caps: a microcosm study with the horizontal flow and artificial turbation

Yu TingNational Taiwan University

With high mobility, toxicity, volatility, and bioaccumulation ability, mercury (Hg) is considered one of the most toxic heavy metals in the environment. Over decades of human industrial activities, wastewater has been discharged to river streams causing severe pollution problems across the globe. Active capping is an econom-ically-feasible in-situ method for sediment remediation; using activated materials to form a thin-layer cap could reduce contami-nant release from sediment to overlying water, subsequently reduce human health risks and ecological risks. This research evaluated the Hg leaching inhibition performance of using different active caps under horizontal flows and sediment turbation operated in micro-cosms with artificial vibration system.

Microcosms designed in this study were with horizontal overlying water flow and artificial vibration systems to mimic sediment turbation. Three activated carbon (AC)/clay combinations of active

caps were tested. The experimental results showed that active caps with AC (3%) + bentonite (3%) and AC (3%) + kaolin (3%) were efficient in reducing both total mercury (THg) and methylmercury (MeHg) in overlying water by 75−95% under 75 days operation. In contrast, AC (3%) + montmorillonite (3%) did not show a significant reduction on THg and MeHg in overlying water, probably due to the unstable property of montmorillonite resulting in the visible suspen-sion of cap particles in the aqueous phase. These experimental results verified the importance of capping stability in settling. All capping groups showed a decrease in oxidation-reduction potential (ORP), indicating a more anaerobic environment was established under caps as compared to the uncapped sediment. The resulted anaerobic environment may increase the MeHg formation potential shown in this study. It is also important to note that with unstable caps, a high concentration of MeHg breakthrough was also observed in the occurrence of turbation in a given depth.

Active recirculation for enhanced reductive dechlorination of chlorinated VOCs in glauconitic sand on a Belgian site

Diederik Valcke¹; Karina Suy¹; Diane Dries¹; Jeroen Verhack²; Isabelle Olivier²; Thomas Van Humbeeck²; Wouter Gevaerts²¹ Mourik n.v.; ² Arcadis Belgium

Enhanced Reductive Dechlorination was selected to treat the groundwater contamination with chlorinated solvents (PCE and degradation products, max. ± 60.000 µg/l). The contamination has migrated to a depth of ± 80 m with the highest concentrations in the upper 45 m. The geology consists of a permeable sandy aquifer until 35 m underlain by a more silty, less permeable layer until 50 m. The plume in the upper aquifer is 200 m wide and 400 m long. There is limited space to install the wells because of the infrastruc-ture present on site.

The remediation project, inclusive a pilot test, started in 2012. A primary limitation of the in-situ bioremediation processes is the difficulty to obtain an optimal contact between delivered amend-ments (electron-donor/nutrients) and the contaminants. However, a well-designed recirculating system provides an engine for the in situ treatment of subsurface contaminants and for the creation of an in situ bioactive zone.

During the pilot test, realized in 2012, 8 injection wells and 4 extraction wells were installed on the site and 8 m³/hr groundwater was recirculated without groundwater treatment. In the pilot test, 30.000 m³ of water was recirculated during a period of 5 months. Complete dechlorination to ethene was proved and no serious well fouling was observed.

Based on these data, the full scale remediation of the site was designed and the possibility to gain heat and cold from the recircu-lated water was evaluated. The gained energy can be used to heat or cool buildings (aquifer thermal energy storage or ATES). The cold and heat demands from different buildings on the site were evaluated and potential scenarios for combination with remedia-tion were calculated.

In 2017, the pilot infrastructure was expanded with 12 injection wells and 12 extraction wells. The full scale remediation based on a recirculation of 20 m³/hr groundwater without groundwater treatment was started in October 2017.

The presentation describes the engineering (pilot, modeling), the construction and implementation of the recirculation system, the selection of the electron-donor, the construction and implemen-tation of the dosing systems and the measures taken during the

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesdesign, the installation of the underground infrastructure and the most recent results of the full scale remediation.

Experiences on this project show the importance of:

• The development of wells

• The choice of material / slot size / filter sand for the wells

• The choice of electron-donor

• The preparation of electron-donor / nutrient injection solution

• The dosing (amount, concentrations, frequency, pulsed feeding) of electron-donor

• The follow-up of the pressures during operation of the recircu-lation system

• The preventive maintenance

All these elements contribute to obtain a constant recirculation flow rate and a stable bioactive zone and prevent the negative influences of excessive biomass growth and clogging of the system / soil.

Microbial degradation of fuel components

Marcelle van der Waals¹; Caroline M. Plugge²; Hauke Smidt²; Jan Gerritse¹¹ Deltares; ² Wageningen University & Research

In the environment, soil and groundwater contamination often occur due to anthropogenic activity. Accidental spills, leaking storage tanks or waste disposal have polluted the surrounding environment with inorganic and organic compounds, the latter including for example aromatic and aliphatic hydrocarbons and ethers. These chemicals pose a risk to the health of the environment, animals and humans. Therefore remediation technologies are needed to clean up the envi-ronment. Bioremediation is considered cost effective, sustainable and can accelerate the natural biodegradation. Selected contami-nants included methyl tert-butyl ether (MtBE), ethyl tert-butyl ether (EtBE), tert-butyl alcohol (TBA) and benzene. Among these contami-nants, benzene is often considered as risk determining compound at fuel-contaminated locations due to its solubility and mobility in aquifers as well as its toxicity. MtBE, EtBE and TBA are gasoline ether oxygenates that are often added to fuels to increase their compress-ibility and efficiency of combustion.

The concurrence of MtBE, EtBE, TBA and benzene in groundwater may affect the microbial degradation potential for both fossil-based and biobased components. We therefore determined the biodegradation capacity of microbial communities in ground-water from a contaminated site for a mixture of MtBE, EtBE, TBA and benzene in microcosms at various redox conditions. MtBE degradation in microcosms was most pronounced under sulphate-reducing and iron-reducing conditions prevailing at the field site. The addition of nitrate and chlorate stimulated benzene degrada-tion, but hindered MtBE, EtBE and TBA degradation. Degradation of EtBE under different redox conditions was not found. However, we found that EtBE was cometabolically degraded during growth on methoxylated and ethoxylated substrates, such as ferulate, syringate, and diethyl ether. Furthermore, we observed that TBA was cometabolically degraded in the presence of MtBE, syringate, vanillate or ferulate.

EtBE was also degraded under micro-oxic conditions in co-cultures of algae and bacteria. Oxygen produced by the algae Chlorella and Scenedesmus was used by the bacteria in the culture to degrade EtBE. Using both nuclear magnetic resonance spectros-copy (NMR) and gas chromatography, TBA, ethanol and CO2 were

detected as metabolites in this degradation process. Stable isotope probing (SIP) with 13C labelled EtBE and comparison of 13C- and 12C-enriched DNA fractions showed Halomonadaceae, Shewanel-laceae, Rhodocyclaceae, Oxalobacteraceae, Comamonadaceae, Sphingomonadaceae, Hyphomicrobiaceae, Candidatus Moran-bacteria, Omnitrophica, Anaerolineaceae, Nocardiaceae, and Blastocatellaceae as predominant bacterial families in the culture.

This work contributes to a better understanding of the ecology and physiology of the microorganisms involved in the anaerobic or micro-oxic degradation of MtBE, EtBE, TBA and benzene.

Implementation of zerovalent iron for source zone treatment via soil mixing

Stef Vansteenberge¹; Hilde Decuyper¹; Nele Vermeiren²; Johan Gemoets³; Ilse Van Keer³; Leen Bastiaens¹ A+E Consult bvba; ² Smet-F&C nv; ³ VITO

The soil and groundwater at a textile manufacturing site in Flanders are heavily polluted with chlorinated solvents. The amount of trichloroethylene in the groundwater is very high (426 mg/l), whereas concentrations of 1,2-dichloroethylene and vinyl chloride are much lower. Within the soil, trichloroethylene is the only pollutant. A pure product layer has been detected at a depth between 7.2 and 7.6 m bgl. The soil consists of sandy clay with very low permeability. Practice has shown that the source zone can’t be removed by traditional techniques such as pump and treat. In addition, excavation is not favourable because the source zone is situated near a building and at a great depth, making excavation of the pure product layer risky and rather expensive. Therefore, in situ chemical reduction of the DNAPL by injection of ZVI (zerovalent iron) was tested in 2014.

The chemical destruction of the chlorinated solvents by addition of ZVI was examined in lab tests. These tests showed a degradation of more than 95%. After 8 weeks, a carbon source was added to stimulate biodegradation. With the carbon source, further decom-position of the chlorinated solvents was achieved. On large scale, because of the great density of iron and permeability limitations of the soil, it is often a problem to keep the iron in suspension during injection and to distribute the iron equally over the polluted zone. To counter this problem, the iron was suspended in a guar gum slurry which was distributed in the subsurface by soil mixing. During drilling, the ZVI-slurry is injected under high pressure and mixed with the soil at the same time, creating a soil mix pile. At this particular site, a total of 14 soil mix piles were installed successfully until 8,4 m bgl, consuming 3500 kg of fine sized micro scale ZVI. In addition, by time, the guar gum biodegrades with release of simple sugars, which is expected to stimulate the anaerobic biodegrada-tion of the chlorinated solvents even further.

Twelve months after the soil mixing, soil concentrations of trichlo-roethylene in the soil mix zone zone already decreased from 43700 mg/kg dm to 81.5 mg/kg dm. In 2017, concentrations were already below 0.02 mg/kg dm. Groundwater concentrations measured until 2017 show that nearly all trichloroethylene has been degraded within the soil mix zone, proving that the technique was successful here. However, in other parts of the source zone, outside the area where soil mixing was carried out, the decrease of trichloroeth-ylene is less distinctive.

The results of this pilot study show that soil mixing may be a promising alternative to injection of ZVI by direct push or by injection in wells. This soil mixing can be used for the remediation of chlorinated solvents in high concentrations in dense soils and at great depth without the removal of any soil material.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesEnhanced reductive dechlorination of PCE and TCE in a source zone via recirculation: Pilot test and results

Pieterjan Waeyaert; Nico LeysJAN DE NUL GROUP

Under the authority of OVAM (the public waste agency of Flanders), a fully automated recirculation system was installed for a pilot test for the removal of chorinated hydrocarbons in an existing manu-facturing plant for electronic devices such as switches and sensors. The groundwater was polluted with PCE (tetrachloroethylene) and TCE (trichloroethylene) in high concentrations with indications of existence of DNAPL (Dense Non-Aqueous Phase Liquid) (>10% solubility). The purpose of the pilot test was to evaluate the appli-cability of enhanced reductive chlorination in the source zone at the high concentrations and to evaluate the effect of the recircula-tion on the bioavailability of the hydrocarbons in the groundwater (desorption from the loamy soil). The test was performed in two depth intervals in which both a central extraction well was installed with four injection wells around it. Groundwater was extracted out of the central well and after addition of a carbon source and nutrients (through an in-house carbon source EnviC) re-injected in the injection wells. The extraction and injection was fully automated and continuously monitored. The settings (max. pressure, injection times, dosage) were adjustable remotely (or by remote control) which led to a limited occurrence of staff on site, not disturbing the activities of the plant.

The test was performed during one year, followed by a monitoring period to verify the duration of the biological dechlorination after shut-down of the recirculation. The carbon source EnviC, specifi-cally designed for the use in a recirculation system to prevent clogging of the wells and piping, wasadded in low concentrations (90-150 mg TOC/l) to obtain the steady sulphate reductive environ-ment and prevent excessive methane production. After one year of recirculation the capacity of the injection wells was lowered due to the bacterial growth in the soil but still sufficient to keep the recirculation running.

The results show a full breakdown of the mother products (PCE, TCE) to ethene. Reductive dechlorination of PCE and TCE occurred very soon but a lag period of approximately 6 months was necessary to obtain the required circumstances in the soil for further reduction of DCE (dichloroethylene) to VC (vinyl chloride) and ethene by the specific species Dehalococcoïdes (DHC) bacteria. The presence of the DHC species was verified by means of a bacterial count.

The test has shown that continuous recirculation at both depth intervals is the perfect method to desorb the mother products form the soil into the groundwater as well as to obtain and maintain a reductive system for enhanced reductive dechlorina-tion in the source zone. However the monitoring after shut-down is still ongoing, it is already clear that with EnviC the reductive environment can be held for a long time after shut-down of the recirculation but that a strong rebound effect of mother products has to be taken into account in the full-scale project.

Upgrading biosparging from plume to source treatment for an ETBE/TBA impacted site

Geert WijnArcadis Netherlands

In this presentation we will focus on a remediation project which is ongoing. This remediation is a perfect example of successful approach by using a bioremediation adapted to the site specific

conditions and a careful step by step approach. Spills and sewer leakages over the years have led to several sources and plumes including ETBE, MTBE and TBA. Since 2012, source zone treatments using excavation and P&T have been applied followed by bioreme-diation of the deeper groundwater.

Site specific conditions made groundwater extraction the most feasible solution for the shallow source zones. This source zone is a 2 m manmade sandy top layer and a 4 m sandy clay layer. Flow and fouling issues had to be addressed but after a pilot a simple but effective groundwater pump system was installed. For the groundwater 6 m below surface we applied a different in-situ approach. Based on successful treatability studies we engineered a full scale bioremediation approach using multiple In-Situ Reactive Zones (IRZ) for one of the TBA plumes (approx. 1.5 hectares). The client requested to keep all systems as simple as possible in order to reduce costs and site interference. We implemented a progres-sive approach so we started with one IRZ in the sandy layer just upstream of the shallow source zone which is describe above and treated with a P&T system. In this first IRZ, a total 9 biosparging wells were strategically situated just outside the production plant. Maximum levels of the contaminant of concern (COC) during start-up were approx. 700-2.000 mg/L. We started with no nutrient dosing system although the C/N/P ratio suggested low or sub optimal natural nutrient resources. A very careful start-up procedure was applied to prevent daylighting of air using low air pressures. An intensive monitoring program was applied to check all design parameters and the progress of the remediation. After 6 months a significant decrease of the COC started and the radius of influence of the low flow sparging system was much greater than expected. After 4 years the plume is disconnected from the source and significantly reduced. As a result of that the full implementa-tion of the other IRZ’s is no longer needed which resulted in a large cost saving for the client. Concentration reductions of >99% have been accomplished. The source zone is not yet fully removed and the extraction system is reaching asymptotic levels. Biosparging has proven to have a positive impact on the shallow impermeable zone as well. We recently investigated the potential of bioremedia-tion for these source zones and other (ETBE) impacted zones at this site using Next Generation Sequencing (NGS). We have proven that the whole site has a potential for aerobic degradation of the COC’s. We found microorganisms and genes responsible for biodegra-dation to be present in the source zones and the lower impacted deeper ground water.

This knowledge is now to be used to optimize the site wide approach. The goal in the long term is to phase out all extrac-tion systems and use bioremediation as the standard remedial approach for this site.

Improve subsequent bioremediation of long-chain crude oil in soil using bio-stimulated Fe-SOM Fenton pre-oxidation

Jinlan Xu¹; Lu Li¹ Xi’an University of Architecture and Technology

The objective of this study is to explore how to stimulate soil indigenous bacteria for the degradation of long-chain crude oil by bio-stimulated Fe-SOM Fenton pre-oxidation. Four bio-stimu-lated and non bio-stimulated Fe-SOM with different iron species concentrations were synthesized. The crude oil-contaminated soil (TPH  =  13221 mg/kg) was pre-oxidized by H2O2 which was catalyzed by bio-stimulated Fe-SOM or non bio-stimulated Fe-SOM, then 80-day bioremediation experiments were carried out. The

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesresults showed that the removal efficiency of long-chain alkanes (C25 – C30) reached 55% – 68% by bio-stimulated Fe-SOM Fenton pre-oxidation combined with bioremediation, which was 1.5 times that of the corresponding value of non-bio-stimulated Fe-SOM. In addition, the livability of hydrocarbon degraders was as high as 70% after pre-oxidation of bio-stimulated Fe-SOM, while the corre-sponding value of non-bio-stimulated Fe-SOM was only 50%. The pre-oxidation efficiency of TPH by bio-stimulated Fe-SOM Fenton (28%) was similar to that of non-bio-stimulated Fe-SOM Fenton, but more DOC and NH4+-N (DOC:3218 mg/kg, NH4+-N:432 mg/kg) were generated by bio-stimulated Fe-SOM than non-bio-stim-ulated Fe-SOM (DOC:1500 mg/kg, NH4+-N:312 mg/kg). Moreover, the biodegradation of long-chain alkanes C25 – C30 (4638 mg/kg, 35%) in bio-stimulated Fe-SOM Fenton combined with bioremedi-ation system was 1.5 times higher than that in non-bio-stimulated Fe-SOM Fenton system. Thus, a good nutritional environment was provided after pre-oxidation by bio-stimulated Fe-SOM Fenton for the recovery of hydrocarbon degraders, where the activity of the hydrocarbon degraders can maintain at a high level. The indig-enous hydrocarbon degraders can multiply rapidly to become dominant bacteria. Long-chain alkanes were induced to become the main carbon sources for indigenous hydrocarbon degraders, and the biodegradation of long-chain crude oil was promoted.

Horizontal permeable reactive barriers with zero-valent iron for preventing upward diffusion of chlorinated solvent vapors in the unsaturated zone

Daniela Zingaretti; Iason Verginelli; Renato BaciocchiUniversity of Rome Tor Vergata

The intrusion of vapors from the subsurface to overlying buildings is one of the major concerns for human health of residents at sites contaminated by chlorinated solvents. For diffuse contamination (i.e. large areas contaminated at a relatively low level), the adoption of traditional clean up techniques implies the use of significant quan-tities of reagents and/or energy that makes the traditional clean up strategies not sustainable. Risk management strategies aimed at

interrupting the migration pathway of vapors into the building are more indicated for this contamination scenario. Over recent years, some researchers proposed a vapor intrusion mitigation system that involves the use of solid potassium permanganate to create a horizontal permeable reactive barrier (HPRB) aimed at treating upward volatile organic compounds (VOCs). In this work, we report the results of lab-scale experimental tests aimed at assessing the feasibility of using granular zero-valent iron to treat TCE vapors as filling material of HPRB. Namely, we examined the reduction of trichloroethylene (TCE) in gas phase by different types of granular zero-valent iron in anaerobic batch vapor systems performed at room temperature. Concentrations of TCE and byproducts were determined at discrete time intervals by analysis of the headspace vapors. Depending on the type of iron used, reductions of TCE gas concentration from 35% up to 99% were observed for treatments of 6 weeks. In line with other experimental studies performed with aqueous solutions, the particle size was found to play a key role in the reactivity of the iron. Namely an increase of the TCE removal up to almost 3 times was observed using iron powders with particle size lower than 425 µm compared to iron powders with particle size lower than 850 µm. The manufacturing process of the iron powder was instead found to play only a limited role. Namely, no significant differences were observed in the TCE reduction by ZVI obtained by water atomization of an iron powder compared to the removal achieved using an iron powder subjected to a further annealing process to reduce the content of oxides. Conversely, the pretreatment of the iron powder with HCl was found to enhance the reactivity of the iron. In particular, by washing the iron powder (425 µm size) with 0.1 M HCl the reduction of TCE after 6 weeks of treatment increased from approximately 80% for the as received material to more than 99% for the pretreated iron powder. The influence of moisture was also investigated, showing a negligible difference between the results obtained at a water content of 10% or 50% by weight. In all the experiments, the only detectable byproducts of the reaction were C4–C6 alkenes and alkanes that can be attributed to hydrogenation of the C-Cl bond. Overall, these results, although preliminary, showed that horizontal permeable barriers using granular zero-valent iron as a filler material may represent an attractive option for the treatment of TCE vapors from contaminated soils and groundwater.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologies

Sustainable Low Temperature Thermal Remediation of Pesticides

James Baldock; Joanne Dinham; Kathryn JohnsonERM

Site investigation activities at a former pesticide manufacturing plant in the UK, identified impacts from kerosene (TPH) and high boiling temperature dieldrin, within saturated gravels that overlie Chalk bedrock. A total contaminant mass of several thousand kilograms was estimated to be present in the target source zone. The TPH was present mainly as Light Non-Aqueous Phase Liquid (LNAPL). Dieldrin was shown to present a potential risk to a nearby river and the Chalk groundwater below. In order to mitigate these risks a source zone remediation strategy was developed and implemented.

A sustainability based remedial options appraisal was undertaken. The results showed thermal remediation could address both the TPH and pesticide impacts, although high temperatures of circa 350ºC would be required to volatilize the dieldrin and achieve a predicted 95 - 99% mass removal. Initially this high temperature strategy using In-Situ Thermal Desorption (ISTD) as the heating methodology was modelled and evaluated using Petrasim PC based software, but attaining the target temperature was identi-fied to be wholly unsustainable in terms of energy consumption and cost.Therefore a more innovative strategy of using Steam Enhanced Extraction (SEE) to mobilize, rather than volatilize, the TPH at lower temperatures was developed and bench tested. The bench-scale treatability study was conducted to determine the effectiveness of thermal remediation activities to reduce combined concentrations of TPH and dieldrin. The results of the bench testing demonstrated that dieldrin was likely solubilized in the TPH LNAPL and could be removed at lower temperatures of between 70 and 100ºC, although total mass removal was expected to reduce to circa 90%.

ERM further engaged with the UK regulatory authority (Environ-ment Agency) to agree a change in the heating methodology from ISTD to SEE; this reduced predicted energy requirements by 80%. Whilst the anticipated mass recovery was also expected to decrease by 5 - 10%, it was recognized by the regulator, via the modelling and bench testing, that the risk could still be reduced to an acceptable level in a manner that factored in cost benefit for the client, substantial indirect reduction in environmental impact (avoidance of large energy requirement) and achieved sustainable land management. The regulators also recognized the recalcitrant nature of pesticides and difficulty of remediation and an endpoint objective was therefore agreed on an asymptotic recovery basis, rather than concentration or mass derived target.

Steam injection, together with simultaneous vapour and liquid recovery commenced on 4 April 2017. Mobilization of LNAPL was observed as temperatures approached 70ºC and dieldrin concen-trations were detected at concentrations greater than had been observed in the laboratory. The majority of the mass was removed as NAPL at average soil temperatures between 70 and 80ºC, confirming success suggested at bench scale. TPH mass removed by mobilization is circa 4,100kg. This innovative approach is likely to have applicability to other chemical and pharmaceutical sector sites.

ThS 4b | Physical, thermal and stabilization techniques

Using the blocking effect of foam for remediation of high permeability contaminated aquifers

Romain Aranda¹; Henri Bertin²; Hossein Davarzani³; Fabien Laurent⁴¹ BRGM; I2M, Université de Bordeaux; ² I2M, Université de Bordeaux; ³ BRGM (French Geological Survey); ⁴ SOLVAY S.A.

Liquid foam has been studied as a blocking agent in porous media, especially for Enhanced Oil Recovery applications. Initially, the goal of foam injection consists to block high-permeability layers in the media in order to reach the oil in low-permeability layers. This approach can also be applied to remediation processes to allow the accessibility to low permeability layers that are usually more contaminated and difficult to treat. Foams can also be used to desorb contaminants due to the low surface tension of surfac-tant or push the contaminant to a recovery well thanks to foam high viscosity. In both cases, the benefits of using foam instead of monophasic surfactant solution is to create a homogeneous high viscous fluid that limits fingering.

In this study, groundwater with high velocity (average of 10m/day) is considered. It is assumed that this velocity is too high to use conventional in situ remediation techniques like oxidation/reduction because of short contact time. The main goal is to create a foam barrier upstream to temporarily divert the groundwater flow away from the treatment area downstream. While the contam-inant is isolated from the groundwater flow, other techniques can be used to actually remediate more efficiently the contaminated aquifer. Moreover, the pilot contaminated aquifer soil is heteroge-neous with a very high hydraulic conductivity (10-4 – 10-2 m/s).

Two different experimental setups were used to obtain the results. The first one is composed of a column of sand or glass beads, instru-mented with pressure sensors to monitor the pressure gradient during foam flow. Mass balance was also conducted to measure the water saturation in the column. The second one is composed of a thin 1 m large and 50 cm high tank to model a 2D flow. The tank is instrumented with pressure and water saturation sensors. In addition, an imaging technique is used to measure the evolution of foam volumes, streamlines and water saturations. During the experiments, foam is injected from the bottom of the tank and water is injected from left to right to model a groundwater flow. Finally, the experimental results are compared with numerical models in order to validate them. The validated model can be then used to simulate foam injection for field scale studies.

The surfactant has been chosen based on low toxicity, foamability and foam stability tests. Then, thanks to the column experiments, a specific behavior of foam in high permeable porous media was identified with two successive different regimes of foam flow (“weak” and “strong” foam) as well as necessary injection conditions for its generation. Finally, the influence of injection parameters on the foam blocking properties, such as the “Resistance Factor”, the residual water saturation, the radius of influence or the stability under a groundwater flow, has been investigated. The parameters studied are the injection method (gas and surfactant co-injection, Surfactant-Alternating-Foam (SAF), foam pre-generation), the flow rates, and the foam quality. The results show the applicability of this technique and its limits for a field usage.

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coal tar mass, as well as solidify any coal tar residual not treated by ISCO. The Capital Region of Denmark completed a full-scale ISCO/ISS remedy designed and implemented to destroy coal tar contam-ination, reduce hydraulic conductivity, and improve soil strength at the former Søllerød Gaswork MGP site in Denmark (Site) in 2018. The full-scale ISCO/ISS remedy was the first of its kind in Denmark.

A rigorous pre-design bench test was conducted to measure the performance of ISCO/ISS in soil core and groundwater samples collected from the Site. The bench tests determined optimum dosages of ISCO/ISS amendments and the effects of treatment on coal tar concentration and leaching, hydraulic conductivity (Kh), and unconfined compressive strength (UCS).

Based on the success of the bench test and supporting published studies, the ISCO/ISS remedy proceeded to pilot test and full-scale implementation in June and August 2018, respectively.Specific challenges to scaling up from bench-, to pilot-, to full-scale imple-mentation included: interference of persulfate chemistry with cement chemistry (e.g., sulfate ions, acid production from persul-fate decomposition); determining the sequence of the treatment configuration; exceptionally limited site access and spatial logistics in a residential neighborhood; and application of the treatment regimen in difficult geology (e.g., peat and clay soils).

In June 2018, the project team implemented a pilot test that included:

• Excavating peat soils to 3 to 5 meters below ground surface (mbgs) with temporary caissons to prevent soil instability;

• Installing five ISS/ISCO columns to treat 140 m3 to depths ranging from 12 to 15 mbgs;

• Testing an ISCO/ISS amendment mix of 8% slag/cement and 3% activated persulfate by dry weight of soil, using a concen-trated persulfate solution in water;

• Developing application procedures and confirming mixing equipment by injecting cement grout on the first auger pass and persulfate solution on subsequent auger passes with a 2m diameter auger;

• Sampling to confirm ISS/ISCO achieved design performance criteria: UCS ≥ 0.35 MPa and Kh ≤ 10-6 cm/s; which correlates to effective treatment and leach reduction.

Full-scale ISS/ISCO implementation included treatment of an 1,800  m3 coal tar source area by installing 75 ISS/ISCO columns with 2 m diameter augers; an ISCO/ISS amendment mix designed to add 8% slag/cement and 3% activated persulfate by dry weight of soil; treatment to depths ranging from 8 to 15 meters mbgs; and performance criteria that consisted of UCS ≥ 0.35 MPa, Kh ≤ 10-6 cm/s, and measurable contaminant reduction. Construc-tion was completed in October 2018 and results to date indicate that ISS combined with ISCO using base-activated (i.e., cement-activated) persulfate is a cost-effective technology for treating the coal tar source area to 15 mbgs in plastic clay soils at the Site.

This presentation describes lessons learned and ISS/ISCO applica-bility to other sites.

Pilot scale “in pile” thermal desorption remediation of mercury and mixed pesticides contaminated soil

Søren Eriksen; Jacob Brix; Jesper HolmKrüger A/S

Thermal desorption remediation of sandy soil from a former chemical waste land fill site (Groyne 42) has been tested in labora-tory and pilot scale.

Remediation of a chemical waste landfill by means of immobilisation

Reinhard De Cleene; Stany PensaertDEME Environmental Contractors

In Flanders, a historical landfill containing inorganic chemical waste residues exists. DEC proposed the plan to remediate this complex site by excavating the chemical waste material and transferring it to external licensed landfills. The big difficulty is the very high heavy metal leaching making it very costly of even impossible to landfill the material when taking account of landfills waste accep-tance criteria. With its experience of chemical immobilisation DEC is convinced that all the chemical waste material can be accepted at the desired external landfills in a cost-effective way after mixing with the necessary additives. A feasibility study was conducted to characterise the heterogenic landfill material and prove the success of the immobilisation with different additives. The plan is to process 1000 ton of chemical waste material every day including excavation, sieving, immobilisation in a mixing plant and trans-porting it. A critical aspect of this remediation project is the control on the immobilisation process. The problematic parameters are the leaching of As, Cd, Pb, Zn and Ba. The immobilisation of all prob-lematic heavy metals to meet the acceptance criteria requires a specific combination of additives and a precise additive dosing. However it is not possible to determine a fitting recipe and dosage based only on the measured leaching parameters as the immo-bilisation result of the heterogenous material is difficult to predict. Therefore during a detailed design phase a tailor-made testing procedure was worked out to find the most suitable immobilisa-tion recipe and dosage in a fast and effective manner using field and lab-scale tests. The testing procedure consists out of 4 steps: sampling, field characterisation, choosing and making test dosages and finally checking the test dosages. The idea of the lab-scale tests is to choose a series of test dosages based on measured charac-terisation parameters on the sample material. The leaching is then simulated on the sample material mixed with test dosages. After numerous immobilisation tests done by DEC it could be concluded that the success of the immobilisation can be tested by two critical parameters: pH and arsenic leaching. If the pH and arsenic leaching of the test dosage sample meet the predetermined requirements, it can be considered as suitable. In practice the immobilisation of the chemical waste material is done by a mobile mixing plant where the additives are precisely added. If possible despite the heteroge-neity, the chemical waste material is also selectively excavated and stockpiled based on screening by a handheld XRF analyser in order to optimize the immobilisation process. The effectiveness of the applied immobilisation after additive and dosage determination by the testing procedure is proven successful during the execution, as for now all the immobilisations are successful.

Full-scale remediation of a coal tar source area using combined in situ chemical oxidation and stabilization/solidification at the former Søllerød gaswork in Denmark

Neal Durant¹; Chris Robb²; Torben Jørgensen³; Lars Nissen³; Anna Toft⁴; Line Mørkebjerg Fischer⁴¹ Geosyntec Consultants, Inc; ² Geosyntec Consultants Inc.; ³ COWI A/S; ⁴ Capi-tal Region of Denmark

In situ stabilization/solidification (ISS) used in combination with in situ chemical oxidation (ISCO) has emerged recently as an attrac-tive alternative to ISS alone, as it offers the possibility to destroy

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that takes place on the surface of solids or liquids, as opposed to flaming combustion which occurs with gasified fuels. In contrast to other thermal processes that require continuous inputs of energy, the smouldering process is self-sustaining following a short duration, low energy input ‘ignition event’. The process is very robust and well-suited to a range of contaminant and soil types; however, like all in situ technologies, contaminant and geological heterogeneities can have a significant impact on the efficacy of the technology.

This presentation will provide an overview of smouldering combustion applied in situ (STAR), then present a series of case studies highlighting the challenges associated with implementing the technology in complex environments, as well as the techniques and strategies developed to mitigate these challenges. Challenges such as “clean” gaps and interbedded clay layers, and mitigation strategies such as “seek and destroy” and surrogate fuels will be discussed.

These techniques and strategies will then be discussed in the context of a full-scale application of the technology as the primary source remedy at a site located in Newark, NJ. The site is a 15-hectare former manufacturing facility impacted with coal tar in two stratigraphic units: a surficial fill and a deeper fine sand unit. Approximately 2,000 STAR ignition points were used to target coal tar impacts below the water table within the fill and fine sand unit to a maximum depth of approximately 15 meters.

The discussion will focus on a lagoon area of the site that has been investigated, treated and remedy verification completed. This area is approximately 0.8 hectares in size and the period of performance was approximately 6 months. Remedy verification was performed and a multiple lines of evidence approach was conducted, comprised of cores to assess free NAPL, laboratory analysis for Extractable Petroleum Hydrocarbons (EPH), Semi-Volatile Organic Compounds (SVOCs), and Volatile Organic Compounds (VOCs), and Tar Green Optical Screening Tool (TarGOST™) for real-time assess-ment of treatment performance. Information on the achieved treatment extent, the remedy verification approach, and costs to apply the remedy to a lagoon of this size will be presented.

Between caravans and boreholes - Challenges of performing in-situ remedia-tion on a camping site in the Black Forest, Germany

Petra Grill¹; Markus Kampschulte¹; Hans-Peter Koschitzky²; Oliver Trötschler²¹ CDM Smith Consult GmbH; ² Universität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung, VEGAS

How do you quickly and inconspicuously extract volatile chlori-nated hydrocarbons (CHCs) on a camping site on the outskirts of a spa town in the northern Black Forest without disturbing the relaxation of the numerous holidaymakers? CDM Smith accept-ed the challenge and supervised the thermal in-situ remediation at a camping site in Bad Liebenzell as consultant and project coordinator.

More than 50 years have passed since the former camera manu-facturer Regula King closed its doors in Bad Liebenzell, in the Black Forest. But the consequences of the production are still in evidence. The CHCs that Regula King used as degreasing agents until the 1960s contaminated the groundwater in the uppermost aquifer.

The Pump & Treat and Soil Vapour Extraction remediation had not achieved the de-sired success after ten years. The state of Baden-Württemberg / Germany decided to conduct supplemen-

Contaminants are mercury, thiophosphate ester pesticides – parathion, methyl parathion, malathion and sulfotep – smaller amounts of chloro phenols and chloro cresols as well as waste from pesticide production – mixed (thio) phosphate esters, elemental sulphur and solvents. The contaminated soil volume of the site is 27000 m3 containing 100 tons of contamination including 67 tons of parathion and 7 tons of mercury. /1/

High remediation efficiencies of well over 99% are required due to high concentrations of contaminants.

Complete removal of pesticides and an 85% reduction of mercury to a level of 6 mg/kg was reported in previous thermal desorption laboratory testing at 300⁰C. /2/

Based on results from lab scale testing removing all contaminants to < 1 mg/kg by maintaining 350⁰C for 2-4 days a pilot scale test was designed. The pilot set up for thermal treatment of 40 tons soil is a 2.4 x 2.4 x 6.0 m steel box fitted with 6 x 5 kW electrical insertions heaters and off gas treatment plant consisting of water injection, condenser, mist separator, activated carbon filters and blower.

The soil for the pilot test contains 440 mg/kg mercury and 1400 mg/kg combined pesticides, primarily parathion.

Five step sequential selective extraction analysis /3/ revealed that 71 % of the mercury is only soluble in the last step, aqua regia, and hence most probably is mercury sulfide. 24% was soluble in concentrated nitric acid probably elemental mercury.

During the pilot test, the soil volume was slowly heated while aerated at a moderate flow of 10 m3/h. The air flow serves two purposes: carrying evaporated contaminants out of the soil and oxidizing mercury sulphide to volatize the mercury in line with processes for winning mercury from roasting sulphide ore.

Safety considerations for operating the pilot scale test includes: Exothermal reactions, production of flammable gasses from pesticide decomposition, concentration of flammable vapors of solvents, sulphur, phenols.

Simulation of chemical reactions and evaporation rates has been used to find safe heating rates keeping concentrations of flammable gasses well below lower explosion limit.

Preliminary results of the pilot testing as of end of Nov. 2018 are the complete elimination of pesticides at 200⁰C and over 95% reduction of mercury contamination at 350⁰C.

The operational experience has shown that the closed system approach is ideal when negotiating complex contaminant mixtures.

[1] Høfde 42, Afgrænsning af nedsivningsområdet, rapport udarbejdet af Rambøll/Cowi/Kogsgaard, 2013, p.18http://www.northpestclean.dk/siteassets/northpestclean/publikationer/npc/2013/2013-12-06-hofde-42-afgransning-af-nedsivningsomrade-1.pdf [2] Steffen Griepke Nielsen et al.: Termisk assisteret oprensning af høfdede-potet, Høfde 42, Harboøre Tange, Miljøprojekt Nr. 1193, Miljøstyrrelsen, 2007, p. 70 https://www2.mst.dk/Udgiv/publikationer/2007/978-87-7052-604-3/pdf/978-87-7052-605-0.pdf [3] N. S. Bloom et al., Analytica Chimica Acta 479 (2003) 233–248

Smouldering combustion (STAR): Meeting remedial goals in complex environments

Gavin Grant¹; David Major; Grant Scholes; Marlaina Auger; David Liefl; Laura Kinsman¹ Savron

STAR uses smouldering combustion to treat contaminated soils in situ. Smouldering is an exothermic, flameless combustion reaction

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impacted soil off site with the exception of highly-impacted soil and non-excavatable soils (by virtue of building stability).

Out of a total of 25 000 m³ of impacted soil, 2500 m³ were treated by thermal desorption on-site (In-Situ and Ex-Situ). The aim of this paper is to focus on ESTD part of the project, the highly-impacted mercury thermopile, corresponding to 260 m³ of contaminated soil.

The soil had undergone a selective separation based on a visual test (presence of smalls mercury balls). The soil which contained visually small balls of mercury was stockpiled. Due to the excessive cost to eliminate these highly-impacted mercury contaminated soils, Ex-Situ Thermal Desorption was applied to reduce the mercury concentration below 50 mg/kg.

At the time of the thermopile construction, 4 samples have been analyzed and had an average concentration of total mercury of 11 700 mg/kg with a maximal concentration of 24 000 mg/kg. After 5 months of treatment time, 27 control samples were taken. The final samples had an average concentration of 48 mg/kg with a maximum concentration of 270 mg/kg. The mercury vapors from the thermopile were sent to a vapor treatment unit to be conden-sated and recovered in an unique tank.

The ESTD and the associated vapor treatment designed by HAEMERS Technologies © and implemented by Biogenie and HAEMERS Technologies to carry out the project is a worldwide premiere for complete and affordable treatment of heavily mercury-impacted soils. This case-study will address the details of said implementation and results.

Scaling up of Dioxin Contaminated Soil Thermal Desorption Treatment: Laboratory tests and pilot conception at Bien Hoa Airbase, Vietnam

Aline JordensHaemers Technologies

During the US-Vietnam War, millions of litres of herbicides were dropped over Vietnam: The Rainbow agents. Bien Hoa Airbase was a joint operating base for the South Vietnam Air Force and the United States Air Force where thousands of barrels of Agent Orange were stored.

Agent Orange was proven to cause severe health issues, including birth defects, neurological problems and cancers. Agent Orange is a mixture of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichloro-phenoxyacetic. Traces of dioxins were also found in some Agents. Indeed, dioxin 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) can be formed by condensation of 2,4,5-trichlorophenol during 2,4,5-trichlorophenoxyacetic synthesis. Dioxins are generally very insoluble in water, are lipophilic and are very persistent.

More than four decades after the Vietnam War ended (in 1975), the stability and bioaccumulation of dioxins still affect the inhabitants. Measures had to be taken to improve living conditions for residents, starting with the remediation of dioxin contaminated soil.

A pilot of In Situ Thermal Desorption (ISTD) and Ex Situ Thermal desorption (ESTD) will be conducted by HAEMERS Technologies © at Bien Hoa Airbase in the beginning of 2019, in combination with soil washing.

To prepare this pilot project, laboratory tests have been completed with contaminated soil from the Bien Hoa Airbase. Treating the soil at +/-350°C and maintaining this temperature during at least 5 days reduces the TEQ-TCDD concentrations by 77,5%: a decrease of 2800 ng/ Kg Ms TEQ-TCDD to 630 ng/Kg Ms has been observed.

tary thermal in-situ remediation of the main contaminated areas (source zone) by means of steam-air-injection.

The contaminated area of approximately 700 m² (contaminated soil volume 4,800 m³) was in the immediate vicinity of a residen-tial area and the local open-air swimming pool and mostly located below a building on the camping site.

To develop the remediation area, 170 boreholes had to be drilled in a narrow grid un-der very difficult site conditions. For removal of the contaminants, a mixture of satu-rated steam and air was injected into the subsoil (500-700 kW steam output) and the vola-tilized compounds were removed by vapour extraction at a rate of approximately 1,000 m³/h.

CDM Smith supervised and coordinated the remediation with all project stakeholders. The remediation was scientifically accompa-nied by VEGAS - Research Facility for Subsurface Remediation, at the University of Stuttgart.

Through the supplementary operation of the steam-air-injection, the former contami-nation centres were successfully remediated at short notice and approximately 730 kg of CHC was removed. The CHC concentrations decreased from 7,700 to 39 µg/L. The thermal in-situ process thus removed within an effective period of just less than 2 years more contaminants than the previous Pump & Treat process over 10.5 years. For the first time, the size of the contami-nated area and the small distance to the groundwater level were factors in the application of the steam-air-injection.

The remediation has been successfully completed in Spring 2017 and for now CDM Smith continues to supervise the project as part of its performance review.

This presentation will outline the challenges of steam-air-injec-tion during continued operation of a camping site, cramped space conditions and a sensitive public and will give an insight in planning and remediation control.

Thermal Desorption of Highly-impacted mercury soils in an Urban Area

Quentin HilbertHaemers Technologies

In-Situ and Ex-Situ Thermal Desorption (ISTD and ESTD) are a tech-nology based on thermal conduction that can effectively treat organic contaminants, independently of large soil heterogeneity. One of its applications is for contaminated properties in urban areas and under existing buildings.

The main principle of the technology resides in installing a network of steel pipes that act as a air/soil heat exchanger to heat up the soil to temperature and pressure conditions at which the contamination is volatilized and recovered above-ground for further treatment.

Following this logic, ESTD is mainly used when small amounts of widely scattered contaminants can be more easily gathered to a single location for treatment rather than decontaminating separately with different ISTD batches. It can also be used when contaminated soil has already been excavated, gathered and stockpiled.

As part of a remediation project, a large volume of mercury-contaminated soil had been excavated by Biogénie below a building southeast of Paris, in Région Val-de-Marne due to a mercury contamination. The impacted soil lies below a building and is surrounded by residential buildings. After a decision-making process, it has been decided to send the maximum amount of

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Sustainable sediment solutions: Stabilization of contaminated sediment

Victor Magar¹; Mark Nielsen¹; Tim Olean²; Michael Mengelt³; Juha Forsman³¹ Ramboll; ² O›Brien & Gere; ³ Ramboll Finland Oy

Marine sediment in coastal areas often is contaminated due to historical industrial and port activities and from runoff from nearby urban areas. Modern redevelopment identifies a need to re-use these former industrial spaces in the creation of new, multi-use areas. Construction activities and shoreline reclamation associated with redevelopment often require dredging and management of contaminated sediments, in some cases to manage navigation and in other cases to reduce human and ecological risks associated with sediment contaminants. Under current regulations, off-shore placement of contaminated dredged sediment us increasingly difficult and requires creative alternatives. Stabilization is a sustain-able technology that can be used to immobilize contaminants and leave the stabilized sediment in place (i.e., in situ stabilization, or ISS) or to stabilize contaminants ex situ to create a usable material for modern urban construction needs. The technology provides considerable benefit when considered in an overall circular economy evaluation because it reduces environmental impacts with alternative disposal methods while creating converting the sediment into a useful resource.

Stabilization and ISS are increasingly considered viable remedies for impacted sediment. Technology advances have greatly reduced technology costs while improving implement ability and reliability. ISS leads to reduced dredging needs, while stabilization and reuse leads to reduced waste. Effective use of this technology can reduce energy requirements and contribute positively to the circular economy.

We will present multiple case studies showing how the application and evaluation of ISS performance. We include post-ISS results from a former manufactured gas plant (MGP; Wisconsin, USA), including surface water, surface sediment, and benthic community measure-ments to evaluate how ISS impacts the ecological community. For ex situ applications, we will discuss the use of sediment stabiliza-tion to find a beneficial use for contaminated sediment at the Port of Helsinki, Finland. We will consider both technical considerations of stabilization and costs.

In situ thermal remediation ~ AMCO superfund site

David Rountree; Paul HegeleMcMillan-McGee Corp.

The AMCO Chemical Superfund Site, located in a mixed residential and industrial area of Oakland, California, was a former chemical distribution facility until its closure in 1989. Subsequent environ-mental investigations identified over 200 constituents in soil or groundwater at the site, of which 98 were potential contaminants of concern. The purpose of this remedial action was to implement Electrical Resistance Heating to reduce the mass of chlorinated volatile organic compounds in the subsurface associated with a light non-aqueous phase liquid source zone, which extended underneath an active glassblowing studio and office building, and into the street under an overpass. In this presentation, we review the design process and discuss innovative approaches that were used to manage challenging or unforeseen conditions and overcome operational constraints.

A total of 175 electrodes and 74 vapor extraction wells were used to heat the subsurface to 101.6°C and recover contaminants. A

However, the minimum initial TEQ-TCDD concentration required is 1000 ng/Kg Ms to observe a significant reduction. These results report that for the dioxins, Thermal Desorption Treatment can ensue efficient outcomes. Certainly, Thermal Desorption functions according to temperature and time and a couple of more days at 350°C will be enough to discharge most of them.

The design of the pilot project at Bien Hoa Airbase has been based on the result obtained by the laboratory tests. The first step of Thermal Desorption is the heating and vaporizing of dioxins impacted soil. The second step consists of recovering and treating the vapors containing contaminants and associated vaporized products.

Various methods exist to treat those vapors. Thermal oxidation is one of this methods. It has been selected for this project because of it does not generate any liquid or solid waste during treatment. By oxidizing the vapor flow at high temperature, only gaseous emissions will be produced. Proper oxidation guarantees compliant air emissions, with no waste left behind.

Electro Bio Reclamation (EBR) as part of a full scale soil remediation project in Ghent

Art Lobs¹; Jonas Wittocx¹; Jeroen Van Acker²¹ Verhoeve Milieu & Water; ² Envirosoil

As part of a redevelopment project in Ghent a soil remediation project with Electro Bio Reclamation (EBR) is conducted. Based on the results of a pilot test to investigate the feasibility of using EBR at this site, a full scale remediation project was designed. The full scale project consisted of three phases, respectively excavation, EBR and thermal enhanced bioremediation by recirculation, The subject of this abstract is the introduction, implementation and the results of the full scale EBR project at the site in Ghent.

The project is located in the middle of a residential area. Since 1962 an auto repair shop with paint spray facilities and a gas station was situated in this place. The use of trichlorethylene as cleaning solvent was determined as the source of the contamination with VOCl (mainly TCE) in the soil (max. 290 mg/kg ds) and the ground-water (max. 220 000 µg/l). Although bioremediation was already identified in both source and plume zone an additional effort was necessary. Since the soil has a very low permeability EBR was selected as a suitable remediation technique.

For the application of EBR multiple electrodes were installed in the contaminated soil with a configuration of hexagons and triangles. By applying alternating current on the electrodes the soil matrix will act as a resistance and heat up. This effect has multiple benefits like (i) release of contaminants from the soil into the groundwater, (ii) increase of the permeability of the soil matrix and (iii) release of TOC for subsequent bioremediation. In the center of every hexagon/triangle a double extraction well was installed to extract mobilized DNAPL and contaminated groundwater which was collected and transported for treatment.

During the heating phase the average temperature of the soil matrix increased from 16°C to 50°C with local values up to 88°C. The maximal concentration of TCE amounted 340,000 µg/l which is about three times the 10%-solubility-value for TCE whereby indica-tions of pure product are present. Water was extracted until all the TCE-concentrations were below 50% of the 10%-solubility-value. In total 176.7 m3 contaminated water was extracted from the source zone. During the next -currently ongoing- phase of the remediation the soil will be cooled down to approx. 25°C and kept that way using the electrodes for thermal enhanced bioremediation. The installed wells will be used as extraction/infiltration filters for recirculation.

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the vaporized contaminants and then treated in an ad-hoc vapour treatment unit.

The soil monitoring includes points of measurement of the depres-sion in the soil and the thermocouples located at different depths. The vapour treatment unit consists of vapour condensation and adsorption on activated carbon filters, zeolites and catalytic oxidation.

The soil temperature, soil pressure, recovery condensate and vapours extracted were the main parameters to understand the evolution of the remediation of the pilot batch.

The treatment was complete when reaching a temperature of 200°C at the cold points for 20 days or 250°C for 3 days.

In relation to this, based on the processing of data related to direct and indirect measurements during the treatment of the first batch and the final test verification (sampling and analysis of soils at different depths), the results showed the complete removal of contaminants in the soil matrix thanks to the concentration values recorded well below the target thresholds and almost always below the detection limit.

The final analysis also showed consistency with the monitoring data: when the target temperature was reached, the maximum extraction of the vapours and the complete removal of the contam-inants was observed.

Integration of innovative geotechnical and environmental solutions enables site redevelopment and protects sensitive off-site receptor from petroleum hydrocarbons

Mike Plimmer¹; Gareth Leonard², Amanda Sterkenburg²¹ GEA Ltd; ² REGENESIS

This award-winning remediation project concerns the redevelop-ment of a former bus depot in Runcorn, UK, which posed unique and complex challenges. Each step in the solution process would have a follow-on effect; therefore a well thought-out, integrated approach was crucial for the project’s success.

The site comprised a mound of industrial waste from the Leblanc process, including several metres of galligu. A bus depot on the site suffered extreme settlement, due to the poor geotechnical properties of the underlying galligu resulting in breakages and leaks from underground storage tanks and pipes.

The leaking fuel migrated through the Galligu into the under-lying ash layer and impacting perched water. The downgradient boundary comprises a steep slope to a canal. Periodically, contami-nated groundwater would egress at ground-level and run over the patios and vegetable patches of the local boat club, into the canal.

The low value of the site prohibited expensive dig and dump. Stabilisation of all of the galligu was not viable due to the thickness and cost . Instead, an integrated solution was used:

• Soil/cement mixed panels were used to support struc-tures, with mixed mattress created under roadways. Installation of these panels altered the groundwater flow; channelling it towards the panel ‘wall’ at the boundary. Here the groundwater would funnel through gaps at a higher velocity and enter the offsite canal.

• An innovative Liquid Activated Carbon (LAC) substrate was used to integrate with the panels. By injecting the LAC into the subsurface, an activated carbon filter was created in between the

treatment system involving over 50 process components, including steam regenerative VGAC and KMnO4-impregnated zeolite beds for vapor treatment, and phase separation, organo-clay treatment, air stripping, activated carbon treatment, and filtration for water treatment, treated the recovered fluids to below specific standards developed for all of the constituents identified. The treatment system had to reach stringent air-quality and water-quality standards while minimizing the use of potable water. Automated vapor intrusion and effluent monitoring during operations allowed for near-real time monitoring and fast optimization of the extrac-tion approach and management of the filtration media, and provided protection to immediately adjacent residences. Inside the glassblowing studio, a false floor was constructed to allow its activities to continue, from which vapors were also scavenged to manage indoor air quality. An aging sewer interceptor, approxi-mately 2.7  m in diameter and located only 3 m downgradient from the electrodes, was protected using a cold water quenching system to keep its exterior to below 30°C. Using live temperature data, this system was modified post-startup by chilling the feed water and installing downhole packers to improve cooling perfor-mance. Ongoing rehabilitation of this interceptor also limited treatment system discharge to night hours only. Summary data were presented on a website to keep area residents informed of site progress.

At shutdown, approximately 17,000 kg of contaminants had been condensed and recovered as product in the treatment system. Lessons learned from this project can be used to inform the design and operation of in situ thermal remediation systems where similar conditions and constraints are encountered.

Thermal desorption with smart burners – Case study for the in-situ treatment of unsaturated soils at the refinery of Gela (Italy)

Katia Pacella¹; Jan Haemers¹; Hatem Saadaoui¹; Gianfranco Caccamo²; Andro Barabesi³¹ Haemers Technologies; ² Icaro Ecology S.p.A.; ³ SIMAM S.p.A.

The site interested by the remediation process through the applica-tion of the In-Situ Thermal Desorption technology, located inside the Refinery of Gela (ENI Group), consists of former discharge for oil residues deposited in the past.

The contaminants are light and heavy hydrocarbons, benzene, polycyclic aromatic hydrocarbons, chlorinated compounds and mercury. The treatment area is divided into 24 batches: Zone A (12 batches of average surface area ≈ 290 m²) and Zone B (12 batches of surface area between ≈ 400 m²). The first batch (A1) was consid-ered as a pilot and its treatment started on 20 of September 2017 and ended on 13 December 2017.

ISTD technology is an in-situ treatment method in which the contaminated soil is heated by thermal conduction. Once the evap-oration point is reached, the volatile contaminants are aspirated through perforated extraction pipes creating a depression in the soil. Soil heating occurs by Smart-Burners, developed by Haemers Technologies. These burners are installed on vertical pipes, called heating wells. The technology can be applied to all types of pollut-ants with a boiling point at atmospheric pressure not exceeding 550 °C.

Concerning the site of Gela, 143 burners were installed for the first batch, positioned on top of steel pipes. In correspondence of each heating element, perforated tubes have been installed in the most distant points (also called “cold points”), used for the extraction of

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiessoil/cement walls. This barrier intercepted the petroleum hydrocar-bons and prevented contaminant egress from the site, protecting the canal. The injection was completed from 4-5mBGL using direct push injection on a 3m spacing along a 30m line.

Validation showed that the barrier stopped contaminant egress from the site (98% reduction to the limits of detection). The canal has shown a reduction in hydrocarbon loading and the groundwater break outs on Boat Club land are now devoid of hydrocarbons.

This innovative integrated geoenvironmental solution allowed for highly effective remediation, protection of a public waterway and cost-effective treatment of a busy and difficult site. It allowed site redevelopment to proceed within budget and was delivered on time. Treatment of TPH in the presence of galligu has not been completed previously to our knowledge. This project recently won an award for Best Conceptual Design at the Brownfield Briefing Awards 2018 in London.

First European thermal remediation of crystalline bedrock

Niels Ploug¹; Jesper Holm¹; Steffen Nielsen²¹ Krüger A/S; ² Cascade Thermal

The peninsula of Kvarnholmen is located only 10 minutes away from downtown Stockholm, Sweden with a picturesque view over the sea. Kvarnholmen is undergoing tremendous development to provide housing for the Stockholm residents. Unfortunately part of the site (29.0000 m3) was contaminated with PCE, so remedia-tion was required before the developers were allowed proceeding building luxury apartment complexes.

The contamination was situated in a crystalline rock with very low porosity and few fractures and had to be remediated from 20 m above to 10 m below sea level.

Site development had to continue building a bridge to the island touching base right at the treatment area. A road, bike and a pedes-trian path through the source zone had to be installed during site installation and kept open during thermal operation.

Addressing a fracture system like this is extremely hard using technologies based on fluid injection. Using Thermal Conduc-tion Heating (TCH), it is possible to heat the entire volume of granite independent of porosity and fractures and thereby ensure treatment even of blind end fractures. Extracting in such a matrix is however not trivial. All heater wells was installed with co-located extraction screen installed in a gravel pack with a grout plug at the top and bottom, making individual extraction control possible. Installing the gravel pack around the heaters was done to short circuit as many fractures as possible making robust and safe removal of vaporized contaminants.

To design the heating approach a numerical thermal model was used to simulate heating under different water flow conditions. Based on these simulations, a total of 105 heater wells were installed to 14 m below the surrounding sea level with a total heater length as long as 32 m. Heaters was boosted to deliver 35% more energy below the water table.

The site clean-up was to be documented using a multiple line of evidence. This consists of water samples, pore gas sampling, off gas removal trends and temperature monitoring of the entire site.

Operations started in January 2017 and power was turned off after 138 days of operation achieving an average temperature of 141 °C

in the target zone. Off gas concentrations performed completely as expected starting at 10 mg/m3 in the beginning of the operation and peaking at 1800 mg/m3 during operation before decreasing to 10 mg/m3 at the end. So off gas removal and temperature indicates thorough cleanup. Water sampling in the treatment zone has been executed on two events 6 & 11 month after shutdown. Concentra-tions are well below the cleanup criteria of 5 mg/l and there is no increasing trend.

It does pose some challenges to evaluated vapor samples on a 100 °C hot site since the equilibrium is shifted towards the gas phase and therefore these samples will be over conservative compared to a 10 °C situation. Most of the samples are below the cleanup criteria at 30 mg/m3 but a few is still above but there seems to be a decreasing trend as the site is still cooling of. Before the conference a new set of water and vapor data will be available. In general TCH has proven effective for bedrock remediation.

Remediation of a site polluted with lindane wastes: Soil flushing pilot test

Aurora Santos¹; Carmen Maria Dominguez¹; David Lorenzo¹; Raul Garcia¹; Miguel Angel Lominchar¹; Jesús Fernandez²; Jorge Gomez³; Joaquin Guadaño³¹ Universidad Complutense de Madrid; ² Government of Aragon; ³ EMGRISA, Empresa Para la Gestión de Residuos Industriales

A small pilot test of soil flushing has been carried out at the Sardas landfill (Sabiñanigo, Spain), contaminated among others by liquid wastes dumped from an older lindane manufacturing factory containing chlorinated organic compounds[1]. The injection of surfactants solutions can improve the extraction of organic pollut-ants with low solubility, usually strongly sorbed or entrapped into the soil pores, increasing their effective solubility in the aqueous phase [2]. Besides, the injection of a low viscosity surfactant solution reduces the viscosity of the organic phase (DNAPL) trapped in pore spaces and enhances its mobility. As a result, this DNAPL can be removed from the soil at a higher rate.

However, applicability and effectiveness of the soil flushing tech-nology is limited by low permeability and heterogeneity of the soil and the adsorption of the surfactants onto the soil. Besides, the potential of dispersion of the contaminants beyond the capture zone and the introduction of surfactants to the subsurface are main concerns. The safe use of the technology requires that flushed contaminants and soil flushing fluid are contained and recap-tured [3]. In this sense, the transport of the injected fluid must be evaluated and modelled.

In this work 5 m3 of tap water containing 13 g/L of a commer-cial non-ionic surfactant–cosolvent formulation and 130 mg/L of a conservative tracer (bromide) have been injected at 0.6 m3/h. The injection well has 3 m of screen length in the permeable layer (hydraulic conductivity between 100-200 m/day), constituted by gravel-sand with some clay matrix, being located at a depth from 12.5 to 15.5 m b.g.l.. This layer is contained between silt and marl layers of low permeability. In some points, the presence of DNAPL was found in the contact between the gravel-sand and the marls layers. Three monitoring wells, located at 2.5, 3 and 3.5 m radius from the injection well (central), were built. Moreover, the hydraulic gradient was quite low (0.0003) and the contribution of the natural flow in the test cell during the injection could be neglected.

After the injection step, the fluid was left in the area for 15 h before the extraction event. Extraction was carried out from the central well and two additional washing events with tap water were carried

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or less mobile, depending on which elements are concerned and which transformations have taken place. These transformations can be also be induced deliberately to facilitate resource recovery. Elements of value such as phosphorus may be recovered from gaseous emissions as well as subsequent leaching of the post-remediation material. Understanding PTE fate during smouldering is essential to developing comprehensive remediation solutions for contaminated sites as well as recovering elements of value during these processes.

Formation of PAH derivatives, increased developmental toxicity and risk assessment after SEE remediation of creosote contaminated soil from the Wyckoff/Eagle Harbor Superfund site

Lisandra Trine¹; Eva Trine²; Courtney Roper¹; Lisa Truong¹; Robert Tanguay¹; Staci Simonich¹¹ Oregon State University; ² US Environmental Protection Agency

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants produced from incomplete combustion and pyrolysis of organic matter, and are among the major contaminants in soils at Superfund sites in United States (US). Steam enhanced extraction (SEE) is an in-situ thermal remediation technique that uses the addition of steam to increase the removal efficiency and recovery of volatile and semi-volatile contaminants, like PAHs, from soil. However, there is limited research on the formation of PAH derivatives during and after SEE of PAH contaminated soils. In this study, creosote-contaminated soil from the Wyckoff/Eagle Harbor Superfund Site in Washington, US was thermally treated with laboratory-scale SEE and analyzed with gas chromatography/mass spectrometry (GC/MS) for PAHs, polar PAHs, nitro PAHs, and high molecular weight PAHs (n=120). PAHs decreased significantly, while polar PAHs increased in mean concentration post-SEE soil. Differ-ences in developmental toxicity were measured between sample extract pre- and post-SEE using the zebrafish embryonic assay by assessing morphological changes and mortality at 24 and 120 hours post fertilization. Lowest effect levels (LELs) were calculated and an additive toxicity was observed when comparing unfrac-tionated extracts to fractionated extracts in pre- and post-samples. A quantitative risk assessment was performed by calculating estimated lifetime cancer risk (ELCR) ingestion estimates, which suggest that risk assessments are underestimating cancer risk by omitting certain classes of PAHs. This study quantified PAH derivatives after SEE, differences in bio-activity of samples pre- and post-SEE, and identified implications for risk assessment. SEE is effective in removing unsubstituted PAHs from contaminated soil, but other, potentially more toxic, PAH derivatives are formed, and these compounds should be considered in future risk assess-ments. Additional research is needed to determine the fate of these compounds during field-scale SEE remediation.

out. Conductivity, surfactant, bromide, chloride and chlorinated organic contaminants (COCs) concentration in the groundwater was measured in the four wells of the test cell. The main conclu-sions obtained are:

- The flow in the gravel-sand layer has a strong dispersive component. A model to describe this dispersion was formu-lated, finding that high anisotropy was inferred from the bromide analysis. Bromide behaved as a conservative tracer.

- The surfactant was not sorbed onto the soil during the injection, increasing solubilization of COCs. However, during the time between the injection and extraction processes, the surfactant was sorbed in the clay matrix and the COCs concentration in the aqueous phase decreased. Dispersion of pollutants out of the cell test was controlled

- The DNAPL viscosity was notably reduced by the surfactant-cosolvent system, improving its extraction rate.

Smouldering remediation and resource recovery from contaminated soils and waste materials

Christine Switzer¹; Precious Chisala Mwanza¹; Andrew Robson¹; Rossane DeLapp²; David Kosson²¹ University of Strathclyde; ² Vanderbilt University

Heavily contaminated sites often have complex contamination issues. Smouldering remediation is capable of destroying 99.9% of heavy hydrocarbon contaminants in place in the soil. The impact of smouldering on the fate of potentially toxic element (PTE) co-contaminants such as lead, cadmium, chromium, and arsenic is essential to understand as part of remediation best practice. In addition, the presence of elements of value such as phosphorus, copper, cobalt, and others in soils and other waste materials represents an opportunity to reclaim value during remediation. In countries with strong regulatory regimes, human health and environmental concerns are important drivers for remediation and resource recovery would bring added value. In countries without strong regulatory regimes, resource recovery may provide an essential economic driver for remediation while also addressing human health and environmental concerns. The aggressive operating conditions of smouldering remediation can be harnessed to enable resource recovery from soils and waste materials.

In order to characterise the fate of PTEs during remediation and identify elements of value, soils and waste materials were contami-nated with vegetable oil or coal tar and subjected to smouldering remediation using a standard methodology. Samples collected before and after contamination and remediation were analysed for total and available PTEs. Testing for available PTEs followed Methods 1313 and 1314 from the USEPA tiered leaching framework to determine pH-dependent availability and column leaching. Soil pH, EC, and organic content were measured to determine changes to soil composition and acidity.

The three main factors that affect PTE mobility are pH/geochem-istry, mineralogy, and soil organic matter content. All of these factors are affected by smouldering. Contaminated materials expe-rience temperatures of 500-1200°C for periods of minutes to hours. Process temperature depends on contaminant type and amount as well as operating conditions. Soil organic matter is destroyed and minerals undergo transformations. Typically, material pH becomes somewhat more alkaline after smouldering although exceptions to this trend have been observed. After these changes in the smouldered materials, PTEs may become significantly more

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Thematic Session (ThS) – Topic 4 Advances in remediation technologies

Best methods for developing a thermal remediation project

Amy Wagner; Timothy WarnerTRS Europe

Provide examples of best practice methodologies for developing a thermal project and alternative contracting techniques for successful remediation projects.

In situ thermal remediation (ISTR) technologies at numerous sites. The ISTR technologies used most are electrical resistance heating (ERH) and thermal conduction heating (TCH), typically at steaming temperatures and above. Practitioners also have applied ERH at sub-steaming temperatures, to accelerate naturally occurring processes, such as the hydrolysis of halogenated alkanes, pesticides and energetic compounds, and the bioremediation of chlorinated ethenes and petroleum hydrocarbons. Proper evaluation, advance data collection, clear remedial goals are the key to success for a thermal remediation. In addition, using innovative contracting methods, combined remedies and flexible designs can help speed clean-ups, eliminating contamination source zones and reusing valuable properties. This presentation will highlight a series of case studies that cover evaluating remediation various contracting methods and innovative use of thermal technologies that achieved and exceeded performance goals and objectives.

Case studies and focus:

• A site where an existing groundwater extraction and treatment system had been operating for several years. The decision was made to include excavation and disposal of shallow chlori-nated volatile organic compounds (CVOCs) contaminated soil, completed in 2011, and in-situ thermal remediation (ISTR) of the deeper impacted soil. The performance criteria were based on temperature and heating duration.

• A site undergoing remediation since 1983, an amendment was issued with an adaptive strategy with a multi-component remedy including ISTR at steaming temperatures, followed by ERH at sub-steaming temperatures to address CVOC sources in soil and groundwater. This site is serving as a model for remedial designs that include the combination of these approaches into a comprehensive source zone and plume solution. New management strategies are beginning to be applied as a result of the success of the remediation using metrics, such as mass flux and mass discharge, to establish performance objectives and evaluate remediation progress.

The presentation will include site background information, remediation timelines, contracting and design details, remedy implementation and results of the source removal and plume attenuation.

In-situ zinc precipitation using inorganic sulphides

Dirk Van Look; Lars Van PasselRSK Benelux

Project background. In Boechout (Belgium), a new residential devel-opment was planned on the site of a former metal processing plant.

The upper soil layers and the groundwater within the first aquifer underneath the site were heavily contaminated with zinc. The groundwater contamination with zinc covers an area of more than 2000 m². It is present to a depth of 37 m and contains zinc concen-trations of more than 1 g/L. The bulk of the zinc can be found in the upper 15 m of the aquifer. The lowest acidity observed was pH 3.5.

Risk assessments showed that remediation was necessary to make the area safe for public and residential use.

Pilot test on zinc precipitation. RSK designed a pilot test to check whether injecting a mixture of sodium sulphide (Na2S), sodium hydrogen sulphide (NaHS) and sodium bicarbonate (Na2CO3) would result in stable precipitation of the dissolved zinc in an iron rich aquifer. The mixture was infiltrated in the aquifer at a depth of 11 m below surface and the zinc-sulphide precipitation technique was demonstrated successfully at this location.

Full-scale remediation. In October 2015, 15 infiltration wells were installed across the zinc plume. The groundwater in these infiltra-tion wells was sampled and analysed to fine-tune the location of the zinc contour.

Then, in 2016, an extra 94 infiltration wells with filter screen at 7–11 m below surface were installed in a 5m by 5m grid. 564 m³ of reagents, 67 m³ of sodium hydroxide and 1,588 m³ of water was infiltrated to treat the contaminated zinc plume covering 2200 m².

In 2017, 40 shallow infiltration wells with filter screen 5–7 m below surface were additionally installed to treat the upper part of the aquifer. 114 m³ of reagents, 6 m³ of sodium hydroxide and 450 m³ of water treated a contaminated zinc plume of 1,100 m².

To restore the original acidity of the aquifer (pH 6.5–7), extra sodium hydroxide was infiltrated, depending on the remaining acidity in the aquifer (above or below pH 5.5).

Environmental soil and groundwater monitoring will continue until 2020, when the residential area is expected to be complete.

Results. The dissolved zinc concentration decreased from a previ-ously high 1 g/L to level below detection limit.

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Combination of enhanced reductive dechlorination and aquifer thermal energy storage – pilot test

Mette Christophersen; Britt Boye Thrane; Lars Bennedsen; Line Mørke-bjerg Fischer; Anne Mette Granhøj Hansen; Bas Godschalk; Maurice Henssen; Nanne Hoekstra; Tim Grotenhuis

Aquifer Thermal Energy Storage (ATES)-systems are highly effective energy-storage systems, and provide energy with low CO2-emmisions. In urban and industrial areas there can be a large need for cooling and heating of buildings and industrial processes. However, in such areas, contaminated sites are often encountered and hampers urban development. Contamination with chlorinated solvents is one of the most frequently occurring contaminations in the deep aquifers relevant for ATES. However, a new approach is to view the combination of ATES and remediation as an opportu-nity, as synergies and benefits are expected for the combination of ATES and bioremediation as the elevated groundwater tempera-ture and flow is expected to increase the degradation rate for the chlorinated compounds.

The conclusions of a literature study conducted in 2016, showed that there still is a great need for practical experiences with the combination of ATES and enhanced reductive dechlorination (ERD) to demonstrate the proof of concept at field scale. Based on the literature study it was decided to proceed with a pilot test.

The purpose with the pilot test is to investigate the synergy effects of combining ATES and ERD and thereby both improving the efficiency of ERD by the elevated groundwater temperature and higher flow and gain energy for heating/cooling of e.g. building at the same time.

In March 2017 a suitable site was found in the Capital Region. The pre-investigations showed that the contamination with TCE is present in the upper 5 m of the saturated zone and that the upper app. 2 m of the saturated zone is oxic. In this part of the aquifer the groundwater model and the pump test showed that it should be possible to pump up to 5 m3/h, which is suitable for an ATES-system.

In late 2017 the warm, the cold and 4 monitoring wells were installed at the site, and in the beginning of 2018 the base line monitoring at the site has been conducted. Due to the short period of the pilot test it was decided to focus on the processes related to accelerating the degradation rate and therefore it was decided to heat the water in a heat exchanger and not install a full ATES-system above ground. The groundwater is extracted from the cold well (app. 10 °C), heated to 20 °C in the heat exchanger and injected again in the warm well. The recirculation of heated groundwater started in March 2018. The resulting redox conditions were not low enough for reductive dechlorination to occur so in June 2018 carbon source (lactic acid and natrium acetate) were added. Moni-toring still showed that no vinyl chloride was produced probably due to the lack of Dehalococcoides, so a bacteria culture containing min. 1*107 Dehalococcoides pr. ml was added in October 2018. In total 9 monitoring events have been/will be conducted including analysis of field parameter, chlorinated solvents and degradation products, redox parameters, isotopic analysis, microbial analysis of groundwater and soil. The pilot test will run until March 2019 and the results will be presented at the conference.

ThS 4c | Combined treatment technologies and technology trains

Technical solution for the removal of PFAS from water

Jürgen BuhlCornelsen Umwelt GmbH

Especially on airport sites aqueous film forming foams (AFFF) were repeatedly used in fire-fighting training areas. Close to the airport in Nuremberg (Germany) it was planned to tunnel under an existing road. Investigations that were required in advance showed that PFAS (per- and polyfluorinated alkyl substances) were detect-able in the groundwater down gradient of that airport site.

In 2010 further investigation on site had identified such a training area as a source area with PFAS contamination in soil and ground-water. The maximum level of PFAS that was detectable in the groundwater reached about 777 µg/l (about 48% PFOS) with an average value in the wells in that area of about 357 µg/l. The groundwater itself showed a pH of about 5.6 and was character-ized by elevated concentrations of dissolved iron (up to 33 mg/l). Furthermore, VOCs, BTEX and hydrocarbons were detectable at moderate concentrations (less than 150 ppb). The ground consists of fine sand as layer on top of bedrock (sandstone).

The owner of the airport and the state of Bavaria had developed a strategy for evaluating the most appropriate remediation technique for this kind of contamination. Several techniques that could be suitable for treating that water were both selected and tested in the lab. Among these techniques had been granular activated carbon of different qualities, ion exchanger, nanofiltra-tion and reverse osmosis. The tests that had been performed in 2012 and 2013 with contaminated water had involved both town water and water from the site.

At the end of that test procedure a solution showed the most promising results that catches the PFAS and generates micro flocs. The formation of micro flocs allows the use of filtration as a process for removing the PFAS. This technique that generates micro flocs was selected for performing field tests and for collecting additional data.

The field test took place then from September until November 2014 with a flow rate of less than 0.5 m³/hr. As the application in the field had confirmed the data from the lab tests the next step was the installation of a full-scale treatment system in September 2015. Due to the groundwater chemistry the final treatment plant did consist of reactor with dosing system and stirrer, filtration, stripping (VOC, BTEX), granular activated carbon and storage tank for sludge. The plant is suitable for a flow rate of about 2 m³/hr.

The process of generating micro flocs and the corresponding filtration are representing the first pre-treatment module of that plant. Data from September until December 2015 have shown the following results: PFAS concentrations between 390 and 480 µg/l were detectable at the inlet of the plant (water from extraction well). This pre-treatment module has removed up to 98% of the PFAS just by filtration of particles that got generated.

Sludge and PFAS were collected together in the storage tank. As the concentration of the remaining PFAS was much lower after that pre-treatment process it was not required to initiate any change of the granular activated carbon in the vessels for almost a year.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesThe first completed example in Europe for the remediation of an aquifer contaminated with chlorinated solvents by a combination of adsorption and biodegradation

Paolo Ciampi¹; Carlo Esposito; Giorgio Cassiani; Marcello Carboni; Marco Petrangeli Papini¹ Sapienza University of Rome

The site of the New High-Speed Railway Station of Bologna is historically affected by contamination due to low and diffuse concentrations of chlorinated solvents, mainly PCE and TCE. The stratigraphic sequence is represented by alluvial deposits. An alter-nation of coarse-grained and fine-grained deposits characterizes the alluvial succession. In order to manage the contaminated site and with the aim of designing an efficient remediation strategy, a first phase of activity dealt with the site characterization and was addressed to better define the hydrogeological setting and the water quality status evolution. The 3D geological/hydrogeo-physical model shows a complex hydrogeological setting, typical of alluvial plains, that can be schematized into three separate aquifers. The two shallower aquifers are relevant for the contami-nation issue. The analysis of the variation over time of the water contaminant concentrations (from 2005 to 2018) allowed us to point out: (i) a low mean level of contamination with a decreasing trend for chlorinate solvents concentration; (ii) the presence of few “hot spots” with a contamination level still slightly above the regulatory limits. Site investigation has been integrated with a microcosm study with the presence of electron donors (lactate). Based on the results, biological reductive dechlorination was recognized as a potential approach for the site remediation but the extremely low CAHs concentration and the consequent kinetic limitation made it unfeasible for the site. The possibility to use a new dispersed colloidal activated carbon (Plumestop™, Regenesis) was experimentally investigated as a site-specific remediation approach. The micrometric carbon with proprietary surface-charge modification to enable dispersion, could be easily injected in the contaminated aquifer creating an in-situ adsorption zone poten-tially able to quickly reduce CAHs concentration and to raise the kinetics of the biological reduction by locally increasing the bioavailable CAHs concentration at the carbon surface. The tech-nology was co-injected with an electron donor (HRC™), to provide initial biostimulation of the treatment. We observed reduction of CAHs concentrations to non-detectable level within only few weeks from the application. The parent compounds (PCE and TCE) and daughter compound cis-DCE have shown reductions of one order of magnitude within first month. A sequential increase of vinyl chloride has been observed in subsequent monitoring data, indicating solvent degradation to be proceeding without limitation despite the significant reduction in aqueous-phase contamina-tion. Full-scale results provide information on the long-term trend of the groundwater treatment onsite. The work illustrates the remediation measures adopted and the results of post-treatment monitoring for a period of 2 years. The results that led to the procedure closure derive from the integration of multidiscilinary data, using a multiscale approach. This research represents the first completed example in European territory for the remediation of an aquifer contaminated with chlorinated solvents by a combination of adsorption and biodegradation.

Use of permittivity, resisitivity and optical density to quantify the efficiency of free product recovery of heavy chlorinated compounds (with chemical and thermal enhancements)

Stéfan Colombano¹; Hossein Davarzani²; Eric van Hullebusch; Ioannis Ignatiadis²; David Huguenot³; Dominique Guyonnet²; Jacques Deparis²; Fabien Lion²¹ BRGM; ² BRGM (French Geological Survey); ³ Université Paris-Est, UPEM

Recovery of chlorinated solvents (CSs) as a free product is mainly based on the pumping and pumping/skimming approach. However, this technique is time consuming and does not allow significant recovery of CSs in the form of free product and its associated dissolved emissions. Our study focuses on the benefi-cial effects of thermal and chemical enhancements for recovering free product composed of heavy chlorinated compounds (Hexachlorobutadiene, Hexachloroethane, Perchloroethylene, Pentachlorobenzene, Trichloroethylene,…). This study is part of the SILPHES project, financially supported by ADEME (French Environ-ment and Energy Agency) in the framework of the “Investing for the Future” (“Investissements d’Avenir”) funding program.

Drainage-imbibition experiments were performed in 1D Cells with 0.1 and 0.5 mm glass beads (GB). The experimental data were modeled with the van Genuchten-Mualem (VGM) capillary pres-sure-saturation function. Parameters α and n, as well as residual and irreducible saturations (Srn and Srw), were obtained in order to use them during mutliphase flow modeling.

Four surfactants (SDBS, Aerosol MA-80, Triton X-100 and Tween 80) were tested at their critical micelle concentration (CMC) . The best recovery yield was obtained with SDBS: 27.6% for 0.5 mm GB and 46.3% for 0.1 mm GB. Experiments with thermal enhancement were also performed at 50°C, however, no significant improvement in the CSs recovery yield was achieved.

The drainage-imbibition experiments were continuously moni-tored by electrical resistivity, permittivity and optical density methods. With these methods, it was aimed to verifiy if Srn could be indirectly estimated in order to use these monitoring methods during the tests performed with the 1D columns and 2D tanks.

The estimation of residual saturations with permittivity fits well with the CRIM model (less than 8% difference). In contrast, the Archie’s law used to model variations in resistivity as a function of water saturation (Sw) variations may overestimate the experimetal data by a factor of 2.

It is possible to monitor the variations of Sw and to quantify Srn taking into account factors of corrections for permittivity and resis-tivity. These factors were quantified according to Sw.

Optical density monitoring shows that Srn can be accurately estimated with a linear relation (R2 = 0.98).

The tests in 1D columns made it possible to fit the two-phase flow model and to confirm the accuracy of indirect monitoring (permit-tivity, resisitivity and optical density).

The pumping experiments in 2D tanks provide (using indirect moni-toring approaches) estimations of the radius of influence (ROI) and of the optimal pumping flow rate (PFR). The ROI of pumping increases significantly with the thermal and chemical enhancements (e.g., it increases two-fold using surfactants). On the other hand, at higher PFRs, the beneficial effect of enhancement is less significant.

Based on the experimental data, it was possible to calibrate numerical model of two-phase flow in porous media (using COMSOL Multiphysics®). In particular, the model can predict the displacement of the water-DNAPL interface.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesTaguchi optimization of process parameters in electro-chemical PFOS removal from contaminated groundwater

Charles-David Dubé; Ruxandra Albu CimpoiaCNRC

Recent studies indicate that electro-chemical treatment can completely mineralize PFOA and PFOS at fast rates and relatively low energy consumption, under room temperature and atmo-spheric pressure. The present study aims the development of knowledge of PFOS remediation topics and is proposed as an early stage of research aiming for the development of a straightforward and economical remediation technology for PFOS contaminated sites. The research focus on the identification and determination of metabolites produced during the observed reduction of PFOS concentration, and on the optimization of operational conditions. The Orthogonal Arrays method (often referred to Taguchi Methods) was used as experimental design technique to determine the most influential controlling process parameters in the PFOS contami-nated groundwater removal performance. Several control factors, such as the PFOS concentration, electronic and ionic conductivity, current density, electrode setup and cell configuration, enhance-ment of mixing and reaction time, are studied. The electro-chemical experiments are performed in HDPE bottles (1L) equipped with an electrolytic cell placed in the bulk liquid. The cell was connected to a power supply (BK Precision, model 1760A). The cathode material is stainless steel, and the anode material is Ti/RuO2 (ElectroCell North America, Inc.). All experiments are performed in batch mode and at room temperature. Present results shown that electro-chemical treatment decrease the PFOS concentration of aqueous media up to 75%. Part of the PFOS is sorbed on electrodes, due to electro-static attraction. Tests are presently underway and full results will be available for analysis and reporting in the near future.

PFAS Treatment of Soil: Demonstration of Multiple Pilot Tests

Norbert Eigen; Alessandro Monteverdi; William DiGuiseppi; Scott GriecoJACOBS

Use of aqueous film forming foam (AFFF) in the military, aviation, oil & gas, and other industries from the 1970’s until recently has resulted in impacts to soil and groundwater in many locations. AFFF contains per- and polyfluoroalkyl substances (PFAS), which have been identified as compounds of interest and are considered emerging contaminants. Recent studies indicate that PFAS are rela-tively common in association not only with fire training areas, as would be expected, but in proximity to aviation hangars, municipal fire stations, wastewater treatment plants, landfills, industrial facili-ties, and transportation crash sites.

Across the world, increasing regulatory scrutiny and public awareness has resulted in numerous jurisdictions issuing screening levels, guidance levels, or mandated clean-up standards in soil and groundwater. Some of these promulgated standards in the US and Australia are extremely low and result in almost universal exceed-ances where samples are collected at facilities where AFFF was used.

Given the likelihood of encountering PFAS-impacted soil, consid-eration of a remedial strategy is important. Thermal treatment of soils impacted by PFAS compounds is a promising technology, however the optimal treatment temperature and time, as well as associated economics have not been thoroughly evaluated.

This presentation provides:

• A summary of current and anticipated regulatory values associated with PFAS-impacted soil. These include ingestion pathways for both human and ecological receptors.

• A review of available soil treatment technologies

• A summary of methods and results from multiple soil thermal treatment testing programs.

o Study 1 utilized direct superheated steam contact for soils starting at 40,000 µg/kg total PFAS. Testing was conducted at 480-954 ºC between 15 and 30 minutes, and demonstrated 97% to >99.9% removal.

o Study 2 utilized direct infrared heating for soils starting at 300,000 µg/kg total PFAS. Testing was conducted from 400-650  ºC between 60 and 80 minutes, and demonstrated 89% to >99.99% removal.

o Study 3 utilized rotary kiln indirect gas-fired heating for soils starting at approximately 2,400 µg/kg total PFAS. This full-scale field pilot was operated at temperature and residence time ranges similar to Study 1, and demonstrated 97.6% to >99.8% removal.

o The intent of our current work is to evaluate lower tempera-tures and longer residence times to potentially reduce cost of operation. Testing Methods and Results from this study will be shared and compared to the previous studies.

Results and lessons learned from previous and recent thermal studies (including future work, data gaps) will be summarized, as well as general cost information / competitiveness with the limited existing technologies non-thermal soil remediation technologies that have been demonstrated.

Evaluation of Established and Upcoming Remediation Technologies

Thomas Held¹; Ian Ross; Jörg Frauenstein²¹ Arcadis Germany GmbH; ² Umweltbundesamt Berlin

PFAS (poly- and perfluorinated alkyl substances) have been used in many household products and industrial processes due to their unique features like water and oil repellency as well as chemical and thermal stability. In particular, the thermal stability enables these compounds to be used in fire extinguishing foams as AFFF (aqueous foam forming films). This usage is a key reason why today PFAS are found as contaminants in many places. Usually the contamination is due to point sources as is true for most environ-mental contaminations. On the other hand, we know today that PFAS production facilities may have caused wide-spread contami-nation of > 100 km² due to contaminant transport via aerosols and subsequent deposition.

Both point and wide-spread sources represent a great challenge for the management of remediation. Currently the remediation technologies are mainly limited to Pump-and-Treat (P&T) with sorption of the PFAS on granular activated carbon (GAC) and soil exchange with subsequent disposal in specialized landfills or high-temperature thermal decontamination. On the other hand, in recent years several new technologies have appeared, some of them currently ready for the market, for example, PerfluorAd (PFAS precipitation approach for water treatment) or Rembind® (product for PFAS immobilization mainly within the soil). Others are still in the phase of lab scale investigation or pilot scale but lacking full-scale experience.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesSince the sorption capacity of GAC for PFAS is low, especially for the short-chain compounds, intensive research has been invested in the improvement of the GAC sorption capacity or in finding alter-native sorbents. The PFAS loaded GAC is thermally regenerated and the evaporated PFAS are destroyed thermally at temperatures > 1.000 °C. Hence, for sustainability reasons a sorbent showing higher sorption capacity and milder conditions for the subsequent contaminant desorption are highly desirable.

Many destructive PFAS technologies require treatment times of several hours which make them prohibitive to be used for contin-uous treatment of pumped contaminated groundwater. They may, however, be used to decontaminate concentrates which arise e.g. after sorbent desorption.

The moderate to high solubility of the PFAS and their low sorption capacity on soil are the reasons why PFAS cause long contami-nant plumes in the aquifer. Such extended aquifer contamination cannot typically be remediated cost-effectively with in-situ tech-nologies. This also holds true for conventional contaminants. Hence, besides P&T, barrier technologies are potentially suitable. PRB-systems (permeable reactive barrier) using GAC do not seem to be the answer. Emerging technologies include downhole foam fractionation approaches, which concentrate dissolves phase PFAS into foam within specialized wells. The specialized wells work in form of groundwater circulation wells.

In the presentation the advantages, disadvantages of the various remediation technologies, field applicability, challenges of treatment trains and applications to manage point and diffuse sources are discussed.

An Adaptive Remediation Strategy to Mitigate Biofouling in a Hydraulic Containment and Ex-situ Treatment System

Kathryn Johnson; James Baldock; Alan Thomas; Colette Couves; Mike Eversman; Kevin MorrisERM

A Hydraulic Containment System (HCS) was installed at a fractured bedrock site in the UK, following identification of Trichloroethene (TCE) at concentrations of up to 450mg/l. The site is an operational manufacturing facility, where TCE was used for approximately 40 years and has been detected at concentrations of up to 1mg/l in downgradient surface water receptors. A Remedial Options Appraisal identified the HCS as the most appropriate contami-nant management strategy and a pumping system was installed to contain the plume and recover TCE. Following system commis-sioning extensive and unexpected fouling was noted within the remediation process equipment, reducing system uptime, effi-ciency and operational performance.

Baseline groundwater sampling prior to system commissioning confirmed groundwater contained high TCE concentrations and pumping commenced as planned. However within 30 days signifi-cant fouling, in the form of bioslimes, was noted in the abstraction wells and treatment equipment (most notably within an air stripping unit and in liquid phase carbon treatment vessels).

The magnitude of the fouling was such that significant amendment of the remedial treatment system was anticipated in order to maintain continuous and safe operation of the HCS. To determine the cause of the fouling and identify appropriate system adapta-tions, a ‘lines of evidence’ investigative approach was undertaken, including an initial program of sampling focusing on the organic and inorganic groundwater chemistry, together with microbio-

logical analyses. The results were used to define additional data requirements and assess the system adaption and treatment strategy required to maintain operation. Identified system adap-tations would be subject to feasibility testing, ahead of full-scale deployment.

The initial evidence from chemical sampling revealed significant concentrations of previously unidentified organic matter that could act as a potential substrate under aerobic conditions. Micro-biological analysis identified the presence of total coliforms, faecal coliforms and E.Coli, which are indicator species for the presence of raw sewage and sanitary waste within the aquifer. A review of the site infrastructure identified a fractured foul sewer, carrying sanitary and kitchen waste as a source.

The results collated illustrate an unusual situation where a complex combination of organic, inorganic and microbial contaminants were considered the source of the fouling and presented both Health and Safety risks and operational challenges. The next steps will include adaptation of the HCS to include additional treatment technologies, such as Ultraviolet sterilization, dosing with biocides and system disinfection. The sewer system will also be repaired to remove the on-going carbon source, although the issue will likely persist for several months after this occurs.

This paper will present results of the chemical and microbiological analyses, how the HCS was modified, along with discussion of how this adaptive strategy was implemented to achieve the project objectives.

Application of Sequenced Chemical Oxidation and Bioremediation for Treatment of a Pharmaceutical Waste Mixture – Full Scale Application

Leah MacKinnon¹; Neal Durant¹; Torben Jørgensen²; Lars Nissen²; Lars Bennedsen³; Mette Christophersen³; Jørgen Christensen⁴; Ida Holm Olesen⁴¹ Geosyntec Consultants; ² COWI A/S; ³ Ramboll; ⁴ Southern Region of Denmark

The Kærgård Plantage megasite on the western coast of Denmark represents one of the most difficult remediation challenges in Scandinavia. Disposal of an estimated 280,000 metric tons of pharmaceutical wastes at the site from 1956 to 1973 resulted in the development of a complex mixture of contaminants in soil and groundwater, including sulfonamides, barbiturates, aniline, pyridine, chlorinated solvents (chloroethenes), fuel hydrocar-bons, mercury, cyanide, lithium and other compounds. Wastes were disposed in six pits that leach contaminants to groundwater. Although the waste pits were excavated down to the water table, residual dense non-aqueous phase liquid (DNAPL) beneath the water table continues to dissolve an impact underlying ground-water. Contaminants in groundwater are estimated to discharge into the ocean, and public health concerns have prompted the closing of a 1.5-kilometer section of beach at the site. Detailed bench and field pilot testing programs identified in situ chemical oxidation (ISCO) and enhanced reductive dechlorination (ERD) as the most cost-effective technologies for remediation of DNAPL residual in the waste pits. Based on a risk assessment, the remedial goal for the site is to substantially reduce the mass flux of chlori-nated solvents migrating from the waste pits to downgradient areas.

In 2018, full-scale remediation of the first waste pit was initiated using the technologies identified in the treatability and pilot test work. This has involved sequenced application of ISCO using peroxide activated persulfate (ASP) for areas with significant

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesDNAPL, followed by ERD for areas with less contaminant mass and/or for polishing following ISCO. The bench, pilot, and preliminary full-scale remediation results to date indicate that ISCO and ERD can be sequenced effectively, and that the required transition between oxidizing and reducing conditions be achieved and managed in the remedial design and implementation process.

This presentation will describe the results from the initial implemen-tation stages for ISCO and ERD at the Site, including a discussion of the challenges associated with applying these technologies in a remote coastal setting, in source areas characterized by high contaminant concentrations and contaminant mixtures. The presentation will also discuss the use of multiple lines of evidence to evaluate the success of each technology in achieving contami-nant mass and mass flux reduction to meet the remedial goals.

PFAS Destruction through Smoldering Combustion (STARx)

David Major¹; Alexandra Duchesne²; Jason Gerhard³; Joshua Brown³; David Reynolds⁴; Gavin Grant¹; Kela Weber⁵; David Patch⁵; Dave Thomas⁶¹ Savron; ² The University of Western Ontario; ³ University of Western Ontario; ⁴ Geosyntec Consultants Inc.; ⁵ Royal Military College of Canada; ⁶ Chevron

The U.S. Department of Defense (US DoD) Strategic Environ-mental Research and Development Program (SERDP) funded a project using STARx to treat PFAS compounds in soils or investiga-tion derived wastes (IDW). IDW includes drill soil cuttings, as well as spent activated carbon (GAC) waste streams generated from treating water from well development and sampling.

STARx system use smouldering combustion for the treatment of contaminated soils and liquid organic wastes. The process is self-sustaining following a short duration, low energy input ‘ignition event’ for low volatility, high energy compounds such as petroleum hydrocarbons. The energy released from the reacting contaminants is used to pre-heat and combust contaminants in the adjacent area. A self-sustaining combustion front propagates vertically upward through the comtaminated media placed within the STARx system, provided that a sufficient flux of air is supplied. Modular engineered base systems have been developed to apply STARx via soil piles. These bases, called Hottpads™, are low profile modules with trafficable surfaces containing the heat and air distri-bution systems for ignition and propagation of the smouldering reaction. The Hottpad modules can be networked together to build a customized system to meet the throughput demands of the project. STARx is being deployed or pilot tested at sites in the Middle East, Australia, Latin America, North America, and South East Asia and China.

Due to the high thermal stability of PFAS, temperatures greater than 900°C are required to destroy these compounds and temperatures at or above 1000°C are necessary to minimize production of short-chained volatile organic fluorines (VOFs) and fluorinated dioxins and furans (PFDD/F). Hydrofluoric acid (HF) will be produced in greater abundance, and VOF and PFDD/F in lesser abundance, with increasing completeness of PFAS combustion. As the PFAS are not contaminants that can support smouldering combustion in and of themselves like heavy hydrocarbons, a surrogate fuel is required. For this study, GAC was used as a surrogate fuel.

Tests were conducted to establish the amount of GAC needed to create smoulderable mixtures that produced temperatures greater than 900°C. Subsequent tests examined the fate of PFAS adsorbed to GAC and then combined with sand, or a soil contaminated with

PFAS and mixed with uncontaminated GAC under smoldering conditions. Results reveal that the smouldering front propagated in a self-sustained manner through the PFAS-impacted mixtures, destroying all the GAC and organic carbon and generating temper-atures in excess of 900°C. Post-treatment concentrations of PFAS in the remaining sand, soil, and ash were below detection limits (0.05 µg/kg). Initial emission analysis indicated that over 82% of the available fluorine was captured as HF with only small amounts of PFAS emitted which could be subsequently captured by activated carbon and treated. Results to date are promising, suggesting STARx may provide an effective remediation technique for PFAS-impacted soils and IDW.

Full-scale application of EHC Liquid technology for the ISCR and ERD treatment of an aquifer contaminated with Tetrachloromethane and Chloroform

Linda Collina¹; Matteo Avogadri²; Patrizia Trefiletti³; Caterina Di Carlo⁴; Alberto Leombruni⁵¹ SGM Engineering S.r.l.; ² Ramboll Environ Italy Srl; ³ Tethys srl; ⁴ Solvay Speciality Polymers, Italy; ⁵ PeroxyChem Environmental Solutions

EHC® Liquid Reagent is an in situ chemical reduction (ISCR) technology designed for treatment of impacted groundwater. It is a cold-water soluble formulation engineered for injection via existing wells, or hydraulic injection networks, to affect the treatment of a wide range of groundwater contaminants. This technology creates strong reducing conditions, and promotes both biotic and abiotic dechlorination reactions. It is composed of two parts: Liquid Reagent Mix; an organo-iron compound, and ELS Microemulsion, which are easily combined and diluted for injection. The addition of organic carbon addition in a saturated zone is well-known to promote conventional enzymatic reductive dechlorination reactions. This happens as carbon in the subsurface supports growth of indigenous microbes in the groundwater envi-ronment. As bacteria feed on the soluble carbon, they consume dissolved oxygen and other electron acceptors, thereby reducing the redox potential in groundwater. As bacteria ferment the ELS Microemulsion, they release a variety of volatile fatty acids such as lactic, propionic and butyric, which diffuse from the site of fermentation into the groundwater plume and serve as electron donors for other bacteria, including dehalogenators. Further, phos-pholipids support remediation by providing essential nutrients (carbon, nitrogen, phosphorus) to bacteria. The soluble organo-iron component consists of ferrous iron (Fe+2) that forms a variety of iron minerals (e.g. magnetite, pyrite), which are capable of reducing contaminants as they oxidize further to the ferric (Fe+3) state via one electron transfer. The ferric ion can be “recycled” back to ferrous, as long as other electrons from supplied carbon and indigenous carbon are available.

The site is situated in a highly industrialized area of northern Italy, where groundwater is historically contaminated with tetrachloro-methane (>10 ppb), chloroform (>10 ppb), hexavalent chromium and, to a lesser extent, PCE and TCE. In the intervention area and downstream of it, 10 standard Pump & Treat wells were located, designed to accelerate the removal of various contaminants. The presence of active pumps in the immediate vicinity of the area affected by EHC Liquid injections, however, could have compro-mised its effectiveness. This is due to the increase in groundwater speed and removal of the injected emulsion. A strategy was devised to shut down some wells and reduce the flow rates of the others, to guarantee sustainment of the all onsite mechanisms. A detailed evaluation of the influence of P&T infrastructure and

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesthe consequent action plan,was based on hydrogeological tests carried out in the field. This included simulations by a mathemat-ical flow model, alloweding design engineers to identify an optimal configuration pumping to achieve the aforementioned purposes.

After 6 months from injection of EHC Liquid into the main source area groundwater, concentrations of CT and CF contaminants were rapidly reduced. The remedial targets were reached in the main piezometers monitoring in the area, also highlighting the establish-ment of clear and enhanced biotic and abiotic reducing conditions.

A Field Comparison of Biogeochemically Enhanced, Biological and Chemical Reduction for Treatment of Chlorinated Organics

Daniel Leigh, Michael MuellerPeroxyChem Environmental Solutions

For over two decades, biological (enhanced reductive dechlo-rination; ERD) and abiotic (in situ chemical reduction; ISCR) reductive processes have been applied to degrade chlorinated volatile organic compounds (CVOCs) in situ. Recently, biogeo-chemical reduction (BGCR); a process which combines biological and chemical processes, has been combined with ERD and ISCR to provide additional mechanisms to more aggressively degrade CVOCs in situ. The BGCR process enhances ERD and ISCR by contemporaneously generating reactive minerals in situ. These minerals have been demonstrated to abiotically degrade CVOCs by the β elimination pathway. This pathway extends treatment longevity and minimizes generation of toxic degradation products, thereby reducing clean-up times. During ERD and ISCR, highly reducing conditions are generated favorable to production of BGCR enhancing iron sulfide minerals, such as mackinawite (FeS) and pyrite (FeS2). BGCR enhancement is achieved by including a source of iron and sulfur with the ERD and ISCR reagents. A recent field study was conducted to evaluate effectiveness of including iron sulfide BGCR to enhance ERD and ISCR for treatment of CVOCs

At a confidential site in California, soil and groundwater was affected by discharge of high CVOC concentrations, primarily TCE. Site conditions were determined to be appropriate for ERD and ISCR. ERM evaluated the potential for BGCR to enhance ERD and ISCR to aggressively treat CVOCs onsite. Two pilot tests were conducted in the high concentration portion of the plume to evaluate effectiveness of 1) BGCR enhanced ERD and, 2) BGCR enhanced ISCR. The studies were conducted by injection of a BGCR enhanced ERD reagent (Geoform Soluble), and a BGCR enhanced ISCR reagent (Geoform Extended Release) at two locations in the affected aquifer. Geoform ER was injected as a slurry with the intention to evaluate its applicability for establishment of a PRB. Geoform Soluble was injected as a soluble reagent for extended distribution for potential later distribution through injection wells. For these tests, reagents were delivered to the subsurface by high pressure direct push technologies. Conservative tracers were also injected to evaluate distribution characteristics of the injection process. Following injection, soil and groundwater samples were analyzed for parameters necessary to evaluate degradation pathways and rates. Additional samples defined reagent distribu-tion characteristics, confirming generation of reactive iron sulfides.

Pilot tests demonstrated that BGCR enhanced ERD and ISCR reagents are very effective for treatment of high concentrations of CVOCs in groundwater. The biological utilization of the organic substrates results in rapid establishment of highly (sulfate) reducing conditions. Establishment of sulfate reducing conditions results in rapid generation of reactive iron sulfides which precipitate on the

aquifer matrix. ERD and ISCR with BGCR provides a more aggressive approach for treatment of CVOCs. The presentation will describe methods and challenges for enhancing BGCR and will summarize the application process and results of these pilot tests.

Combining Strategies for Remediation of Different Gas Work DNAPL and LNAPL Groundwater Contaminants

Helena Nord¹; Jonny Bergman¹; Maria Sundesten²¹ RGS Nordic; ² City of Stockholm

In central Stockholm, a former Gaswork area is now being rede-veloped. The City of Stockholm engaged RGS Nordic to undertake pilot tests in-situ to find remediation solutions, as well as designing in situ-remediations for the entire Gasworks area. The Gaswork have left very complex mix of contaminants impacting the soil, groundwater and shoreline sediments and has contaminated the groundwater down to 20 mbgl (app. 18 mbgl).

Three sets of pilot tests were carried out during 2017 focusing on in-situ chemical oxidation (ISCO), enhanced aerobic biodegrada-tion (ENA) and enhanced desorption. For the ISCO tests RGS Nordic trialled hydrogen peroxide, RegenOx® and PersulfOx® in areas with high concentrations of PAH’s. The ENA trials were focused on areas impacted with lower dissolved phase concentrations of benzene and naphthalene; ORC-Advanced® and PermeOx. For areas where gross PAH/BTEX soil impact an enhancing desorption reagent, PetroCleanze®, was applied in combination with pumping to desorb and remove contaminants from the soil. These pilot tests were performed in coarse sandy soils with gravel/bolder material, with the exception of the ORC-Advanced® pilot test which was performed in clay. All reagents were applied using direct push injection. A larger trial using PersulfOx® was completed in 2018 to further evaluate the efficacy of the full-scale ISCO works.

The ENA pilot test using PermeOx in coarse soil showed >99% reduction of benzene and PAH’s in groundwater. However, the efficacy of PermeOx reduced after 1 year. The pilot test using ORC-Advanced in clay, yielded a sustained reduction of naphtha-lene, but less for benzene, probably due to its mobility in clay and continual influx into the pilot area.

The enhanced desorption facilitated by PetroCleanze® pilot showed a reduction in dissolved phase benzene by app. 70%. For the PAH’s the result was less significant since the baseline concentrations of the soil bound levels were lower than expected.

The highly reactive nature of hydrogen peroxide made utilising the reagent difficult to perform on site with additional health and safety risks to site personnel. Therefore Citric acid was added to the hydrogen peroxide to slow the reaction. However, this slowed the reaction down so much that the rate of remediation was negligible. RegenOx®, however, yielded an 80% reduction in benzene concen-trations in the groundwater. Most of the PAH’s showed increasing levels, probably due to large amounts of soil bound contamination desorbing into the ground water post treatment. The pilot test using PersulfOx yielded a >90 % reduction of benzene and PAH-L’s, e.g. naphthalene by >90 % and about an 80 % reduction of PAH-M’s and PAH-L’s. In the larger pilot test PersulfOx showed to decrease PAH16 by 50-70 %.

The combined evaluation shows that there are in-situ techniques for all parts of the Gasworks site. For the full-scale remediation, a combination of techniques has been proposed, mainly ISCO and ENA. Also, for the treatment of clay, stabilization/solidifica-tion is being considered as a co-method to preserve the required geotechnical properties.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesElectrochemical Oxidation Pilot Reactor Demonstration Project, Coupling Technology for PFAS Destruction

Richard (Rick) Parkman¹; Rachael Casson²; Shangtao Liang¹ AECOM UK; ² AECOM Australia

Per- and Poly-fluoroalkyl Substances (PFAS) have been widely used and released into the environment over the last 60+ years. Among the broad category of PFAS studied, perfluoroalkyl acids (PFAAs), such as perfluorooctanoic acid (PFOA) and perfluorooc-tane sulfonate (PFOS) have been the focus. PFAS have chemical structures involving the extremely strong carbon-fluorine (C-F) covalent bond, representing a class of chemicals that are extremely challenging to remediate. The current trends for treating PFAS impacted water rely on mass transfer technologies (e.g. granular activated carbon [GAC], ion exchange resin [IX-R], reverse osmosis [RO]) that do not destroy PFAS but concentrate PFAS on the selected media or generated brine. The spent media generated require off-site incineration in the case of GAC and single use IX-R or on-site regeneration for reusable IX-R. Other emerging water treatment technologies, such as ozone fractionation (OF) and ex-situ foam fractionation (FF) also produce wastes concentrated with PFAS that require management and/or treatment. Advances are being made in developing destructive technologies, such as electrochemical oxidation (EO), sono-chemistry and plasma, all are producing promising results in the laboratory. This paper will present the latest developments, including optimisation modifi-cations and proof of demonstration results using a pilot scale EO reactor to treat real world PFAS impacted liquids.

The demonstration project was undertaken using a proprietary electrode to destroy dissolved PFAS via EO. The electrode was fabricated and used to mineralize C4~C12 PFAAs and their precur-sors with evidence of complete defluorination and desulfurization. PFAS are destroyed via direct electron transfer on “nonreactive” anodes and generated hydroxyl radicals with relatively low energy consumption. This EO reactor was developed as a coupling tech-nology to treat PFAS concentrated in different wastes generated as a result of separation technologies. This project treated six different types of PFAS impacted liquids, including: RO reject; soil washing effluent; OF concentrate; FF concentrate; untreated wastewater; IXR still bottoms; and PFAS impacted groundwater comingled with volatile organic compounds (VOCs). Pre- and post-treated samples were analysed for 31 different PFAS, Total Oxidisable PFAS (TOP) Assay; perchlorate, chloride, fluoride, sulphate, metals and VOCs.

The EO pilot demonstration treated PFAS from low to high concen-tration ranges in water and PFAS concentrates in liquid waste. For instance results for the treatment of IX-R still bottoms indicated 100% removal of measurable PFAS and generation of 300% of fluoride as an end product, indicating successful mineralization of unquantified PFAA precursors as well as measurable PFAAs. This technology was also capable of simultaneously decomposing high concentrations of total organic carbon (8,000 parts per million [ppm]). This presentation will discuss the results of all testing conducted to date, it will also share the challenges faced during the development including the limitations of the technology.

Tuning activated carbon adsorption by surface chemistry and electric potentials: Perfluorinated alkyl surfactants as target pollutants

Navid Saeidi; Anett Georgi; Frank-Dieter KopinkeHelmholtz Centre for Environmental Research – UFZ

Perfluorinated alkyl surfactants (PFAS) have been used in various application areas because of their unique distinct amphiphilic properties. These properties make also them persistent, bioac-cumulative and almost ubiquitously distributed in aquatic environments. Thus, they have been detected in different water sources all over the world. Activated carbon adsorption is currently the most important treatment method for Perfluorinated alkyl surfactants (PFAS) removal from water. Adsorber operation time is usually determined by breakthrough of the more hydrophilic shorter-chain PFAS, such as perfluorobutanoic acid (PFBA).The aim of this study was a better understanding of the decisive surface properties of activated carbon (AC) for optimal PFAS adsorption. This knowledge was applied for targeted chemical modification of commercially available activated carbon felts (ACFs). In addition, electrodesorption of PFAS from the saturated ACF was proposed as an alternative for regeneration of the adsorbent.For this purpose, several ACFs were characterized physically and chemi-cally with various techniques. Among these ACFs, four of them having different surface chemistries but the same porosity (micro-pores) and fiber’s diameter were selected and applied for next experiments. The electrochemical properties of ACFs were also determined using cyclic voltammetry (CV) in different scan rates to address working potential window for electrochemical experi-ments and specific capacitance of ACFs.First of all, a series of adsorption experiments (equilibrium and kinetics) were performed to study the role of surface chemistry of ACF on adsorption affinity of PFAS. The results proved that there was a significant difference between adsorption affinities of PFAS on these four ACFs. The most influencing chemical characteristics of the ACFs in adsorption of PFAS were identified. After that, it was tried to take advantage of the results obtained here to chemically modify the ACF with lowest affinity in adsorption of PFAS. The modified ACF sample showed a strongly enhanced adsorption. For the optimized ACF sorption coefficients Kd in the order of 107.0 L/kg were obtained for perflu-orooctanoic acid (PFOA) and 104.5 L/kg for PFBA (at loadings of 0.2 wt% on ACF) even in the presence of 5 mg/L natural organic matter (NOM).Afterwards, ACFs were applied as working electrode in a three-electrode electrochemical system. In fact, it was tried to improve further the adsorption affinity for shorter-chain PFAS by polarizing the working electrodes anodically in order to increase the density of positively charged sites on ACFs. Negative potential was accordingly applied on the ACF working electrode to regen-erate the saturated ACFs. Finally, the surface chemical properties and electrochemical characteristics of ACFs were discussed as the effects contributing in electrosorption and electrodesorption of PFAS on ACFs. In summary, this study shows that targeted surface modification of activated carbon combined with electrochemical assistance is a promising approach for improving adsorber perfor-mance especially for shorter-chain PFAS and provides an option for on-site adsorber regeneration.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesIn situ remediation of PFAS using colloidal activated carbon: A review of multiple case studies

Gareth Leonard¹; Rick McGregor²; Kristen Thoreson³; Maureen Dooley³¹ REGENESIS; ² ISRL; ³ REGENESIS Inc.

This presentation reviews data from multiple field sites where colloidal activated carbon has been utilized to remediate PFAS groundwater contamination in situ. Sites discussed include the Solvents Recovery Service of New England superfund site (US) and a former furniture manufacturing facility (Canada). The talk also uses the latest data from lab and pilot studies at other sites, to explain how the risk of PFAS contamination in soil and groundwater can be contained via in situ remediation, using colloidal activated carbon. This new in-situ containment approach offers a far more cost-effec-tive long term solution to stop and contain risk caused by PFAS plumes, compared to existing methods (hydraulic containment). Further important questions, including the ability to distribute the colloidal activated carbon in the subsurface, the long-term efficacy, and design considerations, will also be addressed.

Multiple field sites were treated with a single application of colloidal activated carbon to address PFAS contamination and other comingled contaminants. Depending on any co-contam-inants present, additional remedial agents were also applied to degrade those contaminants. In each case the amendments were applied under low pressure (non-fracking) conditions using direct-push technology. At one of the sites, groundwater was impacted by petroleum hydrocarbons at concentrations up to 6 mg/L in addition to PFOS and PFOA which were present at baseline concentrations of 300 to 3,300 ng/L. In this case, an oxygen release agent was co-applied to promote the biodegradation of the TPH. At another site, TCE was present in addition to the PFAS contamination and a sulfidated zero-valent iron was co-applied with the colloidal activated carbon. Monitoring at all sites is on-going, with current data ranging from 3 months to over two years, and has included analysis of PFOS, PFOA, shorter chain PFASs, and co-contaminant concentrations.For some of the sites to be discussed, laboratory bench tests were performed as an initial step to aid in the field dosing and design considerations. In these cases, site groundwater was treated with varying doses of the colloidal activated carbon to assess for any potential interferences or competition for sorption sites between species present at the site.

Results from field case studies have demonstrated immediate removal of PFAS from the dissolved phase to levels below the US EPA health advisory level when treated with a single application of colloidal activated carbon. The site with the longest monitoring period has maintained its performance with PFOS, PFOA as well as shorter chain species for over two years, with further monitoring ongoing. The colloidal activated carbon treatments, sometimes in conjunction with another remedial agent, were capable of addressing co-contaminants like TPH and TCE. Bench studies also proved helpful in proving efficacy and ruling out the presence of interfering species that would limit performance. Overall, these studies indicate that the in situ application of colloidal activated carbon offers a valid and cost-effect strategy to address the risk associated with PFAS.

In situ chemical oxidation to enhance the performance of an air sparging and soil vapour extraction treatment of chlorinated VOCS in glauconitic sands on a Belgian site

Karina Suy; Diane DriesMourik n.v.

To shorten as much as possible the remediation of a Belgian site contaminated by chlorinated solvents, there was opted for a ‘tech-nology train’ based on chemical in situ oxidation with Modified Fenton’s followed by airsparging combined with soil vapour extraction.

The site is located in a dense urban area and is characterized by limited space and access due to the presence of many buildings. The contamination is measured in soil and groundwater and has migrated to a depth of 15 mbgl with the highest concentrations at 10 mbgl (max. 30.000 µg/l). The contamination extends over 750 m². The geology consists of loamy/clayey sand in the unsaturated zone (about 6 m thick) and glauconitic clayey sand in the saturated zone. Because of the chemistry of the groundwater no biodegrada-tion of the present chlorinated solvents was occurring.

The remediation project, inclusive a pilot test, started in 2010. The challenge for this site was to design a remediation project with a minimum duration taking into account the difficulties of the site:

• Limited access / space to realize civil works and install wells and piping

• Glauconitic character of the saturated zone that makes injection activities more difficult and can scavenge oxidation processes based on radicals

In a first step of the design, in situ chemical oxidation was evaluated to realize a fast mass reduction in the zone with the highest concentration. After a bench-scale test to select the oxidant, 2 injection wells were installed on site and 15 m³ of Modified Fenton’s was injected to determine the performance of an in situ chemical oxidation.

Based on the good results of the pilot test, the full scale remedia-tion of the site was designed as a technology train where in situ chemical oxidation with Modified Fenton’s was selected for a fast mass reduction of the contamination present at 10 mbgl followed by an airsparging and soil vapour extraction to reach the final remediation targets.

In 2013, the in situ infrastructure was installed on site. In total 62 injection wells and 20 soil vapour extraction wells were installed. After 2 injection campaigns of Modified Fenton’s, the airsparging and soil vapour extraction treatment was started. In October 2018, the remediation target was reached. In comparison to other neigh-boring sites dealing with the same problem, the clean-up period by means of the airsparging and soil vapour extraction treatment could be reduced by half thanks to the implementation of focused in situ chemical oxidation in a first phase.

The presentation describes the engineering of the project and the results of the pilot and the full scale remediation.

This project shows the importance of / advantages of :

• Lessons learned on neighboring sites dealing with the same problem

• Engineering of the full scale remediation

• The use of a ‘technology train’ to shorten the clean-up period

• Monitoring & communication during the full scale remediation

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesPerfluoroalkyl and polyfluoroalkyl substances in the environment: origins and feasability in thermal desorption

Aurélien Vandekerckhove; Hatem Saadaoui; Jan HaemersHaemers Technologies

Per- and polyfluoroalkyl substances (PFAS) came into use in 1950’s and since then have been used in numerous industrial and commer-cial applications. PFAS comprises a large group of compounds (> 6.000) consisting of at least a hydrophobic alkyl chain of varying length C_n F_(2n+1). This hydrophobic variety can be completely fluorinated (perfluorinated alkyl substances) or partly fluorinated with at least two fully fluorinated carbons (polyfluorinated alkyl substances).

Compared to the binding energy of C-C bond (347 kJ/mol), the C-F bond (439 kJ/mol) is extremely strong and stable, the strongest in organic chemistry. The chemical and thermal stability of PFAS, in addition to its hydrophobic and lipophobic nature leads to highly useful properties in surfactants (fluoropolymer, coatings, aqueous film-forming foams, etc…) and polymers (textile stain, soil repel-lents, grease-proof, food contact paper, etc…). However, due to its stability, PFAS are resistant to biodegradation, direct photolysis, atmospheric photooxidation, hydrolysis and so forth. Moreover, these compounds are water soluble, so highly mobile.

For a better comprehension of the environmental occurrence and behavior of PFAS and to decrease the long-term impact, it is essential to look at the two main manufacturing processes used to produce PFAS compounds: (1) Electrochemical Fluorination (ECF) – generally results in even- and odd-numbered, branched and linear chains of perfluoroalkyl compounds; (2) telomerization – produces even-numbered, linear chains. ECF lead to a mixture of a linear and ramified compound compared to the telomerization. For this reason, most production today is via the telomerization.

To date, there are hundreds of research studies about PFAS. However, the number and complexity of environmentally-relevant PFAs and the exponential increase in related scientific publications have led to confusion in the environmental community and public. It is essential to use the same language through researches to keep clarity of investigative results and will reduce confusion and support clearer communication.

However, due to the energy required to break the C-C and the C-F bonds, thermal decomposition of these compounds is possible in soil. The use of thermal desorption technologies to recover these products is quite feasible. The article covers the thermal behavior of PFAS-impacted soil when heated at increasing temperatures. Efficiency of thermal desorption for PFAS is presented in function of temperatures, residual time and residual concentration.

Emerging impact of PFAS in Flanders - prioritization of risk locations and sampling campaigns to develop soil management strategies

Karen Van Geert¹; Jonas Rabaey²; Martijn van Houten³; Nele Bal⁴; Griet Van Gestel⁴¹ Arcadis Belgium; ² Witteveen+Bos Belgium NV; ³ Witteveen+Bos; ⁴ OVAM - Flemish Waste Agency

Flanders has decades of experience in dealing with soil and ground-water pollution. The developed approach via soil remediation policy has proved very successful in recent years. This remedia-tion policy mainly concerns heavy metals and the most common organic contaminants associated with activities from the past. It

is becoming increasingly clear that all kinds of new contaminants (also known as Emerging Contaminants) are present in the envi-ronment. For several of these substances, the size and risks in soil, groundwater and sediment are insufficiently known.

OVAM has carried out an exploratory study from this perspective into the presence of Per- and Polyfluoroalkyl Substances (PFAS) in soil, groundwater and sediment. The study is used to establish policy decisions on soil management strategies in Flanders.

A first part of the study includes a literature study on types of PFAS and production as well as behavior and toxicity. The PFAS family includes 42 subfamilies and several thousand substances. This report focuses on the most important families and subfamilies, in particular the perfluorinated compounds and subfamilies perfluo-rinated sulphonic acids and carboxylic acids; the polyfluorinated compounds and subfamilies fluorotelomers and precursors; and the fluoropolymer. PFAS are used in various products and produc-tion processes, in chrome plating processes, in the production of inks, varnishes, waxes, fire-extinguishing foam, cleaning agents, coatings, lubricants, water- and oil-repellent agents for leather, paper and textiles. From 1966 to 1990, production and use grew due to their unique chemical stability and their water and dirt-repellent properties.

The second part of the study includes a selection of relevant risk locations and sampling campaigns. Emphasis was put on the activities with a reasonable chance of PFAS being present, for example producers of PFAS, producers of fire-extinguishing foam, fire training places and fire incidents.

A total of 35 drillings were carried out on 24 selected sites in Flanders and 40 soil samples, 47 monitoring wells, 1 effluent sample and 1 sediment sample were selected for analyses on PFAS.

Based on the results of the samples, PFAS occur in elevated concen-trations in soil and groundwater. In 71% of the groundwater samples at the selected risk locations a concentration of PFAS higher than 100 x reporting limit of 0,5 µg/L was measured. In 42% of the groundwater samples a concentration of PFAS higher than 1000 x reporting limit (> 5 µg/l) was measured.

In 66% of the soil samples at the selected risk locations a concen-tration of PFAS higher than 10X reporting limit (>10 μg/kg ds) was measured. In 24% of the soil samples a PFAS concentration higher than 1000 x reporting limit (>1.000 μg/kg ds) was measured.

PFOS and PFOA were the main compounds, but also other PFAS, such as 6: 2-FTS, occur in several of the analyzed samples. 6: 2-FTS is a precursor that can degrade to persistent perfluoro compounds.

Results of the study will be presented and insight in possible soil management strategies will be given.

Innovative Spin® injection technology pushes boundaries of in situ remediation

Jeroen Vandenbruwane¹; Hans Baillieul²; Anja Vandercappellen³; Karolien Claeys³; Nicolas Soenens³; Jeroen Verhack³¹ Injectis; ² Sodecon; ³ Arcadis Belgium nv

Injection based remedial strategies have evolved over time to mature remediation methods. However, low permeability soils and soils with a high degree of heterogeneity remain difficult to treat. Injection wells are not suited in these circumstances; injection flow rates are too minimal in the case of low permeability soils and injection fluids are injected in the most permeable flowpaths in the case of heterogeneous soils due to the long filter screens.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesIn these circumstances, direct push tool (DPT) injections have been tried as the depth interval of the point of injection is short and injection can focus on very small soil layers. However, DPT injections have several limitations, that narrows its applicability. Soil compaction and smearing at the point of injection reduce the porosity and thus permeability of the soil. This leads to the application of increased injection pressure, what causes short-circuiting and daylighting of the injection product. Moreover, hammering is often used to drive the injection point into the soil. These vibrations cause a preferential channel along the injection rods, leading to blow-out of the injection solution along the rods. Injectis has developed a direct injection technique where compac-tion and smearing at the well head is avoided and hammering is not necessary: the patented Spin® injection technology. As a consequence, injection pressure can be decreased and effects like blow-out and daylighting of the injection product can be avoided.

In order to be able to better steer the injection process, the Spin® injection system is equipped with sensors that continuously measure injection depth, injection volume, injection flow rate, injection pressure and permeability across the entire injection interval. This information is very useful to monitor the injection process. Additionally, the site conceptual model can be refined during the injections as permeability profiles of the soil are gathered for every injection point. Adaptations during remediation can be made, based on this information.

In this presentation we will present the application of the Spin® technology at two different sites contaminated with chlorinated solvents: one with a very low permeability clay layer and one with a heterogeneous geology. Injections with filter screens are not the most efficient option at this moment for both sites. We will discuss the distribution of the injected reagent, problems encountered during the injections and how they were resolved and the effect on the degradation of the contamination. We will also show how the information gathered during the injections can be used to generate e.g. cross sections of the soil permeability.

ThS 4d | Phytoremediation and ecological engineering and nature-based solutions

Planting trees at phytomanagement sites : Recommendations from field trials

Michel Chalot; Stéphane Pfendler; Cyril Zappelini; Damien Blaudez; Lisa CiadamidaroUniversité de Bourgogne Franche-Comté

Phytomanagement has become an attractive alternative to other clean up technologies due to their relatively low cost, potential effectiveness and the inherently aesthetic nature of using plants to clean up contaminated sites. Integrated bioremediation is rapidly gaining in possibility throughout the developed countries espe-cially concerned with pollution problems deriving from industrial, agricultural and urban communities. Afforestation is indeed a potentially sustainable reclamation strategy for contaminated land, post-mining sites, and mine spoil, and has several environmental benefits, such as soil stabilization and visual buffering. Many trees and shrubs show strong environmental adaptations, produce large biomass and can have a significant practical or economical value. The use of fast-growing trees producing a high quantity of biomass can bring significant practical and economic benefits to the recla-mation of marginal lands. The present study aims at identifying shrub/tree species to offer a wider range useful for phytomanage-ment practices, within the ADEME-funded PROLIPHYT proposal. We implemented 3 demonstration sites in France of 1 ha each contami-nated by different potentially toxic elements (PTE) with a total of 47 different woody species planted under short rotation coppice (SRC) scheme. The first site (Carrières) is located in the Paris region, and is a former agricultural soil contaminated by Cd, Pb and Zn from waste waters during the 20th century. The Leforest site is located in the North of France, and is a former agricultural soil contaminated by Cd, Pb and Zn from a Zn/Pb smelter. The third site is located at Thann, North-East of France, and is a tailings pond from the TiO2 extractive industry, with high Fe- and Mn-enriched gypsum red. After four years of growth, the stem and leaf PTE concentrations, tree survival rate and tree growth were assessed. We also evaluated the PTE transfer potential and thereof the decontamination rate. We also characterized the bacterial and fungal microbial communi-ties using Illumina metabarcoding at the three sites for the most relevant tree species. The growth potential/survival rates at T0 + 2 years are relevant indicators of future performances for most trees, although this is not a strict rule. We therefore recommend the use of a panel of (2 - 4) trees rather than a single species. Tree species with high growth performances (Alnus subcordata, Ulmus subcordata and Platanus orientalis) could be considered for the restoration of contaminated sites and for the production of clean biomass, although there is a need to evaluate their yields under long-term SRC schemes. Alternatively, some (hyper)accumulating tree species (from the genera Salix, Betula) could be considered for the recovery of PTE in ecocatalysis / hydrometallurgy processes. Finally, we were able to conclude that fungal diversity is highly driven by site but also by tree species.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesBacteria-assisted phytoremediation for soils and groundwater polluted with organics

Dirk Dubin¹; Mario Clemmens¹; Nele Weyens²; Sofie Thijs²; Jaco Vangronsveld²; Hilde Decuyper³¹ bio2clean bvba; ² CMK - UHasselt; ³ A+E Consult

Trees can pump up to 200 liters of groundwater per day and in this way attract high volumes of pollutants. Organic pollutants are sequestered, transformed and/or degraded by plants together with their associated microorganisms.

Beneficial bacteria are ubiquitous. They can promote plant growth and development and might even degrade organic contami-nants. They are localized in the rhizosphere, but also in the plant’s transport system, where they can degrade (volatile) pollutants taken up through the roots and transported to the aerial parts.

In case of regular phytoremediation, the degradation capacity is uncontrolled. The degradation efficiency is determined by the plants and microorganisms that are naturally present. However, plants might suffer from phytotoxicity and/or volatile pollutants might be transported from the soil and groundwater through the roots and ultimately be released through the leaves.

In order to ensure an efficient degradation and to avoid evapotranspiration of volatiles, bacteria with the appropriate degradation characteristics can be enriched inside the plant by means of inoculation.

Case 1: Bacteria-assisted phytoremediation of soil and ground-water polluted with organics in Roeselare (Belgium)

Due to former activities on this site, soil and groundwater are polluted with 1,1,1-trichloroethane, dichloroethane, 1,4-dioxane and toluene.

On behalf of the OVAM (Public Waste Agency of Flanders), bio2clean (phytoremediation spin-off of Hasselt University), Hasselt University and soil remediation expert A+E Consult are performing a pilot study to examine the efficiency of bacteria-assisted phytoremediation.

In March 2018, 31 poplar trees, 10 willow trees and 191 willow shrubs were planted on an area of 520 m².

Appropriate consortia of bacteria were selected and tested in a greenhouse experiment. In May 2019, the trees will be inoculated with the selected pollutant degrading bacteria. The effects of bacteria-assisted phytoremediation as well as different techniques to measure biodegradation in the root zone and phytovolatilisation are examined. These techniques include state-of-the-art molecular methods to detect the presence of chlorinated-compound degrading bacterial strains (e.g. Dehalococcoides), and quan-titative PCR for the activity of target degradation genes and gas chromatography time-of-flight mass spectrometry (GC TOF MS) for metabolite analyses.

Case 2: Bacteria-assisted phytoremediation of soil and ground-water polluted with organics at a former coke plant in Zeebrugge (Belgium), Interreg project RESANAT

Soil and groundwater are polluted with coal tar, polycyclic aromatic hydrocarbons (PAHs), benzene, toluene, ethylene, xylene (BTEX), cyanides and mineral oil. Although excavation was applied, there is still pollution at this site and surrounding sites. Different scenarios of bacteria-assisted phytoremediation will be examined.

Innovative monitoring techniques such as Compound Specific Isotope Analysis (CSIA), BACTRAPS and iFLUX samplers will be applied. These pilot studies are a test of the code of good practice on phytoremediation of OVAM.

PHYTO-INTEGRATED® Remediation: Expanding phytoremediation by combining engineering, treatment media & vegetation

Edward Gatliff¹; Frank Volkering²; Mike Mueller³¹ Applied Natural Sciences, Inc.; ² Tauw bv; ³ PeroxyChem Environmental Solutions

During the last decade, phytoremediation has become an accepted technology for cleaning up soil and groundwater contami-nants. Phytoremediation, as the ultimate “green technology”, is typically applied to shallow subsurface contaminations at sites with adequate space for the most suitable perennial plants to be installed.

To address deeper groundwater, Applied Natural Sciences, Inc. (ANS) has developed an engineered phytoremediation approach in which a hydraulic connection allows the trees to take up groundwater from target horizons in aquifers below – TreeWell® Technology.

Phytoremediation of groundwater contaminants is based on a combination of groundwater uptake by the trees, aerobic biodegradation by microorganisms in the tree itself (endophytic degradation), and/or in the root zone (rhizodegradation). Many of the common contaminants of concern (COCs), including aromatic hydrocarbons, MTBE, cDCE, and VC can be addressed this way. Several halogenated compounds including PCE, chloroethanes, and chloromethanes, however, cannot be degraded aerobically. One of the distinguishing features of this engineered phytore-mediation approach is that it also takes advantage of anaerobic biodegradation in the saturated column below the root zone.

Results data from several sites in the US and Europe will be presented. In several cases, data demonstrating the fate of the contaminant as it enters the TreeWell column and progresses upward through the saturated zone will also be presented.

In addition to site results, details will be presented on a new development that further expands the applicability of phytore-mediation to compounds with treatability issues, such as 1,1-DCA and Perfluorinated compounds (PFAS). With this development, phytoremediation is engineered to employ the treatment capabili-ties of materials such as zero valent iron (ZVI) which happens to be a material known to be able to rapidly dechlorinate a wide range of COCs. Other materials could also be utilized to address different compounds or compound groups. In this concept, the vegetation functions as a sustainable groundwater pump to draw ground-water from a well screened in a target zone through a replaceable cartridge, or filterpack, integrated into the well, in which primary decontamination or collection can take place.

Fate and distribution of pharmaceutically active compounds in mesocosm constructed wetlands

Alette Langenhoff¹; Yujie He²; Yu Lei¹; Nora Sutton¹; Huub Rijnaarts¹¹ Wageningen University & Research; ² Nanjing University

Accumulation of pharmaceutically active compounds (PhACs) in the environment and their risks to terrestrial and aquatic ecosystems at environmental concentrations (ng/l to μg/l) are confirmed by numerous chemical and toxicological studies. Removal of pharma-ceutically active compounds (PhACs) in constructed wetlands (CWs) is a promising technology, however a complex interplay of different processes. This study provides knowledge to understand removal mechanisms of PhACs in CWs and to enhance PhAC removal.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesThis presentation discusses the fate and distribution of seven PhACs (caffeine, CAF; naproxen, NAP; metoprolol, MET; propran-olol, PRO; ibuprofen, IBP; carbamazepine, CBZ; diclofenac, DFC) in mesocosm CWs will be shown. The effect of irradiation via pre-photocatalysis, substrate composition (mainly sediment) through addition of litter (dead plant biomass), and plants in lab-scale CWs will also be discussed.

Our experiments show that the CWs had a high removal for CAF, NAP, MET, PRO, and IBP (79-99%). All seven PhACs were detected in substrate and plant tissues as well as IBP intermediates. Estimated mass balance of PhACs in CWs showed that sorption dominated PRO removal while other PhACs were mainly removed by biodeg-radation and/or phytodegradation. Pre-photocatalysis significantly increased removal of PhACs except for CAF and IBP, and decreased accumulation of PhACs in substrate and plant tissues of the following wetland compartment. Litter addition in CW signifi-cantly enhanced removal of PRO and CBZ via biodegradation and/or phytodegradation. Plants played an essential positive role in removing PhACs, resulting from direct phytoremediation and indi-rectly enhancing sorption and biodegradation.

To conclude, our CWs showed a short start-up, and for most compounds a high and stable removal. The various processes, photodegradation, sorption, biodegradation, and phytoremedia-tion, all played an important role in PhAC removal. Furthermore, all PhACs and the IBP intermediates were detected in substrate and in plant tissues. Finally, irradiation, substrate composition, and plants can be optimised to further enhance the removal efficiencies by applying pre-photocatalysis, addition of dead plant biomass, and tailored composition of vegetation.

Use of organic amendment and endomycorrhizal fungi for steel slags phytostabilization

Mathieu Scattolin¹; Olivier Faure; Fernando Pereira; Steve Peuble¹ Mines Saint-Etienne

Steel slags are major by-products of the steel and iron industry. Particularly rich in metallic trace elements, these materials are mas-sively stored in slagheaps and can constitute potential nuisance for the environment and public health. Several studies [(Alvarenga et al., 2009), (Mench et al., 2010)] have shown the effectiveness of phytostabilization processes for rehabilitating sites contami-nated by high levels of metals, both because of their sustainable and ecological aspects but also due to their low implementation costs. Recent studies have indeed demonstrated the benefits of using indigenous AMF (Arbuscular Mycorrhizal Fungi) isolates for the phytostabilization of metal polluted soils (Lacercat-Didier et al., 2016) and alkaline mine tailings [(Orłowska et al., 2010), (Girid-har Babu and Sudhakara Reddy, 2011)]. The slagheap studied in this work contains approximately 500 000 tons of slags spread over an area of about 4 ha. A previous study (Bouchardon et al., 2014) carried out on the same site has demonstrated that the use of “Composted Sewage Sludge” (CSS) as an organic amend-ment favors the installation of metallophytes herbaceous species naturally able to grow on this type of substrate. In this work, we evaluated the coupled effects of CSS and AMF inoculation on : 1) the soil pore water composition and metals bioavailability and 2) the vegetation in terms of biomass production as well as accumu-lation of metallic compounds in leaves. Results showed that AMF inoculation led to root colonization and improved K and P uptake. We also observed that the CSS amendment has a critical role on plant growth by decreasing the fluid pH (from 10.5 to 8.5) and thus, the speciation of Al in the system. Indeed, geochemical modelling

run with the PhreeqC program (Parkhurst & Appelo, 2013) revealed that Al becomes soluble, and therefore toxic for plant develop-ment, at a pH higher than 9.

Co-remediation of Pb and PAHs with fungi in urban soil

Felipe Sepulveda Olea; Gillian MacKinnon; Caroline Gauchotte-LindsayUniversity of Glasgow

Organic contaminants and heavy metals are commonly found together as contaminants in urban brownfield sites. This project aims to develop a sustainable bioactive amendment that can immobilize heavy metals and support biodegradation of organic contaminants in soil, focusing in particular in reducing Pb bioavail-ability while supporting degradation of PAHs.

The formation of pyromorphite with phosphate amendments has been shown to be the most effective way of reducing Pb bioavail-ability. Recent studies have demonstrated that Paecilomyces javanicus, a fungus isolated from a Pb-contaminated soil, was able to grow in the presence of metallic Pb, and induce the formation of pyromorphite in a liquid media. Biodegradation of PAHs, by bacteria and fungi, is the most important process responsible for reducing concentration of these contaminants in soil. Pyromor-phite biomeralization by P. javanicus has not been tested in a soil matrix, and the availability of real contaminated soils, allows us to do so for the first time. In addition, the capacity of P. javanicus to biodegrade PAHs can be studied.

Culture experiments with P. javanicus were carried out to observe its response to Pb and PAHs (in the form of Phenanthrene).

ICP-OES analysis was used to study Pb concentrations in solution in the culture media over time, while a combination of SEM/EDX and XRD analysis will be used to identify biominerals within the fungal biomass and compare to abiotic controls.

Liquid-liquid extraction and HPLC analysis was used to study the concentration of Phenanthrene in solution in the culture media over time. To distinguish the contributions of biodegradation and adsorp-tion into the biomass, accelerated solvent extraction of the freeze dried fungal harvest, followed by GC-MS analysis was performed.

Spent grain from a local brewery was tested to assess its suitability for the inoculation and dispersal of P.javanicus in soil, in a laboratory scale experiment. By using sterile grain for the growth and inocula-tion, and non-sterile grain as an amendment in the soil, P.javanicus was successfully introduced and allowed to spread. Periodic moni-toring allowed the observation of fungal growth within the soil, and changes in the soil structure associated to this growth. The use of sequential extraction on harvested soil will allow comparison of Pb speciation between inoculated and non-inoculated soils kept under the same conditions.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologiesPhytoremediation: a practical guideline with decision tools for design, implementation, maintenance and monitoring

Karen Van Geert¹; Dirk Dubin²; Nele Weyens³; Mario Clemmens²; Sofie Thijs³; Nick Bruneel⁴; Catherine Lemmens⁴; Lieve Crauwels⁴; Griet Van Gestel⁴; Jaco Vangronsveld³¹ Arcadis Belgium; ² bio2clean bvba; ³ Hasselt University; ⁴ OVAM - Flemish Waste Agency

By using phytoremediation as a remedial technology, plants are used for the remediation of soil and groundwater pollution. Plants can contribute in different ways to the remediation of polluted soils and groundwater, for example by containment of the pollution on place by extraction of water (phytohydraulics), uptake and accu-mulation of pollutants, mostly heavy metals, in the tissue of the above-ground parts of the plant: (phytoextraction) or degrading the pollution by stimulation of processes provided by bacteria living in symbiosis with the plants (rhizo-/phytodegradation).

Phytoremediation is more than “greening” a classical remediation technology: it is a clear choice for a sustainable remediation alter-native: by choosing another concept, the environmental footprint of the remediation can be drastically reduced.

Until now, phytoremediation is only used to a limited extent in Flanders. Therefore a detailed guideline was made to assist reme-diation experts and authorities in the evaluation of the feasibility and the design of a phytoremediation concept.

The guideline is a state-of-the-art document based on collabo-ration between academics, and experts in remediation and phytoremediation. In this way expertises were combined into a practical and hands-on guideline.

The first part of the guideline includes a literature review with international state-of-the-art of the possibilities of phytoreme-diation, the different phytoremediation techniques in relation to type of pollutants, costs, feasibility tests, etc. In addition, different case studies were used to evaluate opportunities, bottlenecks, effi-ciency, lessons learned, costs, design criteria and results.

Based on the literature review and case studies, a practical guideline with a stepwise approach was composed:

- What information is needed to evaluate the potential of phytoremediation on a site? Evaluation of site characteristics, depth of pollution, …

- Is feasibility testing necessary (based on the type of pollution, remediation goals, the medium of the pollution (soil or ground-water)? What kind of feasibility testing is necessary?

- A decision tree was developed to decide on the type of phytore-mediation and possibilities.

- Design criteria per type of phytoremediation are described.

- An overview of monitoring and maintenance criteria for the evaluation of the remediation goals is given.

- Fact sheets with a comprehensible summary per type of phytoremediation are included in order to be used in commu-nications with clients and other stakeholders.

By means of multiple case studies, the guideline and specific tools will be further demonstrated. The guideline is implemented in the regulatory framework in Flanders, and soil experts need to follow this guideline for soil remediation projects that include phytoremediation.

The aim of the presentation is to give insight in the different tools and decision trees that are included in the guideline to help in the

decision, design, implementation, maintenance and monitoring of phytoremediation projects. The guideline will be available in English.

Sustainable organic subproducts to enhance denitrification in constructed wetlands treating highly nitrate polluted leachates from nurseries

Marc Viñas; Miriam Guivernau; Assumpció Antón; Francesc X. Prenafeta-Boldú; Anna Puerta; Oriol Marfà; Rafaela CáceresInstitute of Agrifood Research and Technology (IRTA)

Agricultural NO3- discharges is a major form of nitrogen spread in the soil and subsurface environment, causing significant damage to humans and aquatic ecosystems. Nitrate content is clearly exceeded in the leachates from horticultural nurseries and the groundwater from horticultural and agricultural activity zones.

Constructed wetlands (CW) has been suggested as a sustainable bio-based solution. In CW, the utilization of sustainable, stable, and cost-efficient organic electron source is crucial to enhance deni-trification treating horticultural leachates. However, the effect of complex organic-based additives (liquid or solid), on denitrifica-tion and physiology and dynamics of native microbiota from CW, is scarcely known.

Initially, the effectiveness of brewery effluent as alternative organic subproduct to enhance denitrification on gravel-based planted horizontal subsurface flow constructed wetland (HSSF-CW), which was set aside a plant nursery, was assessed at field scale. The microbial hydrolysis and fermentation products from brewery effluent (BE) generated were the organic electron source to boost denitrifying activity of leachates inside the CW. An efficient and complete denitrification of leachates (200-350 mg NO3- L-1) was achieved, with nitrate removal of 75-99% , equivalent to 3-8 mmols NO3- · m-2 h-1 or 0.026 mmols NO3- h-1 L-1, when brewery effluent was amended. High throughput sequencing of CW micro-biota revealed that active denitrifying populations were settled up on the gravels in the bottom zone. Currently, the utilization of alternative solid-based organic electron sources as a sustainable alternative is being assessed at lab scale and field scale. Interest-ingly, rice straw and wood pellets materials, improve three to five times the denitrification rates (0.065-0.117 mmol NO3- h-1 L-1) respectively, compared with those achieved with brewery effluent. Microbial populations assessment was conducted by miniaturized Most Probably Number (MPN) to quantify viable anaerobic and aerobic heterotrophic populations, and by qPCR of functional genes linked to microbial denitrification (i.e nosZ) to quantify denitrifying populations. Additionally, both high throughput sequencing tech-niques (16S-Miseq) and qPCR of functional genes was performed to deeply assess the whole microbial community diversity, and to identify key metabolically-active denitrifying bacteria throughout the water phase and biofilms of CWs. The results revealed the importance of microbial diversity attached to biofilms (wood and gravel materials) to better understand the performance of CWs

The utilization of solid electron-sources, such as straw and wood pellets, seems to be an attractive and sustainable alternative to enhance denitrification and other reductive-based biochemical pathways to treat pollutants from oligotrophic water, such as leachates and groundwater, in CWs.

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Thematic Session (ThS) – Topic 4 Advances in remediation technologies

mechanisms are responsible for the removal of tower water frac-tions that hamper physicochemical desalination? The removal of conditioning chemicals, such as corrosion inhibitor benzotriazole and biocides glutaraldehyde and DBNPA will be discussed. In addi-tion, we will discuss the removal of relevant bulk water quality parameters, such as TOC, TP, NO3, TSS and EC; ii) How is the micro-bial activity in the hybrid-CWs influenced by biocides? Biocides DBNPA and glutaraldehyde show serious potential to hamper biological processes in a CW; iii) How does the climate in Western-Europe influence the functioning of the hybrid CWs? Seasonality affects the biodegradation and plant uptake in the hybrid-CW; iv) Is a combination of different CWs needed for optimal removal? A combination of different CWs has shown to optimize the removal efficiency and mitigate potential problems with biocide toxicity.

Comparison of four soil remediation techniques applied to trace elements contaminated soil: a three-year field experiment

Xiaoming WanInstitute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences

Due to high risks of metal(loid)s contaminated soil to human health, the remediation or management of contaminated farm land receives increasing attention from all over the world. The current study compared the remediation efficiency of several remediation techniques on the same piece of land. The farmland is contaminated by earlier mining activities, containing excess amount of arsenic (As), cadmium (Cd) and lead (Pb). Phytoex-traction, intercropping of hyperaccumulators and cash crops, chemical immobilization, plow and mix were selected as the main techniques. The metal(loid)s concentrations in soil, crops, and its distribution in solid and liquid phases were monitored throughout the whole 3-year field experiment. The remediation efficiency was mainly evaluated from the aspects of yield and metal(loid)s concentrations of crops. The costs of these techniques were also compared. The results can, on the one hand, provide information for the land owners or utilizers to select appropriate techniques, and on the other hand, give a clue on how to improve the efficiency of current soil remediation techniques.

Hybrid constructed wetlands for the pre-treatment of cooling tower water prior to desalination

Thomas Wagner¹; John Parsons; Alette Langenhoff; Pim de Voogt; Huub Rijnaarts¹ University

The intake of fresh water for cooling processes accounts for a signif-icant part of the total fresh water uptake in industrial countries. The reuse of discharged cooling tower water in the cooling tower itself could significantly mitigate future fresh water scarcity problems caused by industrial fresh water withdrawal. Discharged cooling tower water has a moderate electric conductivity (EC) of 1500-4500 mS/cm, while an EC of < 1000 mS/cm is typically required for reuse in cooling towers (Groot et al., 2015). Hence, reuse of the cooling tower water in the cooling tower itself requires desalination, which is often done by physicochemical processes. However, physico-chemical desalination of the cooling tower water is hampered by different fractions of the cooling tower water, such as TOC, phos-phates and manually added conditioning chemicals (Lowenberg et al., 2015). These conditioning chemicals, such as biocides, corrosion inhibitors and antiscalants, are used to prevent fouling, corrosion and mineral scaling of the water circuit. The removal of these condi-tioning chemicals and the other fractions prior to physicochemical desalination could enhance the desalination efficiency.

A potential method to remove these conditioning chemicals prior to physicochemical desalination is the use of constructed wetlands (CWs). CWs are man-made wetland systems that make use of natural removal mechanisms, such as adsorption, photo-degradation, biodegradation and plant uptake, for the removal of contaminants from water (Garcia et al., 2009). The dominating removal process in a CW is determined by its water flow. A distinc-tion is made between horizontal subsurface flow (HSSF), vertical subsurface flow (VSSF) and surface flow (SF) CWs. A potential way to enhance the CWs efficiency is to combine multiple CW flow types in one CW train to make optimal use of each CW type its advantages. These combined CWs are called hybrid-CWs.

To determine the applicability of CW pre-treatment prior to cooling tower water desalination, we constructed pilot hybrid-CWs consist-ing of a SF, HSSF and VSSF compartment. These CWs were fed with synthetic cooling tower water and were ran for 9 months. In this oral presentation, we will address the following topcis: i) Which removal

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

of copper sulphide ores and disposed on the ground surface throughout the province. Tailings have been lying in their disposal sites for a long time and no observable reclamation has been carried out. Exposed tailings at these sites may release potentially toxic elements into ground and surface water. In the Copperbelt Province, approximately 10,000 hectares of land are impacted by tailings disposal and most of it is in the proximity of the local community, access roads, and surface waters such as streams. Samples were collected from three different locations in Luanshya, Akatiti dam and Kitwe town with two locations at Uchi and Matindale dams. Leaching tests using the pH dependent leaching method (USEPA M1313) and mineral characterisation (XRD) were undertaken to evaluate the materials for PTE availability. Coupled contaminant transport and geochemical speciation modelling (LeachXS) is under way to evaluate leaching of PTEs across a range of environmentally relevant conditions. This work to understand contaminant characteristics represents a first step towards devel-oping a comprehensive remediation strategy for mine tailings sites in the Copperbelt Province.

Sustainable remediation in the Latin American context

Joyce Cruz Di Giovanni; Oliver Maurer; James Henderson

Currently in Latin America the topic of sustainable remediation has been treated and discussed by several working groups among environmental consulting companies, universities, environmental agencies and industry. In face of this scenario the group NICOLE Latin America and the Brazil Sustainable Remediation Forum (SURF) noted the need to develop a technical document that would help all those involved in the discussions about the subject.

The challenge of the NICOLE Latin America and SURF group during the last two years was to develop a White Paper explaining this subject and its Latin American specificities. Innumerable factors favor the countries and its people, but they are counterbalanced in all cases by dogged circumstances out of the control of the majority of the countries’ inhabitants. The natural resource base of Latin America alone could supply the world’s food and potable water needs for the next 20 years. Growing populations, vibrant economies, and cultural singularities renowned the world-over have place Latin America squarely within the world’s conscious-ness as a growing global force to be reckoned with (NICOLE Latin American, Sustainable Remediation White Paper, 2018).

But, as every inhabitant of the region will tell you, there are problems. Though not a focus of this paper, the many economic and political difficulties, and especially the countries’ infamous levels of corruption, do not detract from the importance of its primary focus: revitalization and restoration of the contaminated areas.

After decades of work in North America and Europe, it is well-known that initial efforts in those regions, focusing on restoration of contaminated areas, were largely misguided. A new method-ology has taken hold and is increasingly at the forefront: the use of green and sustainable remediation practices that have as their fundamental tents not only environmental, but also, societal and economic gains.

The Sustainable Remediation Whitepaper presented here comes at the realization that more established sources of information,

ThS 5b | Remediation goals and strategies

Using lower threshold limits as a stop criteria to prevent overdoing remediation. When is it good enough?

Jacob H. ChristiansenCOWI A/S

Sharing thoughts on sustainable remediation. We experience, while cleaning up hundreds of sites, that overdoing remediation might lead to a negative gain for the environment. A way to avoid this is using lower threshold limits for insignificant contamination.

In Denmark, the regulations on contaminated soil and ground-water are rather comprehensive and well established. This is in particular true when it comes to contamination from privately owned oil tanks for domestic heating.

The Danish EPA has made detailed guidelines and rules for investi-gation and remediation. The guidelines are based on best practice from more than 1,400 remediated sites of this kind. Because of the well-known pattern for contamination from heating oil, the EPA has added a new feature: A lower threshold limit for hydrocarbons in the subsurface (10 kilograms) to prevent overdoing remediation of insignificant contamination. The limit is based on mass, and not on concentration.

The presentation shows how and when the lower threshold limits can be used, and how it has affected the way we now remediate in a slightly more sustainable way. Examples from the EPA guidelines and from actual cases where the threshold limits have been used resulting in site closure, will be presented.

The threshold limits are a way of ensuring that we are not using excessive resources on contamination that are not really posing any environmental risk.

As resources are limited and global warming a growing concern, we need to justify, that any remediation is actually necessary. That the use of resources and the negative environmental impact of a full clean up project can be justified. As this assessment is often quite complicated, we could use lower threshold limits based on mass. If we only focus on concentration limits, we might overdo it, and we might actually make more damage to our environment than protecting it.

Understanding potentially toxic element mobility as a first step toward remediation and restoration of land occupied with copper mine tailings

Precious Chisala¹; Christine Switzer²¹ University of Strathclyde; ² University of Strathclyde, Glasgow

Mining activities generate large amounts of waste that are detri-mental to health and the environment. The history of mining in Zambia dates back to the 1920s and, from its inception, more than 791 million tonnes of copper mine tailings have been created country-wide. The development of disposal practices for solid waste did not consider effects waste may impose on the environ-ment and for this reason, just like in many mining operations in the world, mine waste in the Copperbelt Province included discharge of tailings into rivers, streams and on land. Mine waste affects surface and ground water quality and causes air pollution. This research focuses on the remediation of mine tailings from the Copperbelt Province of Zambia that were generated from the flotation process

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

Challenge: Government, problem owner of a not usable blackfield

Solution:

A land bank equals the gains and losses for all the public owners of the different grounds on the site. A division into 3 separate financial phases minimizes risk. Subsidiaries are creating a financial feasibility of the redevelopment project. All this results in an appealing project for private investors and credit institutions. The implementation of all of the above in a flexible tender procedure, the “competitive dialogue”, combining an objective, open evalua-tion with the possibility of integrating the ideas of the participants, resulted in a a solid public private partnership and beautiful long-term project.

From stand-and-hold towards enhanced bioremediation: bioremediation and 3d modelling at a former manufactured gas plant in Utrecht, the Netherlands

Suzanne Faber¹; Lisanne Keijzer²; Johan Van Leeuwen³; Jan Gerritse³; Tim Grotenhuis²; Ruud Schotting¹¹ Utrecht University; ² Wageningen University and Research; ³ Deltares

The Griftpark

Between 1840 and 1960 manufactured gas factories were situated at the edge of the city of Utrecht. During the manufac-turing process, coals were heated to produce town gas. This also created waste products, including aromatic compounds (e.g. BTEX, PAH), aliphatic compounds (e.g. mineral oils), as well as inorganic compounds (e.g. cyanide). These products made their way into the soil and groundwater. After the factory was closed, by the 1980s, Utrecht had grown so that the site became situated in the city centre. The neighbourhood pressed to have the site redevel-oped as a park. Much to the frustration of the neighbourhood, the contamination at the site was found to be of such an extent that full remediation was too costly. Instead, to protect neighbouring residents, the municipality used a stand-and-hold management technique, implementing a cement-bentonite wall around the site, to the depth of a 55 meter deep clay layer that divides the first from the second aquifer. A clean top layer was applied and the site transformed into a public park. The clay layer, however, contains ‘holes’ and is therefore not completely confining. This causes a risk of contaminants leaking into the second aquifer that is used as a source for drinking water downstream. Currently, groundwater is pumped from the top aquifer, to create a seepage from the 2nd into the 1st aquifer, aiming to protect the 2nd aquifer from contam-inants that are transported with the groundwater. This measure is costly and does not remediate the soil, so that it needs to be continued eternally.

Bioremediaton and modelling at the Griftpark

In 2006, laboratory experiments showed that soil bacteria are able to degrade organic contaminants, even when high concentrations of pure product are present. Around the same time, biodegradation of organic contaminants was observed in aerated groundwater from the Griftpark. Following these developments, the Municipality of Utrecht has commissioned a consortium (Utrecht University, Wageningen University and Deltares) to sketch scenarios for finite aftercare of the Griftpark. The research comprises a combination of field study, laboratory experiments and computational modelling, with the aim to provide an answer to the question whether (stimu-lated) bioremediation is a feasible method to control groundwater contamination at the Griftpark.

largely generated by North America and Europe, do not suffice solely as the expertise needed within a South America context. The document has been elaborated in collaborative fashion with experts from afar, but it is strictly regional, in every sense. The authors hope this document, in so much as it serves as a robust treatment of the technical subject matter involved in Sustainable Remediation in Latin America, is helpful to all affected stakeholders involved in remediation projects.

This presentation will introduce the highlights of the Latin America White Paper and the significant challenges that exist in sustainably remediating contaminated areas in regions like Latin America.

Blue Gate Antwerp

Wolf DepraetereDEME Environmental Contractors

The Blue Gate Antwerp site first developed in 1902 for the purpose of a cluster of petrochemical activities. At its height, it was one of Europeans main gateways for petrochemical products. The rich history is tangible in the relics as the rusty network of overhead oil pipes, giant oil storage tanks. But this petrochemical history comes whit a price. The site is highly polluted on top highly water-logged, creating an overflow risk for the residentials and the surrounding area. Cityof Antwerp, the former owner of the site and thus the liable party of the historical passive of the site wants to redevelop this site to a 100ha to a sustainable innovative business park. The solution is multiple and will be presented in 3 interlinked presentations

Presentation 1: Reuse of soil creating land for the future.

Challenge: polluted and waterlogged site, not fit for use as a business center

Solution: The remediation approach consisted of an excavation and soil treatment. In order to tackle the waterlogged site, a significant land raising is necessary, hence creating an extra soil layer and so mitigation of the humane risks of the pollution. On top of that, land raising creates the possibility to reuse excavated soil from the site, reducing the impact of transport on the environment. A framework for re-use, based on a complex 3Dmodel ensures the boundaries of the legal framework are to be respected.To ensure the risk-based remedial goals will not create a risk, a site specific quick-test has been developed.

Presentation 2: Land and soil creating a sustainable ecology

Challenge: Creating a business park as an ecology on its own and interconnecting with the environment.

Solution:Sustainability based selection criteria for future residents creates an environment where companies find themselves surrounded by like-minded companies. A park management facilitates an interaction between companies, businesses and academics, and so decreases cost, minimizes ecological footprint. A heating network the exchange of energy between residents stimu-lates the use of green energy. A 15 ha green corridor creates green space for commuters and local resident, as well as a extended biotope by connecting the adjacent nature reserve and the green girth enclosing the city center.

The historical heritage, i.e. the pipelines will be restored and inte-grated in the site infrastructure.

Presentation 3: What defines the value of the real estate ? Location, location and … processes

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

• Improved certainty and confidence in remediation outcomes.

The purpose of the NRF is to:

• Establish a nationally consistent approach to remediating and managing contaminated sites;

• Provide practical guidance for those who remediate and manage contaminated sites; and

• Educate and inform government, industry and the community about the issues.

The objectives of the NRF are to:

• Protect human health and the environment;

• Facilitate more effective and efficient remediation;

• Provide net community benefit (including consideration of the broader economic context).

The NRF comprises two principal areas:

• Philosophy, including context and principles; and

• Practice, including practical guidance.

The principles are based on Australia’s Inter-Governmental Agreement on the Environment (1992) and reflected in its state and territory environment protection legislation.

The framework comprises modules and guidelines (24) for the development and implementation of remediation action plans, and for post-remediation matters, including residual contamination.

Chlorinated solvents and redevelopment of an industrial site: the importance of characterisation in the definition of an appropriate treatment strategy

Kenneth JONESERM France

The need to better characterize subsurface media in an area of significant chlorinated solvent impacts (including presence of free phase) and to review previously proposed (and regulator-agreed) management measures generated a technical and administrative challenge for the owner of an industrial site in the context of the sale of their land for redevelopment.

A better characterization of the vertical and horizontal distri-bution of the sub-surface impacts at the site (soil cores, “MIP” borings, multi-level groundwater monitoring wells, analyses of soil, groundwater and soil gas, video inspections of networks), together with a multi-phase extraction field pilot test, led to the rethinking of the treatment strategy for an area heavily impacted by Trichloroethylene.

A better understanding of the subsurface conceptual model also allowed the definition of new treatment objectives which were both technically achievable and protective of identified sanitary and environmental risks. The new goals were accepted by the regulator.

The modified strategy, based notably on an aggressive phase of multi-phase extraction, has been implemented on an active production facility concomitant with the site’s own works as part of preparations for the demolition of buildings. The defined remedial objectives were achieved in a short period of time compatible with the overall site redevelopment schedule. The overall approach can be applied to other areas of the same site as part of their future redevelopment.

In our presentation we will go into detail about the research questions and methods used in this project. We will present the implications of heterogeneity of the subsoil through our 3D hydro-geological model and our understanding of the local natural attenuation processes and opportunities for stimulation. We will explain how these results are integrated into a reactive transport model that will enable us to forecast the feasibility and safety of potential future scenarios at the Griftpark, as well as other similar sites worldwide. Furthermore, we will explain the economic and environmental benefits of transitioning from the stand-and-hold technique to monitored natural attenuation and discuss the social aspects of the redevelopment of a site that is situated in such a central part of town.

Australia’s National framework for the remediation and management of contaminated sites in Australia

Joytishna JitCRC CARE / University of South Australia

Australia’s National Remediation Framework (NRF) provides a nationally harmonised approach for the remediation and manage-ment of contaminated sites in Australia. The draft framework was released for consultation in 2018, and is on path towards finali-sation by May 2019. The development of a national framework for remediation and management was and is supported by site contamination regulators, practitioners and industry.

The NRF complements Australia’s assessment framework, the National Environment Protection (Assessment of Site Contamina-tion) Measure (ASC NEPM). The ASC NEPM was first published in 1999. Given that issues related to remediation and management of contaminated land are common throughout Australian juris-dictions it would be expected that policy, procedures and best practice would be characterised by a degree of uniformity and consensus. This national framework for remediation and manage-ment of contaminated sites codifies existing practice and enhances guidance for best practice remediation and management. The three modules of the framework are:

• Development of Remediation Action Plans (including remedia-tion objectives)

• Implementation

• Post-remediation issues (including residual contamination issues)

Harmonisation of approach and best practice will not only yield commercial benefits but also provide governments and the public an assurance of consistency and competence in the remediation and management of contaminated sites.

A harmonised national approach supports:

• Ready transfer of best practice among jurisdictions

• Use of national expertise across jurisdictions, thereby improving overall standards over time

• Cost efficiencies for remediation

• Common remediation language across jurisdictions

• Training efficiencies, including the ability to ensure that all practitioners meet a recognised professional standard, enhanced workforce mobility and mutual recognition of skills, and enhanced recognition of the contaminated sites profes-sion; and

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

Governance strategies for finalizing contaminated areas

Geert Roovers¹; Ron Nap²¹ Saxion University of Applied Sciences, Enschede/Deventer; ² Municipality of Apeldoorn

Last decades all over the world contaminated areas are detected and (partly) cleaned. Due to lack of resources, such areas were not always fully cleaned. In these cases the contamination was isolated and monitored in such a way that health risks were minimalized and a desired, restricted, use of these areas was still possible. In the Netherlands the estimated amount of such locations is appr. 500. The costs of managing these areas are estimated at at least ca. 10 million euros per year.

These areas with an isolated and monitored contamination are getting more and more interesting for redevelopment. The areas are often located in, or nearby, cities, where economic growth, urbanisation and demographic development make space more and more scarce. Furthermore, these areas are often old industrial areas, which are becoming attractive spots for innovative ways of living, working and recreation. Finally, adaptation to climate change and the desire for healthy cities enlarge pressure ask for new ways of using such areas. Added to the above mentioned costs and new technological, biological en chemical development in the last decades, these developments urge involved actors to come to finalizing the existing management of the contamination, remove the remaining contamination and redevelop the area for new functions.

Despite these urgencies, in the Netherlands this finalizing moves slowly. Therefore, to stimulate finalizing, various public and private actors initiated action-research to detect barriers which hamper the finalizing. From that, they have compiled the newest insights in urban governance and technological developments into nine practical and feasible governance strategies to come to a successful finalizing of these contaminated areas and successful redevelopment of the areas. These strategies consist of elements of communication, urban development, organisational changes and technological innovations. Dependant on the characteristics of an area and its spatial and administrative context, a specific combi-nation of strategies can be applied. The strategies serve as an aid to the owners, managers and developers of such areas. In this proposed article we will describe the barriers which hamper final-izing, present the governance strategies and detect under which circumstances combinations of these strategies can be successful. Finally we focus on the competencies of involved actors, needed to put these strategies into action and realize redevelopment and finalization of contaminated areas. The article will be describe several examples of such areas and the used strategies.

Evaluation of the key success factor of complex remediations based on a case study: “The Mariakerke acid tar dumpsite, Belgium”

Joke Van De Steene¹; Tom Behets²; Stefan Van den put³; Carl De Cock⁴¹ DEME Environmental Contractors; ² OVAM - Public Waste Agency of Flanders; ³ Sweco; ⁴ Sustaineer

In Mariakerke near Ghent (Belgium), bordering a residential area, lies a domestic landfill in which acid tar was dumped in the 70’s. Acid tar is a hazardous waste which originates from the historical production of, in this case, white oils through the use of concen-trated sulfuric acid in the refining process. The mainly solid to pasty acid tar of the landfill is very corrosive due to its low pH, and toxic due to the presence of sulfur dioxide and high levels of petroleum

Sustainable risk management and remediation strategy for a large 21 ha urban brownfield site

Juha Parviainen; Jarno Laitinen; Ari Simonen; Jukka HuppunenRamboll Finland Oy

Härmälänranta is an old industrial area in Tampere (Finland), which is currently undergoing a transformation into residential use. In all, the former industrial area is 21 ha in size. The site has served in indus-trial use from 1936 until 2013. In the early years an airplane factory served in the area, and over the following decades the operations expanded, and versatile workshop and assembly industry were in operation (e.g. trains, trams, metros). During these industrial activi-ties large amounts of oils, metal cleansers and coating chemicals, paints and metal machining fluids have been used. Contemporary master plan of the area became effective in 2014 and the area has been in a state of constant development ever since.

Due to the heavy industrial history, numerous soil, groundwater, soil gas and indoor air investigations have been carried out from 2005 until today, as part of the redevelopment. After the industrial operations ceased in 2013, large-scale demolition of old industrial buildings took place and was followed by extensive soil remedia-tion by excavation and in situ methods. In addition, three separate groundwater remediation pilots were conducted to find feasible technologies for the remediation of chlorinated solvents and oils from the groundwater and engineered solutions for sub-plate vapor intrusion mitigation were tested to develop additional risk management tools for building construction design. The presently redeveloped area is 14 ha in size and it will be home for approxi-mately 3 000 people.

To find the most sustainable strategy for site risk management and remediation, the land owners and developers contracted a consortium of consultants led by Ramboll to engage the regulators and other stakeholder to draft a site plan based on the principles of sustainable risk-based land management (SRBLM). The plan was concluded and agreed upon in 2018 and immediately imple-mented in the site redevelopment.

The strategy for site risk management and remediation integrated the time frame for the redevelopment, under which risk, priori-ties and effects were considered and the choice of management solutions, with assessment of benefits, costs, environmental effects and social acceptability. The decision process also considered the three main components of SRBLM: fitness for use, protection of the environment and long-term care. The actual plan included elements of land management, risk management and remediation to provide a comprehensive toolset of sustainable approaches for adaptive site management.

The presentation will include three main elements: it will introduce the complex brownfield site being one of the largest brownfield development projects in Finland, it will also describe the multi-disciplinary and -stakeholder process for preparing the sustainable risk management and remediation strategy for the site, and in conclusion, outline the content of the site strategy and the key elements included. The presentation will also discuss in a broader context the dilemmas of sustainable redevelopment and land stewardship in practice, as they often contradict with the legisla-tive, contractual and financial aspects of property development.

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

an estimated 2300 managed engineered sites have been built, where in 200-300 cases eternal hydrological measures are active. While containment measures are meant to endure for eternity, the components - sheet piling, slurry walls, groundwater pumping and treatment systems - need on top of regular monitoring and maintenance replacement every 10 to 40 years and are therefore costly to maintain. Moreover “impermeable” walls, in cases are not as impermeable as envisioned on forehand and outward fluxes are feasible.

At the time of construction of these engineered management measures, little was known on anaerobic biodegradation of contaminants in the subsurface. Although still a lot of unknowns last, in the last decades a lot has been published on anaerobic biodegradation in the environment. With these new insights the time has come to re-assess formerly implemented constructions and the way these sites are managed.

To assess the level of management at engineered managed contaminated sites methods were derived to address: 1) ground-water behavior and contaminant transport effects with and without hydrological barriers and groundwater extraction, 2) demonstration of intrinsic biodegradation, 3) biostimulation, and 4) bioaugmentation concepts.

The objective is that this approach leads towards less or no ground-water extraction and treatment, without risks to the environment.

In this presentation we will guide you through the pros and cons of original designs of typical containments and prospects on extensi-fying current measures.

Intensive historical review and sampling campaigns to validate potential hotspots of sediment pollution linked with (former) risk activities

Karen Van Geert¹; Carlo van den Berg²; Dorien Gorteman¹; Goedele Vanacker³; Jan Dewilde³; Katrien Van de Wiele³¹ Arcadis Belgium; ² Arcadis Netherlands; ³ OVAM - Flemish Waste Agency

Sediments are an integral part of nature and aquatic systems. Contaminated sediments have adverse effects on people, the envi-ronment and the economy. OVAM is actively involved in building a pragmatic sediment pollution policy based on source control. In the first phase a desk study was performed. This study resulted in the identification of a list of (former) risk activities with a high potential for sediment contamination. Subsequently, validation of potential hotspot risk activities was performed on more than 100 sites, where a stepwise approach of intensive historical desk study was combined with sampling in the field. The desk study and the validation study provided insight in the impact of sediment pollution in Flanders and will help to define a policy strategy on contaminated sediment.The desk study for the identification of potential hotspots is based on previously conducted research, emission figures and expert judgement. The study revealed the (former) industrial activities which have the most potential to cause sediment contamination. This knowledge was converted in a tiered selection approach to identify locations for validation.4 key factors : Cadastral plots: to identify and locate the hotspots / Risk activities - activities with a relatively higher risk for sediment contamination: to identify (former) industrial sectors: gas plants, tanneries, paper mills, wood preservation, etc / The start date of the environmental permits: to gain insight into historical develop-ment / The number of risk activities and ‘environmental permits’ - related to a cadastral plot. With the available data and criteria, prioritizing potential hotspots is possible in multiple ways: intrinsic

hydrocarbons. Especially the potential for high emissions of sulfur dioxide during excavations and treatment are an important point of attention for future remediation works. The site is part of the nature reserve ‘The Bourgoyen’, partly property of the City of Ghent and partly property of Natuurpunt, an independant organisation of volunteers with the goal of preserving and protecting vulnerable and endangered nature in Flanders.

Since the 80’s several soil investigations were performed and different attempts to launch a remediation have not lead to a solution. By the end of 2016 the Flemish environmental authori-ties OVAM decided to launch two public tenders with the aim to unblock the situation. Two parallel studies were launched: one for the realization of pilot and lab-scale tests and one for the integra-tion of all known aspects into a balanced techniques appraisal and soil remediation project. DEC was selected for the first and Sweco, together with their subcontractor Sustaineer, for the latter.

From the start it was decided to perform the parallel studies in close cooperation between parties and to integrate the constraints and performance indicators perceived by external stakeholders such as ‘The Bourgoyen’ and the neighbourhood. DEC and Sweco therefore started with a joint literature search on acid tar treatment worldwide, a market consultation on innovative techniques and an identification of knowledge gaps to be filled in order to provide a sound technical evaluation.

In April 2017 DEC started with a sampling campaign on site during which 9 trial pits were dug. Representative samples of acid tar, acid tar/soil mixtures and construction waste, were taken and used for a lab-scale feasibility study. During the lab trials, the technical feasi-bility of acid tar stabilisation & solidification, and the production of an alternative fuel for cement kilns or power plants, was confirmed. Recipes were developed for full-scale execution.

The results so far, further demonstrated that the more innovative technologies such as bioremediation using Archeae, and pyrolysis of acid tar to produce liquid fuel, were not applicable.This first assessment led to a preliminary MCA (multi criteria analyses) and a description for the execution of the on-site pilot trials. In preparation and during the execution of these pilot trials, input of Natuurpunt and the neighbourhood has been gathered and included in the approach.

Based on the additional information and stakeholder input gathered during the pilot trials, the MCA was updated, and a soil remediation project will be drafted for final execution of an envi-ronmental issue which has been waiting for a solution for almost half a century.

From contaminated site containment and pump and treat, towards less intensive site management through biodegradation

Johan Van Leeuwen¹; Jan Gerritse²¹ Deltares; ² Deltares, The Netherlands

Remediation during the 1980s was mostly executed by dig and dump or incineration of contaminated soil. Since then a multitude of techniques for in- and ex-situ cleanup were developed. However large and complex sites, such as closed landfills and former industrial sites were due to high cost rather contained by hydro-geological measures than remediated.

Engineered site containments were usually executed by installing impermeable vertical or horizontal barriers in combination with groundwater extraction and monitoring. In the Netherlands alone

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects(gas factory always above a paper mill), historical (brownfields), size (large industrial sites) etc. A research and sampling campaign was performed to verify the results of the study and evaluate and refine different prioritizing methods. Method 1: The hotspots were classified into different scores. 43 sites with the highest scores were examined. 2/3 of the selected sites were correctly identified as a potential hotspot. Contamination of sediment could often not be verified (waterway vaulted, historical course altered). Method 2: To increase the percentage of correctly identified hotspot a few non-specific and very common risk activities were excluded. The Vlarebo-nomenclature as used before 2008, was added to the data to increase the likelihood of capturing “old” industrial sites. Catego-rizing the locations based on scores makes it easy to point out top priorities (2-3 % / ±300 sites) and provides for policy and decision makers the ability to consider aspects like: resourcing, budgets and planning. Because the method results in a geographical data file, the information can be easily linked with other databases. We can integrate our ‘hotspots’ in the sediment monitoring network and dredging database of the Flemish Environmental Agency (FEA). Vice versa, our method can be verified and calibrated, using practical data of the FEA. The presentation will give insight into the methodology, desk study, prioritization criteria and results of intensive validation campaigns.

A Management Strategy to deal with Soil and Groundwater Contamination

Sandra Vasin¹; Hermann Josef Kirchholtes¹; Grzegorz Gzyl²¹ City of Stuttgart; ² Central Mining Institute

Common challenge of many cities in Europe is that natural resources are endangered due to soil and water pollution. Despite carried investigation and remediation measures over decades and current practices of environmental management the soil and groundwater are still remaining polluted. In complex hydrogeological systems, where contaminated plumes are overlapping, technical and administrative activities have to be thoroughly planned and have to be run in a long term. Therefore a sustainable and realistic plan is necessary to be developed.

This “management plan” consists of three basic elements: (i) descrip-tion of flow and contaminant situation and related processes; (ii) definition of target values to be kept or achieved in the future and (iii) definition of necessary measures in soil and groundwater to achieve the targets. The management plan is thus a program for sustainably improving the groundwater quality in the future. Its implementation is secured through early involvement of the responsible authorities and their contribution to the development of the management plan. For that purpose key stakeholders (land owners, polluters, residents, consultants, etc.) are to be involved, as well.

Building on these requirements, the management plans in the AMIIGA project are developed for seven pilot areas in six Central European countries. Diverse local conditions, such as hydrogeo-logical situation, groundwater use, type of contamination, target values, goals, legal frameworks, responsibilities, are influencing the development of each management plan. Despite those diversi-ties, the management plan has been proved to be an appropriate and flexible tool for planning, coordinating and implementing necessary measures for large-scale groundwater contamination.

A major focus of management plans is definition of target values. They have to be defined according to legal aspects in each country. However, the targets have to be realistic and reachable as well. To find a balance between targets in legislations and realizable targets

is a challenging task that is differently solved in different pilot areas. Another important focus of management plans is clarification of responsibilities and securing funding. The management plan is an action plan for at least 5 years, with clearly defined responsibilities, knowledge management (data, information and know-how) and cost estimation.

Based on gained knowledge and experience from all seven manage-ment plan developments, a shared Management Strategy to deal with groundwater contamination is developed. The Management Strategy is a guidance for setting up management plans and initia-tion of its implementation. It comprises legal framework, elements of management plan, procedure, definition of targets, involve-ment of stakeholders and examples of realization (good practices and obstacles with their ways of solution). It is a valuable tool that gives authorities a good basis for the future work in protection of groundwater.

This study was performed within AMIIGA Project (Integrated Approach to Management of Groundwater Quality in Functional Urban Areas), financially supported by the program INTERREG Central Europe 2016 - 2019.

A digital explorer for contaminated stream sediments

Karolien Vermeiren¹; Bastiaan Notebaert¹; Katrien Van de Wiele²; Ward De Cooman³¹ VITO; ² OVAM - Flemish Waste Agency; ³ VMM (Vlaamse Milieumaatschappij - Flemish Environmental Agency)

In Flanders, stream sediment quality data are collected by different local and regional authorities for different purposes. For the decision making on further examination, remediation and/or management of sediments, a web-based spatial modelling tool was developed that collects data from the different authorities. The modelling tool accounts for data on the level of contamination at measurement locations as well as spatial data mapping the potential environ-mental risk and potential for remediation when contamination occurs. Bringing together data of different authorities has resulted in a collaborative approach that allows for a common toolset for remediation and/or management of sediments.

The model weights a set of variables – both technical as envi-ronmental – based on their potential risk of contamination and the potential for remediation. These variables are derived from (i) sediment quality measurements (physicochemical quality, biological quality, ecotoxicity), spatially explicit assigned to stream segments and (ii) spatial databases on environmental aspects which are publicly available in Flanders or derived from the ‘Ruimte-Model’. The ‘RuimteModel’ is a dynamic spatial toolset that disposes of a large spatial database on land use aspects in Flanders at high spatial resolutions. Based on this, a variety of spatial applications are carried out such as land use change simulations, optimizations and allocations.

The model calculates a weighted score for the remediation priority of streams (thus based on pollution and remediation potential) based on the relevant technical and environmental variables for all stream sediments (i.e. each stream segment) in Flanders. The model is accessible via a web-based application that allows to analyze and visualize the accounted technical and environmental characteris-tics of each stream segment. This applications allows end-users to easily consult, analyze and get insight in the model results and is therefore a very useful instrument to involve different stakeholders in the decision making process.

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspectsFlux-controlled remediation & risk management: strategy and examples

Goedele Verreydt¹; Tim Op ‹t Eyndt¹; Erik Bosmans¹; Filip Meesters¹; Pieter Schrooten²¹ iFLUX; ² Cornet & Renard

The use of mass flux and mass discharge in contaminated land management is becoming increasingly successful, however, there is a need for a clear framework for the application of flux-based strategies. This is necessary for both the environmental consultant and the legislator who wants to design and check the flux-based concept. In this presentation we try to meet the need for this flux strategy framework by discussing a number of situations in which a flux-based strategy has a clear social and economic advantage. We focus on spreading risk, sustainability and cost. We will discuss the proposed strategies with pros and cons, in relation to the current legislation, tested and applied to real situations.

The most obvious flux application is the use of a flux-based method in the determination of spreading risk and remediation needs. Spreading risk describes the risk that the spreading of the contami-nation in the groundwater may harm a receptor, whereby a receptor can be both the aquifer itself and the use of groundwater, or a vulnerable ecosystem or surface water in which the groundwater is released. Through traditional methods (Darcy’s law approach), spreading risk is often overestimated because processes such as diffusion, degradation and sorption, dispersion and heterogeneity in material and permeability are insufficiently taken into account.

The use of mass flux in remedial design and the monitoring of remediation efficiency often seems less obvious but therefore no less relevant. By already using flux measurements in the design phase of a remediation, the remedial measures can be more focused, allowing a cheaper and also more sustainable solution. For example, wide hydraulic or reactive barriers can often be reduced to shorter, more focused zones. This is also valid for source zone measures. Moreover, we see that the flux-based monitoring of remediation efficiency can result in a lower financial guarantee or provision for the back-up plan.

We do see a lot of inefficient active groundwater plume control measures that would benefit from a mass flux characterization. Active pump & treat systems and hydraulic barriers not only fail because of the failure of the remedial technology as such, but because of a misjudged starting situating, lacking detailed infor-mation on the dynamics, the mobility of the pollution. This is a shame, of course. In this way the (social) costs can be unnecessarily high.

Flux-based monitoring strategies can help practitioners and legis-lators throughout the whole remediation process.

Defining Site specific water discharge values for 1,4-Dioxane and other compounds – Applying the BATNEEC approach and sustainability principles to improve the overall performance of an ongoing P&T system

Olga Vounaki¹; Elodie Jacquemin¹; Paulo Valle¹; Martin Ohsé; Laurent Crucifix¹¹ ERM BeNe

At an active industrial plant in Belgium, a multi-level remedial strategy has been developed to address a complex cocktail of contaminants present in soil and groundwater. The remedial strategy consisted of (i) installing a hydraulic containment barrier (P&T system) at the downgradient Site border to mitigate to the extent possible off-site contaminant migration, and (ii) a phased approach to remediate the major sources of pollution, within the limits of the BATNEEC principle. The Site remedial strategy was elaborated considering the currently regulated compounds in the Walloon region. However, given the recent changes in regulation in Flanders and the increased focus on 1,4-Dioxane in Wallonia, the site owner performed proactively and on a voluntary basis a prelim-inary investigation to be able to assess the presence of 1,4-Dioxane in soil and groundwater at the Site and the need for incorporating 1,4-Dioxane into the project remedial strategy. Preliminary inves-tigations performed at the Site confirmed that groundwater on site is impacted by 1,4-Dioxane with maximum concentrations up to 7.000 µg/l. The P&T system currently operating at the Site was not designed to treat 1,4-Dioxane. Influent and effluent ground-water concentrations of the P&T system are around 500 µg/l, and the discharge point of the P&T installation is a river located around 600 meters down gradient of the Site. Since the potential modifications in the P&T system required to effectively remove 1,4-Dioxane would have a significant impact on the overall reme-diation cost (both in terms of installation and O&M costs), the financial provision reserved for soil and groundwater remediation costs would have to be considerably increased. In order to continue incorporating the BATNEEC principle in the overall strategy, ERM engaged all key stakeholders (Site owner, regulators) in a broader and deeper reflection around the need to treat 1,4-dioxane in the P&T system. The same reasoning was used for the other compounds of concern in order to streamline the discharge values of all compounds and increase the overall system perfor-mance. Following discussions with the regulators, ERM performed multiple mass discharge calculations to define what would be the acceptable discharge concentrations of 1,4-Dioxane and the other compounds into the river in order to not affect the water river quality, which is classified as “good to very good”. The calcula-tions considered the river flow rate that is exceeded 9 months a year, and the lowest flow rate measured (i.e. the flow rate that is, under normal conditions, exceeded 350 days/ year), in order to be precautious. Due to the lack of local surface water standards for 1,4-Dioxane, ERM performed a literature research on its toxicity for aquatic organisms and proposed to use as acceptable concentra-tion in surface water a maximum concentration of 5 µg/l , which represents 10% of the drinking water guideline level of 50 µg/l (WHO, Guidelines for drinking water quality, 2011) Considering the volume of water discharged by the P&T system in the river, a threshold of 1,4-Dioxane of 700 µg/l would lead to a surface water concentration of 0.5 µg/l in the river.

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

ThS 5c | Sustainable and socio-economicevaluation & public perception related to remediation, societal participatory approaches

Gone with the wind - Soil gas diffusion to street level mitigation plan during tunnel excavation in the TLV LRT Red Line project

Tomer Ash¹; Edo Guttman²; Shlomit Doten- Gissin¹ WSP; ² Geo - Prospect

During the tunnel excavation on the Tel Aviv Red Line LRT Project, contaminated soil and high concentrations of soil gas contami-nants were encountered. The source of the contamination was from an old fuel station, located under main traffic artery in the Tel - Aviv Metropolitan area, where the soil and groundwater contami-nation has not been treated, resulting in the abundant presence of volatile organic compounds (VOC). Following the TBM penetrating this contaminated soil & groundwater, soil gases were forced to the street level. This resulted in odder complains from nearby residence and the evacuation of 16 families from their houses (for a period of 3 months). The Israeli Ministry of Environmental Protection (MoEP) demanded a 4-month Halt in construction to better investigate the phenomena.

The project’s environmental team liaised with tunneling, soil & water contamination experts to tried to locate similar case studies to consolidate an effective mitigation plan, only to realize the lack of available information. This scenario had not occurred elsewhere in the world, to the best of our knowledge.

There were three components to the problem: To secure the TBM machine wile stopping. The security of the residents, and the ability to predict the behavior of the gas.

Tunneling and Environmental experts collaborated to create a mitigation plan based on adaptation of the mining materials composition and carrying out a tunnel and street level monitoring program.

The proposed plan allowed decision makers, to adopt the recom-mended monitoring program, which meant continued excavation along the Red Line route without delays in the schedule and with on substantial additional cost.

The significant achievement in the process, was overcoming uncer-tainty through the collaborative work of interdisciplinary experts and the need to consolidate a comprehensive action plan for implementation on a major infrastructure project in Israel.

Our team of experts created a clear mitigation plan that needed to be approved by the MoEP and other municipal authorities involved.

The management of the process led to the creation of trust relations with the regulatory bodies. and communicate to the meaning of the information received; environmental, regulatory, planning and engineering to a complete picture.

We succeeded in formulating the comprehensive mitigation measures that assist the TBM passing the contaminated area without a significant environmental event, and in fact gave the accompanying regulatory team the opportunity to authorize us to continue without stopping in other contaminated areas.

This is an environmental event that necessitates diving into areas beyond the specialization, such as the mining materials composi-tion and tunneling processes.

The Presentation will refer to the process we have gone throw, the challenges in working in uncertain conditions, knowing that any action might affect residence in a highly dense populated area, navigating between different aspects of this event – professional and social. It will also describe the methodology adopted for exca-vation during the rest of the project to mitigate and minimize risk.

Do we have sufficient information to assess the sustainability?

Pär-Erik Back¹; Jenny Norrman²; Lars Rosén²; Yevheniya Volchko²; Tore Söderqvist³; Petra Brinkhoff⁴; Rita Garcao⁴¹ Swedish Geotechnical Institute; ² Chalmers University of Technology; ³ Anthesis Enveco; ⁴ NCC AB

The Swedish Environmental Code is based on the concept of sustainable development. It is therefore appropriate to base the choice of remedial actions at contaminated sites on sustainability, adhering to the national legislation, the United Nations’ global Sustainable Development Goals, and the ISO Standard on Sustain-able Remediation. However, such sustainability assessments have until now had limited use in Swedish remediation projects. In the research project SAFIRE (Sustainability Assessment For Improved Remediation Efficiency), relatively extensive sustainability assess-ments were made in four case studies, both publicly and privately funded projects, using the SCORE (Sustainable Choice Of REmedia-tion) sustainability assessment method. One of the objectives was to investigate what kind of sustainability information was available and what was missing, all with the aim to improve the ability to include sustainability assessments in the general remediation process. All case studies were in the risk management phase, i.e. risk assessments had been made and remediation alternatives had been formulated.

The method used was analysis of data availability: all required sustainability information was classified according to avail-ability and analyzed statistically. The data in SCORE is coupled to sustainability indicators and each indicator belong to either the environmental, the socio-cultural, or the economic sustainability dimension. In addition, each indicator concerns either on-site or off-site effects, as well as effects associated with either the reduction of the source contamination or the remedial activity. The information for each indicator was classified in three classes: ‘information readily available’, ‘information acquired’, and ‘informa-tion lacking’. The first and last classes are self-explanatory, while the second refers to information that, in one way or another, could be obtained during the sustainability assessment.

The results indicate that there is a big difference in availability of data regarding the three sustainability dimensions. As expected, information regarding environmental effects was more readily available than for the socio-cultural dimension, with economic information somewhere in between. Another interesting result was that more data was available on economic effects due to the remedial activity (e.g. remediation costs) than on economic effects due to source contamination (e.g. changes in access to ecosystem services). Not surprisingly, the situation was opposite for the envi-

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspectsronmental dimension as site investigations typically focus on ecological and human health risks due to the source contamina-tion. Generally, about 20 % of all required sustainability information was readily available, about 70 % could be acquired in the process, and the remaining 10 % was lacking.

Although this analysis was based on only four case studies, it is believed that some general conclusions can be made. One such conclusion is that socio-cultural information usually is not available, but often can be acquired from stakeholder workshops. How much information that can be acquired is, of course, a matter of time and budget limitations.

How SuRF-UK’s detailed checklist of sustainability assessment criteria / indicators has been used to date in the UK and elsewhere and its 2019 revision

Paul Bardos¹; Hayley Thomas²; Nicola Harries³¹ R3 Environmental Technology Ltd; ² Shell Global Solutions International B.V.; ³ CL:AIRE

Over the past 10 years or so, sustainability considerations have become more widely recognised in contaminated land manage-ment. It is now widely accepted as crucial to remediation planning and implementation, on an increasingly global basis.

A range of sustainable remediation frameworks and guidance documents have been now published around the world, along with a special issue of sustainable remediation knowhow in a major environmental journal. Sustainable remediation standards have also been agreed: ASTM (2013) and ISO (2017).

Sustainability assessment depends on an agreed set of indi-vidual sustainability criteria being agreed by those carrying out an assessment, that is also either agreed with or persuasive to the stakeholders they wish to take note of the assessment. In 2011 SuRF-UK brought out guidance on a checklist of sustainability criteria for consideration in drawing up (or framing) assessments, often referred to as “Annex 1”, which acts as a checklist. These criteria are organised across 15 “headline” categories, five for the environment element of sustainability, five for the social and five for the economic. The SuRF-UK Annex 1 remains the most comprehensive and detailed guidance to support the election of sustainability assessment criteria for sustainable remediation planning and option appraisal. It has been widely used in practice in the UK, and has been discussed and applied in international technical and research papers.

This paper sets out how this guidance was developed and the rationale behind its structure and approach. It describes its use in remediation option appraisal in the UK and other countries. It then reviews the lessons learned from its initial use in the UK and the opinions and findings of international commentators in the inter-national technical literature. The indicator set is currently under revision, and this is expected to be completed by March 2019. So this paper will conclude with HOW lessons have been learnt and will also be the international launch for the revised indicator set.

Applying sustainability principles in evaluating alternatives for remediation projects in South Africa

Theo Ferreira¹; Paul Bardos²¹ GeoRem Environmental Contractors; ² University of Brighton, Brighton, UK, r3 Environmental Technology Ltd.,

Sustainable remediation is a concept that has developed in practice over the last 15 years as remediation industries have matured in the US and Europe. The process of identifying sustainable remediation is defined by SuRF-UK as “the practice of demonstrating, in terms of environmental, economic and social indicators, that the benefit of undertaking remediation is greater than its impact and that the optimum remediation solution is selected through the use of a balanced decision-making process.” The primary purpose of reme-diation is to eliminate, reduce or manage contamination risks to human health and the environment, but may also have unintended or associated consequences that need consideration. Technical and commercial performance parameters are generally used as the primary guidance in implementing remediation projects in South Africa, often with limited evaluation of sustainability. A consistent framework in which sustainability can be considered at various stages of project design can provide a useful decision-making tool in these cases. Specific guidance in this regard is often limited in developing countries and resources like those developed by SuRF-UK can provide a basis for local implementation.

For this discussion a specific remediation technology in the form of vapour and groundwater treatment by Granular Activated Carbon will be evaluated against other options using a qualitative sustain-ability assessment. Typically, once the GAC is saturated, it can be regenerated or must be replaced. Limited options for commer-cial regeneration are available, therefore spent GAC in South Africa is generally disposed to hazardous landfill. Hence material is not recycled, and organic contaminants are landfilled instead of being thermally destroyed. GeoRem has been considering the use of alternative options, including biofiltration which may be more sustainable from a local and national perspective. This paper presents a qualitative sustainability assessment comparing the deployment of these alternatives for a Multiphase Extraction system at a remote site. The assessment is based on. ISO 18504:2017 (Soil Quality—Sustainable Remediation) and the SuRF-UK Annex 1 indicator set.

Using sustainability assessment principles, several options can be weighed up to provide a sound basis for technology selection. The same principles can be applied for broader decision making on remedial measures and project feasibility. Several unique local factors relating to Logistics, Climate and Infrastructure have been found to influence the assessment outcomes and play a significant role in the outcome of the assessment in the African context.

Sustainability assessment of in-situ remediation techniques using the SCORE method

Luca Franceschini¹; Jenny Norrman¹; Lars Rosén¹; Gitte Lemming Søndergaard²¹ Chalmers University of Technology; ² Technical University of Denmark

The concept of sustainable remediation is playing an increasing role in remediation projects, highlighting the contradictory effects of such activities and, as a consequence, several sustainability assessment methods have been developed. The Sustainable Choice Of REmediation (SCORE) method and tool is based on multi-criteria decision analysis (MCDA) and provides a transparent sustainability assessment of alternative remediation strategies

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

In addition to this basic indicator set, three other indicator sets are defined to address the different needs for information of three large stakeholder groups (research, policy and practice) within the soil remediation sector. The indicator sets are chosen based on the statistical analysis of an international survey send out in the beginning of 2018. The survey measures the preferences of respon-dents with connections to soil remediation over several different indicator categories: financial, environmental, technical, site value, governmental and social indicators.

The basic indicator set contains those indicators that were consid-ered most relevant for an investment analysis by the respondents and includes, among other things, cost description, potential land use after remediation and estimation of human risk. The three addi-tional indicator sets add indicators that are specifically important to people working within each of the target groups. Based on a factor analysis the indicators included in the survey were grouped in eight themes. Several of these themes where then linked to each of the target groups allowing the construction of the three specific target group indicator sets.

This resulted in an indicator set for practitioners that included, complementary to the basic indicator set, additional indicators concerning the practical issues of soil remediation projects (e.g. a BATNEEC analysis). These additional indicators allow for the inclusion of more information on the feasibility of different tech-niques and on the situation on site within the investment analysis. For people working in policy, site valuation turned out to be a significant additional theme for an investment analysis, including indicators such as future land value. This can be linked with the importance governments attach to the redevelopment of remedi-ated sites. The indicator set designed to address the preferences of researchers included additional indicators related to financial support, local residents and neighbourhood, and boundaries and uncertainties allowing for a broader but also more detailed overview of the soil remediation project.

Designing a sustainable remediation project with deep socio-economic impact

Mathieu MorlayCOLAS Environnement

Whishing an extension, a school group planned to start the earthwork on the very beginning of summer 2017. Very quickly, the contractor informs the client that they were dealing with contami-nation of the soils and the ground waters.

Regrouping a kindergarten, primary school and secondary school, the responsibility is shared by the mayor, the department (subdi-vision of a French region) and global environmental authorities. Dealing with a very sensitive use of the site, a consultant is awarded for the preliminaries studies. Up to 71 mg/Kg/MS of PCE and TCE are measured in the soils, about 9000 µg/L of the same contami-nants in the ground waters. The School had been built on a former chemical plant, which had never been registered.

Social representatives of the schools parents, the mayor and the director of the department decided during summer 2017 to close the school for 2 years to be able to clean up the site. In Parallel, another site will be dedicated to welcome the children in bungalows for the 2 next years.

To deal diligently with the risk and since time is a factor, the clients and the consultant had decided from the end of the second inves-tigation campaign to award a remediation contractor to ensure the design of the very right remediation plan.

at a contaminated site. Alternatives are compared to a reference alternative, considering a number of key criteria in the economic, environmental and social sustainability dimensions. Each criterion is assessed by indicators, considering on-site and off-site effects of the remediation activity itself and of the source contamination removal. SCORE gives a sustainability evaluation of the different alternatives, accounting for positive and negative environmental and social effects, and performing an economic evaluation by means of a cost-benefit analysis (CBA). Social and environmental effects are represented by semi-quantitative scorings, whereas the economic effects are monetised as far as practically possible within the scope of the assessment.

SCORE has been applied at a number of sites, with remediation alternatives involving traditional excavation and landfilling of the contaminated soil, at times coupled with other ex-situ tech-niques. In this study, a method to include the assessment of in-situ techniques in the SCORE framework by means of a streamlined life-cycle assessment (LCA) was developed. The main causes of environmental impacts of the in-situ-techniques were identified and new indicators in the environmental domain were created. Effects on soil, groundwater and surface water were scored with information based on literature. Effects on air and non-renewable natural resources were scored performing a streamlined LCA.

The developed method was tested on a case-study site with PAH contamination in both soil and groundwater to 15 m depth. Five alternatives combining ex-situ and in-situ techniques were compared: (i) 5 m soil excavation and in-situ chemical oxidation (ISCO), (ii) 1 m soil excavation and stabilization/solidification (S/S) and ISCO, (iii) 5 m soil excavation and bioremediation, (iv) 1 m soil excavation and S/S and bioremediation, and (v) 5 m soil excava-tion and in-situ thermal stabilization. Due to data constraints in the case study application the complexity of the site was simpli-fied and some important assumptions were made. Given the assumption that all five alternatives will meet the clean-up goals, the results of the sustainability assessment showed that the tech-niques involving the least amount of soil excavated and landfilled obtained the highest scores.

The strength of the method is that it can be applied to any remedi-ation project, allowing the assessment of remediation techniques that use different technologies, such as in-situ vs in-situ, in-situ vs ex-situ and ex-situ vs ex-situ. Currently, the suggested method is being tested on a real site contaminated by chlorinated solvents and results are expected to be available in 2019.

Indicator use in soil remediation investments: views from policy, academics and practice

Lies Huysegoms; Sandra Rousseau; Valérie CappuynsKU Leuven

Soil contamination poses a potential risk to human health and ecosystems. To address this global problem, soil remediation tech-nologies have been developed, new legislation has been put in place and high-quality technological equipment is being used. However, the economic aspect of soil remediation has received less attention even though the total cost of soil remediation in Europe is estimated to be 119 billion euro. Frameworks and tools are available (for example SuRF-UK framework) to address economic aspects of soil remediation, but an established set of well-defined indicators is currently lacking.

This paper aims to address this gap by introducing a basic set of indicators for the investment analysis of a soil remediation project.

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspects

vs. disposal. Feedback on the working process, the SCORE tool, and its input into the decision process was collected after the SCORE analysis. A major reported advantage of the SCORE-process was the structure and documentation it provides, i.e. transparency. Also, the fact that social and economic effects are considered in a broader sense than is typically done in remediation projects was regarded as providing a robust basis for decision. Some method-ological changes have been implemented in the SCORE tool as a result of the case studies, pinpointing the importance of case studies as a vital part of method development. For the BT Kemi case study, it has now been decided to make a new investigation of in situ remediation methods as a potential way of improving the environmental performance of the remediation.

Can sustainable remediation be efficient and effective?

Lars Rosen¹; Robert Anderson¹; Jenny Norrman¹; Yevheniya Volchko¹; Tommy Norberg¹; Pär-Erik Back²; Tore Söderqvist³; Henrik Nordzell³; Malin Norin⁴; Petra Brinkhoff⁴; Rita Garcao⁴; Helena Andersson⁵; Kristina Sjödin⁵¹ Chalmers University of Technology; ² Swedish Geotechnical Institute; ³ Anthesis Enveco; ⁴ NCC AB; ⁵ The Geological Survey of Sweden (SGU)

Although site remediations provide reduced risks to the environ-ment and human health, responsible organizations in Sweden and elsewhere are concerned about slow progress, high costs, low level of innovation, and environmental footprints of these remediations. It is now widely recognized that sustainability assessments are needed to provide a holistic decision-support for sound prioritiza-tion of remediation efforts. But can sustainable remediation also be perceived efficient and effective in reaching remediation goals at the project level?

The overall aim of the SAFIRE (Sustainability Assessment For Improved Remediation Efficiency) research project was to evaluate if sustainability assessments can improve the efficiency and effec-tiveness of site remediation, and if so, in what ways? The SCORE (Sustainable Choice Of REmediation) method, developed at Chalmers University of Technology in Sweden, was applied in five major on-going remediation projects in Sweden. Based on the results from the case-studies we investigated how a broad sustain-ability perspective differs from more traditional perspectives in terms of efficiency and effectiveness of prioritized remediation alternatives. SAFIRE was a trans-disciplinary project between academia, state agencies, Swedish municipalities, and private land developers.

The SAFIRE project resulted in novel insights on how to integrate sustainability assessments in the process of selecting and designing remedial actions, on how to acquire necessary input informa-tion through investigations, stakeholder involvement and expert elicitation, and on how sustainability assessments can impact the choice of remediation strategy. The project showed that applying a more comprehensive and broad sustainability assessment can result in a decision support that is substantially different in terms of remediation extent, costs, and remediation technology than what is provided by more traditional approaches for evaluating reme-diation alternatives. It is concluded that sustainability assessments typically support decisions that represent middle-of-the-road solutions that balance positive and negative effects. Consequently, applying a broad sustainability assessment typically promotes remedial actions that are neither the most efficient with respect to common efficiency indicators (e.g. cost per amount contaminant removed), nor the most effective with respect to common effec-tiveness indicators (e.g. total amount of contaminant removed).

COLAS Environnement proposed his expertise regarding to lab tests and In-Situ pilots tests. The geology was an important concern, eventually a mix of multi layers of clay on 5 m and then fractured bedrock.

Inspired by the PCT model from the new French contaminated site guide (April 2017), the purposes of the technical interaction between COLAS Environnement and the consultant were about exploring difficulties together, adapting the investigation program related common goals, testing efficiently several In-Situ Methods and eventually to commit about the right balanced remediation solution.

The remediation strategy is directly inspired by a collegial decision between all the parties. The downtown localization of the site, the small spaces in the city, the lack of space on site, the social impact (related to school people and neighborhood) and the delay were central to reach a consensus. Obviously, regarding to the context, the representatives of the clients has been monitored by the envi-ronmental authorities.

Stakeholder involvement in sustainability assessment of remediation strategies – method and application

Jenny Norrman¹; Tore Söderqvist²; Yevheniya Volchko¹; Pär-Erik Back³; Lars Rosén¹¹ Chalmers University of Technology; ² Anthesis Enveco; ³ Swedish Geotechnical Institute

Sustainable Choice of REmediation (SCORE) is a multi-criteria decision analysis tool developed for assessing economic, envi-ronmental and social sustainability of remediation strategies at contaminated sites. In SAFIRE, a transdisciplinary research project, SCORE was applied and evaluated with input from, and together with, stakeholders in five case studies at which the decision about selection of remediation strategy is still to be made. One of the case studies is at the BT Kemi industrial site in the town of Teckomatorp, south Sweden. The company BT Kemi manufactured pesticides from 1965 and secretly buried drums with organic pollutants. As a result, the site is associated with a famous Swedish environmental scandal culminating in 1977 when the factory was forced to close. Parts of the site was first remediated in the late 1970s and later during 2008-2014, but there is still remaining contamination. The current project is publicly funded and run by the municipality, and the final remediation will take place in the coming years. One of the main goals of the remediation project is to change negative public attitudes towards the town and to remove the stigma associated with the site. In the SCORE application, the social sustainability was assessed with selected stakeholders in a workshop, the economic sustainability by means of a cost-benefit analysis with input from stakeholders, and the environmental sustainability together with consultants and the project leader based on the site investigations and environmental (human health and ecological) risk assessment. Additional information from the public for the assessment of social and economic sustainability was collected by means of a question-naire sent to randomly selected residents. The main results were that alternatives with a higher degree of removal of contaminants got a higher ranking in the SCORE analysis, primarily due to social and economic factors, but that these alternatives also had relatively large negative secondary environmental effects. The preferred alternatives involved a high degree of soil excavation and handling of the excavated masses either by disposal or thermal treatment and reuse. An additional analysis of the energy source indicated that the use of renewable gas (ethanol) in the thermal treatment facility resulted in a somewhat higher ranking of thermal treatment

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Thematic Session (ThS) – Topic 5 | Strategies and management of contaminated land incl. legal, social and economic aspectsHowever, compared to a typical private perspective, which priori-tizes low cost and short remediation time, a broad sustainability perspective typically promotes more effective solutions with respect to e.g. contaminant removal and risk reduction. Compared to a traditional public perspective, which prioritizes risk reduction, a broad sustainability perspective typically promotes more efficient solutions with respect to e.g. cost per amount contami-nant removed or cost per unit risk reduction. For publicly funded projects in Sweden it is thus concluded that a broad sustainability perspective would likely lead to less expensive projects and a better rate of site completions within given time budgets.

Relieving community stress related to soil remediation by performing an elaborated on-site GC-MS air monitoring

Arnout Soumillion¹; Wim Vansina¹; Pieter Buffel¹; Samuel Van Herreweghe¹; Yves Van den Bossche²¹ Witteveen+Bos Belgium NV; ² OVAM

Recently, the attention for human exposure to hazardous substances during soil remediations and excavations has increased. Ingestion or skin contact are quite easily observable and controllable exposure routes, mostly resulting in rather chronical symptoms. Exposure through inhalation, on the other hand, is very difficult to monitor because of the high variability in space and time.

A recent case of the OVAM in which a potential ‘exposure through inhalation’ risk was clearly exemplified, is a soil remediation project in the middle of a residential center of a small town called Dikkel-

venne (Belgium). Continuous monitoring of the concentration of distinct airborne substances was required because of the different individual exposure limits. The low exposure limits of the contami-nants of concern provoked a need for a low level detector such as a GC-MS.

A ‘lab in the field’ performed continuous real-time and on-site measurements. Every one and an halve minute, a data point was analyzed. The sampling locations could also easily be moved because of the mobility of the ‘lab in the field’ unit and by using a multiple-entry valve thanks to which multiple sublocations can be sampled simultaneously. For each data point, the component specific concentration is compared to the imposed limit by an automated data interpretation script. This script is programmed to send a message to the on-site environmental supervisor in case one of the limits is exceeded. The environmental supervisor can take immediate corrective actions to the remediation contractor in order to reduce the concentrations or he can proceed to the evacu-ation of the workers and/or the local residents if necessary.

Thanks to the substance specific measurements, we were able to avoid an unnecessary interruption of the remedial works and to inform all stakeholders on a continuous manner. Also, we were immediately able to objectively arbitrate after receiving a complaint from a neighbor about ‘the presence of a strange odor’ linked to the remediation.

In summary, we can state that a soil remediation in densely populated areas can be very disturbing. An elaborated monitoring of the air quality during an active remediation is a great tool in assuring the local community that the adverse effects of the soil remediation are under control and it provides the soil expert in the field with a strong communication tool.

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Thematic Session (ThS) – Topic 6 | Land stewardship

all of its values [Ref. 1]. Land Stewardship (LS) has a wider scope than Sustainable Land Management (SLM) or Brownfield (BF) rede-velopment. Where SLM focusses on the sustainable use, protection and management of land, LS also looks at the understanding of the natural and social values land represents, both at sites in transition/redevelopment as at sites in continued use.

With a large working group Nicole and Common Forum have drafted a concise report on the definition of Land Stewardship and the components Stakeholder Involvement, Options Appraisal and the most important elements of Natural and Social Capital. It also contains a chapter and example on the Economic and Social value that an industrial site in operation can represent. This way of thinking also represents a paradigm shift from an industrial site being a potential threat to the environment to industrial land contributing to the delivery of welfare and employment to the community. Such an activity can also provide the means to enable investments in the natural, social and economic value of land.

Since the publication of the booklet in summer 2018 NICOLE and Common Forum have moved further, aiming at a common position and at an operationalization of the concept. The latest findings will be shared during the conference.

Towards multifunctional urban surface water: understanding current and future surface water uses

Suzanne van der Meulen¹; Nora Sutton²; Huub Rijnaarts²¹ Wageningen University and Deltares; ² Wageningen University

Urban water quality and water use are key themes in creating the sustainable city of the future. There is growing demand for use of urban water for recreation, urban farming, thermal energy provision and other uses. Densification of urban areas puts pressure on urban water systems to provide multiple services. The potential supply of services is limited by water quality, quantity and accessibility of water bodies. Urbanization and industrialization have affected these parameters, while extreme wet and dry periods resulting from climate change will exert an additional pressure on urban water systems. At the same time, water quality in European cities improves. Together with technological advancements, this results in new opportunities for urban water use.

In the context of changing demands and changes in water quality, researchers and practitioners suggest delineation of manage-ment units that give priority to different water services. This will support management of multifunctional uses and guide invest-ments in urban waters. These notions support the need for a good understanding of the spatial and time specific opportunities and vulnerabilities for multifunctional use of urban waters. It also calls for water management measures to enhance potential provision of multiple services.

Existing water quality standards provide criteria for assessment of ecological quality of urban water and for a few single services, such as drinking water extraction or swimming. Scientific literature and assessment frameworks on aquatic and urban ecosystem services provide a basis for broader assessment of water quality for services that contribute to human well-being. However, they do not yet provide a scientifically underpinned and integrated assessment framework for urban surface waters taking into account all and multiple services, temporal and spatial variability and sound indi-cators and criteria for service potential, use and demand. There is also a lack of historic and future-oriented studies that analyse the dynamics of urban ecosystem services in a systematic way.

The aim of the FUNqyWATER research project is to develop an

ThS 6a | Valuations of SSW systems: natural capital accounting, ecosystem service assessment and soc-ec CBA

The Nature Value explorer: valuing the benefits of green and blue infrastructure.

Inge Liekens¹; Steven Broekx; Alistair Beames¹ VITO

Nature-based solutions can assist planners to meet contemporary challenges (e.g. health and wellbeing, biodiversity, climate change and air quality). Where to develop and preserve which type of green or water to establish solutions for many problems simulta-neously, however, is not straightforward. The online Nature Value Explorer tool (www.natuurwaardeverkenner.be) was originally meant to calculate the impact of nature development projects on ecosystem services, but was extended with an urban version. Its aim is to support local authorities in providing the right green or blue measure in the right place in urban environments, paying attention to the quality and the functions of the green infrastructure and the trade-offs between ecosystem services and biodiversity. Cities can also estimate the effects of existing and planned green and blue infrastructure on reaching sustainability goals. The rural version of the tool estimates the value of 13 different provisioning, regu-lating and cultural services. The urban version builds on a specific typology of urban green and uses other valuation methods specifi-cally suitable for urban environments. Ecosystem services which can be valued include urban farming, air quality, urban heat islands, carbon sequestration, water retention and health and wellbeing.

The presentation will outline the user requirements for such a system and the valuation methods used and demonstrate the results of a case. It will also discuss the challenges that arise when developing such a practical tool: simplifying complex things; being user-friendly, transparent and flexible enough to address future questions and include new insights; and being accurate and scien-tifically reliable.

LAND STEWARDSHIP, Investing in the Natural, Societal and Economical capital of Industrial Land

Hans Slenders¹; Claudio Albano; Margot De Cleen; Co Molenaar; Lida Schelwald; Robert Spencer; Bianca Nijhof; Roger Jacquet; Nicholas Tymko; Laurent Bakker; Horst Herzog; Pascal Mallien; Jordi Boronat; Paul Van Riet¹ Arcadis Netherlands

Land Stewardship a mutual interest of NICOLE and Common Forum

The current way of production, use of resources, land and natural capital is not sustainable. Transitions in energy, mobility, circular economy, food production and city development are needed. We need to transform towards a restorative and circular economy, based on value creation and where public and private stakeholders cooperate to achieve public and private goals. Land restoration, land use and land management (land stewardship) are key in this transform.

The Network for Industrially Co-ordinated Sustainable Land Management in Europe (NICOLE) and the Policy makers of the Common Forum have executed a study on Land Stewardship. Land Stewardship being the recognition of our collective responsibility to retain the quality and abundance of our land, air, water and biodi-versity, and to manage this natural capital in a way that conserves

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Thematic Session (ThS) – Topic 6 | Land stewardship

basis for improved environmental risk assessment (ERA) within the APPLICERA (Applicable site-specific environmental risk assessment of contaminated soils) framework. Using the SF Box (Soil Function toolBox) method, the framework (1) differentiates the effects of contamination on SFs from the effects of other soil qualities essential for soil biota, and (2) provides the basis for improved soil quality management in remediation projects.

Two remediation alternatives were defined for the case study site, situated in the suburban industrial area of Kubikenborg, the municipality of Sundsvall, Sweden, based on (1) traditional ERA using guideline values derived from species sensitivity distribu-tion models which reflect dose-response effects of contaminants, and (2) the APPLICERA-framework, respectively. The first alterna-tive implied extensive excavation of the entire area, on-site soil washing, and disposal of the waste. The second alternative implied less excavation, leaving intact the area covered, at the present, by vegetation, i.e. grass, bushes and trees. Taking uncertainties into consideration, the social profitability of these alternatives has been evaluated relative to the reference alternative, i.e. no remedial action taken, by means of cost-benefit analysis, including semi-quantitative assessment of ESS at the case study site.

Although the APPLICERA-framework implies additional costs associated with extensive sampling and analyses relative to the traditional ERA approach, it provides improved management of contaminated sites with respect to environmental risks, soil quality and prioritization of economic resources. In contrast to the first alternative which is based on traditional ERA, the second one was associated with less negative effects on ESS at the site, e.g. remedi-ation of metals by salix naturally occurring at the site, local climate regulation and noise reduction by trees, pollination, and landslide and erosion prevention. The second alternative was also associated with less total costs for remediation, i.e. less costs for the remedial action, costs for risks of traffic accidents and costs for release of carbon dioxide.

assessment framework that enables identification of opportuni-ties and vulnerabilities for multifunctional use of surface water services and that provides a starting ground for exploration of water management options to optimize multifunctional water systems. The first results of this ambitious project will be presented here. The research reveals trends in urban surface water use and future demand for services. This is needed to identify the services that should be included in the framework and to provide guidance in selecting indicators for water quality. An overview of current surface water use will be presented, with examples from Europe and Northern America. Anticipated future surface water use will also be presented, which provides a strong basis for under-standing future water use trends. Together, the results presented give a strong motivation for the need of a framework to assess and support current and future surface water use in sustainable cities of the future.

Assessing costs and benefits of improved soil quality management in remediation projects: A case study from Sweden

Yevheniya Volchko¹; Lars Rosén; Pär-Erik Back; Annika Åberg¹ Chalmers University of Technology

Soils are a non-renewable resource within a human lifespan. They carry functions fundamental for the well-functioning ecosystem and delivery of ecosystem services (ESS) to humans. Contaminants in the soil may threaten soil functions (SFs) and, in turn, hinder delivery of ESS. On the other hand, some specific soil properties, e.g. pH, clay contents and organic matter, may reduce mobility and bioavailability of contaminants in the soil, while providing favorable conditions for soil biota. Assessment of the soil quality, in the broader sense than contaminant concentrations, forms the

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economy

Sustainable conversion of a former sewage plant to “liveable nature”. A new recreational industrial landscape

Hans BengtssonRamboll

Former industrial areas and brownfields are today often converted to housing and commercial use when situated centrally in cities. This is often driven by the demand for urban development and the resulting economics. The question is therefore what to do with former industrial properties and areas that are not “blessed by urban growth”. How do we make sure that these properties and areas outside the urban zones are not left as polluted indus-trial ruins. The trendy word today is liveable cities – but how do we make “liveable nature”.

The presentation doesn’t give the answers but gives an example from a case where a former sewage treatment plant is to be converted in to a recreational nature area in a sustainable way and at the same time incorporates climate adaptation.

The aim of the project is to convert the polluted property of a former sewage plant in to a recreational nature area. The project focuses on maximum reuse of soil and materials to prevent unnec-essary environmental load and transport. New underground basins are established to reduce the load in connection to cloudbursts and sewage water producing a lot of intact clean soil. This soil is reused for capping polluted soil and for reshaping the landscape that originally was in the river valley of Mølleåen. Polluted soil is also reused based on thorough risk assessments. The old constructions are not removed but instead secured to introduce a new landscape story of the old sewage plant. The basins and filters are filled with soil and plants are introduced in these to give a new story that the neighbors and residents of the area can enjoy.

The project is an example of how the handling of climate adap-tation and site pollution can be done in a combined sustainable way. “Liveable nature” requires that different technical experts work together; environmental technicians within soil and biology, landscape architects, water engineers etc.

The presentation will focus on how the project came to live and how the planning and tendering process has been done. The project will not be finished at the time of the presentation but can hopefully function as an inspiration to others.

Reuse of thermally-cleaned soil and tarmac granulate: health, environment and public emotions

Ellen Brand; Frank Swartjes; Arjen Wintersen; Michiel Rutgers; Piet OtteRIVM - National Institute for Public Health and the Environment

A circular economy (CE) approach is part of our way to build a sustainable world. As such, the Dutch government stimulates the reuse of contaminated soil and discourages the disposal in landfills. The application of residual streams within a CE approach will have potential effects on the quality of soil and groundwater. Regulation facilitates the controlled and save reuse of materials, but how does this turn out in practice?

7a1 | Circular land use and brownfield regeneration

Sustainable soil management

Arense Nordentoft¹; Susanne Arentoft¹; Anette Specht²¹ Region Midtjylland; ² Rambøll Danmark A/S

In Central Denmark Region 6 million tons of excavated soil are transported over shorter or longer distances annually – resulting in large economic and environmental consequences. Can we do better? There are many factors and actors involved in the process. However; it is possible to introduce more sustainability if we work together across authorities, industry and other stakeholders. Hence; Central Denmark Region has instigated a two year project which aims towards more re- and upcycling of soil. The project is driven by a steering group of representatives from the Central Denmark Region and from four different municipalities in the Region.

The project began in January 2018 with a kick-off workshop inviting all 19 municipalities in Central Denmark Region. The aim of this workshop was to identify common challenges and needs as well as important stakeholders. Challenges and needs were surpris-ingly few, and through a prioritisation process two main objects were chosen to be transformed into action and deliverables in the project:

1) A template for municipal strategy of excavated soil.

2) A stronger network and exchange of knowledge between all important stakeholders.

After a dialogue in the steering group the template has been extended to include:

A) A forecast tool to predict the amount of soil excavated within each municipality over a period of 10-15 years.

B) A classic report template for use and inspiration when working on the municipal strategy.

C) A list of inspiration including 20 existing soil reuse projects of different types and sizes.

These products were ready for use by the end of 2018. Furthermore, based on municipal data, a 12 year projection of the excavated soil amounts in Central Denmark Region is available.

The need for new solutions is obvious - clearly identified through the interest of the subject and the number of attendants at the workshops and meetings. Thus; workshop 2 in June successfully gathered 70 people including municipalities, consultants, archi-tects, contractors, soil receivers and utility companies. Besides introducing the attendants to the strategy template other important subjects were eagerly debated. Soil stock exchange, lime stabilization and local planning to name a few. Networking and exchange of knowledge will be further developed by workshops or meetings bi-annually. It is obvious that different stakeholders have different drivers, but sustainability with a triple bottom line: People, Planet, Profit makes an inspiring and dynamic starting point leading towards the common goal.

So far the project has clearly confirmed that breakdown of bound-aries between stakeholder and different disciplines is the key to success. We can only encourage even more networking on the subject. We are, of course, eager to hear from anybody with new angles, good ideas, curiosity to or with knowledge of the subject.

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economy

In several European countries and regions guideline values for heavy metals and organic contaminants, among other param-eters, determine whether a soil can be reused or not in a given application. In the context of circular economy, the local applica-tion of excavated soils should be preferred, although soils with a specific composition may be suited for beneficial application at more remote locations, asking for a harmonization of the condi-tions for reuse of excavated soils. Moreover, much emphasis goes to soil quality in relation to its potential risk for humans and ecosys-tems. Parameters that describe the civil-technical quality of the soil are not systematically recorded, although they are necessary to determine whether a specific application (e.g. certain construc-tion purposes) can be envisaged. In some countries and regions, all relevant aspects of management of excavated soils (supply and demand of excavated soil, certification, transport, temporary storage, etc.) are already coordinated by a central organization. In contrast, in some other countries, information on quantities of excavated soil, as well as on quality of the excavated materials, is not available, and a systematic approach for the management of excavated soil should be implemented.

Circular land use: every step counts

Thomas De Romagnoli¹; Pieter Schrooten²¹ Brussels Environment; ² Cornet & Renard

Land is a valuable resource. However, contaminated land seems to lose much of its value as long as a stigma of soil contamination is present. Brownfields or other types of contaminated land are not considered to have a potential contribution to the economy or society as long as the contamination has not been remediated, the site has been redeveloped and a new land use has been installed. This way of thinking results in many sites not being used to their full potential for several years or even decades. This because no intermediate use, prior to the full remediation and redevelopment, is envisioned.

During the presentation we want to show the potential for inter-mediate land use to create an added value, social, environmental and/or economical. Even abandoned sites create costs for land owners (prevention of vandalism, maintenance,…), as well as for society (negative impact on the community adjacent to the site) and the environment (increase in pressure on nearby greenfield sites). Several initiatives already showed the potential for the intermediate use of contaminated land. Such examples are: the temporary management of vacant sites providing space for social initiatives by the surrounding community, for new businesses and artists, turning brownfields in recreational sites accessible to the public and removing the contamination stigma, using contami-nated sites to grow biofuels,...

Currently, the intermediate land use initiatives are limited and small scaled. They are mainly driven by small communities because of local needs. There are several reasons why this alternative approach on land use is not a common practice today. Site owners are often not aware that intermediate land use is an option and the value it could represent. Or they are reluctant to allow inter-mediate land use because of the liabilities they might face towards the temporary site users. Besides, this approach is not yet explic-itly imbedded in governmental policies. In many cases the current legal regulations are not fit for intermediate or temporary land use. They lack the flexibility to allow for a quick start-up of limited in time economic activity. Finally, in contrast to legal temporary occu-pation of buildings, for which organisations exist that facilitate the legal process, this seems not yet the case for temporary land use.

In the Netherlands, thermally-cleaned soil and tarmac granulates (hereafter TCS) are reused in different constructions works such as road foundations and sound barriers. TCS is raw soil material that is heated (>500°C) to remove organic contaminants so that it can be reused. Metal contaminants remain in the final product and must comply with regulation with regard to leaching and total concentrations. Reuse of TCS is from an economic and envi-ronmental viewpoint viable. It limits our need for primary mineral resources such as sand and gravel, it is a cheaper alternative than these primary resources, and it limits our burden on landfills. TCS is permitted in Dutch building works.

Recently the use of TCS was questioned after being used as a filler in the building of dykes. Initial analysis of the TCS in a dyke in the south of the Netherlands has shown that the TCS still contained contaminants that should have been removed after heating of the soil. Furthermore, the properties of the material differed much from soil, the pH was very high and concentrations of some contami-nants did not meet the legal quality standards. These findings were reasons for concern amongst residents and questions arose about health risks and the environment.

Building work can cause increased concentrations of particulate matter in the air for a short time period. Combined with the fine particle fraction of TCS, nearby residents can be exposed to partic-ulate matter from the thermally cleaned soil. Besides health risks, also effects on the environment (soil, groundwater and surface water) can be at stake. All leading to the overall question: is the TCS suitable as a filler for use in a dyke and which precautions should be taken before, during and after construction?

A risk evaluation was started that included a health and ecological risk assessment. Residents were exposed to TCS for approximately two years during building works and had experienced major nuisance of particulate matter from the worksite. The residents were interviewed to determine the exposure characteristics during and after completion of the works. By use of a human risk assess-ment model the potential health effects of contaminants in the TCS were determined. Ecological effects were evaluated for soil, ground-water and surface water via a source-path-receptor approach and available risk standards. Also, the suitability of the surface water for use as irrigation water and for watering of livestock was assessed. Finally the potency for leaching of contaminants from the dyke was determined.

We will present the results of a risk assessment for the use of TCS in a dyke in The Netherlands. Furthermore, the role of public percep-tion on the reuse of materials will be expounded.

Soil and circular Economy: state of the art on the reuse of excavated soil in Europe

Valérie CappuynsKU Leuven - University of Leuven

Soil and land can be considered as non-renewable resources, which should be handled with great care to avoid their degradation, and eventually depletion. A healthy soil is absolutely necessary to deliver the functions associated with the biological cycle in the circular economy. In the technical cycle, one of the vital services provided by soil, is the delivery of mineral resources. In the present paper, the focus will be on the beneficial reuse of excavated soils in engineering and building applications. The current status of the generation and reuse of excavated soils in different European countries is presented, and issues, challenges, and good practices are analyzed.

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economyWith the presentation we want to initiate a roadmap that will further identify the barriers and the potential for different types of contaminated sites, in different settings and with different types of land use. In this way, we want to show to land owners, citizens, municipalities and government authorities the value that underused land could bring to their society. Land is valuable, let’s use it wise, at every step.

Geochemical background over the Parisian Basin: from the setting up to the practical use for circular reuse of excavated soils

Claire Faucheux¹; Coline Eychène²; Marie-Charlotte Favre³; Samuel Coussy⁴¹ Geovariances; ² Soltracing; ³ BG Consulting Engineers; ⁴ BRGM (French Geological Survey)

With Europe setting recycling targets for construction waste at 70% by 2020, and a significant demand in raw materials, the construc-tion sector represents a major stake for the circular economy. Reuse of excavated soil is one of the components likely to be developed in the Île-de-France and Normandie regions (France). The Great Urban Development project deals with large amounts of excavated soils, which management is likely to be optimised through an offsite reuse for other construction projects. It is now crucial that the quality of the soil at the receiving site is maintained once the excavated material is added.

However, stakeholders of this industry are facing a regulatory gap and a lack of references in terms of offsite reuse and soil exchange between construction sites. A good knowledge of the composition of the soil – for different kinds of areas (residential, industrial…) – will facilitate the study of potential offsite reuse. This geographical understanding of the average concentrations in soil is very useful for a wide range of applications, such as facilitating diagnosis inter-pretation by experts investigating potentially contaminated sites.

The GEOBAPA project has been supported by the ADEME, by the Île-de-France and Normandie regions and by the French Ministry in charge of Environmental Affairs in order to build a geochemical back-ground baseline for the regions of Île-de-France and Normandie. The GEOBAPA project has been led by SOLTRACING, BG Ingénieurs Conseils, GEOVARIANCES, the BRGM and Althea Ingénierie.

The geochemical background baseline of the Parisian basin is the first multi-regional reference frame providing natural and anthropic compounds’ concentrations in soils - including urban zones. The work combines soil quality data from past scientific and urban development projects with data produced as part of this research program, leading to the statistical analysis of more than 3000 pieces of data.

In 2018, the pilot phase has been led to produce the first results of geochemical background over three zones of the Parisian Basin. The presentation will describe methodological choices made to set up the geochemical background and how results can be trans-ferred for practical use. These values have then been tested on real case studies to collect the feedback of using geochemical back-ground values as referential for offsite recovery of excavated soils. These concrete operations allow us to conclude on the operational perspectives for these new referentials, becoming more and more developed: how are they perceived by public owners? How do they modify the understanding of clean soils and their quality over the years? How to communicate results to be used for circular manage-ment of excavated soils? How can they influence the amount of potentially reusable excavated soils?

The SURICATES project – Pilot reallocation of 200.000 tons of sediment within the river in Port of Rotterdam, the Netherlands

Hans GrootDeltares

Sediment management is a major economic challenge for ports, waterways and cities with more than 200 million t/year dredged in Europe to maintain and develop water transport capacity for economic activities. As social and environmental pressures on dumping at sea increase, management costs increase and dumping possibilities decline, leading to the need for new options for sediments reuse to maintain and expand navigable access capacity.

Sediment reuse still faces direct cost issues in market conditions and no regional/local global cost/benefits methods currently evaluate added value in local long term impacts.

Using sediment for mitigation measures for erosion and flood risk requires changes in standard practice, and a demonstration of its attractiveness and long term safety. New reuse solutions for large sediment volumes will have a strong impact on ports and waterway economies, and citizen safety.

Material needs for flood and erosion protection in NL, combined with the choice of nature development to restore and maintain vulnerable habitats has led to large programmes like the ‘Room for the River’ and ‘Sand Engine’. The difference between NL (and Flanders) and other NWE member states is to define sediments as a soil, and not as a waste. International collaboration is needed to demonstrate the attractiveness of sediment reuse for erosion and flood risk mitigation to NWE end users through implementation for real site conditions.

In order to achieve this the project “Sediment Uses as Resources In Circular And Territoral EconomieS (SURICATES)” was approved within the INTERREG VB NWE. In this project partners from France, the United Kingdom, Ireland and the Netherlands collaborate in demonstrating reuse of dredged sediments in pilot applications.

SURICATES will develop methodologies and technologies supporting reuse strategies beyond pilots through:

1 Sediment reallocation within the system

2 Demonstrate pilot equipment to accelerate dehydration of dredged sediments

3 Bio-engineering with sediment

4 Concrete made with cement and sediment for erosion and flood protection

5 Sediment as a pozzolanic material

We will present the preliminary results of the pilot of the realloca-tion of 220.000 tons of sediment for bank nourishment in the Port of Rotterdam. To reallocate 200.000 tons of sediment, 500.000 m3 of sediment must be dredged from a clean part of the port, not impacting the erosion/sedimentation rate in the harbour.

Reallocated sediment must be traceable within the inter tidal area and coastal zone to establish a nourishing impact on the river bank and coast. To do so, the sediment origin has to be distinguishable from the mostly marine sediments in this part of harbour. Specific and dedicated dredging have to be done. To monitor the distribu-tion of the sediment within the river system different monitoring techniques are developed:

a. Bathymetry surveys (multi-frequency echo-sounder, LIDAR)

b. Glass fiber to monitor the change in bathymetry

c. Use of rare earth elements as a tracer to fingerprint the sediment

d. Use of drones to register changes in topography and shallow bathymetry

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economyChallenges of brownfields regeneration for housing needs in urban space (case study area: Brno city in the Czech Republic)

Petr KlusáčekInstitute of Geonics, Academy of Sciences of the Czech Republic

Circular land use and brownfields regeneration become very important issues as they create an alternative for uncontrolled suburbanisation related to many serious economic, environ-mental and social problems. Before 1989, in the former socialistic Czechoslovakia, the development of new housing project was especially based on the large collective housing plan and the most frequently realized housing project were in form of the panel houses. The return of market economy after 1989 opened the new era of dominance of individual housing projects and the residen-tial suburbanisation became very intensive in the surroundings of the large Czech cities (e.g. Prague, Brno). In this transition period, huge decline of many different economic activities took place (industrial, military, agricultural etc.) which resulted in enormous occurrence of brownfields. Their regeneration is quite complicated process because in order to redevelop successfully the brownfields it is necessary to interconnect technological (demolition, conver-sion, decontamination), architectural (morphology, continuity, aesthetics), legal (ownership, regulation, planning and buildings permits) and social (presentation, communication, negotiation) know-how. This contribution analyses the regeneration process of selected brownfields for housing needs on the territory of Brno city (second largest city in the Czech Republic) from perspective of the different groups of stakeholders. The research was conducted by means of qualitative interviews with the selected key stakeholders (e.g. developers of housing projects, owners of flats, representa-tives of self-government) with objective to identify main obstacles and barriers complicating the more intensive use of brownfields for housing needs.

Acknowledgements

This contribution was supported by the Czech Science Foundation (Geography of recycling urban space, 17-26934S).

Remediation strategy for Gdansk Shipyard as an example of brownfield management in Poland

Karol Pawelczyk¹; William Leys¹; Jan Van Schaeren²¹ AECOM; ² ReVive

Background/Objectives. Gdansk Shipyard is an iconic place in Poland. Here Communism started to fall in 1980 with the birth of “Solidarity” labor union, led by Lech Walesa. The shipyard operated since mid-XIX century, expanded after World War II and closed in 1996 after bankruptcy. Ever since activities at this area have been continued till present day by numerous companies active in industrial production and services. Part of this area covering approximately 16 hectares, located in the proximity of Gdansk city center and developed with old, industrial buildings was bought in 2017 by the Belgian brownfield redeveloper Revive together with Alides, in order to transform the area into a bustling and sustainable new district called Stocznia Cesarska. Due to the long industrial history soil contamination was present. Revive and Alides appointed AECOM to assess, investigate and elaborate the remedial strategy for the encountered soil contamination. In addition AECOM facilitated the collaboration with the Regional Environmental Protection Directorate (RDOS) in Poland during the whole project.

Approach/Activities. A phase 2 investigation was performed to determine the extent of the contamination and to allow an assessment of the economic and environmental risks. The site is contaminated with metals on the majority of the area. Additionally several hot-spots were impacted with PAH, petroleum hydrocar-bons and phenols. Based on the risk assessment, Revive and Alides purchased the property. Next a remedial plan (RAP) had to be prepared. In this phase close communication with the officials of RDOS to set the technical boundary conditions and goals of the remediation was crucial. The remediation approach should assure the elimination of risks for human health and the environment but also had to be cost effective, taking into account the vast contami-nated area. This risk-based approach was accepted by the officials and was possible due to the recent implemented Polish remedia-tion regulations.

The risk based remediation approach involves the removal of the hot spots impacted with TPH, PAH and phenols, and capping of all remaining area with either buildings and paved surfaces or a layer of clean soil on the unpaved areas. A good understanding of the conceptual site model, legislation and procedures and the good cooperation with the regulator led to the issuance of the decision approving the Remediation Plan in 2018. Remediation will be combined with the planned redevelopment process.

Due to economic growth and increasing residential prices, brown-field development is growing in Poland. This project has illustrated the potential and willingness for sustainable brownfield redevelop-ment in Poland.

In addition it can be stated that the ‘Flemish’ approach and knowledge of risk based remediation combined with the imple-mentation of European Legislation gave Revive and Alides confidence to make international brownfield redevelopment steps. In this perspective the knowledge regarding soil and brownfield remediation, as facilitated by the OVAM during the last 25 years, forms a very strong base to create an export and knowledge sharing product.

Rawfill-project : Innovative characterization(or investigation) of landfills and smart decision-making as part of the circular economy.

Eddy Wille¹; Renaud Derijdt²; Claudia Neculau³; Michaël Van Raemdonck¹¹ OVAM - Public Waste Agency of Flanders; ² Atrasol; ³ Spaque

The shift from a linear to a circular economy is one of the main policies in the EU. Many initiatives focus on resource efficiency, realized by a transition from waste management to sustainable material management. Urban mining is becoming an important supply of resources in the 21st century. This approach diverts our attention from the remnants of the linear economy: former landfills.

Although the EU-average landfilling rate is less than 40% and furthermore diminishing, estimations pointed out a huge amount of former landfills (over half a million). Most of these sites lack state-of-the-art environmental protection systems, leading to local pollution, land-use restrictions and even global impacts. Fortunately, these threats can be transformed into opportunities, as large volumes of resources (materials, energy and land area) in these landfills can be recovered through Landfill Mining (LFM).

In order to implement LFM widely, Interreg NW Europe RAWFILL tackles several barriers. The main challenge for stakeholders is the profitability risk due to the lack of reliable data on the recovery

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economy

The paper will present the results of numerous studies we conducted over the years to discuss and demonstrate why using the approach outlined here is a scientifically defensible and a sustainable option. We demonstrate why continuing to regulate on the basis of total pollutant concentrations is not a good science and continue to lead to a loss of best use of a valuable and finite resource (i.e. the soil). This goes against the community expectation and a circular economy that focuses on maximizing the reuse of resources and products. Hence, the need for industry and regulators around the globe to make science, community, and the circular economy the backbone of on setting the best soil management policy.

It is pleasing that the origin and age of pollutant are more consid-ered in assessing the risk. We have investigated this trend over many years and this paper will provide details about the evolution of this trend over the years around the world.

Despite an observed improvement, a lot of money continues to be spent on making decision on land use based on total concentra-tions of pollutants. We will address why this is a serious economic, community and resource conservation matter.

The paper concludes with why the regulatory total concentrations, still being used widely are “brain blockers” and what is a better alternative.

Monitoring of soil-like materials in view of potential re-use

Ute Kalbe¹; René Schatten; Tony Szuppa¹ Federal Institute for Materials Research and Testing (BAM)

Paragraphs 6 to 8 of the proposed amendment to the German Federal Soil Protection and Contaminated Sites Ordinance contain new requirements regarding the application of soil-like material outside of a rootable soil layer. For example, it is intended to enable reusing of soil-like materials containing regulated substances in concentrations between the single and double precautionary values (PV), provided that the limit values for the eluate are complied with. The aim of a running project (funding code UFOPLAN 3716 74 203 0, German Federal Environmental Agency) is to fill data deficits for soil-like materials which meet the above-mentioned criteria to promote circular economy and conservation of natural resources. Different soil-like materials of various origin (for example dredged material, banquet peeling material, urban and meadow soils) are considered with a special focus on PAHs. A major challenge in sample acquisition is the relatively narrow target range of the PAH content between 3 and 6 mg/kg dm considering a high measure-ment uncertainty at this concentration level.

The contents of PAHs, heavy metals and other inorganic elements in solid matter are determined following established standards. In addition, the soil-like materials are characterized concerning particle size, pH, conductivity, SOM, TOC and carbonate content. To determine the eluate concentration, column tests according to DIN 19528 and batch tests according to DIN 19529 at a liquid/solid ratio (L/S) of 2 l/kg and 10 l/kg are performed comparatively.

The results show that the new requirements of the planned amendment to the Federal Soil Protection and Contaminated Sites Ordinance certainly opens additional possibilities for reuse of soil-like materials. Even most soil-like materials within 2-3 x PV comply with the eluate value for PAH (0.2 μg/l) both in the batch test and in the column test at L/S 2 l/kg. Selected inorganic substances lead to similar evaluations. Therefore, the application of such soil-like materials outside of rootable soil layers would be possible. Previously, those materials were often used for landfill

potential. Even in the NWE region, inventories of the 100.000 LFs are inadequate, as they lack relevant data on the economic potential (quantity, quality and value of materials). Furthermore, traditional LF exploration methods are prohibitively expensive as they require analysis of multiple excavated waste samples.

RAWFILL develops an evidence-based, cost-effective enhanced landfill inventory framework (ELIF), an innovative LF characteriza-tion by geophysical imaging and guided sampling, and a two-step Decision Support Tool (DST) to allow smart LFM project planning, prioritization and interim use.

During this session, Rawfill-partners will emphasize the necessity of broad data collection in order to redesign the traditional risk-based landfill management into a dynamic resource supplying system. The inventory will be explained in relation to a compre-hensive Conceptual Site Model taking into account cross-cutting policies such as Sustainable Development Goals, Climate change and Land management.

The first step in the planning process will be demonstrated by a straight forward easy to use decision support tool (DST 1). The objective of this DST 1 is a quick scan of the landfill site potential and delivering guidance to the next steps to take. Given the expected low success rate of exploration and the long duration between the exploration phase and the effective mining, an interim use phase will follow the DST 1. An overview of those usages will be given.

ThS 7b | Reuse and upgrading of SSW & products; recovery of valuable resources; improving ecological functioning

How does contaminants bioavailability help sustainable soil use - science vs reality

Fouad AboGHD Pty Ltd

Pollutants risk in soils continue to be assessed, largely based on total concentrations. Little, albeit increasing attention has been given as to the real value that total concentrations of pollutants offer in the context of sustainable and stewardship of land (e.g. as compared to assessing the soils and plants health using the bioavailability concentrations). Plants are the better indicators for soil health; plants absorb bioavailable portion of pollutants. However, rarely pollutant concentrations in plants are considered in assessing toxicity of contaminants.

Generally, samples are not taken from plant when doing site contamination assessment. So are we missing a better use of science to assess soil sustainability and its stewardship?

In an urban environment, contaminated “soils” are largely different from standard soil classification, hence behaviour of contaminants are not readily predictable. This makes considering plant even more important as an essential part of contamination risk. Will discuss the soil science community recognising urban soil ‘anthropogenic soil” as a separate category.

We will discuss the relation between the level of bioavailability (bio-coefficient) in numerous sites and for a range of pollutants we have conducted over the years. We have demonstrated that such a meth-odology is more efficient than the commonly used total chemical extraction based method. Of course, the relevance of chemical extraction varies depending on the extraction method and soil type.

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economy

To investigate these issues a consortium has been set up between Verhoeve Milieu & Water, Proefstation voor de Groen-teteelt (Resaerch station) and BPK (Plant Nursery). Together they started the project ZuNuRec which means the ‘purification and nutrient recuperation’. It is a concept in which the crop protection products are removed from the drain water by means of ‘Advanced Oxidation’ and the nutrients are recovered via ion exchange. These nutrients can then be reused as a fertilizer in a recirculation system. Moreover the purified water can be analyzed on various param-eters with the aim of re-using it. This project is part of the program ‘Flanders Circular’.

Concerning the practical implementation the nutrients are recovered by letting the drain water flow over multiple resins. The current configuration of the unit consists of one cation resin for the removal of the cations (K, Ca, Mg,…) followed by 2 anion resins for the removal of the anions/nutrients (nitrate, phosphate,…). At the moment the resins are saturated they are flushed with chemicals to regenerate the resin and recuperate the ions/nutrients in a concentrated volume. These nutrients can be reused as fertilizers in the cultivation of young plant material. The purification of the remaining water is executed by advanced oxidation processes which make use of ozone, hydrogen peroxide and UV light.

ThS 7c | Nature based solutions: effectiveness for long term ecosystem services for soil & water

From contaminated space toward a meaningful place: reactivating soil, land and cities

Inge De Vrieze¹; Annelies Van Gucht²¹ OVAM; ² OVAM - Public Waste Agency of Flanders

A new future for the site “North Sea Bunkers”

Due to the “Protocol Trusty”, the OVAM was able to acquire a property located at the harbor of Ostend, for one symbolic euro. For years, the firm “The North Sea Bunkers” was a deposit for fuels. De legacy of this activity was a severe contamination of petroleum in soil and ground-water. The previous owner was bankrupt and therefore not able to pay for the soil remediation. Moreover, the estimated remediation costs were far above the sales value of the site.

The storage tanks and the building of the coast department were demolished, to make a thorough excavation of the hotspots possible. The main building, property of OVAM, situated at the harbor, could be retained.

The site has a unique location on shore. It lies on the border of two areas with on the one hand the redevelopment to residential area and on the other hand the existing port area. The port area has a fall back in terms of economic growth, such as many other port areas. Due to its specific position, the site has a strong potential for the launch of new dynamics on the Eastern Shore. Besides, the city of Ostend, is working with Architecture Workroom Brussels on a development strategy for the Eastern Shore.

Considering the remediation of the groundwater on the site is a long-term project, making the space temporary unavailable for further development, OVAM investigated the possibility of temporary use.

construction. In the future, a utilization in the adjacent environ-ment by backfilling, recultivation, renaturation, composting or landscaping would be conceivable.

Environmental Impacts of Lake Sediment Reuse as A Phosphorus-Rich Soil Amendment

Mina Kiani; Asko Simojoki; Jure Zrim; Olga Tammeorg; Petri Pentinen; Priit TammeorgUniversity of Helsinki, Finland

The crop phosphorus (P) demand is mostly covered by the appli-cation of non-renewable mineral P-fertilizers. The finiteness of rock phosphates and increases in fertilizer prices have underlined the need for nutrients recycling in agriculture. Further, excessive fertilizer applications go beyond the crop demand leading to the P transfer into water bodies, causing their eutrophication. Sediment removal from eutrophicated shallow lakes not only can be an effective method for lake restoration but also provides the potential of recycling nutrients from sediments in crop produc-tion. There is a paucity of information regarding the environmental impacts of reusing sediments as soil conditioners on agricultural lands to preserve nutrients and respond to crop demands. This research aims to find the best practice for reusing lake sediments in agriculture and landscape engineering in terms of agronomic performance as well as economic and ecological sustainability.

The study was conducted in the shore of a 1-ha heavily eutro-phicated lake from which sediments excavated. Four different sediment application methods were tested in a RCBD design with four replicates in 2017-2018. The treatments were pure topsoil, a mixture of soil and biochar on top of the sediment, a mixture of 2.5 cm of biochar with top 20 cm of sediment, and a 75–100 cm layer of sediment directly on topsoil. There was not the risk of heavy metal, PAHs, and PCBs contamination in sediment samples. The moisture content was significantly higher in sediment plots. Sediment phos-phorus was sufficient to re place fe rtilizer application in the plot. Sediment emitted up to 1.6 times more CO2 than topsoil which were probably due to higher moisture content and high rate of soil organic matter decomposition (supported by higher LOI value and higher temperature in sediment). However, Biochar addition signif-icantly helped to reduce NH3 emission from sediment.

Our results emphasize the importance of recycling sediments in terms of both agronomic and environmental benefits and consid-ering the alternatives to minimize the environmental effects and nutrient losses.

ZuNurec: purification and recupuration of nutrients for Flemish greenhouse wastewater

Jonas Wittocx¹; Els Berckmoes²¹ Verhoeve Milieu & Water; ² Proefstation voor Glastuinbouw

Due to the presence of nutrients and crop protection products drain water is a significant problem in the greenhouse horticul-ture sector. Because of the current standards it is not allowed to discharge drain water on the sewage or surface water. The manure decree obligates the growers to handle this on an environmental responsible way which means they can either use it on their land or they must let it be treated by a certified treatment center. The land-use of the drain water has important limitations and points of attention whereas the treatment is very expensive. A solution for this issue is highly desirable. In addition it is questioned if the nutrients can be recuperated and reused on a practical scale, espe-cially in recirculation systems.

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economy

re-Generation: Reusing brownfield sites for renewable energy crops). Initial monitoring was continued for a five-year period, including comparisons of the productivity and contaminant uptake in short-rotation coppice willow (Salix spp.), Miscanthus (Miscan-thus x giganteous) and reed canarygrass (Phalaris arundinacea) 1.

The results show that even after ten years, statistically signifi-cant differences can be observed between the SOC, nutrient and contaminant concentrations for the two highest application rates compared to 250 t.ha-1 or no compost. This concurs with the results of energy crop monitoring which showed that rates of 500 t.ha-1 or more were required to allow optimum establishment and productivity of energy crops 1. Annual release rates and half-lives of compost-borne nutrients and contaminants can be deduced by comparison of current soil concentrations to the original loadings calculated from original compost analyses and application rates. Soil organic carbon additions for different compost application rates over the first decade are compared to those required to meet the four per mille initiative launched at COP21 in Paris in 2015.

Acknowledgement: RL would like thank the British Land Reclama-tion Society legacy funding initiative for financial support.

1 Lord (2015). Reed Canarygrass (Phalaris arundinacea) outperforms Miscan-thus or willow on marginal soils, brownfield and non-agricultural sites for lo-cal, sustainable energy crop production. Biomass and Bioenergy. 78, 110-125.

Amended vegetation filters: a new nature based solution to treat wastewater, increase groundwater resources, recover nutrients and produce biomass

Virtudes Martínez-Hernández¹; Jorge Antonio Hernández-Martín; Raffaella Meffe; Ana de Santiago Martín; María Isabel López Heras; Covadonga Alonso-Alonso; Blanca Huidobro; Adriana Alonso González; Leonor Nozal; Irene de Bustamante¹ IMDEA Water Institute

A Vegetation Filter (VF) is a non-conventional water treatment technology where wastewater and/or treated water is applied for the irrigation of a forestry plantation. The treatment is carried out by the mutual action of soil, microorganisms and plants. The sorption capacity of the soil together with the C/N ratio of the water to be treated are essential parameters to maximize the efficiency of the two main processes responsible for contaminant attenua-tion: sorption and biodegradation, respectively. In this sense, the addition of two soil amendments, woodchips and biochar, has been tested as a strategy to improve nutrient and pharmaceutical attenuation in VFs. We expect that woodchips increase sorption sites and stimulate microbial activity by incorporating extra organic carbon to balance the C/N ratio. We hypothesise that the addition of biochar as a soil amendment considerably increases sorption sites and favours the establishment of the soil microbial community due to its high surface area. Besides their properties, both amendments have the advantage of being provided from the VF itself following therefore a sustainable and resource recovery approach.

To test these hypotheses, batch and infiltration experiments have been carried out at laboratory scale. A stock solution of synthetic wastewater (SWW) was produced mimicking the real composition of the wastewater used to irrigate a pilot scale VF. Batch tests were performed using an amendment/SWW ratio of 1:20 and an NH4+ initial concentration ranging from 6 to 600 mg L−1. To investigate the attenuation of nutrients and pharmaceuticals during vadose zone infiltration, three unsaturated infiltration experiments were performed. The systems contain natural soil, natural soil amended

For long, OVAM’s vision was to integrate remediation with rede-velopment of sites. Moreover, in recent years we increased our ambitions by supporting territorial development toward circular areas.

We do this by kind of ‘acupuncture pilot-projects’, were we re-use space by remediation and try to enhance the maturation of new meaningful places within territorial development. For this we work in co-creation with local stakeholders, local authorities and urban planners.

It is in fact a tailor-made approach with goal setting to redevelop specific ‘contaminated’ spaces toward meaningful places with focus on local societal challenges. Through careful tuning with the city of Ostend and involved stakeholders, it became clear that in this area local social projects enhancing contact & co-working between the two neighborhoods would be activating.

OVAM prepared the old building to guarantee safety, so that a non-profit organization with a matching vision of temporary filling with focus on circular economy can use the place for several years.

The presentation will point out how, with an open view and not afraid of searching beyond the borders of a traditional soil reme-diation, a soil remediation can contribute to make steps forward to a circular economy, on different levels.

Suggestion: We are convinced this is an interesting topic for an oral presentation, not only for topic 7a) Circular land use and brownfield regeneration , but it can also be presented under topic 6b or 7c.

In addition, we are also prepared to organize a free session since we know several cases considering integrated soil remediation with redevelopment towards circular places.

Long-term benefits of using green waste compost in land restoration as part of the Circular Economy

Richard Lord¹; Ruben Sakrabani²¹ University of Strathclyde, Glasgow; ² Cranfield University

Green waste compost is a widely available, low cost material suitable for soil amendment in the restoration and landscaping of brownfield sites for open space, forestry or ecological improve-ment. However little information exists in the academic literature on the long-term effects of compost addition to brownfield soils. A useful source of organic matter, which enhances soil functions, it containing total N, P and K which are initially unavailable to plants or groundwater leaching, released by degradation of the organic matter as a long-term slow-release source of nutrients. Protocols for topsoil-forming purposes often require one-off applications rates greater than are permitted in annual agricultural applications, with total N and P additions far exceeding limits set by the Nitrates Directive, Water Framework Directive, N or P sensitive zones. Due to its origin, typically as source segregated waste from urban areas, it characteristically contains above background levels of potentially toxic or phytotoxic elements, especially Zn, Cu, Pb, Cr, Ni, Cd, Hg, B, which are presumably also released into soils by breakdown of the resultant organic matter.

This paper will present the results of the reinvestigation of soil nutrient status and soil organic carbon (SOC) contents 10 years after brownfield soils were amended with differing rates of PAS100 quality compost in 2007 as part of a Waste and Resources Action Programme Trailblazer project. At the 1 ha Rainton Bridge site in NE England, either 250, 500 or 750 t.ha-1 of compost was spread and incorporated prior to planting of four energy crops, part of the EU Life Programme BioReGen Project (Biomass, Remediation,

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Thematic Session (ThS) – Topic 7 | Land, soil, water and sediment in the circular economy

the opening of new recycling platforms but also new technology requirements. For example, at present, few recycled gravels are used in construction materials such as concrete and this could be increased. The presentation will develop the levers identified (tech-nological barriers, taxation, social acceptability, political issues) and the results of the projection according to the scenario chosen.

Tidal wetland restoration projects as a nature-based solution: characterization & design considerations

Niels Van Putte¹; Patrick Meire; Goedele Verreydt; Stijn Temmerman; Piet Seuntjens; Poul Bjerg; Ursula Mc. Knight; John Devlin¹ Universiteit Antwerpen

The restoration of tidal wetlands along estuaries and coasts is often considered as a nature-based solution that can provide a multitude of services of great social, economic and environmental value to humankind. Tidal wetlands do not only decrease flooding risks and benefit biodiversity, they also store carbon and have the capacity to improve water quality in tidal rivers by the removal of nitrogen and phosphorus. Therefore, the number of tidal wetland restoration projects worldwide is rising fast. Nevertheless, there are more and more indications that restored tidal wetlands develop only slowly and do not deliver these ecosystem services to the same extent as natural tidal wetlands. In a previous study, we found that historical agricultural soil compaction in restored tidal wetlands has altered the soil structure, reducing porosity and forming an impermeable barrier for groundwater flow. We hypothesize that this imperme-able barrier puts constraints on the cycling of nutrients and hence on the water quality improving function of restored tidal wetlands. Given the increasing rate at which tidal wetlands are restored, there is a critical need to optimize the design guidelines for future tidal wetland restoration projects in an attempt to mitigate this problem.

The ultimate goal of this study is to formulate innovative viable design criteria to be implemented by the hydraulic engineering sector. The implementation of these guidelines will serve to reverse the effects of historical soil compaction by physically altering the structure of the soil by e.g. ploughing and/or mixing the soil with organic wastes. In this way, these physical alterations are expected to jumpstart the development of restored tidal marshes and the delivery of their ecosystem services, especially water quality improvement by nutrient cycling. To be able to formulate these design guidelines, we first aim to develop novel insights in groundwater flow and its effects on biogeochemical functioning in restored versus natural tidal wetlands.

In a first step, we characterize the differences in soil structural properties between a natural and a restored tidal wetland along the Scheldt estuary in Belgium. Furthermore, we also measure groundwater and nutrient fluxes using the newly developed iFLUX technology & the Point Velocity Probe. The results of the field study will then be combined in a numerical groundwater model. From this model, we will derive the design guidelines for future tidal marsh restoration projects.

Stakeholders for this project include academic researchers, the hydraulic engineering sector (e.g. DEME, IADC), marine and dredging consultants (e.g. IMDC), the waterway authorities (e.g. the Flemish Waterway) and nature agencies (e.g. ANB). As the hydraulic engineering sector is increasingly making a switch towards ‘building with nature’, the goal of this study fits perfectly in their long term business strategy.

with woodchips and natural soil amended with biochar. SWW was applied following the irrigation schedule of the pilot scale VF. Oxygen concentrations and water contents were monitored along the flow path.

Batch experiment results demonstrate that sorption affinity of NH4+ onto biochar (average Kd = 73.5 L/kg) is one order of magnitude higher than onto woodchips (average Kd = 7.7 L/kg). Hysteresis index (HI) in both amendments is higher than zero demonstrating a hysteretic behaviour. Results from the infiltration experiments show a high attenuation of total phosphorous (PT) (> 95%) in the three porous media and of total nitrogen (NT) in the soil amended with woodchips. Indeed, the average total nitrogen (NT) removal in the amended soil with woodchips is 82.7%, whereas in natural soil and natural soil amended with biochar, NT is not at all reduced. In these two porous media, all the NH4+ input concentra-tion is transformed to NO3-. It is evident from our research, that the amendments with woodchips are more effective for nitrogen removal than amendments with biochar. Woodchips act primarily as a labile source of carbon promoting biodegradation, being more effective for nutrient attenuation than the sorption capacity of biochar. To confirm this result also for pharmaceuticals, experi-ments are currently under development and outcomes will be presented at the conference.

To what extent can secondary mineral resources replace primary mineral resource ?

Jules Simonis¹; Daniel Monfort Climent¹; Céline Blanc¹; Barbara Chollet²¹ BRGM (French Geological Survey); ² Region Provence-Alpes-Cote d›Azur

New regulations in France attempt to take into account a circular economy in order to regulate the material flows from quarries. The south-east region of PACA was chosen to develop a large-scale model of primary resources versus secondary resources. Based on an exhaustive inventory of installations, this study identifies brakes and levers to develop secondary resources uses and simulates various scenarios for the next 14 years in order to assist in the political decision-making process.

All secondary mineral resources that can be used as substitutes for quarry materials have been studied (e.g. track ballasts, excavated soils, glasses) but the presentation will focus on aggregates and their substitutes. While this resource represents the main volume of mineral material transported within the region, it is the one for which the recycled materials rate of use is the lowest. In 2015, secondary materials represented only 3.7 million tons, out of the 24.5 million tons of aggregates produced in the region.

In order to increase the proportion of recycled materials used in construction sites, an inventory has been carried out. More than 200 installations were surveyed (recycling platforms, industries, quarries, landfills) to identify as precisely as possible the volumes involved, the capacities, the market difficulties. More than 50 project owners were interviewed in order to take into account the trend and nugget effects (major construction sites) in the future to determine the future gravel requirements and their position on the use of recycled materials. The presentation will show the results of this broad survey by highlighting the main locks and levers identified.

Following this observation, scenarios will be presented proposing important recycling rates for the coming years. For each recycling rate, the means to be implemented is identified. This may involve

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A risk site is defined by the Soil Decree as land on which a facility is or was established or on which an activity is being or was conducted that can cause soil contamination. These activities or facilities are listed in the VLAREBO implementation. To counter and prevent soil contamination, these risk-sites are required to undergo a preliminary soil investigation at the time of property transfer, on a periodical base or by closure of certain installations that could cause soil contamination.

To get an overview of all these potential contaminated sites in Flanders and identify those that still need to be investigated, the OVAM has compiled the land information register, in which the data of the local inventory of each municipality in Flanders is exchanged. With the help of OVAM and external experts, the local inventory of 306 out of 308 Flemish municipalities has now been completed, leading to a full overview of all risk-sites in Flanders.

It can be concluded that there are 85000 risk-sites in Flanders. Half of these sites have not been investigated yet. These sites generally include risk-sites with historical risk activities. Some of them are even newly identified risk-sites, where in the local inventory historical envi-ronmental permits with VLAREBO categories were linked to these sites. It is crucial that these sites are investigated to trace possible long-existing soil contamination. Therefore, the Soil Decree states that sites with historical risk activities or facilities must undergo a one-off preliminary soil investigation before 2021, 2023 or 2027 depending on the VLAREBO category of the risk activity.

For the risk-sites owned or used by the municipalities or public insti-tutes, the OVAM in cooperation with external expert Arcadis created a list of all risk-sites that are owned or used by each municipality and public institute, based on the local inventory and summarized the action per risk-site that still have to be performed. This way, the municipalities and public institutes are aware of the actions required by them and can set an example for the common civilian and companies to take responsibility to reach the deadline of 2036.

In conclusion, by using the database of risk-sites generated by the local inventory, all historical contaminated sites in Flanders can be traced and addressed to be in remediation by 2036. Not only will this safeguard our next generation with a fit for purpose soil, it will also help to reduce the pressure on open space in Flanders, since contaminated land can become available again for redevel-opment, sparing the already sparse open, green areas in Flanders. This presentation will give insights among others into the set-up of the database, the methodology of smart sheets and the exchange of data with municipalities.

Groundwater model of a large desert area in Algeria for groundwater resources impact assessment

Michele Remonti¹; Chiara Aquino¹; Andrea Gigliuto¹ ERM Italia S.p.A.

A regional groundwater flow model has been developed for the water-related risks management for the gas exploration of the Msari Akabli block in Algeria. Msari Akabli perimeter is located in the Tidikelt region of the Aloued District, Adrar Province, in the Central sector of Algeria, Southeast to the Grand Erg Occidental and South to the Tademait plateau, in the middle of the Sahara desert. The block extends 160 Km from North to South and about 80 Km from East to West, with a surface area of about 8.000 Km2. Some villages are included within the block’s perimeter; the largest of those is Aoulef (around 44.000 Inhabitants). The area is one of the driest area of the world, with annual rainfall of about 0.0 – 0.7 mm, annual average temperature of 27-28°C, annual maximum temper-

The application of passive sampling to monitoring of plant protection substances and pharmaceuticals in ground water

Jasperien de Weert¹; Foppe Smedes²; Nanne Hoekstra¹¹ Deltares; ² Recetox

In agriculture, plant protection substances (PPS) are used to protect the crops and manure is used to fertilize the soil. These PPS and antibiotics that may be present in the manure can be migrate through the soil and enter the ground water. This process can take years, but it will also take a long time before measures to protect the ground water from these substances will have an effect. Detecting contamination by organic substances like PPS at concentration levels well below quality standards can help to take measures in an early stage especially important to protect the drinking water wells. Regular monitoring is performed by pumping ground water and taking a liter of water sample. Due to this low water volume, the limit of detection is relatively high. Using passive sampling can increase this volume and therewith the limit of detection.

In cooperation with the Province of North Brabant in the Nether-lands we redeveloped the silicone rubber sampler for application in two ground water wells. For sampling of the more hydrophilic compounds we applied Empore disks. Because of the limited flow in the ground water wells we tested the application in static conditions and with refreshing the well water twice a day by pumping. Before and after the deployment of the samplers, regular water samples were taken to compare the results of the two monitoring techniques.

The results showed that with passive sampling a higher number of substances were detected in comparison with the water samplers, especially on the Empore disks. These were compounds like iprodion, oxamyl, isoproturon, metalaxyl en metolachlor that were measured in concentrations in the ng/l range. These substances were not detected before. Usual suspects like BAM, simazine and diuron, that are often detected in the regular monitoring were also present in both the water samples and the passive samplers. Also a couple of antibiotics and other pharmaceuticals were detected.

The effect of pumping on the sampling rate was limited. Conse-quently, it is sufficient to statically deploy the samplers what makes it an effective and simple tool to detect PPS and pharmaceuticals in ground water wells. After this study we applied the passive samplers in more projects for monitoring PPS and other compounds. During the presentation results of the different project will be shown and the added value of using passive sampling for monitoring ground water quality will be discussed.

Database of risk-sites in Flanders: Tracing and tackling historical soil contamination to safeguard a fit for purpose soil for our future generation

Inge Jambon¹; Claudia Rongen¹; Karen Van Geert¹; Bart D’Hollander¹; Kathleen Baets²; Kristel Declercq²; Inge De Vrieze²; Annemie Maes²; Nathalie Van Trier²¹ Arcadis Belgium; ² OVAM - Flemish Waste Agency

To tackle the problem of historical soil contamination and to guarantee a fit for purpose soil for our future generation, the Flemish waste agency (OVAM) imposed 2036 as deadline in which all historical contaminated sites must be in remediation. To trace historical soil contamination all potentially contaminated sites or so-called risk-sites must be identified and investigated.

Posters – 1a | Big data, smart data combinations

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Not all effects of projected climate variability are equally likely to result in disruptive and costly damage for contaminated site management; some risks, such as gradual warming, do not present the same potential for increased operational expense, as more intense effects like extreme weather events, and some regions are not projected to experience significantly altered climate. ERM is therefore focusing its analysis on extreme weather events that could result in illicit discharges. This poster describes ERM’s approach to this increasingly recognized need.

Interreg project sullied sediments: Set-up of a decision support tool on remediation techniques for contaminated sediments

Anissa Smits¹; Goedele Kayens²; Herman Brangers¹; Goedele Vanacker²¹ Witteveen+Bos Belgium NV; ² OVAM

As a part of the European Interreg project Sullied Sediments, an on-line decision support tool (DST) on remediation techniques for contaminated sediments is being developed. The aim of this project is to create a knowledge sharing platform on the different remediation techniques for contaminated sediments that are currently available. The ultimate objective of the project is to make the decision on an optimal remediation technique easier for soil remediation experts, policy makers, problem owners and other stakeholders in Europe. The DST can also be used as a first step in BATNEEC evaluations used for sediment remediation projects.

The project team conducted extensive research on the current available remediation techniques for contaminated sediments in Flanders and abroad. This included both in-situ techniques such as monitored natural attenuation (MNA) and capping as ex-situ tech-niques such as excavation and treatment at for example thermal treatment facilities. Because the feasibility and estimated cost price of ex-situ techniques largely depends on how the sediment is being processed, transported and de-watered, these factors were also investigated in more detail.

All the data collected within this study will be presented in a summary report and more importantly, will serve as input for the database of a decision support tool.

When using the decision support tool, the user will be asked to answer a number of questions. These questions relate to, among other things, the contamination situation, the geotechnical prop-erties of the sediment, the properties of the watercourse, the remediation objective, the duration of the remediation works and the impact on the environment. Based on the answers given by the user, the DST will make a selection of the techniques that are suitable for this specific contamination situation. In case of ex-situ techniques, the user may have to fill in a number of supplementary questions, based on which the DST will make a selection between the different dewatering techniques, transport and processing options.

The various remediation techniques will be further explained in technical information pages, extracted from the database, in which a description of the technique will be given and the advantages and disadvantages of the technique will be explained in more detail. Furthermore, these technical information pages will contain an estimate of the cost price of the technique in question, based on different cases or references.

An important part of the web-tool will be reserved for stakeholders, such as waterway managers and contractors. These authorities will be consulted in the (near) future and asked to provide (new) insights, which can be included in the decision-making process of the tool.

ature of about 35°C and maximum temperatures in the summer season reaching up to 50-55°C. The area hosts some of the most characteristics oasis of the Sahara desert, like those of Timimoun, Alouef and Tamentit.

The most important aquifer in the area is the Continental Intercalaire (CI), one of the two main hydrogeological units of the Northern Sahara system (SASS, Système aquifèr du Sahara Septentrionel). The CI in the area of interest is an unconfined aquifer, comprised of a sequence of continental clayey sands and sandstone referred to Albian, Aptian and Barremian ages (Early Cretaceous), overlying impervious Palaeozoic folded units representing the aquifer base. The aquifer has a thickness of about 80-150 m in the area of interest. The CI aquifer is exploited by local populations since thousands of years by means of water wells and by traditional drainage trench named “foggaras”, feeding the main villages and palm groves.

A steady-state GW flow model has been developed and prelimi-nary calibrated to make preliminarily predictions on the possible water-related impacts of the gas exploration activities, including seismic acquisition and drillings. The model has been executed with the finite-difference numerical code MODFLOW 2005.

Points of interest of the model are the pinch out the CI aquifer in the Southern sector of the study area, where the Palaeozoic bedrock outcrops, and the simulation of the foggaras network. Particu-larly, the foggaras geometry has been modelled considering the elevation of the ground at the outflow zone of the foggaras and applying to each trench a slope of the 0.1 %, defined in literature. The foggaras has been simulated using a Drain boundary condition, which allows the water outflow the model if the GW head is higher than its base elevation.

The model outcomes have been used to develop the Water Management Plan for the exploration and construction project, helping the stakeholders to understand the main water-related criticalities of the project and minimizing them.

Risk at the intersection of climate variability and contaminated site management

Owen Rudloff; Venkat KolluruERM

ERM is offering a service to contaminated site managers concerned with the impacts of climate variability on their remediation obliga-tions. Some geographies are already experiencing meteorological effects consistent with IPCC projections of 21st century climate variability. These effects, ranging from higher intensity hurri-canes in the Caribbean, to extensive coastline loss and permafrost thawing in the Arctic, to drought and intense heat in the tropics all pose serious threats to a number of sector. The threat posed to contaminant remediation sites is, however, exacerbated due to the increased potential for illicit discharge and subsequent environmental damage as a consequence of a number of these meteorological phenomena.

These phenomena all pose severe risks to physical remedia-tion infrastructure and containment systems in place to prevent the migration of contaminants offsite. To address this risk ERM is providing clients with downscaled climate risk assessments focusing on extreme events to evaluate the risks posed by climate change at an individual site level. ERM can offer an assessment of exposure to natural hazards; assess current and climate change extrapolated hazard vulnerabilities and develop GIS overlays to visually represent the potential difference; develop a risk matrix to identify short-term and long-term adaptation needs; and design adaptation measures that can be taken.

Posters – 1a | Big data, smart data combinations

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- Regarding safety aspects, it highly reduces risks as no operator is required on board.

- The automation of the survey process allows to minimize the time for collecting data and allows to have full control and high precision on the distribution and density of the measurements.

- The peculiar configuration of the vessels, driven by air propel-lers, allows to operate even in presence of algae formation or floating debris, which are frequently present on dam basins.

Pollution assessment by means of multivariate analysis and multispectral imagery in the surrounding soils of a derelict Hg-As mine

Carlos Boente; Lorena Salgado; Silverio García-Cortés; Nerea García-González; Arturo Colina; Eduardo Rodríguez-Valdés; José Luis R. GallegoUniversity of Oviedo

The abundance of Hg and As ores in Asturias (NW Spain) provoked the emergence of a mining district during the period between 1940 and 1970. The lack of appropriate technology, environmental awareness and regulations in that period caused a severe damage that nowadays persists after more than 40 years of abandonment of Hg production. This situation was exacerbated by the absence of restoration plans for the brownfields thereby promoting pollution in the surrounding soils of the waste stock-piles and ruined factories. One of the most impacted area is La Soterraña site, where As and Hg tailings were indiscriminately dumped in soils and the pollution was distributed in the area by wind erosion and water runoffs, affecting a vast extension of land.

The aim of this study consists in studying the impact and the reach of Hg and As pollution in soils of the surroundings of the brown-field. To do this, a soil sampling campaign (100 samples) was carried out in a 1 km radius from the center of the former facility, being specially focused in grasslands. The results (ICP analyses) obtained were interpreted using geochemical tools, including multivariate statistics and geostatistics. A second approach was carried out on the basis of remote sensing methodologies by means of multi-spectral analysis with images from: a) Sentinel-2 satellite; and b) drone-coupled Parrot Sequioa camera. These were used to identify areas with secondary accumulation of waste mixed with natural soil, to evaluate vegetation indexes to detect possible alterations of the flora, and to examine possible correlations with high concen-trations of Hg and As in the soils. Bands used for the interpretation were: Green, Red, Red Edge and Near Infrared for all images.

More than 90% of samples surpassed the Soil Screening Levels of As or Hg. Particularly, maximum concentrations in soils for Hg (860 ppm) and As (9,920 ppm) were found in the nearby soils of the brownfield. After a cautious treatment of outliers, multivariate statistics revealed that Hg is associated to clayey soil aggregates, while As is strongly correlated with Sb and showed a higher mobility. Samples were also classified by hierarchy clustering, this revealed clear trends in the groups formation in terms of their location and their proximity to the pollution focus. Spatial distribu-tion for Hg and As was also mapped by ordinary kriging.

Likewise, remote sensing allowed the evaluation of vegetation stress (higher in the closeness of the waste stock-piles), and the detection of parcels in which, probably, waste taken from the brownfield area was used for landfilling. In addition, the area down-stream the brownfield was pointed as the most affected after the interpretation of the image indexes thus suggesting the relevance

The information used in the database is meant to evolve and needs to be updated regularly, in order to be able to provide users with the most recent information on contaminated sediment remedia-tion techniques.

In the future, the DST can be connected with other tools or appli-cations concerning environmental issues, such as the Flemish “Waterbodemverkenner”, enabling to exchange information on an even greater scale.

Use of drone technology for single beam bathymetric survey of a hydroelectric dam reservoir located on the Tuscan-Emilian Appennine

Christine Ballarin¹; Andrea Moroni¹; Ester Nana¹ AECOM URS Italia S.p.A.

The work presented deals with the application of a low draft drone boat equipped with an echo sounder system and a GPS system to carry out the bathymetric survey of a hydroelectric dam reservoir located on the Tuscan-Emilian Appenine.

Activities were aimed at surveying the bottom of the reservoir following the Italian Dam Technical Authority request of carrying out a single beam survey to evaluate bathymetric changes produced by sediment deposition in the area of bottom spillway and of its surrounding.

The low draft drone boat was equipped with the following instru-ments: a dual-frequency GPS antenna for the plano-altimetric survey linked to the national network “italpos”, which allowed real-time corrections, and a single beam echo sounder using either a wired or Bluetooth connection. Measurements were taken continuously using a 1-second resolution interval. A professional hydrographic software package onboard the vessel was acting as data-recorder and real-time monitoring mean.

The bathymetric survey was performed using either manual or automatic navigation modes. The manual mode was used in those areas requiring detailed analysis (i.e. bottom sink area and its surrounding and in proximity of the shores) while the automatic one, enabled by the onboard autopilot, was employed in the rest of the areas using a preset spiral path (spacing of 10-15 m between parallel lines) and preset transversal sections. Throughout the survey more than 11000 points were recorded, which were then post-processed and used to create a 1m x 1m DTM through kriging interpolation. This allowed building transversal and longitudinal sections of the reservoir as well as the reservoir elevation-capacity curve. The drone technology was provided by AerRobotix s.r.l..

Furthermore, the whole study allowed to carry out indirect assess-ment of the bottom spillway state of conservation and the amount of deposited sediments, as well as the reduction percentage of the reservoir storage.

The application of the drone boat has the following advantages:

- The low draft of the drone is very useful in the case of strong sedimentation leading to reduced water levels, or when the movement of sediment must be avoided, especially when those sediments are contaminated.

- The ease of transport and deployment reveals to be very useful, especially when the reservoir is not accessible via road. In fact, it avoids the use of helicopters, which is essential in the case of traditional surveying through a boat, reducing considerably environmental impacts and costs.

Posters – 1c | New technological developments

157

shown to be difficult in practice. There is therefore an increasing interest in developing methods to document the effect of sub-slab ventilation solutions.

Computational Fluid Dynamics (CFD) is a recognized tool for modelling air flow in buildings, tunnels etc. Through recent years attempts have been made to describe flow patterns in sub floor systems by using CFD modelling. In 2016 a project was performed by Cowi to emulate the flow in compartments (e.g. crawl spaces) under floors. This project showed that increased pressure to the systems quickly entailed turbulent flow which can introduce problems when the aim is to control the airflow.

In 2017 a project was performed by the Capital Region of Denmark and Ramboll to assess whether CFD-modelling (and a freeware tool) could be applied to assess airflow in balanced ventilations systems in simple-geometric cells in a ventilation layer. This project clearly showed that CFD-modelling is a powerful and very useful tool in predicting and assessing the flow, pressure and the pollutant patterns in sub-slab flow cells with simple geometries.

In a new study performed by Rambøll (2017) CFD modelling has been conducted to assess the influence of obstacles in the sub-slab ventilation system and to include more complex flow cell geome-tries that are often the case in modern building designs. This study was financed by the Danish Environmental Protection Agency (published July 2018).

The presentation will show the results of both projects from 2017 and give the audience insight into:

• Governing mechanisms when designing sub-slab ventilation systems

• How internal square foundations and skew angles affect the distribution of air velocity and airflow in flow cells

• How it is possible to make adjustments to drain configurations in a way that improves the distribution of air flow

of leaching and water run-off & washout effects, especially active during winter months. Finally, areas of bare ground in grasslands were also observed in the images obtained, in coherence with points where high concentration of Hg or As were measured. On the whole, the combination of geochemical and remote sensing tools has been shown as promising approach for addressing extensive soil pollution.

Modelling of air flow in capillary break layers - A new approach to determine governing mechanisms in balanced ventilation systems preventing vapor intrusion of volatile pollutants

Jakob Skovsgaard; Hans BengtssonRamboll Environment & Health

Intrusion of volatile pollutants represents a risk to indoor climate in buildings at many sites. In Denmark, it is a widespread and commonly used practice to apply active or passive balanced venti-lation systems in the capillary break layers. This is done in order to reduce air concentrations to a level that complies with the appli-cable threshold values.

Increasing building activity in former industrial areas/brown-fields converting these areas into housing, institutions and commercial buildings is a consequence of urbanization. In these projects handling of polluted soil introduces costs to the building projects. But also, the presence of volatile pollutants like chlori-nated solvents, has shown to be a challenge to indoor climate in buildings. Introduction of a sub-slab ventilated layer has together with other remedial measures been discussed through the last decades. Controlling the air flow pattern in the ventilation layer and thereby the efficiency of the ventilation systems has however

Posters – 1c | New technological developments

158

The characterization of NAPL plumes, arising from spills and leaks from landfills and industrial facilities, and the monitoring of reme-diation processes are challenging tasks, specially in the case of Dense NAPLs (DNAPLs). The difference of density with water make DNAPLs migrate vertically towards the bottom of the aquifer gener-ating vertical plumes with complex 3D distribution. Non-intrusive screening methods (both geochemical and geophysical) are promising tools to obtain semi-quantitative, almost real-time 3D spatial information about the NAPL distribution in the sub-surface, allowing the monitoring of the advance of NAPL fronts and of the progress of remediation efforts. In this work, a combination of geophysical and geochemical tools is applied to the monitoring of an operation of injection-extraction of surfactant at a site contami-nated with a complex DNAPL mixture. Previously to the remediation, a tracer test was conducted in order to obtain estimates of the surfactant’s residence times. As a geochemical tool, Radon deficit technique was applied. The systematic measurement of Rn allows to obtain emanation maps, which can be interpreted, given the preferential partition of Rn into DNAPLs, as the surficial evolution of DNAPL saturation in depth. Electrical Resistivity profiles (ERT) were obtained to monitor variations in resistivity values during the injection and extraction operations. In addition, preferential flow directions were obtained during the assays through Spontaneous Potential (SP) profiles. Both, geochemical and geophysical, tech-niques results showed a good agreement. The Radon surface maps showed an increasing concentration trend, suggesting a reduction of DNAPL soil saturation. The ERT profiles showed the concentra-tion differences between the injection and extraction processes, as well as a preferential flow zone, coinciding with the one found with spontaneous potential. The preferential water fluxes obtained with geophysical techniques were in agreement with the low radon concentration singularities found in the geochemical maps. Thus, the combination of geophysical and geochemical tools seems to be promising in the monitoring of clean up processes in sites affected by DNAPLs.

Improvement of traditional investigations by prior geophysical measurements

Helle Blæsbjerg¹; Anja Melvej; Flemming Jørgensen; John Ryan¹ Central Denmark Region

Geophysical investigation methods has frequently been utilised in Danish groundwater mapping. The resolution of the upper soil layers has been inadequate for contaminated site investigations. Now, improved and new geophysical methods are qualified for high resolution interpretation of the uppermost geology.

The contribution of geophysical measurements to the tradi-tional concept for investigations of contaminated sites is tested. The project is part of the EU Interreg TopSoil project working on improvement of climate resilience by demonstrating and testing solutions for managing the top soil layers.

Traditionally, contaminated sites are investigated by drillings, soil- and water samples and soil gas measurements. Sampling points are based on potential existence of point source pollutions detected from historical archives, by interviews etc. Based on the first exami-nations subsequent point data are acquired in order to delineate the hotspot and/or plume. This approach contains a substantial uncertainty especially in a heterogeneous geological setting, thus a solid risk assessment implies a large number of point data.

The objective is to clarify if expenses and/or time can be reduced by adding an areal subsurface mapping (3D) to the investigation programme prior to the point data collection. Beside cost efficiency

A forensics-multivariate approach to the complex pollution affecting the environmental compartments in an industrial area

D. Baragaño¹; Nora Matanzas¹; Carlos Sierra²; José Luis R. Gallego¹¹ University of Oviedo; ² University of León

An environmental forensic study was developed in an industrial area of the shoreline close to Avilés, north Spain. Previous infor-mation about the site suggested potential Zn, Pb and As affection exceeding soil screening levels. The current study started with a geochemical characterization of the superficial soils that revealed anomalous metal(oid)s concentrations (Potentially Toxic Elements; PTEs) affecting samples taken both in anthropic fillings of the industrial parcels and in natural environments of the surroundings (sand beach, dunes).

The generated geochemical database (70 samples, 51 elements) was subjected to univariate and multivariate statistics. Factor Analysis by means of Principal Component Analysis (PCA) and Varimax rotation was carried out and six factors explaining more than 88% of the total variance were obtained. Moreover, in order to obtain groups of samples with similar geochemical profile, a cluster analysis was carried out by means of Ward’s algorithm and Squared Euclidean distance. Once sample groups were defined selected samples of each group were subjected to complemen-tary analysis such as hydrocarbons affection, lixiviation tests for heavy metal(oid)s, As and Hg speciation, grain-size distribution and mineralogical/microscopy analysis.

The univariate study showed normal distribution and low standard deviations for most elements, whereas some of the target PTEs revealed non-normal distributions and very high values in some samples (above Soil Screening Levels, with remarkable enrichment factors). As regards as factor analysis, the first factor (34% of total variance) revealed relevant PTEs (Zn, Pb, Hg, Cd and Cu) grouped together with high loads and clearly connected with the industrial activities taking place in the study area. A second factor could be associated with clayey materials (high loads for K, Al), a third one was leaded by lithophile elements probably related to the natural geochemical background in the area (V, REE), a fourth factor with elements typically bounded to iron oxides (Mo, Ni, Cr, Sn, Fe), a fifth one was composed of carbonate-forming elements (Ca, Mg), and finally, the last one only included As and Sb in coherence with the heterogeneous spatial distribution of these elements different to the other PTEs in the area. Furthermore, clustering grouped the study samples in six groups, each one of them characterized for high load of one of the abovementioned factors (factor-score matrix). This was useful to approximately define geographically zones with distinct geochemical profiles within the whole study area and therefore to identify hot plots to be assessed in a risk assessment approach. Results of the complementary screening for organic pollutants, the addressing of PTEs available fractions and samples mineralogy were also useful to identify sources and pathways for pollution in the environmental compartments studied.

Combined geophysical and geochemical tools to monitor DNAPL decontamination processes

Barbara Biosca; Fernando Barrio-Parra; Ana Artalejo; Miguel Izquier-do-Díaz; Eduardo de Miguel; Jesús Díaz-Curiel; Rafael Medina FerroUniversidad Politécnica de Madrid - ETSI Minas y Energía

Non-Aqueous Phase Liquids (NAPLs) are the object of global concern since they pose risks to human and environmental health.

Posters – 2a | Advances in assessment of risk and monitoring of soil, sediment and water quality

159

the aim is to replace part of intrusive methods with non-intrusive methods and also to improve the risk assessment based on the areal subsurface mapping data. The final output should be recom-mendations for a better integrated practice.

The aim is to reduce the number and optimize the location of point data with geophysical mapping performed prior to any detailed investigations. This mapping was carried out with the tTEM instru-ment. tTEM is a small transient electromagnetic system towed after an ATV with a speed of 10-20 km/hour. The depth of investigation is up to 70 meters.

The testing has been carried out on polluted sites originating from two former landfills and two agricultural contractors. The geolog-ical settings are primarily composed of quaternary sediments like clay tills and meltwater sands.

A: Landfill leachate threatens the local drinking water abstrac-tion. tTEM mapping indicates potential dispersal pathways allowing an optimized siting of boreholes.

B: An agricultural contractor has caused a pesticide contamina tion that threatens the local drinking water abstraction. tTEM mapping indicates a coherent micaceous clay layer that will reduce the need of boreholes substantially as the mica clay layer will retain pesticides in the upper aquifer.

C: Landfill leachate threatens a major drinking water abstraction. tTEM mapping indicates a potential clay barrier that controls the dispersal of the plume. This knowledge enables improved in-depth investigations and reconsiderations regarding reme-diation strategies.

D: An agricultural contractor has caused a pesticide contamina tion that may or may not threaten one or more local drinking water abstractions. tTEM mapping indicates a thin clay layer in the upper layers of a buried valley. This clay layer has turned out to be decisive for the risk assessment.

Sources, fate and impact of polycyclic aromatic hydrocarbons in soils of a broad industrialized area in Northern Spain

Carlos Boente¹; Diego Baragaño¹; Alicia Fernández-Braña; José Luis R. Gallego¹¹ University of Oviedo

One of the principal industrial locations of Northern Spain is Langreo, a municipality that in the past had a powerful economy linked to heavy industry and mining. In fact, more than one century of coal mining and industrial activities (power plants, metalworking, fertil-izer, pharmaceutics, etc.) has triggered the release of hazardous pollutants such as polycyclic aromatic hydrocarbons (PAHs) or heavy metal(loid)s. PAHs are among the most important classes of organic pollutants. They can be widely dispersed through atmospheric depo-sition or stream pathways, being thus spread in air, water, sediments, and also soils. PAHs have been catalogued as mutagenic or carcino-genic compounds. On the other hand, heavy metal(loid)s consist of a group of inorganic contaminants that have long residence times and are easily assimilated by natural organisms.

Therefore, the main goal of this work is to assess sources, fate and impact of the PAHs in the soils of Langreo municipality and to ascertain whether they are related to the occurrence of heavy metal(loid)s reported in previous studies of the area. To this purpose, the research has been accomplished by means of the analysis of 16 PAHs for 150 soil samples, which complemented a previously available database of 37 chemical elements (including heavy metal(loid)s) for the same samples. These were taken all along the municipality after a careful design through transects that

were equidistantly distributed by considering the geomorphology of the area, an inventory of brownfields as well as the different uses of soil. Results were examined through different assessment tools as uni- and multi-variate statistics, geostatistics, and molecular diagnostic ratios for PAHs.

Results revealed high concentrations that exceeded the Soil Screening Levels (SSLs) for several PAHs in many samples; moreover, point-source (outliers) and diffuse sources were distin-guished. Particularly, the SSL of benzo[a]pyrene, a carcinogenic compound (group 1-IARC), is broadly surpassed in a wide surface of the total area; this suggests that the current Spanish SSL for this pollutant could not be appropriate for densely industrialized areas. In addition, other possible carcinogenic PAHs (group 2B-IARC) such as benzo[b]fluoranthene, benzo[a]anthracene and dibenzo[ah]anthracene presented also concentrations surpassing the limits. In this context, multivariate statistics showed that PAHs distribu-tion is partially correlated with that of the inorganic pollutants with the highest enrichment factors in the study area (e.g. Pb). Here it was also aimed to classify the PAHs by means of several molecular diagnostic ratios, in order to address petrogenic or pyrogenic origins thereby distinguishing different sources (coal, other fossil fuels, etc.). Selected samples were also subjected to GC-MS forensic tools that allowed a more detailed identification of sources and a complete fingerprint of hot-points that should be more deeply studied. Finally, geostatistics allowed representing the spatial distribution for the PAHs of concern.

In sights within a remediation project: Use of data dashboards to interrogate and understand a modern groundwater remediation project

Andrew BroadwayERM UK

The use and variety of in-situ technologies for source zone reme-diation has increased rapidly over the last two decades. During this time, a number of process and fluid delivery methods have been refined to improve technical performance, sustainability and overall efficiencies. However, it is only more recently that the role of data management has been recognised as key to enabling remedi-ation programmes to be managed safely, be performed effectively in a cost effective manner, and achieve regulatory ‘close out’.

The presentation will outline the approach taken by ERM to collect, process, manage and interrogate data from multiple sources within a groundwater remediation system. This is focus on an on-going ERM solvent recovery project, at a fractured bedrock site in the UK. Data collection was integral to the remediation design with remote operation and data access built into the equipment. Data from the multiple level logger, flow meter and water quality meters was transferred via a 4G data connection to a central database off –site; while field was collected data using Tablets running a bespoke application. Final visualisation and interrogation of the data was via a Power BI dashboard incorporating additional statistical analysis using R. This approach has significantly reduced data processing time and onerous reporting requirements, enabling the system to be rapidly optimised, and meaning the US based client can easily review progress online at their convenience.

This and the other case studies presented show that whilst the tech-nology basis for many of the remediation techniques has not changed significantly, integrated data management is advancing rapidly and is critical to achieving efficiencies from a safety, time, cost and carbon footprint perspective, irrespective of the remediation technology deployed. This is a trend that is expected to continue to evolve.

Posters – 2a | Advances in assessment of risk and monitoring of soil, sediment and water quality

160

On the use of geophysical monitoring to monitored DNAPL extraction

Jacques Deparis¹; Antoine Joubert²; Benjamin Francois¹; Thomas INVERNIZZI²; Ali Iravani¹; Alain DUMESTRE²; nicolas fatin rouge³; julien maire³; delphine kaifas⁴; aurelien triger⁴; pierre-yves klein⁴; Quentin Giraud⁵; Benoit Paris⁵; David Cazaux⁶; David Ca¹ BRGM; ² SERPOL; ³ Université de Franche-Comté; ⁴ Sol Environment; ⁵ Intera; ⁶ INOVYN

Industrial activities in France has led to emergence some abandoned and polluted sites. After many years of research on the cleaning up the soil, the contamination of the soil because of DNAPLs (Dense Non-Aqueous Phase Liquid) is still one of the main environmental concerns.

Conventional In situ monitoring of the treatment is expensive, invasive and can be insufficient as the information provided is restricted to vertical profiles at discrete locations with no informa-tion between sampling locations. Geophysics allow spatializing borehole information. These include the utility of geophysical methods to characterize, monitor and quantify soil remediation. The physical characteristics of a pollutant are very different from those of water, monitoring, surveillance, surveillance, surveillance, monitoring, flow monitoring, flow change ([1], [2]). Among the wide range of geophysical methods available, electrical geophys-ical parameters, (i.e. resistivity and chargeability), is well adapted in order characterized the pollution and to monitor migration of DNAPL through saturated porous medium ([3]). These parameters depend, amongst others, on DNAPL presence and concentration.

Geophysical monitoring of cleanup was carried out on an experi-ment site equipped to monitor time-lapse changes in electrical properties (resistivity and chargeability) by systematic 2D tomog-raphies. 96 stainless steel electrodes with a spacing of one meters along a line are used for the profile. Piezometrical level of the water/DNAPL interface was measured during the depollution process. Pumping phases have been carried out in order to overcome as far as possible technical limits. First step consists of pumping DNAPL in a static state, then groundwater are pumped, in a so called process “upwelling”. During this step, injection of pumped (salt) water was carried at the extremity of the site.

The result shows that the resistivity decreases along time around 8 meters depth, which matches the polluted zone defined by geochemical borehole analyses. Indeed, the salt water takes the place of the DNAPL. In fact salt water is less resistive than the DNAPL explain why we observe a decrease of the resistivity. Our results argue that electrical measurements is able to monitor DNAPL depollution process and will allow us to give a practical non-intri-sive method of monitoring and evaluating in situ remediation.

In parallel, laboratory study have been realized in order to study the electrical properties of pollutant. The pollutant is a mixture of chlorinated organic compounds with the density of 1660 (kg/m3) and viscosity of 0.0045 (Pa.s.). Each experiment is realized through three series of drainage and imbibition process under columns (5.56 cm long, diameter of 5.80 cm) in order to estimate residual saturation of pollutant. Packed small cells are used in order to obtain the relation between resistivity and saturation (calibra-tion curve). The glass bead’s size, temperature, and surfactants are varied for different experiments. The goal of this experiment is to propose a triphasique empirical model linking the water/soil/pollutant system.

Evaluation of biodegradation and biostimulation potential within a chlorinated ethene-contaminated aquifer using advanced monitoring tools

Anko Fischer¹; Petra Bombach¹; Kevin Kuntze¹; Joachim Richter²; Annika Beckmann²¹ Isodetect GmbH; ² HPC AG

Bioremediation strategies are cost-effective and low-invasive for cleaning up contaminated sites (Majone et al. 2015). However, their application requires a thorough understanding of the geochem-istry, hydrogeology and microbiology of the contaminated field site, under both natural and engineered conditions (Majone et al. 2015). One major challenge is to provide evidence of biodeg-radation processes and to quantify the removal efficiency. Besides conventional methods such as assessment of concentrations of pollutants and redox parameters, advanced monitoring tools are recommended for the evaluation of pollutant biodegradation (Bombach et al. 2010).

In the present study, we investigated the in situ biodegradation of chlorinated ethenes (CE) within a contaminated aquifer using compound-specific stable isotope analysis (CSIA; Fischer et al. 2016) in combination with qPCR analysis of taxonomic (anaerobic: Dehalococcoides spp.; aerobic: Polaromonas JS666) and functional (anaerobic: tceA, vcrA, bvcA; aerobic: etnABCD, etnE) genes (Hug et al. 2013, Mattes et al. 2010). Only genes of anaerobic CE degrada-tion could be detected. This indicated that main CE degradation occurred under anoxic conditions, which was confirmed by redox parameters. CSIA revealed complete CE degradation. Based on the CSIA results, in situ degradation of CE was quantified.

In order to verify the results of qPCR analysis and CSIA as well as to investigate the potential of biostimulation for enhancing CE degradation, a laboratory microcosm study with 13C-labelled TCE, cis-DCE, and VC (Fischer et al. 2016) was conducted under in situ-like conditions without and with O2-addition using sediment and groundwater from the field site as inoculum. Reductive dechlo-rination of VC under anoxic conditions was proven by the detection of 13C-ethene confirming the complete dechlorination of CE. Oxygen addition led to the mineralisation of VC as well as cis-DCE, which was detected by the formation of 13C-CO2. The aerobic biodegradation of VC was faster than the reductive dechlorination of VC under anoxic conditions, demonstrating the potential for enhancing CE biodegradation at the field site.

The results of the multiple-line-of-evidence approach provided a solid base and important requirement for future management decisions at the field site.

Bombach, P. et al. (2010): Current approaches for the assessment of in situ biodegradation. Appl. Microbiol. Biotechnol. 86, 839-852.

Fischer, A. et al. (2016): Application of stable isotope tools for evaluating natural and stimulated biodegradation of organic pollutants in field studies. Curr. Opin. Biotechnol. 41, 99-107.

Hug, L. A. et al. (2013): Overview of organohalide-respiring bacteria and a proposal for a classification system for reductive dehalogenases. Philos. Trans. R. Soc. B 368, 20120322.

Majone, M. et al. (2015): In situ groundwater and sediment bioremediation: barriers and perspectives at European contaminated sites. New Biotechnol. 32, 133-146.

Mattes, T. E. et al. (2010): Aerobic biodegradation of the chloroethenes: pathways, enzymes, ecology, and evolution. FEMS Microbiol. Rev. 34, 445-475.

Posters – 2a | Advances in assessment of risk and monitoring of soil, sediment and water quality

161

A sensitive method for determination of legacy and emerging perfluorinated alkyl acids (PFAAs) in environmental samples (water, soil, sediments, and sludge) using liquid chromatography tandem mass spectrometry

Devanathan Gnanasekaran; Sven Herremans; Kris De Koninckx; Evy Weyn; Noor Van Looveren; Luc Deren; Marc Van RyckeghemSGS Belgium NV

Perfluoroalkyl and polyfluoroalkyl substances (PFASs), including the perfluoroalkyl sulfonic acids (PFSAs) and perfluoroalkyl carbox-ylic acids (PFCAs) are a group of compounds with unique properties including resistance to degradation, thermal stability and unique surface tension. Due to these properties, PFAS compounds have lead to being used extensively in a wide range of industrial appli-cations and variety of commercial products. PFAS have received substantial attention, primarily due to abundant applications, envi-ronment persistence, bio-accumulation and pose potential threats to ecological and human health. Therefore, the primary production of some of these molecules (legacy PFAS) and related chemical species are banned but numerous alternative chemistries (ex; GenX) have emerged to replace the discontinued species. In this study, a method was developed for the determination of legacy compounds including perfluorooctanoic acid (PFOA), perfluo-rooctane sulfonate (PFOS), and perfluorohexane sulfonate (PFHxS) and the emerging alternative chemical species (FRDs) in different types of water (ground water, surface water and waste water), soils and sediments/sludges using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC–MS/MS). The extraction capacities and separation efficiencies were tested with different cartridges and columns. The method uncertainty, recovery and precision were determined and found to agree with the reference methods. The quantification limit comprised in the water samples were with the range of 1–5 ng L−1 and in sediment 0.05-0.1 ng g−1 range. This method was applied successfully to quantify individual PFAS in environmental samples.

AMIIGA project as an example of advanced investigation, assessment and remediation of groundwater contamination crossing the urban areas and adjacent hinterlands

Grzegorz Gzyl¹; Petr Kohout²; Sandra Vasin³; Donata Balzarolo⁴; Marco Ghirardi⁵; Joerg Prestor⁶; Goran Gjetvaj⁷¹ Central Mining Institute; ² Forsapi Ltd.; ³ City of Stuttgart; ⁴ Lombardy Region; ⁵ Municipality of Parma; ⁶ Geological Survey of Slovenia; ⁷ Faculty of Civil Engineering, University of Zagreb

AMIIGA project tackles the issue of complicated groundwater contamination crossing administrative borders. In 6 Central European countries, representing the typical groundwater contam-ination problems, AMIIGA project is testing advanced investigation and assessment tools:

• statistical analysis to explore large monitoring datasets

• numerical modelling to spatially delimit the boundary of the plumes

• CSIA (Compound Specific Isotope Analysis) to distinguish between contaminant’s sources and demonstrate degradation processes

• BMT (Biological Molecular Tool) to evaluate the capability of indigenous microbial consortia to degrade contaminants in situ.

In Milan (IT) the management of groundwater, the main drinking water source, need to distinguish between point sources and diffuse contamination. AMIIGA tools application like CSIA, inverse modelling and statistical methods helps in decision making process to plan and select measures of intervention.

In Stuttgart (DE) groundwater contamination by CHC originates from industrial city district. It migrates through complicated geological structure and poses a risk to mineral springs. Numerical modelling of contaminant transport investigates plumes in public areas. An efficient monitoring of groundwater quality trends is designed with the help of representative observation wells.

In Jaworzno (PL) innovative remediation by reactive bio-barrier is tested for groundwater contaminated with pesticides. Both BMT and CSIA, to verify chemical and biological degradation, were tested. The contamination spread is investigated by numerical modelling to assess if the plume originating from the area of chemical plant groundwater poses a risk to drinking water resources.

In Novy Bydzov (CZ) the pilot application of biologically enhanced reductive dehalogenation is tested as a perspective remedia-tion technique for planned full scale remediation of groundwater contaminated by CHC. The innovative BMT is used to assess the effectiveness of the process.

In Ljubljana (SI) different contamination sources threaten the drinking water supply from the aquifer beneath rural hinterland and city core. Contamination plume of desethyl-atrazine from the past agriculture activities, chromium plume from industry and new emerging pollutants represent highest risk. Numerical modelling, CSIA and BMT are used for sources identification and risk management.

In Zadar (HR) the water supply depends on the karst aquifer which is at risk due to uncontrolled sewage disposal at rural areas. The Zadar pilot action gives an opportunity to test numerical modeling in karst conditions.

In Parma (IT) the groundwater is contaminated by CHC in the very center of the city. Numerical modelling and backtracking, BMT and CSIA are employed to find the possible contamination sources and the conditions of an effective Natural Attenuation.

The variety of undertaken measures and goals of pilot projects will be tailored to the key indicators for managing of groundwater contamination in urban areas and hinterlands. Further recom-mendations will be given by the project expert panel, whose cooperation and practice represent the truth added value of the project.

Development of vertical cross section distribution investigation for chlorinated hydrocarbons in gravel geology

Hsin Lan Hsu¹; Shen Chieh Lin¹; Wen Tzu Liu²; Yu Chieh Chou²¹ Industrial Technology Research Institute; ² Tricorntech Corporation

The traditional contaminated site investigations mainly focused on the two-dimensional surface information which is not sufficient for environmental forensic of Dense Non-aqueous Phase Liquid (DNAPL). The transportation path of this pollution is complicated because of its insolubility. In addition, DNAPL may be present in the subsurface in various physical states which are difficult to predict the distribution of the target in the unsaturated zone. Building a three-dimensional conceptual site model can clearly clarify the vertical cross section of underground environment. High Reso-lution Site Characterization (HRSC) is an appropriate solution to

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investigate if there are significant seasonal variations in the back-ground levels in outdoor or indoor air, and if various factors are consequential in relation to the background levels; e.g. tobacco smoking, wood stove heating, rural/urban areas, town/city size, habits/methods of venting, traffic etc.

Two sampling rounds were conducted, in November 2015 (131 sites) and May 2016 (142 sites), respectively. The methods included filling in of a questionnaire concerning all factors that might have an influence on background levels of VOC in indoor and outdoor air. Passive sampling by ORSA-tubes was conducted in a standard-ized manner in the outdoor and indoor air, and were analyzes by a professional laboratory (TVOC as C6-C35, BTEXN and C9/C10-aromatics). Statistical analyses were carried out, identifying statistically significant trends in the collected data.

In the Danish regulatory framework, the background levels of benzene and TVOC (C6-C35) are the compounds causing difficul-ties in relation to risk assessment at contaminated sites. More than 99% of all indoor and outdoor measurements of benzene are above the Danish regulatory criteria of 0,13 µg/m3. For indoor air, the median values are: May: 0,44 µg/m³, Nov.: 0,66 µg/m³. For outdoor air the median values are: May: 0,28 µg/m³, Nov.: 0,50 µg/m³. 29% of all indoor measurements of TVOC (in un-contaminated Danish homes) are above the regulatory criteria of 100 µg/m3. Hence, background levels of (primary) benzene and TVOC are of impor-tance when assessing the risk for vapor intrusion of benzene or VOCs from a subsurface contamination to the indoor air. Smoking and wood stove burning are identified as major contributors to high background benzene levels in residential areas. Surprisingly, benzene concentration in outdoor air are found to be at the same level in rural and in urban areas.

Functional bacteria for phenanthrene degradation in petroleum-contaminated soil during nature attenuation (NA) and bioaugmentation (BA) processes revealed by DNA-stable isotope probing

Jidong Liang; Sha Gao; Man Zhang; Zijun WuXi’an Jiaotong University

DNA-stable-isotope probing (DNA-SIP) as a culture-independent method was used in this study to reveal functional bacteria for phenanthrene degradation in petroleum contaminated soil during nature attenuation (NA) and bioaugmentation (BA) processes. A mixed bacteria culture named LG (isolated from the in-situ petroleum contaminated soil by culture-dependent method) was used as inoculum for BA. Comparing to NA, LG addition in BA treatment has not only increased the phenanthrene degradation significantly but also changed the bacterial community evidently. As expected, enhancement in phenanthrene degradation rate of about 10% has come out in BA in the third day compared to NA. However, it is surprisingly that the abundance of all strains in LG has decreased after 3 days incubation and has not been labeled as functional microbes in phenanthrene degradation. Instead, some new taxa have been identified in BA as functional bacteria which were different from natural attenuation (NA). The PAH-ring hydroxylating dioxygenases alpha subunits (PAH-RHDα) gene was quantified by real-time quantitative polymerase chain reaction (qPCR) in third and sixth incubation days, and the results showed that BA has stimulated the production of PAH-RHDα for phenan-threne degradation compared with NA. In conclusion, this study has proved that BA was a promising bioremediation method and DNA-SIP as a culture-independent method provided a new sight in functional bacteria identification.

collect exhaustive site characterization information including hydrological, geological parameters and contaminant distribution. However, providing a sufficient data density cannot be obtained in a cost or time efficient way, it is necessary to have the support of real-time pollutant data which can provide the location of the screen and the well depth on-site.

The objective of this study was to develop a cost-effective vertical cross section distribution investigation for chlorinated hydrocar-bons through a detection system which is capable monitoring the target compound in real-time. Several DNAPL sites in gravel aquifer were chose to be the experiment object since most contaminated sites in Taiwan were located in a gravel layer. The concept of the investigation method was to refine borehole process by offering DNAPL concentration distribution profile along the drilling depth immediately. The first stage of the experiment was to evaluate the analysis accuracy of a portable gas chromatography (MiTAP DNAPL, Tricorntech Corp.) which equips a detector specific to chlo-rinated hydrocarbons by measuring the concentration of target compounds in the groundwater. In the second phase of the experi-ment, MiTAP DNAPL was introduced to the DNAPL site investigation procedure for real-time detection. Groundwater samples which were corresponded to various depths were collected by bailer during the interval of casing pipe installation. Finally, this investiga-tion was further applied in tracing the contaminant source plume. All the experiment data as mentioned above were compared with the result acquired by standard investigation method announced by Environmental Analysis Laboratory (EPA, R.O.C.).

Preliminary results have shown that the qualitative and quanti-tative analysis of chlorinated hydrocarbon in the groundwater via MiTAP DNAPL and gas chromatography-mass spectrometry individually present a high consistency. The application results of MiTAP DNAPL on the vertical cross section distribution inves-tigation for chlorinated hydrocarbons methods showed a similar trichloroethylene concentration underground distribution profile with the standard investigation method. The effect of our investi-gation method on tracing the DNAPL source plume could provide an approximately potential source extent in a relative low cost way. In conclusion, vertical cross section distribution investigation for chlorinated hydrocarbons in gravel geology offered a cost and time efficiency way for forensic techniques of environmental pollutants.

Hydrocarbon background levels in Denmark in indoor and outdoor air

Boerge Hvidberg¹; Per Loll²; Per Novrup¹¹ Central Denmark Region; ² Dansk Miljoeraadgivning A/S (DMR A/S)

Indoor and outdoor air typically contains volatile organic compounds (VOCs) from both outdoor and indoor sources. The VOC levels originating from such sources can be referred to as “background levels”, when assessing the potential for vapor intrusion of VOCs from a subsurface contamination to the indoor air. When measuring VOCs directly in indoor air at contaminated sites, the resulting concentration will contain a contribution from background sources as well as a contribution from the subsurface contamination. When determining whether or not remediation of sub-slab contamination is warranted, or remediation goals are met, it is important to know if the presence of volatile organic compounds (VOCs) in indoor air is primarily from background sources, or primarily from subsurface contamination.

Aim. The primary study objective is to produce updated back-ground hydrocarbon levels in both outdoor and indoor air, at non-contaminated Danish homes. Secondary purposes are to

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30-90 cm and 90-150 cm below the sediment surface (bss). Deeper sediment intervals were assessed at 150-cm intervals. Based on the field screening, samples were selected for NAPL mobility testing by water-drive method. Water-drive tests were performed on 33 samples to measure NAPL mobility after passing three porewater volumes of water through approximately 5-cm diameter and 5-cm thick sediment subsamples. The water drive tests included TPAH measurements and pre- and post NAPL saturation measurements using the “Dean Stark” method.

The multiple lines of evidence collected in OU2 were evaluated to characterize the potential for NAPL mobility and to delineate the remedial action boundaries. Twenty-five of the 33 NAPL mobility tests produced no NAPL. The remaining samples indicated some NAPL production during mobility testing. Water drive test results and corresponding PAH data were used to identify TPAH concen-trations associated with NAPL mobility. The other lines of evidence, when correlated to TPAH concentrations, were used to provide additional confirmation of NAPL-related boundaries. Ultimately, the proposed sediment remediation area includes 1) areas that pose an unacceptable risk to human health due to the potential for contact with NAPL and related elevated PAHs in surface water, 2) locations with unacceptable ecological risks associated with elevated COCs in sediment, and 3) areas where the presence of surface NAPL sheens are known to occur.

Innovative, multi technique investigation for residual NAPL presence in order to assess bedrock remediation at a site in Sweden

Patrik Nilsson¹; Jonas Bruzell¹; Rogier De Waele²; Michela De Camillis²; Martin Slooijer²¹ Projektengagemang AB; ² GreenSoil International B.V.

GreenSoil BV and Projektengagemang (PE) have undertaken several field studies to identify potential residual chlorinated solvents in fractured bedrock below a 27,500 m2 metal manufacturing site in southern Sweden. Historic site operations included degreasing of metals and spray painting. A faulty solvent pipe resulted in a 1,4 km long diffuse plume of TCE. The volume of lost product is unknown, but in excess of 200 kg was recovered from soil in the source area between 2012 -2018.

The site is located on permeable, glacio-fluvial deposits, above a significant groundwater protection zone. Depth to bedrock, which is composed of granitic gneiss, ranges from 5 to approximately 16 m.

Fracture zones can be significant migration pathways for rapid contaminants transport. The locations of down-gradient, plume hot spots show a strong correlation with such structures. It was therefore proposed that residual NAPL may not only occur in, but also have migrated extensively downwards, with dissolved phase migrating laterally in the bedrock fracture zones.

In order to determine the potential presence of residual NAPL in bedrock, which likely constitutes a secondary source area feeding the plume, an investigation was proposed using a combination of bedrock investigation techniques.

Geological mapping, focused on fractures in outcropping bedrock near the site, was used to develop a geophysical resistivity study of the subsurface geology surrounding the site. Three 400 metre long lines, aligned to intersect the detected fracture sets, were laid out in optimal directions along and down-gradient of the site to intercept likely target sets. Interpreted profiles from the lines indicated a major, 100m wide fracture zone directly under-neath the source area which projected extension aligns with the

A contaminant mass recovery model for electrical resistance heating sites: Comparison with actual data

David Rountree¹; John La Chance¹; Paul Hegele²1McMillan-McGee Corp.²Euremtech-McMillan McGee Europe

Typical operational questions faced at Electrical Resistance Heating Sites include:

• When have asymptotic conditions been achieved?

• What is the contaminant mass remaining?

• How long should operations continue to achieve a particular concentration goal?

Timely and accurate answers to these questions may help to minimize operational duration and cost. A contaminant mass recovery model is presented incorporating electrical heating, convection, heat loss, and thermal conduction, as well as vapor- and groundwater-phase contaminant transport to an extraction well. This model may be useful in providing accurate answers to the above questions at Electrical Resistance Heating Sites.

A model for contaminant mass recovery using first principles was extended by adding thermal conduction, and vapor- and ground-water-phase contaminant transport to an extraction well. This model is then compared to contaminant mass recovery data from actual sites for evaluation and calibration.

Results from modeling indicate that geometric considerations alone have significant effect on contaminant mass recovery. The relative effects of vapor mass transport also has a significant effect. The model results are compared to actual site data, and rules of thumb relating contaminant mass recovery rates and contaminant mass remaining are evaluated.

Characterizing NAPL conditions and chemical risks in support of river sediment cleanup

J Mark Nielsen¹; Kim Groff¹; Victor Magar¹; Victor Magar¹; Helen Fahy²¹ Ramboll; ² Fahy Associates

Sediment located along the Hudson River, in the northeast U.S., is impacted by historical activities, including the manufacturing of paving and roofing materials and oil recycling. These historical activities resulted in the presence of polycyclic hydrocarbons (PAHs) and nonaqueous phase liquids (NAPLs) within a 10 hectare study area. Multiple remedial alternatives, including in-situ treatment and capping, have been identified to reduce ecological risks. This presentation discusses the results of site investigations that were used to delineate remedial action boundaries based on an under-standing of NAPL migration potential and sheening.

Site investigations were conducted in 2018 to supplement a remedial investigation with the objective to: 1) identify and delineate the distribution of site-related NAPL and PAHs in river sediments; 2) identify specific sediment areas that may pose unac-ceptable human or ecological risks associated with the presence of NAPL. These results were integrated with existing informa-tion (offshore chemical, hydrological, and ecological conditions) to define the limits of site-related impacts that warrant reme-diation. Field methods included the collection of 9 m sediment cores for field screening. The cores were delineated at ~5 to 10 cm intervals, from top to bottom using 1) visual observations for NAPL; 2) ultraviolet light (UV) fluorescence; 3) FLUTe liner paper reactivity; and 4) photoionization detector (PID) readings. Total PAH (TPAH) concentrations were measured at 0-15 cm, 15-30 cm,

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Chinese sampling guidance does not properly evaluate sampling error, which is the major source of error for soil environmental monitoring data. To improve sample representativeness and confi-dence in analytical data, decision unit multi increment sampling (DUMIS) has been proposed and successfully used for expedite investigation of contaminated sites in the US, Canada and Denmark etc. Yet, it has never been demonstrated in China. The objectives of the present study is to explore the suitability of modified DUMIS in performance evaluation of immobilization of a Ni and Pb contami-nated site in China.

The demonstration site was a former inorganic salts producer, located in Shandong province, China. Environmental investigation showed that industrial activities and illegal burial of hazardous waste have caused soil contamination of Ni and Pb at the site. Ex-situ immobilization was proposed as the remedy. Contaminated soil was excavated and mixed with immobilizing agent using ALLU sieving and mixing equipment. Treated soil was then piled up for curing followed by confirmation sampling.

In compliance with existing Chinese remediation confirmation guidance, decision unit (DU) was set as one DU per 400m2 or 500m3 soil. For each DU, a multi increment sample was taken with a hand auger from top 0-20 cm of 50 subsample points evenly distributed within the DU. In one of the field DU, two sets of triplicates were taken, one by DUMIS method (50 subsample points) and the other by the routine method (9 subsample points). To evaluate the field sampling error, triplicates were taken from 10% of DU in the field.

The results showed that the relative standard deviation (RSD) of all field triplicates ranged between 3.8% and 66%. The triplicates with high RSD were collected from pit wall or pit bottom with lumps of Ni containing hazardous waste.

This study demonstrated that DUMIS method produces high quality data which greatly improved the confidence in remedia-tion performance evaluation at the site. Therefore, DUMIS method has great potential to be applied in remediation performance evaluation in China. More sites varying in contaminant types, reme-diation technologies need to be tested to draft tailor made DUMIS guidance in China.

37Cl- and 13C-compound specific isotope analysis and biomolecular tools to monitor chlorobenzene biodegradation

Tatiana Stella¹; Andrea Franzetti¹; Francesca de Ferra²; Ilaria Pietrini²; Giovanna Carpani²; Orfan Shouakar-Stash³; Ramon Aravena⁴; Luca Alberti⁵; Massimo Marchesi⁵¹ University of Milano-Bicocca, Milano, Italy; ² Decarbonization and Environmental R&D, ENI Spa, Italy; ³ Isotope Tracer Technologies Inc., Waterloo, Canada; ⁴ Department of Earth and Environmental Sciences, University of Waterloo, Canada; ⁵ Politecnico d

Monochlorobenzene (MCB) is frequently found, along with higher chlorinated benzenes, in the subsurface nearby industrial areas as result of its widespread use as a solvent. Thus, the design and implementation of innovative techniques to assess the biodegra-dation potential for MCB of an impacted-site represent a crucial issue. Within this frame, an integrated approach based on dual Cl- and C-Compound Specific Isotope Analysis (Cl- and C-CSIA) and Molecular Biology Tools (MBTs) was developed as supportive tool to estimate the occurrence of MCB aerobic degradation at contaminated sites. At first, a new analytical method for 37Cl-CSIA of MCB was developed by gas chromatography continuous flow isotope ratio mass spectrometry (GC-IRMS) to couple with

shape of the plume. The source zone was subsequently targeted through drilling of three 40m deep bedrock borings, in which a combination of NAPL FLUTe™ and FACT™ liners were inserted. These liners will show a stain where a product-bearing fracture intersects the borehole liner. The activated carbon liners collect and trap any dissolved phase product migrating in intersected fractures. The carbon is then analysed to show the relative concen-tration variation of contaminants down the length of the borehole. Thus, the reactive liners allow determination if, and to what depth, free phase product occurs along the intersected fractures in the boring, whereas the FACT allows determination of the depth of impacted groundwater in that location. Boreholes where staining or dissolved phase TCE occurs are scanned using an acoustic tele-viewer to identify the strike and dip of impacted fractures. The flow in fractures is measured using loggers while seasonal groundwater level fluctuations are monitored using Divers.This iformation is used to predict the impacted areas, and will direct additional bedrock boreholes to delineate the size and depth of the source zone.

This session describes the results of the multiple technique investi-gations and how this new conceptual model is used to design and improve product recovery from the site.

Use of innovative techniques to determinate volumes of contaminated sediments in Flanders

Els Ryken; Ward De Cooman; Nico Meyskens; Niels BillenVMM (Vlaamse Milieumaatschappij - Flemish Environmental Agency)

The Flemish Environment Agency (VMM) monitors sediment quality and quantity in its watercourses. Starting from 2018, the VMM has been using an Unmanned Survey Platform (USP) for soil sediment volume calculations. This USP is easy to transport, very mobile and deployable in locations with limited access. The device can navigate autonomously or can be steered manually. Acoustic techniques allow to measure the thickness of the sediment layer in various watercourses. From this, the volume of sediment that needs to be removed can be calculated. These data are shared with contractor companies, allowing them to offer accurate quotations and to plan and execute dredging activities in an efficient and effective manner. Quality control can be easily monitored during and after dredging activities.

Application of decision unit multi-increment sampling (DUMIS) in performance evaluation of immobilization of a nickel and lead contaminated site: a case study in China

Jing Song¹; Roger Brewer²; Wei Tang¹; Genyan Xu¹; Xin Gao¹; Juan Mao¹; Yang Qian¹¹ Institute of Soil Science, Chinese Academy of Sciences; ² Hawaii Department of Health, USA

In recent years, brownfield sites have become an important source of land for urban redevelopment in major Chinese cities. According to Chinese laws, contaminated sites have to be cleaned up before land transaction and redevelopment.

National and regional technical guidelines are available to evaluate the performance of remediation. However, current guidelines are based on discrete sampling method. Due to the inherent hetero-geneity of pollutant distribution, the representativeness of discrete samples has been proven questionable. In addition, relevant

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metals and metalloids in the storage site, and to understand the relationship between the release of toxic trace metals and metal-loids and chemical characteristics in the rock. The level of variation in toxic trace metals and metalloids released by 6-hour batch and 24-hour batch leaching tests depended on the element, and the level of toxic trace metals and/or metalloids release by the 24-hour batch leaching test was higher than those by 6-hour batch leaching test. In the 24-hour batch leaching test, the coefficient of variation were 17.5% for B and 18.2% for F, respectively, while those were 43.8% for As, 48.5% for Se, and 40.5% for Pb, respectively. In the relationship between sample size and estimated error by statistical analysis, the error of sample size at 5 rocks masses were 21.7% for B and 22.8% for F, while those were 54.3% for As, 60.2% for Se, 50.3% for Pb, respectively. Those errors were corresponded to 16-36% of the variation at 50 rocks messes. The positive liner relationship was found between the level of toxic trace metals and metalloids and the pH of excavated rocks while the negative liner relation-ship was found with the amount of amorphous Fe (pH, As: r=0.791, Se: r=0.442, Pb: r=0.752, Amorphous Fe content, As: r=-0.795, Se: r=-0.464, Pb: r=-0.729). Amorphous Fe, ignition on loss, electron microscopy analysis suggests that the pH variation within the excavated rock results from the formation of iron hydroxide by the dissolution of the siderite and/or oxidation of pyrite. A large variation in the release of toxic trace metals and metalloids was observed at pH of 10 although within < pH of 10, there is a corre-lation between the release toxic trace metals and metalloids and pH. The factor resulting in such variations should be elucidated in future studies.

Enhanced data collection in the field: Onsite, high resolution VOC analysis in soil and ambient air during investigation and remediation of a chlorinated solvent contaminated site

Wim Vansina¹; Arnout Soumillion¹; Yves Van den Bossche²; Pieter Buffel³; Samuel Van Herreweghe¹¹ Witteveen+Bos Belgium NV; ² OVAM; ³ EnISSA

From the 1950’s up to 2001 a wool factory was located on a site situated in the center of a small village called Dikkelvenne (Belgium). Those former industrial activities have led to a contami-nation of soil and groundwater with chlorinated solvents of which traces have been found in a natural spring 150 meter away. The OVAM (the public waste agency of Flanders) has appointed Witteveen+Bos Belgium to design a remediation concept for this contaminated site.

The success of soil investigations and remediation designs is highly depended on a solid and constantly adjusted conceptual site model (CSM). The CSM is built by collecting data from the site under investigation. Underestimation of the contaminated area and or pollutant load can lead to an inadequate remediation design resulting in project failure, budget overshooting and residual risks. A detailed visualization of the contaminant situation will provide the consultant an improved insight in the source, pathways, exposure and remediation alternatives. The whole process of delineation and mapping of the contamination can become a very intensive and time consuming task. Despite the low detection levels and broad and accurate analysis spectrum of analysis tech-niques in laboratories, a large portion of the accuracy is already lost during the traditional sampling, handling and conservation in the field. Environmental consultants are sometimes blindfolded by the final analytical certificate which give them a false sense of certainty. Furthermore the number of data points is often very low compared

13C-CSIA. Afterwards, samples (groundwater and sediments) from a heavily MCB contaminated site were collected and MCB aerobic biodegradation microcosms were set up under both natural (NA) and enhanced (ENA) conditions to evaluate MCB degradation rates, to calculate 13C and 37Cl isotope enrichment factors associated to the aerobic degradation process of MCB and to assess the presence of catabolic genes potentially involved in the biodegradation of MCB. MCB degradation was significantly enhanced by adding inorganic nutrients. As a matter of fact, MCB was completely degraded in ENA microcosms within few days of incubation. On the basis of these results, the evaluation of C and Cl isotope fractionation was performed on ENA microcosms. A negli-gible fractionation for 13C was observed (δ13CMCB up to 0.7‰). Conversely, δ37Cl data showed a small but significant fractionation which is a reflection of a secondary isotope effect. On average, enrichments higher than 2.5‰ were measured for a decrease in concentrations over 95%. Furthermore, since isotope enrichment factors strictly depend on the enzymes involved in the degrada-tion reactions, quantitative Polymerase Chain Reaction (qPCR) analyses were performed to assess the presence of two functional genes possibly involved in the aerobic MCB degradation pathways, namely toluene dioxygenase (todC) and phenol hydrolase (phe) genes. qPCR results showed a significant increase in todC gene copy number with respect to its initial levels suggesting its involve-ment in the MCB aerobic degradation and the possibility to use it as functional site-specific biomarker for such process. In conclu-sion, this study demonstrated that the application of a dual isotope approach (37Cl vs 13C) can be useful for distinguishing anaerobic and aerobic processes in field studies. Furthermore, the quantifica-tion of the copy number of catabolic genes which catalyse different transformation reactions can provide additional information concerning the degradation pathway. Although the increase of the copy number of catabolic genes cannot provide unequivocal proof of bacterial degradation activity, it can still give greater confidence for CSIA data interpretation from contaminated sites, particularly in MCB aerobic biodegradation for which the fractionations can be somehow limited.

Chemical characteristics and toxic elemental release from excavated shale and its variation

Shoji Suzuki¹; Toshihiko Miura²; Kazuki Ide²; Kenichi Ito³; Masahiko Katoh¹¹ Meiji University; ² Obayashi Corporation; ³ University of Miyazaki

Huge amount of tunnel-excavated rocks are generated from urban and mountainous areas in association with effective utilization of the underground space and construction of modern and high-speed railway and road around the world. The excavated rock often contains toxic trace metals and/or metalloids at the background level of geosphere. Excavated rocks is concerned when toxic trace metals and/or metalloids are released exceeding the environmental standard for soil (0.01 mg/L) due to the physicochemical alteration by exposing water of air after the excavation. The excavated rock is expected test using pure water with liquid-solid ratio of 10 and 6 hours contacting time was applied for environmental risk assess-ment of excavated rock. One of the concerns of risk assessment is sampling representative. When the risk assessment, one rock mass is collected from about 300-500 m3 of temporal storage site for excavated rock. However, it is not understood the representa-tive of rock sample collected by such procedure. Therefore, in this study, we randomly collected 50 rock masses from about 100 m3 of temporarily storage site for excavated shale generated in tunnel construction to evaluate the variation of release of toxic trace

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procedures for subsequent chemical and ecotoxicological testing of soil and soil materials Part 3: Up-flow percolation test) in ISO/TC 190 (Soil quality), SC7 (Soil and site assessment) WG6 (Leaching test) and related studies, including evaluation of repeatability as well as effects of flow rate and initial saturation time, are carried out under the leadership of Japan,

Accumulated knowledge of different soil using this test can play an extremely important role for the following stage after standardization of the test. In recent years, several studies have applied contaminated soil to the up-flow column tests. However, a few cases were related to naturally contaminated soil. This study examines the leaching characteristics of boron and fluorine from naturally contaminated soil and simulated soil by using the up-flow percolation tests.

Six soil samples used in this study are 3 types of naturally contami-nated soil, 1 simulated soil, 1 anthropogenically contaminated soil, and 1 source-unknown soil. For the naturally contaminated soil, N-1 was fine-grained marine sediment, N-2 is sandy marine sediment, and N-3 is naturally contaminated terrestrial soil. Each sample was wet-sieved ( < 2 mm). The up-flow percolation tests are performed according to the procedure described in the ISO/TS 21268-3.

In this study, up-flow column tests using 6 soils are conducted aiming to evaluate leaching characteristics of fluorine and boron.

BoronThere is no significant difference for the shape of breakthrough curve between naturally contaminated soil and simulated soil. The maximum concentration at L/S=0.1 and subsequent rapid decrease of concentration are observed. It is confirmed that inclination of concentration decrease is slow as CEC of the soil increases.

FluorineThe shape of breakthrough curve obtained from simulated soil is different from others. Similar to boron, maximum concentration is observed at at L/S=0.1 for the simulated soil, whereas other soils samples show a different pattern with concentration increase after L/S=0.1, followed by appearance of maximum concentration, and concentration decrease.

Future studies will be conducted by increasing numbers of soil samples and target substances to establish the database for naturally and anthropogenically contaminated soil and investigate the possibility to identify the source of contamination according to results of the up-flow percolation tests.

to the investigated area and volume. Since hydrogeology and contaminant concentration can vary on a small scale (centimeters), a limited data set can be problematic and will result in a CSM with considerable data gaps, uncertainties and wrong conclusions.

To update the CSM and to verify the horizontal and vertical extent of the contaminated area, Witteveen+Bos Belgium decided to carry out a number of EnISSA-MIP probings. This GC-MS based improved version of the Membrane Interface Probe system, generates detailed depth profiles of the VOC’s. Because of the sensitive detector, also the delineation of plume concentrations (10’s of μg/L) for the different degradation products is possible. The EnISSA-MIP investigation has been combined with the Hydraulic Profiling Tool to collect more data on soil permeability, which allows us to gain insight into the different migration pathways and the soil layers where to expect ‘storage’ of the chlorinated solvents. High perme-ability intervals were detected and correlated with the presence of sandstone and boulder deposits. However, the EnISSA-MIP inves-tigation was only used in a later stage of the investigation and the number was rather limited, the 7 EnISSA-MIP logs performed to check and update the CSM resulted in 210 data points for each evaluated compound, or 70 ’information meters’. A comparable investigation effort, i.e. 7 monitoring well’s with 1 or even 2 screens would have resulted in only 7 or 14 data points or ‘information meters’. A 3D application was used to visualize the results.

Leaching characteristics of Fluorine and Boron from artificial and non-artificial contaminated soils using up-flow percolation test

Tetsuo Yasutaka¹; Yukari Imoto¹ National Institute of Advanced Industrial Science and Technology

In evaluating environmental risk caused from contaminated soil, it is important to know leaching characteristics of the related contamination substances. Leaching tests can be grouped into Compliance Tests, checking if result values of the target substance comply to the standard values, and Basic Characterization Tests, clarifying characteristics of target substances leaching from soil. The Basic Characterization Tests include up-flow column tests, serial batch tests, and pH(stat) leaching tests. The international standardization of the up-flow percolation column test is now in progress. Investigation of robustness for ISO/TS 21268-3 (Leaching

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An innovative technique to evaluate commingled plumes and assess remedial progress - A case study

Craig CoxCox-Colvin & Associates, Inc.

In the mid 1990’s, raw water samples from a municipal well field in the Midwestern section of the United States detected low concen-trations of chlorinated solvents. In response to these detections, the environmental regulatory body overseeing the well field began to investigate groundwater quality associated with poten-tially-responsible industrial facilities located upgradient of the well field. Four industrial facilities were identified as potentially-responsible parties and were asked to participate in a cooperative investigation/remediation effort. Instead of forming a coopera-tive group, each industry chose to complete its own assessment. By coincident, all of the industries used generally the same set of chlorinated solvents at their facilities, and were located along a common groundwater flow path.

Regional groundwater investigations were undertaken by the industries to determine the nature and extent of contamination. Data collected as a result of the investigations were shared, and a common database application developed to facilitate assessment. The investigation, completed over a period of four years, resulted in the collection and interpretation of groundwater samples from nearly 500 individual sampling locations.

To determine the allocation of responsibility, locate other poten-tially-responsible parties (additional source areas), and monitor source area and groundwater remediation efforts, an innovative approach to data interpretation was developed. Using GIS software, contaminant ratios in the form of “pie” charts were plotted for every groundwater sample collected in the study area. Based on the information collected, it was demonstrated that the ground-water contaminant plume complex consisted of six distinct plumes extending for 7.5 kilometers and reaching a width of 1 kilometer.

An underlying assumption of the approach is that when contaminated groundwater exits a source area, its contaminant ratio is established and remains constant even though the total concentration declines as the plume extends downgradient. This is especially true for chlo-rinated VOCs because the rate of biologic degradation in aerobic conditions is minimal. Another underlying assumption is that ground-water flow lines represent no-flow boundaries, and that the degree of transverse transmissivity is minimal. Changes in the contaminant ratios, therefore, indicate the presence of a new source area.

The advantage of this approach is that: 1) it can incorporate data collected from a variety of sources (domestic wells, monitor wells, temporary groundwater sampling transects, production wells, etc.); 2) does not require specialized analytical techniques; and 3) can be used with historical data sets. In addition, the same charac-terization techniques can be used to monitor groundwater quality improvement following source area remediation efforts.

This presentation will discuss the 20-year history of the project from discover through remediation. Three separate remediation projects will be documented and the effectiveness of the technolo-gies used will be demonstrated using the visual characterization techniques developed for the project.

LDPE passive samplers for assessing risks for groundwater related to hydrocarbons leaching from soil

Daniela Zingaretti¹; Iason Verginelli¹; Renato Baciocchi¹; Raffaella Borrelli²; Alessandro Oldani²; Fabio Vago²; Luciano Zaninetta³¹ University of Rome Tor Vergata; ² eni s.p.a.; ³ Syndial

Leaching of hydrocarbons from the vadose zone to groundwater represents a critical migration pathway in risk assessment of contaminated sites. Therefore, innovative approaches are needed in order to evaluate it correctly, allowing to overcome the limitations due to the simplistic approaches used in the leaching models used in risk assessment standard procedures. In this work, the leaching behavior of hydrocarbons (HC) from a diesel range organics (DRO) contaminated soil has been investigated by passive sampling with a LDPE (Low-Density PolyEthylene) film. The feasibility of this approach, which allows to sample only the (bio)-available fraction of hydrocarbons, was tested by comparing its results with those obtained from batch leaching tests performed on the same soil. Soil samples used for the tests were collected from a former gas station and were characterized by DRO average concentration of 8000 mg/kg. Batch leaching tests on soil samples were performed using deionized water at different liquid/solid ratios, i.e. 0.26, 2, 5 and 10 l/kg, in a 100 ml Pyrex bottle on a horizontal tumbler for 24 hours, with or without the addition of a LDPE film (70 um thick) of approximately 200-300 mg weight. At the end of the test, the supernatant and eventually the LDPE film were extracted with dichloromethane and the extract analyzed by GC/FID for HC concentration. From the HC concentration in the LDPE (CPE), the HC aqueous phase concentration (CW) was calculated using the equilibrium partitioning constant between the two phases (KPE-W (24 h)), estimated through calibration performed at the same conditions of the leaching test, starting from standard aqueous solutions of HC, in the presence of a LDPE film. The log(KPE-W (24 h)) was estimated between 3,5 and 4. The results obtained for the leaching tests derived from LDPE samplers provided quite repro-ducible data, with HC concentration in the aqueous phase between 4 and 10 mg/l, for all the tested L/S ratios. These values were close to the ones inferred from the aqueous phase extracts, for the tests performed at L/S ratios equal to 5 and 10 l/kg, whereas the results obtained at L/S ratio of 2 without LDPE film were not reproduc-ible due to the interference related to the presence of particles in the liquid. The risk for groundwater calculated with the Risk-net software 3.0, based on the ASTM-RBCA approach, starting from the soil concentration were close to the ones estimated from LDPE or leaching data when HC speciation and soil limit of saturation were accounted for, whereas it was higher of more than one order of magnitude when the soil limit of saturation was not accounted for, as foreseen by the guidelines issued by the Italian ministry of environment. The results obtained in this work suggest that LDPE can be used as in-situ passive samplers to estimate the available HC concentration leached from contaminated soil to the groundwater. The data provided can be then used in risk assessment models to correctly estimate risk for groundwater from leaching of contami-nants from the vadose zone, thus overcoming the limitations of leaching models starting from soil contamination data.

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for creating a 3D model depicting the situation. The model revealed a large contamination plume spreading from the main source zone located under the foot of the landfill in an old drainage system area. Furthermore, it helped us to determine several other source zones and to understand new facts about former activities at the site, which significantly affected the contamination spreading.

Based on the 3D model developed, 70 new direct push moni-toring/injection wells together with 8 conventional monitoring/pumping wells were installed in the forest, and soil samples were taken during their installation. Results of analyses of both the soil samples and groundwater samples correlated with the results of the MIP investigation.

Based on this detailed investigation, a remediation strategy was developed, using combined treatment technologies based on ISCO and aerobic biodegradation of target contaminants, in combina-tion with a pump and treat system. The actual remediation of the contamination plume will start next year, after the source zone treatment via its excavation and landfill restoration.

This extensive investigation approach is unique, especially in Central Europe, and proved to be a powerful tool for creating relevant conceptual site models of such complicated sites.

Oil spill forensics: Polluter does (not) get away with it

Arnout Laureys¹; Luc De ren²; Marc Van Ryckeghem²; Sven Herremans²¹ SGS; ² SGS Belgium NV

Advances in Oil Spill Forensics Using Combined Biomarkers and Isotope Ratio Technique

Oil and related petroleum products are vitally important in our daily lives both at home and in business/industry. Unfortunately, oil spills and contamination are a side effect of these prolific uses. The efforts to determine liability when contamination occurs, to recover cleanup/remediation costs, have grown dramatically in the last decade. Environmental forensics has emerged as a discipline directed toward this goal.

Oil is a complex mixture of components, which makes it chal-lenging from an analytical perspective. The formation of oil, which is a natural process, makes it possible to select and differentiate specific characteristics of the oil. Biological markers or “biomarkers” are one of the most important hydrocarbon groups in petroleum. Relative to other hydrocarbon groups in oil such as alkanes and most aromatic compounds, they are more degradation-resistant in the environment. Also biomarkers formed under different geolog-ical conditions and ages may exhibit different fingerprints. These components can be detected in low quantities in the presence of a wide variety of other types of petroleum hydrocarbons by the use of gas chromatography/mass spectrometry (GC/MS). Chemical analysis of environmental samples for biomarkers generates valuable information for environmental forensic investigations to determine the source of spilled oil. One needs to be careful as the determination of biomarkers as the sole parameter can lead to false or misleading conclusions and thus needs to be well interpreted.

In recent years, stable isotopes, primarily determined through the use of combined gas chromatography -- Isotope Ratio Mass Spectrometry (GC-C-IRMS)¬¬¬ -- has emerged as an additional important tool in environmental forensics. Determination of stable isotopes is not new, having been around for over 50 years. The ability to determine the isotopic composition of individual compounds in complex mixtures is relatively new and came about with the development and commercial availability of GC-C-IRMS in the late 1980s and early 1990s.

Development of a fast determination of PFAS as a sum parameter in soil and aqueous samples

Norbert Klaas; Sofia EngelmeierUniversität Stuttgart, Inst. für Wasser- und Umweltsystemmodellierung, VEGAS

Per- and polyfluoroalkyl substances (PFAS) are of increasing concern since they are found in soils and in the ground water. These types of substances cover a wide range of chemical classes of com-pounds. According to the OECD the name PFAS represents 4730 distinct substances, from which only about 20 can be analyti-cally encompassed. This is mainly caused by the unavailability of respective standard compounds, but also entailed by the great variety of the chemical properties of the different chemical classes.

This situation leads to a demand of a sum parameter to assess the “grey range” of organo-fluoro compounds which cannot be assessed by the standard HPLC-MS analytics. Analytical techniques have been developed for such a sum parameter, based on the incineration of the sample and capturing the evolved HF, followed by an ionchromatographic determination of the fluoride. This technique requires a complex analytical instrumentation which is not available in most of the laboratories.

A new idea is based on a destruction of the organic substances by fusion melt and a wet chemical or ionchromatographic determina-tion of the fluoride.

The poster will cover the principle of the method as well as the sample pretreatment for solid and liquid samples.

Detailed direct-sensing investigation of contamination at an old landfill site Brezinka

Vladislav Knytl; Petr Dosoudil; Ondřej LhotskýDEKONTA a.s., Volutová 2523, CZ-158 00, Prague 5, Czech Republic

Use of direct-sensing tools forms an important part of a contami-nated site investigation. The appropriate use of these technologies generates valuable data sets for further decision making and reme-diation design. The Dekonta company has recently used these tools within a remediation project at a site located in eastern part of the Czech Republic. During the communism era, an old sand quarry served as a landfill for various wastes from a factory producing paints and varnishes, as well as from a pharmaceutical factory. Inappropriate waste management activities at the site caused signif-icant pollution of the surrounding environment by a wide range of contaminants. The landfill had no isolation and rainfall water leaked directly into the groundwater. Over decades, a large contamination plume of chlorinated hydrocarbons (mainly 1,2-dichloroethane and chloroform) and BTEX (mainly benzene and toluene) had emerged. Major risks from this pollution are related to potential contamina-tion spreading to a nearby stream. Although satellite images did not show significant effects on the present vegetation, the entire aquifer under the forest is contaminated heavily. The sloping terrain and swampy forest represented a real challenge for the direct-sensing investigation and future remediation efforts.

All these factors led us to perform a large MIP (Membrane Interface Probe, Geoprobe, USA) investigation for detailed delineation of the contamination plume leaking from the landfill area. The actual site investigation consisted of 150 MIP spots. The new method OIP (Optical Image Profiler, Geoprobe, USA) will also be used for supplementary investigation, in order to determine the character of the waste in the landfill body.

All the gathered data from this extensive investigation were used

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XRF data as big data opportunitie

Jasper SchmeitsTauw bv

Using technological developments is more and more cumin for soil investigations and remediations. The usage of XRF is a good example of it. It gives a great advantage because the results are directly presented. Numerous studies proved that the XRF provides, if used correctly, better and more accurate soil sampling results than the much more labour-intensive method of conducting laboratory analyses. Until now the XRF is used to “replace” normal laboratorial analysis, but the potential is much bigger.

Nowadays we put a lot of energy in sampling soils and to normal way of using these samples is to make a selection of these samples to present to a laboratory. This selection excludes al lot of samples and in some cases samples are being mixed. This is financial driven and from the expansive samples we only use less then 10% of the sampled material. The opportunity with the XRF is to do a lot of measurements within the same budget of the “normal” selection of lab analysis. The expensive taken samples can be used all to give a better insight in the pollution of a location and eventually this results in less visits to the location to get extra samples.

Due to examples of projects is explained how this big data system-atic of usage of XRF-data can be benificial:

- XRF measurements within Dommeldal – large area around the Dommel were more then 5.000 XRF measurements are done in borings until 1 meter (every 20 cm an XRF measurement)

- XRF measurements for lead contamination on childplay-grounds – 40 XRF within a area of maximum of 500 m2

- XRF-research compared to normal NEN-research (in construc-tion: NEN-Research of the future?)

Screening for 21 perfluorinated organic compounds in Czech wastewater treatment plants

Jaroslav Semerad; Nicolette Hatasova; Tomas CajthamlInstitute of Microbiology of the Czech Academy of Sciences

Nowadays, a large group of perfluorinated organic compounds (PFCs), widely found in both terrestrial and aquatic environment, are classified as emergent and often characterized as persistent pollutants. High global production of PFCs, very slow breakdown and high mobility are the main reasons why these compounds are detected worldwide more frequently. Despite low toxicity, the half-life of elimination shows the potential of PFCs to bioaccumu-late in living species. Due to this, there is a big need to monitor the potential way of introduction of these compounds to the environ-ment, as well as to monitor their subsequent fate. According to the current knowledge, some of the PFCs are also able to accumulate in sludge. However, the situation in the Czech Republic has not been monitored and evaluated yet.

The presented study deals with monitoring of the occurrence of 21 PFCs in wastewater treatment plants (WWTPs) in the Czech Republic using a newly developed and validated LC-MS method. A series of 10 WWTPs from small towns to large cities were sampled. The water (influent, effluent) and solids (sludge) were extracted (SPE and ASE), purified and proceeded to analysis.

The results showed that 10 perfluorinated carboxylic acids (PFCAs) in the concentration of 2–101 ng/g, perfluorooctane sulphonate (PFOS) and other sulphonates in concentrations of 2–38 ng/g even

Combining the use of biomarkers and isotope ratio can lead to greater accuracy and confidence in the forensic results. In some cases the GC-C-IRMS may be the only possible technique for finger-printing due to lack of biomarkers.

Temperature and exposure history strongly influence gasoline ether oxygenate (ETBE) biodegradation in groundwater

Emma Mallinson¹; Henry Nicholls¹; Mike Spence²; Stephen Rolfe¹; Steven Thornton¹, Matthijs Bonte3

¹ University of Sheffield; ² Concawe; ³ Shell Global Solutions International BV

Ether oxygenates (EOs) have been added to gasoline since the 1970s to reduce vehicle emissions and improve air quality. Methyl tert-butyl ether (MTBE) has historically been used extensively in this context, but ethyl tert-butyl ether (ETBE) is now favoured in European markets (average concentration of 1.63 m/m3). To manage risks from accidental fuel releases it is important to understand the environmental fate of ether oxygenates and in particular their subsurface biodegradation potential. Although considerable research has been completed on the biodegradation of MTBE, knowledge of microorganisms capable of biodegrading ETBE is relatively limited. Previous studies have shown the initial stage of ETBE biodegradation is catalysed by a cytochrome P450 encoded in the eth gene cluster. However, it is possible that other, yet uncharacterised genes, are also involved.

In this study subsurface aerobic ETBE degraders from a European gasoline release site have been isolated and characterised to: (i) understand subsurface conditions that favour ETBE biodegrada-tion, and (ii) support the screening of sites for in-situ biodegradation potential. The ETBE biodegradation potential of the site microbial community was first assessed in microcosm studies. In microcosms constructed with aquifer material and groundwater from the zone of impact, ETBE was rapidly degraded with no lag, indicating an established population of ETBE degraders. In contrast, microcosms constructed with aquifer material and groundwater from up gradient of the release zone only degraded ETBE after a lag of 40 days.

ETBE-degrading microcosms were sampled at intervals during the experiment to investigate the temporal evolution of the microbial community and its ability to aerobically biodegrade ether oxygen-ates. Microcosm samples were first plated onto mineral agar media containing either ETBE, MTBE or the intermediate metabolite, tert‐butyl alcohol (TBA). After incubation at 10°C, a total of 750 randomly selected isolates were evaluated for growth on separate ETBE, MTBE and TBA mineral media. The isolates were scored based on their biodegradation capability, with re-testing of sub-cultures to confirm observations. The growth data were then analysed and clustered by degradation capability using heat maps.

Selected isolates were further examined by molecular analysis to identify phylogeny via 16S rRNA sequencing, and to detect known ETBE and MTBE-biodegrading genes. Where organisms are negative for known genes, whole genome sequencing will be employed to identify any novel genes. Isolates will also be cultured under different conditions to investigate the effect of environ-mental conditions, such as temperature, presence of co-substrates (oxygenate mixtures, BTEX and ethanol) and ETBE concentration on ether oxygenate biodegradation rates

This study has identified the organisms capable of EO biodegrada-tion at a gasoline release site. Furthermore, these organisms have provided a platform for testing metabolic capability under different conditions, along with potentially supporting the development of molecular tools that can be applied to screen sites for bioremedia-tion potential towards ETBE.

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the client. Remedial goals are risk-based and selected using the BATNEEC principle. One of the main goals during remediation is that all mobile LNAPL should be removed.

The formation of LNAPL is a complex process and is dependent on many criteria. Factors such as the texture of soil and characteris-tics of the oil contaminant all have an influence on the retention capacity of the soil. Due to the presence of several soil textures and the types of oil found on-site, using a generic target value deemed to be inconclusive. As such, a site-specific LNAPL screening protocol was developed which allowed for a rapid screening of the potential for LNAPL formation.

The development of the screening protocol started off with an extensive sampling campaign at 22 locations of the site. Soil and groundwater samples were collected at each location via trial pits, monitoring wells and percussive liner drillings. Analytical results such as total TPH content, oil characteristics, organic matter content and grain size distribution were combined with visual observa-tions during sampling. Samples were then used to assess existing LNAPL test protocols. The collected data was checked for correla-tions between visual observations, analytical results and field test outcomes. Although some field test protocols looked promising, overall results were unsatisfactory. As such it was decided to develop a site-specific test protocol.

The developed test indicates when the ability of the soil to absorb TPH contamination is exceeded and therefore a potential risk for LNAPL formation cannot be excluded. This test was then inte-grated in a decision making criterion. During remediation, samples undergo the test protocol: if test results are positive, the soil is treated, even though the measured concentrations could be below the calculated risk-based target values. The protocol is applicable on a wide range of types of soil (from gravel backfill to clayey sands) and has been a huge help during remediation. Instead of focusing solely on a calculated target value, geophysical site-specific param-eters are now taken into account to be able to use a risk-based approach.

in the sludge from small-town WWTP were found. Some of the compounds were detected in influents in concentrations several times lower than in the respective sludge samples which supports a theory of sorption on sludge. However, some of the sulphonates and PFCAs were also detected in the effluent from WWTP which indicates an insufficient treatment process. The results of this first screening of PFCs in the Czech Republic emphasize the need for deeper and more extensive monitoring and identification of potential sources of their origin.

Development and implementation of a “rapid site-specific LNAPL screening protocol” at a former petrochemical cluster in Antwerp, Belgium

Jan Van den OuwelantAECOM Belgium BVBA

Located along the river Scheldt, close to the city of Antwerp, is Blue Gate Antwerp. A site first developed in 1902 for petrochem-ical activities. At its peak it was one of Europeans main gateways for petrochemical products to Europe. Its petrochemical history resulted in a total of 305.000 m³ of soil impacted with TPH and about 2.500 m³ of pure product which was present as light non-aqueous phase liquid (LNAPL). What was once a state of the art petrochemical cluster is now a 100 hectare underused, highly polluted site.

After years of mapping the contaminants, a public-private partner-ship was awarded to Blue O’pen to remediate and redevelop the brownfield site. DEME Environmental Contractors, as part of the Blue O’pen consortium, appointed AECOM to assess and develop the remediation strategy for the site.

One of the many challenges encountered during the project was setting of remediation goals which meet the requirements of the regulator and coincide with the ideology of eco-effectiveness of

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River. In the opposite, the Lahn River is characterized by a high frequency of impoundments, low flow velocities, and eutrophic conditions. Especially during summer low water situations, the suspended matters of the Lahn River and its tributaries differ signifi-cantly in grain size composition, proportions and quality of organic components, and stored heavy metal amounts. This leads to the question of whether the quality of suspended matters influences the quantities and binding behavior of its heavy metal load. The objectives of the investigations were: 1) an inventory of the heavy metal amounts present in water, sediments and suspended matter of the lower Lahn River and its tributaries, 2) the analysis of heavy metal binding preferences in suspended matters and sediments, and 3) the assessment of transport behavior of heavy metals in the water phase during a low water situation. For this purpose, sediments were sampled from the longitudinal course of the Lahn River and from its tributaries in areas situated in proximity to their mouths. Water and suspended matter samples were collected during an over-average low water period in late summer of 2018. To distinguish dissolved and particulate transported elements, the water samples were separated in two halves. To analyze dissolved element amounts, one half of each sample was filtered < 0.45 microns. The second half was prepared by an acid in-bottle digestion method and used to analyze the total heavy metal contents of the water phase. Suspended matter and sediments were analyzed by the BCR sequential extraction method.

Strong differences in the heavy metal load of sediments and suspended matter were found between different tributaries. High concentrations of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) occurred especially in tributaries crossing former centers of mining and metallurgy. The Lahn River showed a tendency of increasing Cd and Zn concentrations in sediments and suspended matters within its longitudinal course. Cu and Pb were mainly bound organically in suspended matters and sediments. Both elements showed low dissolved concentrations within the water phase and compara-tively high particulate bound fractions. In opposite, Zn and Cd were marked by higher exchangeable proportions in sediments and suspended matters. Both elements frequently showed increased dissolved concentrations in water samples and were characterized by higher proportions of the dissolved fraction compared to the particulate proportions. The results show different transport and accumulation tendencies for Cu and Pb compared to Cd and Zn.

Evaluation of the effect of soil properties and experi-mental parameters on cadmium sorption in soil using the multiple linear regression approach

Yukari Imoto¹; Tetsuo Yasutaka¹ National Institute of Advanced Industrial Science and Technology

The sorption and desorption of heavy metals in soils are key to assessing heavy metal transfer to groundwater and plants. Sorption is affected by soil properties such as pH, cation exchange capacity, and organic matter content. Several models have been developed to predict heavy metal sorption using soil properties. Most common for measuring the sorption behavior of heavy metals in soil are sorption experiments; their results can be fitted to sorption isotherms. Multiple linear regression (MLR) analysis was conducted in this study to estimate Cd sorption in soil using soil properties and experimental conditions as explanatory variables. The aim of the study was to investigate the manner in which experimentally obtained sorption isotherm constants for heavy metals are affected by soil properties and experimental parameters.

For MLR analysis, we gathered experimental data for 72 soils from the literature. The resultant dataset contained information

Cross pumping test applied to characterize the hetero-geneity of hydraulic properties of a contaminated aquifer

Théo De Clercq¹; Abderrahim Jardani²; Laurent Thannberger¹¹ VALGO; ² CNRS - M2C

The assessment of hydrodynamic properties of an aquifer is usually carried out by pumping test in which the hydraulic responses to a constant or an harmonic pumping flow are analyzed by the analytical equations to only get the average values of the transmis-sivity hydraulic and storativity coefficient. While Transmissivity is about how much water can be transmitted horizontally, storativity is about the capacity of the soil to hold water (like a sponge) and thus to imply a delay of a water migration (such as tidal wave). In this work we have developed the harmonic pumping test as an interesting and innovative approach to characterize spatially the heterogeneities of a contaminated aquifer by identifying the preferential paths of the groundwater flow and contaminants. The approach relies on a harmonic extraction of the water at the pumping well and recording the piezometric fluctuations in many neighboring wells.

The use of such a tool permits: i) to limit the quantity of pumped water in particular if it is contaminated; ii) to analyze and exploit even the hydraulic signals with the smallest amplitudes; iii) to facili-tate the extraction of hydraulic signals/oscillations due to harmonic pumping test from other hydraulic fluctuations such as tide; iv) to image the spatial heterogeinity of the hydraulic properities.

For really heterogeneous mediums, presenting for example foun-dations or embankment, the upstream measurements should be a 3D inversion of electrical resistivity. Base on the principle that hydraulic conductivity and electric resistivity may be linked, the heterogeneities have quite the same geometry. The inversion of the pumping lowering data can start with a model taking into account these electrical heterogeneities to help the model to converge easier.

The interest of the approach has been demonstrated when the tool was successfully applied on the site of the former Petit-Couronne refinery near Rouen. This mega-site has a very extensive hydro-carbon pollution, in a complex hydrogeological context: tides, karsts, paleo-channels and 80 years of anthropic remodeling. The understanding of the operation of the subsoil is essential to choose the best solutions of depollution. Therefore 30 wells were placed on the hydrocarbon-contaminated alluvial aquifer in order to improve and study the effectiveness of hydrogeophysical tools to monitor the remediation activities.

Heavy metal binding behavior in sediments and suspended matter as a factor of water quality in the catchment area of the lower Lahn River (Germany) during an extremely low water period

Jens Hahn¹; Laura Berresheim¹; Virginia Zils¹; Alexandra Brinke²; Wiebke Schoenenberg¹; Christian Opp³¹ University of Koblenz-Landau; ² Federal Institute of Hydrology (BfG); ³ Philipps-University of Marburg

The lower Lahn River (Germany) is characterized by strong heavy metal accumulations in sediments and suspended matter, which can largely be considered as a consequence of historical ore mining within the catchment area. Its tributaries are marked by shallow water depths, high flow velocities and they transport significant amounts of sediments as well as suspended matters to the Lahn

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regarding Freundlich isotherm constants (logKf and n), soil prop-erties (pH, cation exchange capacity, organic matter content, and sand, silt, and clay contents), and experimental conditions for batch sorption tests (liquid-solid ratio, maximum value of initial concen-tration of Cd, background electrolyte concentration for univalent and divalent cation salts, contact time, and agitation intensity). MLR models for logKf and n of Cd were developed using various combinations of explanatory variables. The performance of the model was evaluated by adjusted R squared values and modeling efficiencies. The construction and evaluation of the model were repeated using 1000 random split training/testing datasets. The regression analyses were performed using R version 3.5.1.

In the MLR model that was the best fit for logKf of Cd, pH, cation exchange capacity, sand content, maximum initial concentration, background electrolyte concentrations of divalent cation salts, and contact time were significant variables. Results of standardized partial regression coefficients showed that the most important variable was pH, followed by background electrolyte concentra-tions of divalent cation salts. These two variables were positively and negatively correlated to logKf of Cd, respectively. In the model that was the best fit for n, the most important variable was pH, followed by maximum initial concentration. These variables were negatively correlated to the n of Cd. Model performance was generally better when both soil properties and experimental conditions were used as explanatory variables than when only soil properties were used. This indicates that Cd soil sorption was dependent on experimental conditions as well as soil properties. Thus, taking into account experimental conditions and soil prop-erties for assessing soil sorption characteristics of heavy metals in different soils and using experimental methods is effective.

Archaeology as a tool in soil studies

David JanssensADEDE

Changes in the legislation in June 2016 have attributed more importance to archaeological desk-based assessments. As a consequence, archaeological companies have started to employ the results of various soil studies as these can contribute to the archaeological appraisal of the area under investigation, offering information a past excavations, presence of disturbed soil, etc. Furthermore, these studies provide information on any pollution which might be present in the area under investigation, which in turn can protect the health of the archaeological team when fieldwork is to be conducted.

Over the last two years we have noticed that soil sampling for the purpose of the investigation of pollution can be considered of a low resolution. As a consequence local, small scale, polluted areas can be missed within the overall study area.

ADEDE believes that archaeology can assist in determining the location of these small polluted areas. There are two stages of the archaeological process during which this could happen:

1. during the execution of the desk-based assessment;

2. during the performance of trench survey. During a trench survey 10% of the study area is excavated according to a set, pre-deter-mined, grid and 2.5% at random. And this down to the undisturbed C-horizon. This 12.5% covers a much larger area then a standard OBO, as such, the archaeological study be employed as an addition to the existing soil study.

As the necessity for conducting an archaeological study and for

conducting a soil study are based on different criteria, it is not possible to integrate the soil study and the archaeological study on a systematical basis. We do however suggest that the creation of a tool which would allow observations relevant for the soil study to be reported could contribute to our overall knowledge of the area under investigation.

Resilient soil and water ressources, understanding the water beneath your feet - in a changing climate

Rolf Johnsen, Anja MelvejCentral Denmark Region

Across the North Sea we share different challenges with near surface groundwater and climate change.

The Topsoil Project explores the possibilities of using the top soil layers to solve current and future water challenges concerning water quantity and quality. It looks beneath the surface of the ground, predicts and finds solutions for climate related threats like flooding during wet periods and droughts during summer seasons. The overall objective of the Topsoil Project is the joint development of methods to describe and manage the uppermost 30 m of the subsurface, in order to improve the climate resilience and protect the environment of the North Sea Region.

24 partners across the North Sea work together in 16 different pilots to find new investigation techniques and management approaches.

Advanced geophysical methods are being developed and tested within the project.

Models to predict climate scenarious are being set up on the basis of the hydrological, geological and chemical measurements.

Five shared challenges across the pilots:

1. Groundwater Flooding in towns and agricultural areas.

2. Saltwater intrusion into freshwater reserves.

3. The need for a groundwater buffer to store water in periods of excess rainfall.

4. Better knowledge and management of soil conditions.

5. Understanding of the capacity to break down nutrients and other environmentally hazardous pollutants.

Re-release and phases of arsenic temporarily re-sorbed on excavated marine sedimentary rock under redox condition

Masahiko Katoh; Akihide Kamata; Toshihiko Miura; Kazuki Ide

The massive rock naturally contaminated by hazardous elements including arsenic is excavated, in particular at urban and mountain area, for effective use of underground space and construction of modern and high-speed railway and road around the world. Excavated marine sedimentary rock oftentimes contains the low level of framboidal pyrite, and arsenic is released from the framboidal pyrite due to the physicochemical changes after the excavation such as increase of specific surface area, exposure of water and air. The level of arsenic release increases with the atmo-spheric exposure after the excavation, but that decreases with the further atmospheric exposure due to the re-sorption on iron

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trichloroethene dominate, the presence of DNAPL of chlorinated solvents is apparent). From the geological point of view, the site bedrock is formed by Ordovician shales overlain with the thin clay layer forming the perching layer. Perched aquifer is developed in the above lying fill layer. The deeper aquifer is bound to the zone of weathered bedrock. The difference between watertables of perched and deeper aquifers is only between 0.5 and 1.2 m.

A combined hydrometric and geochemical approach was used in this study. Hydrometric data included groundwater hydraulic heads, precipitation rates, aquifers permeability, and geochemical data included contaminants concentrations in soil gas, ambient air (using passive sampling approach), perched and deeper aquifer, further the concentrations of basic ions, silica as a natural occurring tracer, and conductivity of groundwater in both aquifers.

The study showed that originally considered stagnant perched aquifer system is dynamic in both vertical and horizontal flow, further that the perched groundwater fluctuation affects the level of contamination in soil gas. The study results were incorporated in the updated conceptual site model used in the feasibility study for selection of the optimal future solution of the site currently desig-nated for the redevelopment.

A geological approach to model and visualize contamination pathways; traditional modelling versus Environmental Sequence Stratigraphy (ESS)

Léon Voogd¹; Johan Valstar², William Leys1

¹ AECOM; ² Deltares, The Netherlands

In the south east of the Netherlands former manufacturing site processes caused a contamination with Chlorinated Volatile Organic Carbons (CVOC) in the soil and groundwater. The contami-nation migrated through the silty and clay top layer to end up in aquifers with a high velocity leading to a plume of several km in length and approximately 150m wide. The source area was inten-sively investigated but the majority of the contamination load at the present time seems to be in the groundwater, but the plume area was not delineated for more than 1 km from the source zone.

Instead of a traditional remediation where for example a pump and treat and biological degradation was proposed in a remedial plan a concept was developed where the plume would discharge in an existing stream at a swampy area (by seepage) downstream of the plume. Combined with natural degradation this would lead to a cost effective and sustainable remediation solution. This concept however needs to be proven in order to obtain a licence from the authorities with approval to abandon the traditional ways of remediation.

A local model was created by scaling an existing regional model and adding local borehole information data. The calculated pathways showed a good agreement with the monitoring wells used for delineation and they ended up in a brook several kilo-meters further downstream. The model prediction for both the exact seepage location and the magnitude of biodegradation were considered quite uncertain. Due to the strong dilution in the brook, concentrations of the VCOC in the surface water are expected to be considerably lower than the legal norms for surface water, even in the case biodegradation and also volatilization in the surface water was neglected. From a risk point of view active remediation would not be necessary.

To prove the modelled migration path of the plume and its final interception in the stream additional evidence needed to be collected. This was done by means of passive diffusion sampling

hydroxide precipitated by the oxidation of framboidal pyrite. This means that the arsenic release is naturally suppressed with the longer atmospheric exposure. The excavated marine sedimentary rock is expected to be re-used without posing any environmental risk due to limited disposal sites. The re-use of excavated rock is possibly exposed to redox condition because of re-use as road embankment. The aim of this study was to understand the re-release and phases of arsenic that has been released from the framboidal pyrite and re-sorbed on excavated marine sedimentary rock.

One excavated marine sedimentary rock containing framboidal pyrite was provided, and crushed under 0.5 mm particle size. The crushed sample was exposed to atmospheric exposure for 30 days keeping in aerobic environment at room temperature. After the atmospheric exposure, the sample was subjected to the batch leaching test, and evaluated the level of arsenic release as a function of contacting time. Using the samples after the batch leaching test, the redox test was performed. The samples were placed in the vial bottle with 0–2% glucose and microbial inocu-lation. The bottles were kept for 2 weeks at 25℃, and then the amount of arsenic re-released, arsenic phases, and amorphous iron contents was evaluated.

The levels of arsenic re-released at Eh of less than 0 mV were higher than those at Eh of 200–300 mV. The arsenic re-sorbed by the atmo-spheric exposure was not released stably with further oxidation condition. In contrast, the amounts of arsenic re-released at the redox condition exceeded that of arsenic naturally suppressed by the atmospheric exposure, suggesting other sources of arsenic release by the redox condition. The amounts of arsenic re-released by the redox condition was positively related with the amounts of iron released. The amorphous iron/aluminum oxide bound arsenic phases decreased after the redox test. These indicate that the arsenic was released from the amorphous iron with the concur-rent of reduction. No structural changes of framboidal pyrite were not confirmed by the SEM observation. This study suggests that the appropriate treatment should be required in the case that the excavated marine sedimentary rock is re-used at the site exposing the redox condition.

Role of perched aquifer in the fate of the contaminants: Case study

Petr KozubekENACON s.r.o. and Charles University Prague

Understanding the directions, rates, and controlling mechanisms of contaminant transport is fundamental to any successful ground-water mitigation measures effort. On contrary relatively little is known about the role of perched aquifers in the fate of contami-nants at the contaminated sites. The initial remediation plans usually consider the perched aquifer to be a stagnant or trapped saturated zone above an impermeable perching layer (fine-grained stratum) without significant effect and thus the role of perched aquifer is often omitted.

The objectives of this study are to illustrate the dynamic nature of perched aquifers. Perched water may represent an important subsurface pathway for facilitating, or a barrier for inhibiting, contaminant transport from the ground surface to the regional aquifer, and complicating contamination problems in several ways. It applies in particularly for cases of the subsurface contamination presented by volatile organic compounds.

The study site is the pharmaceutical facility located in Prague, the capital of the Czech Republic heavily impacted by cocktail of volatile organic compounds (toluene, chlorobenzene and

Posters – 2c | Soil-sediment-water interaction and system dynamics

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Sorption isotherms showed that fluorene was preferentially retained in non-contaminated soil comparing to 9H-fluorenone. This result was confirmed by column experiments: the mass of 9H-fluorenone sorbed in the soil column was four times less than the mass of fluorene sorbed in the soil column. This preliminary result show that O-PACs could be more mobile in soils than PAHs, meaning that an impact on groundwater could be observed down-stream a contaminated site at a greater distance of site boundaries comparing to PAHs. Given their potential toxicity and persistency in soils and groundwater, further research is already in progress to understand mechanisms responsible for O-PAC transfer in soils.

Characterization of water flow in the unsaturated zone of vegetated lysimeters using stable water isotopes and modelling

Arno Rein; Fatemeh Shajari; Florian EinsiedlTechnical University of Munich

Agricultural activity is intensified globally for satisfying food demands of an increasing world population. This often is accom-panied by the intensive use of agrochemicals like fertilizers and pesticides, leading to the pollution of soils, groundwater and surface water and adverse effects on ecosystems and human health. Due to an increasing contamination of groundwater with nitrate and pesticides, drinking water wells are threatened, or have already been abandoned, in many regions. Preliminary knowledge is needed to assess subsurface contamination and potential impacts to groundwater which also includes water flow character-istics within the unsaturated zone.

We have studied the water flow in two lysimeters installed at a test field south of Munich, Germany, where maize was cultivated. Lysimeter soil cores are characterised by sandy gravels (Lysimeter 1) and sandy-clayey silt (Lysimeter 2). Pesticides were applied once a year according to common agricultural practice. Lysimeter outflow water was sampled regularly on a weekly basis and analysed for stable water isotopes (2H/1H and 18O/16O) as well as for the concentration of pesticides and some of their metabolites. Signifi-cant peaks of pesticide concentration in lysimeter outflow water were observed in many years shortly after application. Some of the monitored metabolites exhibited strong accumulation in outflow water. To analyse processes responsible for these observations, as a first step, stable water isotopes were used as natural tracers. Obser-vations were interpreted with help of lumped-parameter models (LPM), for deriving mean transit times of water (T), dispersion properties (dispersion parameter PD). Different assumptions were compared concerning tracer input (infiltration) and the possible contribution of preferential flow paths. An emphasis was also on specific water uptake processes induced by the maize plants.

Preliminary results indicate higher mean transit times T for the silt (362 days) than for the gravel (129 days), and dispersion was more pronounced for the silt with a PD of 0.7 (versus 0.12 for gravel). These observations can be explained by the dominance of finer pores for the silt, leading to slower water movement (higher T) and an increased tortuosity (higher dispersion) as compared to the gravel. Extending the model approach for considering preferential flow, in addition to soil matrix flow, led to a further improvement. Assuming 13% and 10% contribution of preferential flow for gravel and silt, respectively, could describe observations more adequately. First comparison of results obtained by the LPM with those from numerical water flow modelling (Hydrus 1D) showed well correspondence. Water flow characterization using stable water isotopes coupled to LPM application has the advantage of

in the stream around the expected interception point to delineate the exact seepage/interception location and Membrane Inter-phase Probe (MIP) CPT half way the expected plume.

The MIP CPT proved the path of the plume about halfway and the diffusion samplers proved the modelled interception point of the plume in the stream.

Further MIP CPT investigation is planned downstream of the first MIP CPT location in the plume and traditional monitoring of groundwater in existing wells and spot sampling of the surface water will continue to prove the concept and absence of risks of the CVOC contamination. The final presentation will contain the latest results.

Oxygenated polycyclic aromatic compounds (O-PACs) transfer in soil and groundwater - Experiments at the laboratory scale

Julien Michel¹; Jue Wang¹; Olivier Bour¹; Sophie Dorge²; Cécile Joyeux³; Didier Le Nouën³; Gwenaëlle Trouve²¹ INERIS; ² Université de Haute Alsace, Institut de recherche Jean-Baptiste Donnet, Laboratoire Gestion des Risques et Environnement; ³ Université de Haute-Alsace, Université de Strasbourg, CNRS, Laboratoire d›Innovation Moléculaire et Applications (LIMA)

A lot of PAH-contaminated sites can be identified in industrial-ized countries. Among these PAHs, only 16 of them have been listed by the US EPA as priority pollutants given their high toxicity. However, it has been documented that other polycyclic aromatic compounds (PACs) can be found at these sites and may contribute to the risk for humans and the environment. Particularly, oxygen-ated PACs (O-PACs) should be considered. They are emitted from the same sources as PAHs and therefore can be found in soils of former coking plants, gasworks or wood preservation facilities. In addition, they can be formed by oxidation of PAHs in natural attenuation as well as during remediation treatments. Their study at PAH-contaminated sites could be significant because: (i) they are more persistent than other transformation products of PAHs, (ii) their ecotoxicity is proved and they may be more toxic than PAHs and, (iii) O-PACs are more polar than PAHs and therefore more water soluble, leading probably to a higher mobility in soils and to a higher risk for human health and the environment. Previous studies at the laboratory scale showed a preferential release of O-PACs in water from contaminated soils comparing to PAHs. In order to decide if these compounds should be included in the management of polluted sites and soils, their migration in soils should be evaluated.

In this context, O-PAC transfer in soil was studied at the laboratory scale and compared to PAH transfer. A model PAH (fluorene) and a model O-PAC (9H-fluorenone) were selected for this test. Batch sorption experiments were carried out and sorption isotherms of fluorene and 9H fluorenone were obtained. Then, two leaching experiments were carried out under saturated conditions using a glass column (i.d. = 1,5 cm, h = 5 cm) containing a non-contami-nated soil. In the first column, a solution containing fluorene was injected from bottom to top. 9H-fluorenone was injected in the second column. Both solutions were prepared in nitrate calcium solutions. The leachates were collected at the column outlet and fluorene as well as 9H fluorenone concentrations were monitored in the collected fractions with a spectrofluorimeter to determine their breakthrough curves. When sorption was completed (i.e. concentrations at the column outlet were the same than concen-trations at the column inlet), a nitrate calcium solution was injected in both columns to monitor the desorption of both compounds.

Posters – 2c | Soil-sediment-water interaction and system dynamics

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Posters – 2d | Human and environmental health risk assessment

Methodological approach for the protection of workers at an active industrial contaminated site in Mantua (Italy)

Gabriele Beretta¹; Serena Noli²; Sabrina Saponaro¹; Elena Sezenna¹¹ Politecnico di Milano; ² Petroltecnica SpA

In active factories with potential contamination of soil and ground-water, it is necessary to preserve the health of workers and, at the same time, keep the activities in place. To this end, site-specific risk assess-ment can be used to highlight potentially critical exposure pathways and to direct investigations in different matrices (i.e., soil gas, emissive flow, ambient air, etc.) in order to evaluate, on the basis of several lines of evidence, the concrete health risk for human receptors at the site. In the present work, the methodological approach adopted for the Versalis factory in Mantua (Italy) is reported.

The risk assessment was carried out considering the potential contamination in surface soil, deep unsaturated soil and ground-water. As exposure routes for surface soil, indoor and outdoor particulate matter and vapor inhalation, dermal contact and soil ingestion were considered. Indoor and outdoor vapors were considered for deep soil and groundwater. For the exposure frequency, source-specific values were used, according to the use of the different areas of the site. Where necessary and possible, the default values for building parameters were replaced by site-specific data.

For areas with exceeding of the calculated target limits (CSR) in relation to the indoor volatilization pathway, the results of soil gas monitoring campaigns were used; in the case of outdoor vapor inhalation, emission flow measurements were also used.

For some sources in surface soil, the only critical contaminant in relation to the calculated health risk was ethylbenzene, a substance in the production cycles of Versalis; as such, this contaminant is measured in the monitoring plan related to Plant Risk Assessment Document.

Vinyl chloride, which is not part of the Versalis production cycles and was detected in the surface soil of an area beyond the calcu-lated CSR, was monitored in the indoor ambient air of the buildings within 30 m from the source. Surface contamination by polychlo-rinated biphenyls, dioxins / furans and asbestos has not been included in the risk assessment procedure, as it will be completely removed; while waiting for the approval of the remediation project, monitoring of the ambient air (outdoor and/or indoor particulate matter and/or vapors, according to the area) have been scheduled. As all these substances are not part of the production cycles of the factory, the results will be compared with the concentrations to which the general population can be exposed.

Impact of mercury contamination at a chlor-alkali site on Apis mellifera and its products

Michel Chalot¹; Cyril Zappelini¹; David Cazaux²; Stéphane Pfendler¹¹ Université de Bourgogne Franche-Comté; ² INOVYN

In the last decade, honeybee (Apis mellifera) collaps was reported. This decline is attributed to mite’ infection (Varroa destructor), presence of new predators (Vespa velutina), chemical treatment (e.g. insecticide), and various diseases (bacteria, virus). Increasing papers reported the effect of potentially toxic elements (PTE) such

a comparatively low data need (measured water isotope input and output as a function of time), and it requires only two fitting parameters for matrix flow (T and PD). In a next step, preferential flow paths (which may have contributed significantly to observed pesticide concentration peaks) will be investigated in more detail by site measurements and modelling.

Heavy metals in Technosols under different aquatic conditions - risk assessment for an former mining area in Hessen (Germany)

Collin J Weber; Christian OppPhilipps-Universität Marburg

In recent decades, heavy metals as environmental pollutants have been considered in many cases in the context of former mining areas. Since the 1960s, at the latest, fundamental knowledge about the environmental effectiveness of heavy metals in these areas has been obtained and developed. These substances still represent an unsolved issue for humans and the environment today. Despite a multitude of studies around this topic, some mining regions in Europe have been neglected until today. Several of them are also characterised by a high presence of heavy metals in Technosols and could be regarded as temporary chemical sinks. In many post-mining landscapes, Technosols are predominantly found which have developed from mining dumps, sedimentation basins or other anthropogenic deposits. Do heavy metals remove from Technosols by remobilisation or by water transport and thus pose a direct risk to their surroundings is a crucial question in the frame of the envi-ronmental risk assessment in the surroundings of former mining areas. Under changed climatic conditions and the frequency of extreme weather events, this question is especially relevant.

The “Schelder” forest area is known for its Devonian red iron ore resources and with over 2,500 years of mining history, ranks among the most important in Central Europe. Until the 1970s, intensive mining, processing and further processing of the ores was carried out here, which resulted in a large post-mining landscape. Other research showed that the relatively low heavy metal content is particularly widespread in river floodplains in the extended surroundings of the mining area. In contrast, first studies have shown that very high heavy metal contents can be found in indi-vidual Technosols within the area. The question therefore arises whether Technosols in the area provide stable conditions for the temporary storage of heavy metals and whether they act as a chemical sink or if they can be discharged in the future. During the project which will be presented here, the distribution of heavy metals within the mining area was investigated by systematic sampling of soil profiles (1-4m), especially from different Techno-sols and floodplain soils. In addition, samples of surface waters and mine waters next to the soils were investigated for their heavy metal concentrations. In parallel to soil and water standard analysis for estimating the binding and transport of heavy metals, metal contents were determined by ICP-MS. Initial results show that convenient conditions exist for the immobilisation and storage of heavy metals in Technosols. However, discharges from the mining area are caused by both surface water and mine water. Especially the Technosols in former sedimentation basins show high heavy metal contents in dependence of groundwater and infiltration water levels. Despite the stable conditions, a clear discharge of the heavy metals into a floodplain could be observed at a short distance. A planned rehabilitation of parts of the study area, which entails a change in the aquatic conditions, is a particular challenge for the risk assessment carried out here.

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that pepper leaves could be used as relevant biomonitor due to its low BDL (1.45 ng m-3), and finally that Solanaceae fruits can be considered as a safe food in our industrial context.

Assessment of the bioaccessibility of metals in soils through inhalation and ingestion pathway for human health risk assessment

Irene Jubany¹; Sandra Casas¹; Neus Bahí¹; Eva Schreck²; Jérôme Viers²; M. Teresa Condesso de Melo³; Nuno Barreiras³; Marilyne Soubrand⁴; Matthias Monneron-Gyurits⁴; Emmanuel Joussein⁴¹ Fundacio CTM Centre Tecnologic; ² Université de Toulouse, CNRS; ³ Instituto Superior Técnico – Universidade de Lisboa; ⁴ Université de Limoges

Particle inhalation and ingestion are an important human exposure pathway of heavy metals in contaminated soils. Although health risk assessment associated to these environments is usually based on total metal(loid) content in the particle, using a bioaccessibility approach may be more accurate to quantify real exposure. Bioacces-sibility is defined as the potential of the metal(loid) to mobilise from its soil matrices to the human digestive and respiratory systems.

SOIL TAKE CARE project is an international project co-financed by FEDER (Interreg Sudoe) that aims at improving the management and rehabilitation of contaminated soils in the south of Europe, comprising regions of Spain, Portugal and France. In the context of this project, methodologies for the determination of bioaccessible metal(loids) though inhalation and ingestion pathway have been tested and health risk assessments have been conducted in three different contaminated sites: Cartagena-La Unión (Spain), Estarreja (Portugal) and Viviez (France).

In this work, methodologies for the determination of the bioacces-sibility of metals through inhalation and ingestion are presented and discussed to highlight the advantages and limitations in each case. Inhalation and ingestion bioaccessiblity of the soils and air particles was determined using in vitro models. In vitro models based on human physiology have been developed as simple, cheap, and reproducible tools to investigate bioaccessibility of soil contaminants.

Results obtained within SOILTAKECARE project comparing health risk assessment using total and bioaccessible content are also discussed in this work. Results obtained with this type of tests highlighted the importance of using bioaccessibility for health risk assessment in order to accurately estimate the exposure risks and additionally, to determine the most bioaccessible elements so to be considered in the management and rehabilitation plan of the area.

Investigation and risk assessment of chemical plant effluent spill

Jane Oakeshott1, Paulo Valle²1ERM UK; 2 ERM nv

Pump failure occurred in the effluent treatment works at a chemical manufacturing plant in the UK. The failure lead to loss from the effluent tank of a mixture containing dimethylaniline (DMA). Action by the site managed to retrieve some of the spill but the remainder was lost to ground. Investigation was imme-diately instigated to track the spill, with DMA being recorded in the surrounding drainage ditches but DMA was also found in the underlying shallow groundwater.

The ditches were part of a larger network which ultimately drained to an estuary. The surrounding ditches were isolated and pumped

as Cd, Cr, Pb in soils on honeybees. In this regard, honeybees is considered directly dependent on natural environment conditions and it has been proposed as possible bioindicators for the deter-mination of environmental status. In this study, hives from both Hg-contaminated ([Hg] = 5 ng.g-1 DW soil) and non-contaminated sites were sampled. Mercury concentrations of honey, beeswax, pollen, propolis, royal jelly, bee broods, worker bees, queen bee and drones were measured every two weeks during a beekeeping season. Furthermore, eight of the most abundant honey flowers in this area were also monitored. Results showed that royal jelly, bee broods, queen bee, honey and drone Hg content were lower than 1 ng.g-1 D Wt whereas in beeswax, worker bees and pollens were between 1.5 and 5 ng.g-1 D Wt. Propolis was the only sample showing significant higher concentrations (15 to 30 ng.g-1 D Wt). In order to determine the propolis origins, we are currently sequencing DNA from propolis samples. Concentrations of Hg were also measured in flowers and results showed concentration between 4 and 10 ng.g-1 D Wt. In addition, honeybee colonies viability and strength were evaluated. Results demonstrated that honeybees were not affected by the presence of Hg at this site. According to this hypothesis, the queen eggs laying was similar to the control (non-contaminated area) as well as the bee popu-lation and honey production. In conclusion, beekeeping practice at this Hg-contaminated site did not seem to affect bees and bee products, except propolis, which Hg level however remained at very low levels.

Mercury transfer in Solanaceae species

Michel Chalot; Mohamad AssadUniversité de Bourgogne Franche-Comté

Tailings dumps at chlor-alkali plants poses serious threaten to the surrounding environment and populations, as they are often enriched in a number of process-derived contaminants such as Hg. This specific environment requires Hg stabilization to prevent air pollution by evaporated Hg, which can be achieved through plant covers and also the selection of non-accumulating Hg crops. However, the risk of Hg transfer to nearby urban gardening crops needs to be evaluated. Plants leaves are considered as a net sink for atmospheric Hg; however, most studies related to Hg uptake by crops have used leaf vegetables, whereas the case of fruit vege-tables and especially from the Solanaceae family was less studied. In addition previous studies have exposed leaf vegetables to both Hg polluted soil and air without taking into account the Hg uptake pathway. The aim of the present work was to evaluate the relative contributions of root and atmospheric pathways by growing fruit vegetables (pepper, tomato, eggplant) as well as tobacco plant on either control or polluted substrates under controlled exposure conditions. We showed that foliar Hg concentrations significantly increased with age, reaching 543, 572, 368 and 433 ng g-1 dry mass for pepper, tobacco, tomato and eggplant respectively, whereas all fruits showed two orders of magnitude lower Hg accumula-tion than leaves. Unexpectedly, we did not observe significantly different Hg concentrations in leaves of plant grown either on the control or on polluted substrates when grown at the time in growth chambers. By calculating fresh masses of fruits to be consumed to reach tolerate daily intake (TDI) of Hg, we demonstrated the lack of risk for edible parts. It appeared that pepper was the most sensible plant from the Solanaceae family for atmospheric Hg. We conducted a second experiment to determine leaf background values, effect detection limit (EDL) and biological detection limit (BDL). Our set of data prompted us to conclude that Hg entry into Solanaceae leaves is exclusively through an atmospheric pathway,

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as heavy metals. The binding of heavy metals to MP particles has already been detected in aquatic media and is therefore expected to happen within soils. After initial detection of MPs in floodplain soils in Switzerland, the question arises to what extent other flood-plain soils are also contaminated with MPs. Since floodplains are known as dynamic chemical sinks and spatial transport routes, they should be considered for an understanding of MP dynamics and the development of environmental protection concepts.

This PhD project concept aims to investigate the spatial distribution of MP in floodplain soils and their interactions with heavy metals, taking into account different catchment areas and different MP sources, depending on various land uses. Targeted sampling of flood-plain soils in the environment of rivers in Hesse (Germany) makes a quantification of MP contents possible. The floodplains will also be sampled after flood events in order to investigate their influence on the spatial MP distribution. Within the project, a targeted inves-tigation of MP particles will be made possible combined with soil standard analysis (e.g. texture, humus content, …). MP will be gravi-tationally separated from the mineral soil after destruction of organic matter. The detection of MP will be carried out via thermal gravi-metric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR). Next to this, heavy metal contents of soils and of separated MP itself will be determined by the use of ICP-MS. The project will start in spring 2019 with an initial sampling at 10 locations in each of three different river floodplains, which will be supplemented with an event-related sampling and subsequent analysis. Further sampling at other sites and analyses are planned in 2020.

Ecological risk associated with persistent free radicals in contaminated soil

Ying ZHANG¹; Xi GUO; Ruixin YANG¹ Dalian University of Technology

Environmental persistent free radicals (EPFRs) are detected in the clay, mineral or humic part of the soil, especially in soil contaminated with phenolic compounds, e.g., catechol. To clarify the detailed information on the formation of EPFRs, we mimicked its generation with contaminated soil in our laboratory and performed toxicity tests with luminescent bacteria (P. phosphoreum) to examine their biotoxicity. Our results showed that higher EPFR concentrations were generated at a lower pyrolysis temperature of 300˚C. Toxicity tests revealed that EPFRs could significantly inhibit the lumines-cence of P. phosphoreum with dose-dependence. Comparatively, the ·OH radical has been detected at higher concentrations in the system with UV radiation. Thus, we speculated that the generation of ·OH may be a crucial contributor to its toxicity. Our results aid in understanding the detailed information on the formation of EPFRs in contaminated soil, as well as the basic biotoxicity data of EPFRs, which will be helpful for further potential environmental risk assessments.

out but the relationship between the surface water and ground-water was not well understood, and there remained concerns about potential impact on the estuary. Monitoring of ground-water revealed elevated concentrations of other substances in addition to DMA which were not part of the original spill. There were no published environmental quality standards (EQS) for DMA or these other contaminants. The logical inference was that these substances appeared to be breakdown products but there were limited/negligible published references to support this, combined with limited information on environmental parameters.

This presentation looks at the investigation, risk assessment and remediation undertaken over the following years of less common contaminants including the approach to:

- absent EQS;

- assessment of contaminant data from pumping wells and borehole & ditch network to investigate the hydraulic regime and relationships between contaminants to inform the detailed quantitative risk assessment (DQRA);

- mass balance and DQRA; and

- sustainable and pragmatic remediation.

3a | Sampling and analysis of diffuse and emerging contaminants

Dynamics of mikroplastic and interactions with heavy metals in floodplain soils – Conception of a PhD project

Collin J WeberPhilipps-Universität Marburg

One of the greatest challenges of current environmental research and the society is posed by plastics and especially by microplastic (MP) with a particle size of less than 5 micrometres. In recent decades, the environmental relevance of MPs has therefore been investigated therefore mainly been using the example in marine ecosystems. In connection with an increasing worldwide produc-tion of plastic products, such as the 57 million tons of plastic produced annually in Europe, research has started to identify the sources of plastic pollutants. After investigating rivers as possible transport paths for plastics from land to sea, current research is increasingly focusing on soils. In recent years, various studies have shown that MPs enter soil and water in different ways, such as wastewater and sewage sludge, decomposed plastic waste or tyre abrasion. At present, the effects of MPs on the environment are known insufficiently. Studies suggest that MPs may be toxic to organisms (including humans) as they can absorb MPs through the food chain. The environmental relevance of MPs could assume significantly higher dimensions than previously considered, because of interactions with other environmental pollutants, such

Posters – 3a | Sampling and analysis of diffuse and emerging contaminants

178

PFAS impacts on solid waste landfills

Scott Grieco; Alessandro MonteverdiJACOBS

An increase of concern regarding PFAS introduction to the envi-ronment has expanded from drinking water as a primary media of concern and is including evaluation of landfill leachate contri-butions to public wastewater treatment plants and ground water near unlined landfills. Australia’s National PFAS management plan has identified landfills as a source of PFAS to be addressed. The US National PFAS management plan is anticipated to also address landfills.

A considerable focus of PFAS transfer to the environment is through historical use of Aqueous Fire Fighting Foam (AFFF). However, prior to 2003 only 3% of annual PFAS production supported AFFF; approximately 86% was used for textile (carpet, fabrics) and paper/packaging coatings, most of which end up disposed of in municipal solid waste landfills (Schultz, 2003).

Landfill leachate PFAS concentrations are in the ranges of several hundreds of ng/L, which are tens of times higher than those in wastewater treatment plant (WWTP) effluents (Lang et al., 2017; Sinclair and Kannan, 2006). As more than 60% of landfill leachate are discharged to WWTPs (EREF, 2017), high levels of PFASs in landfill leachate may make WWTPs hesitant to accept landfill leachate for co-treatment, especially if increased regulations on PFAS become effective in the future. It is necessary to develop a treatment strategy to remove PFAS from landfill leachate.

This paper presents:

• Summary of PFAS concentrations measured in landfill leachate

• Results of study that quantified PFAS released from materials disposed in solid waste landfills

• Discussion of oxidizable precursors and how they impact landfill leachate PFAS concentrations.

• Understanding fate of PFAS within biological leachate and municipal treatment systems (both liquid and solid phases)

• Potential treatment technologies for PFAS and impacts as applied to landfill leachate

PFAS site investigations at two airports in Norway

Liv Marit Honne; Kristin Moeller Gabrielsen; Dorte Harrekilde; Mette ChristophersenRambøll Danmark A/S

Pollution with PFAS is widespread and there is a growing concern with respect to the extent and scope of activities required when investigating soil and groundwater pollution at sites where PFAS have been used. Due to it’s geographical demography, Norway has 45 public as well as several military airports, where PFAS have been used in AFFF (aqueous firefighting foams). This has led to widespread contamination of soil, surface water, groundwater, sediment and biota.

The aim of the talk is to present experience and lessons learnt from PFAS investigations performed at both a closed down airport and an operating airport that is currently being rebuilt and expanded.

The Norwegian approach to PFAS investigations will be presented with a focus on describing the following issues:

• Norwegian regulatory background, incl. threshold values

• Attention on PFAS in Norway

Pharmaceuticals: Critical or negligible?

Bernd EccariusERM GmbH

A large variety of pharmaceuticals is in use, of which most are not fully metabolized in the body. The majority of the wastewater treatment plants are not able to treat these compounds and the discharge still contains up to 10 µg/l of pharmaceuticals, which will be further diluted in rivers and groundwater, but ultimately show up in drinking water. A source treatment at hospitals, in waste-water treatment plants or latest during drinking water production is possible, but expensive. If pharmaceutical sites are the sources mainly due to leaking sewers, the magnitude of the problem is generally much larger.

During investigation of a pharmaceutical site up to 10 mg/l of pharmaceuticals were detected in groundwater, which is > 4 magnitudes higher compared to generally detected groundwater levels of < 1 µg/l. The suite of pharmaceuticals comprised e.g. anesthetics, analgesics, narcotics and antispasmodics. Historic and recent chemical sewer leaks are the suspected sources for the groundwater contamination, which is further evidenced by other compounds used for the pharmaceutical production, e.g. BTEX, CHC, MTBE, 1.4-Dioxane, polar solvents and alcohols. Due to on-going substance findings, the regulator requested a non-target screening to detect all relevant compounds, which revealed another 200 previously unknown compounds.

A pilot P&T system with a stripping unit and vapor/liquid phase GAC filters was installed as an emergency measure close to a recently discovered chemical sewer leak. An existing nearby well was used for groundwater extraction to provide immediate hydraulic capture. Whereas most VOCs and pharmaceuticals could be effec-tively treated with the GAC filters, the MTBE and 1.4-Dioxane was only treatable with a high air / water ration. Less than 10% of the polar solvents were stripped, but only minimally adsorbed to GAC. Unfortunately, the PVC filter screen of the 2011 extraction well collapsed after less than 1 year of operation due to the extreme solvent concentrations of up to 1 g/l. As a result, the treatment system was flooded with sediment and needs to be replaced.

The difficulties with this suite of substances are not only the analyt-ical detection methods and limits, but also the few data regarding threshold limits in groundwater, soil and air. There are limited possi-bilities to calculate threshold limits with e.g. the US-EPA regional screening levels and many inconsistencies with toxicological data in risk assessments (e.g. according to the Threshold of Toxicolog-ical Concern (TTC) concept or tolerable daily intakes (TDI)), which complicates the negotiation with regulators about remediation and discharge limits or goals.

As long as not all sewers are repaired, the current strategy agreed with the regulators is a complete hydraulic capture to prevent further downgradient migration. The treatment system will combine many steps like pre-treatment (for iron, arsenic and H2S), stripping and air treatment (of VOCs), GAC (for SVOCs and pharma-ceuticals), biological treatment of polar solvents and alcohols and GAC as a polishing step. Furthermore, the possibilities of in-situ treatment with thermal remedy or ISCO will be checked.

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The results of the risk assessment identified perfluorooctane sulfonate (PFOS) as the risk driver even with conservative appli-cation of surrogate toxicity. The mass balance and hydrodynamic surface water modelling demonstrated the PFAS mass associated with the AFFF source provided negligible contribution to the PFOS measured in the marine environment. The TOP Assay results from the marine environment indicates the standard analysis of PFAS underestimates the presence an additional PFAS mass by a factor of 2-3. Consideration of TOP Assay did not change risk assessment outcomes.

The use of risk assessment in developing remedial strategies for PFAS contamination

Peter NadebaumGHD Pty Ltd

Developing remedial strategies for sites where soil and ground-water are contaminated by Per and poly-Fluoroalkyl Substances (PFAS) is challenging. Because of the uncertainty associated with the risks posed by this group of contaminants, precautionary criteria for soil, groundwater and surface water are being adopted, and some of these can be below the normal levels of analytical detection and concentrations found widely in the environment. There can be uncertainty as to whether effects will occur or not, and hence difficulty in undertanding the level of risk and whether and what form remediation or management should take.

This paper draws on the Australian experience, and outlines various considerations that can be helpful in understanding the level of risk, avoiding unnecessary conservatism, and developing a response that is proportionate to the risk. Commentary will be provided on various key questions that arise, such as:

Soil contamination: what are the average concentrations relevant to exposure; will garden produce and poultry products be consumed; what other exposure routes are applicable; which PFAS are present and their potential for uptake and risk; is the exposure of terrestrial animals of concern.

Groundwater contamination: will groundwater be used and what for (eg potable use, swimming pools, irrigation, stock), and therefore what risk-based criteria should apply; what assumptions underlie the criteria and are the exposure situations consistent with these.

Surface water contamination: will surface water be used and what for; are there associated animals and ecosystems that need to be protected (eg fish, birds); how can the latter risks be quantified; can management practices result in acceptable concentrations (eg normal holding times for oysters).

General considerations: very low contaminant criteria correspond to very low contaminant mass - what are the implications of the disposition and quantity of contaminant in soil and groundwater, and leaching and transport; ideally response should be propor-tionate to the risk and reflect the principles of sustainability – how might we respond accordingly. Reference is made to ISO 31000 (Risk Management) and ISO 18504 (Sustainable Remediation).

• Sampling and analysis

• Distribution of PFAS in soil, freshwater, seawater, sediment and biota

• Sources and delineation of contaminants

• Risk assessment

• Remedial issues

The presentation will show results from the investigations and describe a conceptual model for transport and mobility of PFAS in soil, groundwater and surface water. As the airports have used different PFAS over a long time, assessment of analytical results often requires an assessment of the composition of PFAS in the investigated media.

Risk assessment in Norway is challenging due to lack of national threshold values. More over challenges in choosing applicable remedial methods will be discussed with a focus on describing how to remediate at the source area.

Addressing challenges/uncertainties in PFAS risk assessment

Ken Kiefer; Darren ReedyERM Australia

Per- and poly-fluoroalkyl substances (PFAS) represent a complex mixture of thousands of individual compounds with documented wide-spread legacy impact in the environmental. Assessing risks to PFAS mixtures presents multiple challenges including:

• Identifying exposure pathways through bioaccumulation without relying solely on modelling;

• differentiating site-related PFAS to PFAS from other potential sources;

• addressing potential risk to measured PFAS compounds without existing toxicity criteria; and

• addressing potential risk to “unknown” PFAS not measured in standard laboratory analysis.

A site-specific risk assessment approach is presented to evaluate the extent of potential harm caused to human health and the envi-ronment from a defined release of Angus Tridol S3 3% (Aqueous film forming foam) AFFF to a marine environment, the Brisbane River estuary in Australia.

To address the challenges, the risk assessment included:

• an extensive environmental investigation that involved collecting surface water, sediment and aquatic biota from various phyla and trophic levels.

• the use of surrogate toxicity data to measure PFAS compounds without existing toxicity criteria;

• source mass balance estimates coupled with hydrodynamic surface water modelling; and

• semi-quantitative uncertainty assessment of the results of Total Oxidisable Precursor Assay (TOP Assay) analyses conducted to indicate the potential for “unknown” PFAS in the environment.

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RESPONSE project: Reactive transport modelling of point source contamination in soils and groundwater

Bertrand Leterme¹; Lana Geukens²; Diederik Jacques¹; Vanessa M. A. Heyvaert³; Marijke Huysmans⁴; Cas Neyens⁴; Jérôme Schoonejans⁵; Erik Smolders²; Dirk Springael²; Bas van Wesemael⁶; Jan Walstra³¹ SCK•CEN, Institute for Environment, Health, and Safety; ² KULeuven, Depart-ment of Earth and Environmental Sciences; ³ Royal Belgian Institute of Natural Sciences, OD Earth & History of Life, Geological Survey of Belgium; ⁴ Vrije Uni-versiteit Brussel, Department of Hydrology and Hydaulic Engineering; ⁵ Service Pédologique de Belgique asbl; ⁶ Université catholique de Louvain, Earth and Life Institute

RESPONSE aims at improving the use of coupled reactive transport models to simulate the fate of inorganic and organic contaminants for environments in which a fluctuating shallow groundwater table induces strong hydraulic, physico-chemical and microbial gradients. More specifically, we want to identify the minimally required available parameter set to predict reactive transport of inorganic pollutants and improve/simplify modelling of the microbial mediated reactive transport of organic pollutants. The objectives are addressed in the context of typical groundwater pollution problems encountered in old municipal landfills sites and cemeteries. After a preliminary screening of multiple sites, three case studies were selected where more detailed investigations have been taking place.

One site is a former municipal landfill, where redox zonation and contamination by As and Pb is observed. There, RESPONSE will investigate to what extent available and mapped hydrological and geochemical information is sufficient to predict the migration of pollutants. This hypothesis is tested by comparing predictions using site specific measured parameters (soil and subsoil hydraulic parameters, in-situ groundwater flow characterization, etc.) with predictions using parameters inferred from existing hydrological/geochemical data available in data bases.

The two other sites are cemeteries where several herbicides have been found in groundwater. On these sites, 2,6-dichlorobenzamide (BAM) – a persistent metabolite of herbicide dichlobenil – is of particular interest. Soil and groundwater samples were collected and the BAM mineralization potential of microbiota is tested in the lab. It is hypothesised that BAM degradation is strongly affected by DOC quality (measured through specific UV absorbance) and quantity. RESPONSE will investigate whether predictions of dichlobenil and BAM migration in soils and groundwater can be improved by taking into account DOC quality/quantity (cf. poster Geukens et al.).

An integrated tool has been developed for simulating water flow and reactive solute transport in the subsurface focussing on the water table interface. This is achieved by loosely coupling the existing HYDRUS, MODFLOW, MT3D-USGS and PHREEQC codes at the lowest level and adding functionalities for the transfer of solute concentrations. The HYDRUS package for MODFLOW (Seo et al., 2007) has been updated and PHREEQC functionalities are coupled to both the unsaturated zone (based on HPx software; Jacques et al., 2018) and the saturated zone.

The poster will present in more details the objectives, first results and next steps of the RESPONSE project.

Occurrence of pesticides in groundwater in and around graveyards and pesticide biodegradation capacity of the corresponding topsoils

Lana Geukens; Bram Verreydt¹; Jan Walstra²; Bas van Wesemael³; Vanessa Heyvaert²; Marijke Huysmans⁴; Cas Neyens⁴; Jérôme Schoo-nejans³; Bertrand Leterme⁵; Diederik Jacques⁵; Erik Smolders¹; Dirk Springael¹¹ Division of Soil and Water Management, KU Leuven; ² Royal Belgian Institute of Natural Sciences, OD Earth & History of Life, Geological Survey of Belgium; ³ Earth and Life Institute, UCL; ⁴ Department of Hydrology and Hydraulic Engi-neering, VUB; ⁵ Institute for Environment, Health and Safety, SCK-CEN

In addition to their application on agricultural land, pesticides are or were used at various public places such as graveyards, but the impact of such activities on groundwater contamination has been less studied compared to agricultural land. In this context, a groundwater screening was performed at multiple graveyard sites in Flanders and Wallonia, for the occurrence of pesticide residues in the phreatic groundwater. The most detected compound (eight out of eight sites screened) was 2,6-dichlorobenzamide (BAM), a known transformation product of dichlobenil (DB), which is a herbicide commonly used for private purposes. DB was banned since 2009, but strongly sorbs onto soil particles and hence provides a long-term ‘source’ of the highly mobile metabolite BAM, which leaches to and contaminates the groundwater. Given that microbiota are known for their high adaptability as it comes to degradation of xenobiotic organic compounds (XOCs), such as pesticides, we hypothesise that the long-term application of DB in these public places might have resulted into the development of DB/BAM-degrading microbiota.

To study this, topsoil samples were taken in and around the examined graveyards at locations where DB had been applied. Currently, these soil samples are being examined for the presence of DB, their capacity to transform DB into BAM and their capacity to degrade/mineralise BAM.

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the Loire Estuary: vineyards, urban areas (former landfills, allotment gardens, and road environment), former uranium mines, and the estuary. The methodology considers three main connected steps: sources of contamination (origin and characterization), transfers (mobility in the environment, evolution of use) as well as impacts and heritage (including management options and patrimonial considerations).

We focus on classical and emerging contaminants: metals that are toxic at low doses like lead and mercury, oligo-elements such as copper and zinc that become toxic at high doses, emerging contaminants such as PGE (platinum-group elements) or pharma-ceutics, and radionuclides including uranium and its decay chains. In addition to site-scale approaches, Cu contamination is studied at the regional scale. Indeed, the content of Cu has doubled within the last 30 years in the mussels of the Loire estuary, the receptacle of all water-borne contamination.

The multidisciplinary and even interdisciplinary approaches developed within the POLLUSOLS program will be illustrated (case of urban sites and former mines). The partners are looking forward to European collaboration. They can offer their “in the field” experi-ence around various sites and watersheds.

Knowledge impulse for Dutch delta approach for water quality

Hilde F. Passier¹; Jappe Beekman²; Laurens Hessels³; Peter Schipper⁴¹ Deltares, The Netherlands; ² RIVM - National Institute for Public Health and the Environment, The Netherlands; ³ KWR - Water Cycle Research Institute, The Netherlands; ⁴ WEnR - Wageningen Environmental Research, The Netherlands

How are we dealing with water quality objectives, where can we join forces to improve water quality? Collaboration of knowledge institutes is essential, and authorities and other stakeholders must have access to all knowledge that helps sustainable management of the environment.

The quality of groundwater and surface water in the Netherlands needs to be improved. Former Minister Schultz van Haegen and involved organizations in the areas of drinking water, agriculture and horticulture, nature, industry, recreation, healthcare, and knowledge, signed a declaration on improving water quality. With this plan of attack, the ‘Delta Approach for Water Quality and Fresh Water’, the organizations join forces to resolve problems on fertil-isers, pesticides, and emerging issues like pharmaceutical residues and microplastics.

Knowledge on water quality is present at several institutes in the Netherlands. The institutes Deltares, KWR, WEnR, RIVM; aligned with PBL, STOWA, WVL; strengthen their collaboration for the Delta Approach. The institutes work closely together with regional and national partners, companies, authorities and citizens. Co-creation and balance between partners are important. Goals are to unlock knowledge; to build a common, coherent, applicable knowledge base; to increase awareness; to learn across sectors; to design solutions and scenarios for sustainable use of water. To achieve these goals, we share practical and theoretical knowledge, exchange data, improve coordination of the different research programs and initiate projects to put the knowledge into practice to improve water quality and reach objectives of the European Water Framework Directive. In 2017 a start was made in projects on urgent short-term water quality issues. Meanwhile, the partners created a knowledge agenda with these priority topics for the next four years:

- Knowledge valorisation: to ensure that developed knowledge will have value in practice.

The evolution of global regulation for per- and poly-fluorinated alkyl substances (PFAS)

Nanda Hermes; Andrea Herch; Jennifer ByrdERM

Global interest in PFAS has increased over the last five years. As data emerge regarding the prevalence and potential effect of these compounds, regulatory scrutiny has increased on facilities that have manufactured or used PFAS or PFAS-containing materials. Several countries, and regions within those countries, have begun to establish regulatory guidelines with a focus on mitigating the human health and environmental risk associated with the release of PFAS into the environment.

Because PFAS have been used in such a large variety of commer-cial and household goods, low concentrations of PFAS have been detected not only in environmental media near manufacturing facilities and firefighting/firefighting training areas, but also in wastewater treatment plant effluent, landfill leachate, and surface water far removed from industrial areas. PFAS are also detected in the blood stream of populations in Europe, North America and other industrialized areas. The large-scale exposure risks have led to public demand for swift government action.

This presentation will focus on the evolution of PFAS regulations across the world, with a focus on rationale behind the development of compound specific advisory levels. The presentation will include a discussion of the evolution of regulatory standards and look at the development of guidance documents in Australia, the United States, and some countries within the European Union. Although regulatory standards have been set in several countries for at least some PFAS compounds, the body of toxicology data available for these chemicals is still not yet fully developed. The presenta-tion will discuss what is known and what is not known about the potential effects of PFAS compounds on human health.

Developing effective regulations and guidance for PFAS with the continued emerging new science has presented challenges in many countries. The presentation will conclude with lessons learned from areas where regulatory limits have been issued for PFAS compounds.

POLLUSOLS: diffuse contamination from land to sea

Cécile Le Guern¹; Béatrice Bechet²; Chloé Besnard³; Sophie Bretesche⁴; Nicolas Briant⁵; Ghozlane Fleury³; Liliane Jean-Soro²; Joël Knoery⁵; Alexandra Lepinay³; Gilles Montavon⁴; Oscar Navarro Carrascal³; Béatrice Plottu⁶; Marjorie Tendero⁶; Thierry Lebeau³¹ BRGM; ² IFSTTAR -IRSTV; ³ Université de Nantes; ⁴ IMT Atlantique; ⁵ IFREMER; ⁶ Agrocampus Ouest

Human activities (transport, industry, agriculture,...) are sources of many contaminants that can be disseminated into the environment through various ways, impacting soils and sediments. Small quanti-ties of any compound dispersed over a large area may amount to “a nonpoint source pollution”, with a persistence of several decades.

POLLUSOLS is a research program focusing on the issues of nonpoint source pollution on the land-to-sea continuum. It aims at a) struc-turing research teams from different fields (biology, sociology, chemistry, psychology, physics, economics,...), b) improving the understanding of the pollution cycle, and c) proposing relevant tools for managing soils and sediments impacted by diffuse pollution.

The partners apply a common methodology on different types of experimental sites reflecting environmental and societal issues on

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o In situ chemical oxidation (with several combinations

of oxidants / catalysts)

• Bench-scale test on groundwater:

o GAC treatment (adsorption capacity and optimal

contact time are determined)

o Chemical oxidation (with several combinations of oxi- dants / catalysts)

The poster will also report the results of GAC treatment of ground-water contaminated with PFAS from pump&treat systems and dewatering projects at several sites.

The ENSOr stakeholder platform -Emerging policy challenges on New SOil contaminants

Kris Van Looy; Johan Ceenaeme; Nele Bal; Griet Van GestelOVAM - Flemish Waste Agency

Two topical examples to set the scene. The environmental risks of fluorinated, brominated and chlorinated organic chemical compounds with their strongly persistent character in the envi-ronment and broad application in recent times, makes it a widely spread diffuse pollution, for which it becomes difficult – highly impacting land and soil management practices – to define critical loads and set regulations. As another emerging contamination, only recently the health risks of micro- and nanoplastics come to be highlighted. Nowadays the marine plastic threat to our marine environment and economy reached the headlights, finally, but only 10% of mismanaged plastic waste reaches the sea, and 90% ends up … in the soil.

OVAM -the Public Waste Agency of Flanders- initiated that interna-tional cooperation, combined with a multi-stakeholder bottom-up approach, as the way to achieve this aspiration. Therefore, we organized a platform and a first international workshop on Emerging policy challenges on New SOil contaminants (ENSOr). We formulated the following questions to an international group of experts and stakeholders: Is the sense of urgency of emerging contaminants in soil sufficiently mapped and perceived? Do emerging contaminants also create new responsibilities? Do we have to re-invent the liability of producer, user or regulator? How to proceed in policy making for soil conservation with emerging contaminants?

With this initiative we focus on the exchange of knowledge, experiences and encountered challenges between researchers, policymakers, experts and problem owners. We try to identify steps towards a policy that benefits all. The stakeholder platform that emerged will present its white paper to the entire stakeholder community, to the European and national policy level and to you, on the sense of urgency for new policy on soil emerging contami-nants, in light of the diffuse pollution sources of many persistent organic pollutants; the strength of ENSOr’s quadruple helix stake-holder model (researchers, policymakers, experts and problem owners), making way to a soil & land stewardship for preserving healthy soils. In the presentation, the conclusions from the first ENSOr meeting will be presented as well as the first ideas of the white paper.

- Multi-actor chain explorer: to apply experiences from the multi-actor chain-approach of pharmaceuticals to reduce emission of other substances.

- Social sciences: to influence the behaviour of stakeholders to improve water quality.

- Effect-based monitoring and mixture toxicity: to develop assess-ments of water quality based on effects of toxic substances, to determine where measures should be taken.

- Aquatic ecology: to quantify biotic-abiotic relationships to design measures.

- Plant protection products: to identify sources and routes of (residues of ) plant protection products to propose specific measures.

- Veterinary medicines: to assess emissions of veterinary medicines and effects on water quality, as a basis for taking measures.

- Nutrient measures: to apply system knowledge to create action perspective for farmers with tailor made measures, to improve mineral management and water quality, and increase awareness.

- System knowledge for brackish waters: to assess ecology of brackish waters, bottlenecks and measures.

- Groundwater quality: to quantify long-term diffuse pollution of valuable fresh groundwater resources, natural attenuation and retention, and to develop tools to support groundwater quality management.

Treatability of PFAS in soil and groundwater: results of bench-scale tests and full scale experience

Karina Suy¹; Diederik Valcke¹; Stefan Vanhille¹; Johan Gemoets²¹ Mourik n.v.; ² VITO

Per- and polyfluoroalkyl substances (PFAS) are a class of stable compounds widely used in diverse applications. These emerging contaminants have unique properties due to carbon-fluorine (C-F) bonds, which are some of the strongest bonds in chemistry. High energy is required to break C-F bonds, which results in this class of compounds being recalcitrant to many degradation processes. Some PFAS can travel for miles from their point of release, as they are mobile and persistent, potentially creating large plumes in groundwater.

The need for remediation of PFAS is growing as a result of more regulatory attention to this new class of contaminants. PFAS comprise more than 3.000 individual compounds. Thus far the focus of environmental analyses and regulations has generally been limited to between 10 and 20 compounds as the perfluo-roalkyl acids (PFAAs) which are persistent, can be highly mobile, and are increasingly reported to bioaccumulate. PFOS (perfluo-roctane sulfonate) and PFOA (perfluorooctanoic acid) are the most commonly regulated PFAS.

Commissioned by OVAM, several (bench-scale) treatability tests are currently realized on soil and groundwater contaminated by PFAS (mainly PFOS and PFOA). Adsorptive as well as destructive remedial technologies are tested. Results are expected in January 2019.

The poster will report the results of these bench-scale tests:

• Bench-scale tests on soil

o Physico-chemical treatment (soil washing)

o Thermal treatment (optimal temperature and heating time of the rotating kiln are determined)

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The Rate of lindane biodegradation in different constructed wetlands

Aday Amirbekov; Roman Spanek; Pavel Hrabak; Alena SevcuTechnical University of Liberec

The harmful effect of an insecticide γ-hexachlorocyclohexane (γ-HCH, lindane) on the environment and organisms is well known, and although field application was banned in 2010, contamination of soil and water is alarming.

The aim of this two-year study was to compare removal of γ-HCH and its isomers in different constructed wetlands at a heavily contaminated site. Wetland A mimicked natural shallow-water wetland, wetland B was filled with organic substrate to support biodegradation, and on the inflow of wetland C, there were three permeable reactive barriers filled with iron sponges, wetland E filled with biochar. Specific genes were assessed for their potential in lindane biodegradation in all wetland biotops. The water and sediment samples were collected for DNA extraction and analysis by real-time quantitative PCR (qPCR) to determine total bacterial biomass, and presence of functional genes (LinA, LinB, LinB-RT, LinD). Based on the qPCR results, water and sediment samples from one part of the wetland system (A,B, C and E) were chosen to be analyzed by next-generation sequencing (NGS) to estimate the bacterial diversity.

The genes confirming the presence of enzymes involved in aerobic and anaerobic lindane biodegradation were detected in all of the samples. The NGS results indicated different bacterial diversity between sediment and water samples. Amount of the functional genes and the diversity of microbial community in constructed wetlands was influenced by many factors such as weather conditions, water flow rate and different treatment of each wetland. Generally, the diversity of bacterial community totally changed comparing to last year. Sulfur and iron reducing bacteria dominated in the outflows of wetlands during the second year. The lindane degrading genes were mostly present in B and A wetlands. Chemical data show decreasing concentration of total HCH in the inflow comparing to outflows from wetlands. In B wetland, there was highest amount of Desulfovibrio which was involved in dechlorination of lindane.

Enhanced reductive Dechlorination Pilot Test: Importance of the preliminary investigations to improve the design of the intervention

Matteo Avogadri¹; Alessandro Botti; Aldo Trezzi; Riccardo Asnaghi¹ Ramboll Italy S.r.l.

The characterization activities carried out within an important industrial site in Central Italy highlighted the presence of an area with high concentrations of Chloretenes (PCE, TCE, DCE and CVM) in soil (up to 10,000 mg/Kg) and groundwater (up to 40,000 μg/L) and a rather complex geological-hydrogeological framework, due to the presence of two aquifers not well defined with different groundwater flow direction.

The characterization activities carried out within an important industrial site in Central Italy highlighted the presence of an area with high concentrations of Chloretenes (PCE, TCE, DCE and CVM) in soil (up to 10,000 mg/Kg) and groundwater (up to 40,000 μg/L) and a rather complex geological-hydrogeological framework, due to the presence of two aquifers not well defined with different groundwater flow direction.

Organo-layered double hydroxides nanoparticles as sorbents for chlorinated hydrocarbons in natural systems: sorption capacity and long-term stability studies

Virginia Alonso de Linaje¹; Marco Mangayayam²; Amaya Sayas³; Vicente Rives⁴; Ruben Espinosa⁵; Dominique J. Tobler²; Kim N. Dalby²; Nicolas Bovet²¹ AECOM/University of Salamanca; ² University of Copenhagen; ³ AECOM; ⁴ University of Salamanca; ⁵ AECOM Australia

Chlorinated hydrocarbons (CHCs) have been widely used as solvents in industrial processes, which has led to numerous events of uncontrolled releases into subsurface environments. As such they often remain as contaminants of concern in soils and groundwaters. To treat CHCs contaminated sites, in situ injection of reagents that break the C-Cl bonds (e.g. oxidation by perman-ganate or hydrogen peroxide, and reduction by zero valent iron), are most often implemented. But CHCs can only be fully degraded under very specific and hence often rare subsurface conditions. Far less attention has been given to reactants that trap, i.e., immobi-lize, CHCs without redox reaction involved; hence minimizing the formation of, sometimes, even more toxic daughter products.

In the last decade, a variety of minerals have been investigated as potential sorbents for CHCs in water. In particular, layered double hydroxides (LDH), which consist of metal (MIII/MII) hydroxide layers that sandwich anionic species and water, have emerged as promising sorbents due to their tunable particle/surface proper-ties and anion exchange capacity. For example, by placing organic species (e.g., surfactants) into the LDH interlayer, the LDH’s hydro-phobicity can be substantially enhanced, and thus also its sorption capacity towards CHCs. While this has been demonstrated before,1 nothing is known about how these organo-LDHs behave once injected into the subsurface. How will its structure and sorption capacity be affected by exposure to diverse and changing water chemistries (e.g., pH, salinity)? How selective are these organic-LDH towards the different CHCs in multi-component systems as they exist at contaminated sites?

In this study, we (a) synthesized and characterized organo-LDH, (b) determined sorption isotherms for individual and ternary CHCs systems, (c) compared sorption coefficients in different geochem-ical matrices, and (d) evaluated their long-term stability in natural systems. Altogether, we evaluated the application of organo-LDHs as remediation agents and best approaches to use them as economic sorbents for CHCs in complex natural systems.

Organo-LDHs with intercalated dodecylsulfate (C12H25SO4) were synthesized via cooprecitation. Sorption coefficients (Kd) derived from linear sorption isotherms for individual CHCs (trichloro-ethylene, trichloromethane, 112-trichloroethane) are inversely proportional to their hydrophobicities. Additionally, results from CHC ternary system suggest that there is no sorption competition between sorbates, and diverse groundwater compositions should not affect the organo-LDH sorption capacity. Organo-LDHs that were exposed to contaminated and natural groundwaters for a 2-month period did not display significant changes in bulk crystal structure. This indicates that organo-LDH sorbents are fairly stable reactants and they could perform over extended periods. Overall, these results are promising for the future application of organo-LDHs as a cheap and fast solution to reduce CHCs concentrations in groundwater. [1] Zhao & Nagy (2004) Colloid Interface Sci. 274: 613.

Posters – 4a | Bio-, nano-, and chemical remediation

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literature were used. Most of the measured δ13CCF and δ37ClCF in both field sites were within or very near the isotopic range of known commercial CF and they did not differ significantly across the studied boreholes to confirm that CF biodegradation was occurring. Such results pointed out that direct release of DCM into the aquifers of both field sites was, likely, the main source of DCM’s contamination. Interestingly, for one of the field sites, none of the microcosm experiments showed signs of biodegradation, even those inoculated with a commercial bacterial consortium capable of CF and DCM biodegradation failed, suggesting inhibition issues. In this site, in contrast to CF, δ13CDCM and δ37ClDCM values across the studied boreholes were outside the range of known DCM commercial solvents and showed significant differences between them. However, δ13CDCM versus δ37ClDCM values in a dual isotope plot were not consistent with a biodegradation trend. This could indicate that measured isotopic shifts for DCM could be due to industrial transformation processes, that took place in the plant before DCM’s release into groundwater, rather than to biodegrada-tion of DCM in the subsurface. On the other field site, however, the only δ13CDCM and δ37ClDCM data point was outside the isotopic range of known commercial DCM and was consistent with a CF to DCM anaerobic biodegradation trend, suggesting that biodeg-radation was feasible to some extent. This was supported by the complete elimination of CF and DCM that observed in all the micro-cosms constructed with groundwater of this contaminated aquifer. Based on these results, a potential remediation strategy is proposed for each field site and it will be presented in this conference.

Composting of wastewater treatment sludge containing various new emerging pollutants

Tomas Cajthaml¹; Klára Michalíková¹; Lucie Linhartová¹; Petra Kočí²; Ondřej Lhotský³¹ Institute of Microbiology, Czech Academy of Sciences; ² Institute for Environ-mental Studies, Faculty of Science, Charles University; ³ DEKONTA a.s.

Composting process has been recently proved to be an efficient decontamination technique for remediation of materials contami-nated with organic pollutants. The process relies on the action of microorganisms to degrade organic materials, resulting in ther-mogenesis the temperature inside the composting pile can reach 75 °C. For remediation purposes, the composting substrate (based on agricultural-waste mixture of optimum nutrient ratio) is simply mixed with some portion of contaminated material. This tech-nology has become a popular as and reliable management option for bio-wastes deriving from either municipal, agricultural or indus-trial areas. The process has been proved to be efficient in removal of polycyclic aromatic hydrocarbons and also related pollutants. The aim of this work was to show ability of the composting method to degrade various micropollutants including pharmaceuticals and personal care products, xenoestrogens and other relevant compounds e.g. perfluorinated aliphatics. The process was tested under controlled conditions simulating real conditions including thermogenesis at different contaminant concentration levels as well as with real sludge samples. The process was monitored using analytical technique and also using ecotoxicological approaches including endocrine disrupting activities. The results showed that composting is very efficient in terms of reduction of micropollutant concentrations and the residual amount of the used xenoestrogens, pharmaceuticals and personal care products varied from 60 to 10% of the original amounts including such persistent compounds as triclosan and chlorhexidine.

A Pilot Test of Enhanced Reductive Dechlorination (ERD), a remedi-ation technique that combines the use of chemicals and biological processes to degrade compounds with a high number of chlorine atoms to non-chlorinated compounds (e.g.: ethene, methane), was designed in the most contaminated area in order to evaluate the applicability of this technique for the full scale implementation.

Before proceeding with the installation of the Multiple Injection Workstations, used to inject the organic substrate, some prelimi-nary activities were realized: a Membrane Interface Probe (MIP) investigation, the installation of several monitoring piezometers and a pre-intervention groundwater monitoring campaign (both in chemical and biological terms).

The MIP investigation allowed obtaining a better understanding of the spatial distribution of the contamination, to build up a three-dimensional stratigraphic model of the area, to highlight the presence of a layer with higher hydraulic permeability and to find out the different flow directions of the groundwater and the contamination plume in the shallow aquifer.

The monitoring piezometers installed in both the aquifers confirmed the different groundwater flow direction between the shallow aquifer and the deep one, and allowed to find out the real depth of the deep aquifer bed.

The fact that the deep aquifer bed is deeper than that the previous characterization activities indicated and taking into account the type of contaminants, which tends to migrate in depth, led to the need to deepen the Multiple Injection Workstations.

Preliminary surveys of the area have been completed through a groundwater monitoring campaign in order to get chemical and biological data before the intervention.

The results and the information gathered during the preliminary investigations were very useful to improve the design of the Pilot Test, in terms of where, at which depth and how much organic substrate to inject.

Dual C–Cl isotopic assessment to elucidate origin, fate, and potential bioremediation treatment of chlorinated methanes at two industrial multi-contaminated aquifers

Natàlia Blázquez-Pallí¹; Orfan Shouakar-Stash²; Jordi Palau³; Alba Trueba-Santiso⁴; Joan Varias¹; Marçal Bosch¹; Albert Soler³; Teresa Vicent⁴; Ernest Marco-Urrea⁴; Mònica Rosell³¹ Litoclean; ² Isotope Tracer Technologies Inc.; ³ Universitat de Barcelona; ⁴ Universitat Autònoma de Barcelona

The present work aimed at understanding the biogeochemical dynamics that were taking place at two industrial sites impacted by multiple toxic chlorinated compounds, being chloroform (CF) and dichloromethane (DCM) the most relevant. In both sites, a detailed characterization of the hydrochemical conditions of groundwater and an assessment of the natural bioremediation potential of the aquifer was performed through the analysis of (i) contaminants’ concentrations and (ii) carbon (δ13C) and chlorine (δ37Cl) stable isotope ratios across the contamination plume. In addition, bios-timulation and bioaugmentation tests were performed in the laboratory using microcosms prepared with groundwater from the sites. For field data interpretation, known commercial solvents’ isotopic compositions as well as characteristic dual C–Cl isotope slopes for CF and DCM degradation by different bacteria from the

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Nanoremediation of chlordecone polluted soils

M. Gil-Diaz¹; S. Diez-Pascual¹; H. Macarie²; S. Bristeau³; M.C. Lobo¹¹ IMIDRA; ² IRD, Aix Marseille Univ, Avignon Université, CNRS, IMBE; ³ BRGM, Laboratories Division

Chlordecone is a synthetic chlorinated organic compound which has been used as an agricultural pesticide against the banana black weevil in the French West Indies between 1972 and 1993. It is highly persistent, has a high potential for bioaccumulation and biomagnification and can be transported for long distances. It is classified as a possible human carcinogen and is very toxic to aquatic organisms. It is included in Annex A of Stockholm Conven-tion. Currently, no use or production of chlordecone is reported but it is still present in soils where it was applied, as well as in surface and underground waters, and its transfer into the food chain have been demonstrated. Thus, the remediation of these soils is a priority.

Nanoscale zero valent iron (nZVI) is a strong reductant with a large surface which has been widely studied for the immobilization of metal(loid)s and the degradation of chlorinated pollutants. The bimetallic ZVI nanoparticles are based on the addition of a small amount of a transition metal such as Pd on the nZVI surface, which acts as a catalyst increasing the reactivity of the nanoparticles. The nZVI-Pd particles have been effective for the reductive dechlori-nation of halogenated organic pollutants in water samples. Some experiments have concluded that iron sulfide nanoparticles (nFeS) can be used for the degradation of chlorinated organic compounds in groundwater samples. Other authors found promising results using µZVI for the degradation of chlordecone in soils. Neverthe-less, no data are available regarding the effectiveness of nFeS and nZVI-Pd for the remediation of chlordecone-polluted soils.

The objective of the present study was to evaluate the effectiveness of two types of iron nanoparticles, unstabilized nFeS and stabilized nZVI-Pd, for chlordecone degradation in two polluted soils (A and B) collected from Guadeloupe. Soil A was an andosol with an acidic pH (5.3), high content of organic matter (13.4%), with a silty loam texture, and a mean concentration of chlordecone of 14 mg/kg. Soil B was a nitisol, with a pH slightly acid (6.1), 3.7% of organic matter, a silty clay loam texture and a mean concentration of chlordecone of 1.1 mg/kg. Soil samples were mixed with nFeS (Nanoshel) at 5% (weight, 2.8 g Fe per 100 g soil), or nZVI-Pd (NanoIron) at 10% (weight, 1.6 g Fe per 100 g soil) and water. After 30 days of incuba-tion at 28 ⁰C, soil samples were collected, air dried and chlordecone was quantified by GC-MS/MS. The results showed a significant reduction of chlordecone concentration in both soils treated with nZVI-Pd (74 and 96% in A and B, respectively). Thus, the addition of bimetallic nanoparticles nZVI-Pd could be a remediation strategy for chlordecone-polluted soils. Further experiments are necessary to determine the degradation mechanism. Regarding nFeS, a slight decrease of the pesticide concentration was detected although it was not statistically significant. The lower effectiveness of nFeS can be due to these nanoparticles were not stabilized and aggregation phenomena can be produced, reducing their reactivity.

Acknowledgements. REHABILITA CTM2016-78222-C2-1-R (AEI/FEDER, UE), FP-16-NANOREMED (IMIDRA, Spain).

Remediation of soil polluted with lindane wastes by using persulfate activated by alkali: Kinetic Model Discrimination

Raul Garcia; Aurora Santos; David Lorenzo; Arturo RomeroUniversidad Complutense de Madrid

Old lindane factories generated high amounts of wastes composed by HCH and other Chlorinated Organic Compounds (COCS), often dumped in non-secured landfills in the surroundings of the production sites, as happened in two landfills in Sabiñanigo (Spain). Some of the wastes comprised a liquid residue composed of HCH isomers, benzene and chlorobenzenes, forming a dense non-aqueous phase liquid, DNAPL. This organic phase migrated through the subsurface by gravitational forces with a high impact on groundwater and soil pollution [1].

In this work the remediation of a soil obtained from a recent borehole drilling (April 2018) at the Sardas landfill was studied using alkaline persulfate at lab scale. The soil corresponds to the gravel-sand horizontal layer (12.5-15.5 m b.g.l.). Groundwater flows through this layer due to its higher permeability (100-200 m/day) although the small hydraulic gradient in the area results in a low value of the Darcy velocity. Due to the clay matrix contained in this layer an adsorption of the COCs present in the groundwater took place, yielding a significant pollution of the soil.

Soil obtained at depth from 13.5 to 14.0 m was sieved to particles lower than 2 mm. A number of 28 COCs in soil has been identified and quantified after ultrasound extraction with MeOH, finding a total COCs value about 3500 mg/kg of dry soil. About 2500 mg/kg of them correspond to hexaclorocyclohexane and heptachlorocy-clohexane isomers.

Persulfate activated by alkali (NaOH) has been selected as the oxidant system. This oxidant system has been proved to be stable and effective in abatement of the COCs in the groundwater of the landfill [2]. The scope of this work is to obtain the corresponding kinetic model, that is a key tool to optimize the oxidant and activator dosages and the contact times required for COCs abatement in soil.

Batch experiments have been carried out using a slurry with the soil and the aqueous solution with the oxidant and activator. Persulfate concentration ranged from 20 to 100 g/L and activator to oxidant molar ratio has been changed from 1:1 to 4:1. Vials were sacrified at different reaction times and remaining persulfate was measured as well as the COCs concentration in aqueous and soil phases. Times required for 90% of the COCs abatement ranged from few to several weeks depending on the operation conditions. HCHs and Heptachlorocyclohexanes suffered a quick alkaline dehydrochlo-rination to thrichlorobenzenes and tetrachlorobenzenes, being these compounds further mineralized with time.

The authors acknowledge financial support from the Comunidad Autonoma of Madrid (Project S2013-MAE-2739 CARESOIL-CM) and from the Spanish MINECO (Project CTM2016-77151-C2-1-R) and the Aragon Government and EMGRISA Company for the supply of samples.1. Fernández, J., M. Arjol, and C. Cacho, POP-contaminated sites from HCH production in Sabiñánigo, Spain. Environmental Science and Pollution Re-search, 2013. 20(4): p. 1937-1950.2. Santos, A., et al., Abatement of chlorinated compounds in groundwater con-taminated by HCH wastes using ISCO with alkali activated persulfate. Science of the Total Environment, 2018. 615: p. 1070-1077.

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The first part of the presentation will be focused on an innovative In Situ Chemical Reduction (ISCR) reagent, comprised of highly dispersible colloidal ZVI (cZVI) particles coated in glycerol and suspended in water to create an injectable liquid. The presentation will show lab testing of the technology as well as pilot and full scale treatment case studies. Data will be shown to demonstrate the efficacy in cZVI in the degradation of chlorinated hydrocarbons, pesticides, haloalkanes, energetics and other toxic volatile organic compounds (CVOCs), through direct abiotic chemical reaction and ZVI-assisted anaerobic biological degradation.

The second part of the presentation will introduce a specially formulated colloidal activated carbon and electron acceptor amendment. The substrate adsorbs residual contamination in the groundwater, reducing the potential for plume development from secondary source contamination. The combination of rapid and controlled release electron acceptors incorporated into the technology promotes the onset of natural syntrophic biological degradation to assist in the attenuation of the residual contami-nant mass. Applications include placement into excavations to target high levels of residual petroleum hydrocarbon contamina-tion at fuel stations or oil spill locations.

The presentation will be of useful to environmental consultants, remediation contractors, site owners and regulators, who are interested in increasing their remedial options for cost-effec-tive treatment of sites impacted with chlorinated solvents and petroleum hydrocarbons.

Soil remediation of a Chloride contaminated site in Nangtong, China, using Electro-Reclamation

Art Lobs; Edward Van de Ven; Xue FeiVerhoeve Milieu & Water

At the Nantong (China) site a Chloride contamination was observed in both soil and groundwater (former ponds). The contamination was caused by the use of HCl acid for cleaning of metals. The soil consists of silty clay.

Electro Reclamation (ER) was selected as the remediation method. This technique uses Direct Current to facilitate transport of loaded particles (i.e. heavy metals) through the soil. The negatively charged Chloride will migrate towards the positively charged Anode electrode. The accumulated Chloride at the Anode site is removed by refreshment and treatment of the electrolyte at the anode site. The electro kinetic migration process is not dependant on the soil permeability and therefore well suitable for the low permeable silty clay on the Nantong site.

Prior to field application, Verhoeve Milieu & Water BV (VMW) performed a so called Turbo test in a laboratory setting to investi-gate the ER feasibility for the Nantong site. The major conclusions from the Turbo test were:

• Chloride can be removed from the silty soil by ER from the initial value of 1,700 mg/kg dm to below detection limit (< 50 mg/kg dm);

• The necessary anode and cathode spacing for field application is determined to be 1.7 to 2.0 m;

• The necessary energy for full scale application is 50 kWh/m3;

• The calculated remediation time is short : 4 to 7 weeks.

Based on the Turbo test data, the full scale remediation system was designed and installed on the Nantong site. For the 3 ponds

Multi-dimensional (carbon and chlorine) stable isotope analysis for the assessment of chlorinated compounds remediation

Sara Herrero Martín; Clara Torrentó; Mònica Rosell; Jordi Palau; Cristina Domènech; Raúl Carrey; Manuela Barbieri; Neus Otero; Albert SolerGrup MAiMA-University of Barcelona

Compound specific isotope analysis (CSIA) of contaminants provides unique information to identify their sources, to assess and quantify their natural degradation processes, and to monitor the success of remediation strategies at contaminated sites. This is due to the fact that non-destructive abiotic natural processes such as dispersion, sorption or volatilization produce a decrease in concen-tration, but generally do not cause significant isotope fractionation. In contrast, biotransformations and chemical reactions involve the formation or cleavage of chemical bonds, leading normally to enrichment of heavy isotopes in the remaining substrate.

The analysis of different elements within the same molecule (multi-dimensional isotope analysis) provides more robust information for source identification and for the characterization and monitoring of degradation processes.

Chlorinated compounds, such us: carbon tetrachloride (CT), chlo-roform (CF), tetrachloroethylene (PCE), trichloroethylene (TCE), cis-1,2-dichloroethene (c-DCE), have been widely utilized for many years as solvents, cleaners, dry-cleaning and degreasing agents. Environmental pollution caused by these compounds usually results from their industrial manufacturing and use, commonly by their inappropriate handling and storage.

We have established in our laboratory state of the art methods for carbon and chlorine CSIA of chlorinated compounds, but also working in close collaboration to other international partners and consultancies. Here we present diverse studies (at laboratory and field scales) in which we have applied C and Cl CSIA for the identification of contaminant sources, characterization of degradation processes, and assessment and quantification of natural attenuation or induced remediation strategies (including biostimulation, permeable reactive barriers (PRB) or in situ chemical oxidation (ISCO)).

The results of the different studies presented here provide a robust demonstration of the power of stable isotope analysis as a tool to assess the remediation of chlorinated compounds.

Two in situ remediation innovations: (1) Wide distribution micro-scale colloidal zero valent iron and (2) Source-area petroleum hydrocarbon retardation and degradation

Gareth Leonard¹; Kristen Thoreson²¹ REGENESIS UK Ltd; ² REGENESIS Inc.

Innovative nature of the proposed topic

This presentation will introduce two new in-situ remediation tech-nologies that have recently been launched in Europe. Both are ideal for treating high contaminant concentration levels cost-effectively, with minimal site disturbance.

The talk will discuss the theory behind each of the remedial tech-niques, what contaminants can be treated and in what geological settings. Laboratory development will be discussed and examples of beta sites and full-scale applications will be shown.

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extending over 760 meters downgradient, discharging into a creek. Highest concentrations of CT (approximately 1,500 ug/L) are located near the source area. To limit further plume migration, a PRB was installed across the plume width to passively treat CT. The PRB was constructed by injecting EHC slurry via a line of direct push injection points. EHC is composed of slow-release, plant-derived organic carbon plus micro-scale Zero Valent Iron particles. Inflowing groundwater is sulfate rich (~120 mg/L), potentially affecting substrate consumption rates and treatment zone reactive life. The presentation reviews geochemical parameter response and CT removal rates downgradient of the PRB, comparing them with theoretical calculations on ZVI consumption rates. The calcu-lations are discussed relative to the >10 year PRB longevity and mechanisms for its extended life.

21,770 kgs of EHC were injected into an area measuring approxi-mately 82 m long x 3 m wide x 2.75 m thick. The PRB was installed along a road and extended across the width of the plume to limit further migration. PRB effectiveness is measured at two compliance wells located 21 and 42 m downgradient. Monitoring is performed on a bi-yearly basis and includes CVOCs and geochemical param-eters. Total Organic Carbon is monitored as a reagent indicator while ORP, DO, nitrate and sulfate are monitored to assess down-gradient zone redox conditions. No direct iron measurements were performed, but iron consumption rates were estimated based on inflowing concentrations of terminal electron acceptors.

CT removal peaked 16 months after installation at > 99%. Two years later, these rates decreased slightly to approximately 95% removal and have stabilized at that level for over 10 years, continu-ously supporting inflowing groundwater treatment. Significant TOC increase was measured 21 m downgradient from the PRB during the first two years. TOC levels have returned closer to back-ground levels, suggesting that the more readily degradable carbon component had been consumed. During this initial phase redox conditions reached their lowest point, with concurrently reduc-tions in inflowing nitrate and sulfate. After TOC levels returned closer to background, sulfate levels moved closer to inflowing concentrations, while ORP remained significantly below back-ground. Theoretical ZVI consumption calculations suggest the ZVI may be consumed after 2.7 years if reacting stoichiometrically with inflowing sulfate. However, geochemical data suggest that ZVI alone is not supporting significant sulfate reduction. The probable explanation for such long PRB reactive life is the formation of an iron sulfide minerals based reactive zone created downgradient during initial sulfate reduction phase, and since acting as an electron reservoir. This zone may also be continuously rejuvenated by low levels of TOC in inflowing groundwater (~2 mg/L) and from the hydrogen produced from ongoing ZVI corrosion.

Clean-up of an Israeli site contaminated with petroleum hydrocarbons – Case study

Petra Najmanova¹; Petra Innemanova¹; Yair Lavi²; Itay Keret²¹ DEKONTA, a.s.; ² NEGEV ECOLOGY

DEKONTA has successfully performed a bioremediation project of soil contaminated with petroleum hydrocarbons in Beer Sheva railway station in Israel in cooperation with the Israeli company NEGEV ECOLOGY, in a short period from January till May 2018. The ex-situ biodegradation technology was used for the treatment of more than 2,000 m3 of soil heavily contaminated with petroleum hydrocarbons (initial concentration above 16,000 mg/kg). The aim of the treatment was to meet the TPH limit of 5,000 mg/kg, to enable disposal of the soil at a waste landfill.

together 46 anodes and 68 cathodes were installed and connected to the Electrical Supply Unit and Electrolyte Treatment Unit. The picture below shows an overview of the remediation site.

Endocrine disruption potential of widely used antimicrobial compounds revealed. Can they be biodegraded?

Klara Michalikova; Lucie Linhartova; Martin Ezechias; Tomas Ca-jthamlInstitute of Microbiology of the Czech Academy of Sciences

Antimicrobial compounds frequently used in oral care products (toothpastes and mouth washes), chlorhexidine (CHX), hexa-decylpyridinium (HDP) and octenidine (OCT), menthol (MEN) and thymol (THM) were recently revealed to interfere with human sex hormone receptors pathways (Michalikova et. al). The extensive consumption of these antiseptics and disinfectants in everyday household activities and their substantial increase in production worldwide suggest possible contamination of aquatic ecosystems and bioaccumulation in biota. Monitoring in the environment and bio/degradation of these compounds is needed in order to reduce possible risks towards human health and wildlife. In vivo biodegradation by white rot fungus Irpex lacteus was employed to investigate the capability of its enzyme apparatus (manganese-dependent peroxidase, MnP, versatile peroxidases, VP and laccase, Lac) to eliminate synthetic antimicrobials CHX, OCT, and HDP. Upon investigation done so far, I. lacteus in static culture was able to degrade only CHX. Residual concentration of CHX related to respec-tive heat-killed control was 25 ± 8% after 21 days of incubation. Additionally, a set of in vitro experiments employing concentrated extracellular liquid was performed to elucidate the involvement of particular enzymes on the degradation mechanism. It was found out that MnP activity (supplemented with MnSO4 and H2O2) contributes to the CHX degradation. In this case a 75% ± 4% of CHX in comparison to the heat killed control was decomposed after a 10-day incubation period. Reaction conditions mediating Lac activity and VP activity did not trigger any CHX degradation within a 10-day experiment. Further research elucidating the biodegrada-tion mechanisms of antimicrobial substances CHX, HDP, and OCT driven by ligninolytic fungi is required.

References:Michalíková K., Linhartová L., Ezechiáš M., Cajthaml T. (2019): Assessment of agonistic and antagonistic properties of widely used oral care antimicrobial substances toward steroid estrogenic and androgenic receptors. Chemosphere 217 (2019), 534-541.Acknowledgement:This work was supported by the Czech Science Foundation project no. 17-15678Y.

Influence of sulfate reduction and biogenic reactive minerals on long-term PRB performance in a sulfate rich, high flow aquifer

Josephine Molin; John ValkenburgPeroxyChem Environmental Solutions

Grain storage fumigation operations resulted in Carbon Tetra-chloride (CT) groundwater impacts in a farming community. High site groundwater flow (~210 m year) resulted in the CT plume

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The biotechnological method for remediation of soil or sludge contaminated with petroleum hydrocarbons (TPH) is based on the ability of certain bacterial strains to utilize TPH as a source of carbon and energy for their growth. Contaminants are decom-posed by aerobic biochemical pathway to non-toxic final products (carbon dioxide and water).

A spontaneous biodegradation process on the reclaimed site was very slow for the following reasons: absence of the specific micro-flora able to decompose the present hydrocarbons, low solubility of the present pollutants, non-homogenous distribution of the organic pollutants, deficiency of oxygen and specific nutrients, etc. To accelerate the decontamination process, it is convenient to create the ideal conditions for bacterial growth - especially the following parameters are usually optimized: temperature, humidity, concentrations of oxygen and nutrients in the treated soils.

The bioremediation technology applied by DEKONTA in Israel was based on biological decontamination of soil, water and sludge polluted by TPH using the bacterial preparation BIOTECH. The appli-cation of this preparation was approved by the relevant authorities.

The influence of fertilizer addition on the biodegradation rate was monitored during the treatment by respirometry. A simplified tool for measuring respiration activity was developed, to evaluate the fertilizing effect directly on site. Correlation between TPH concen-tration in a sampling point and respiration rate was evaluated. The initial value of the correlation coefficient r = 0.24 after 15 min of measurement and r = 0.23 after 30 min was low, and did not show significant correlation between the soil contamination and its respiration in the beginning of the measurement. But two days after fertilization, the respiration rate increased rapidly and was in strong correlation with the TPH concentration, especially after 30 min of measurement (r = 0.94). Apparently, application of the fertilizer YARA as a source of nutrients in a sufficient amount led to development of the optimum conditions for the biodegradation process.

The average concentration of C10-C40 dropped to 4,043 mg/kg after 5 months of the treatment, with the degradation efficiency of 75 %. The bioremediation was performed under the optimum conditions to decompose petroleum hydrocarbons to harmless compounds, carbon dioxide and water, within a short period.

Coupling bioremediation-chemical oxidation for TPHs removal from industrial soils

P Pinilla; M Gil-Diaz; P Garcia-Gonzalo; M.C. Lobo; Sergio Diez-PascualIMIDRA

Soil Pollution by Total Petroleum Hydrocarbons (TPHs) constitutes a concern of general interest due to their high toxicity and persis-tence in the environment, which involve a risk for human health. In this sense, it is necessary to propose specific remediation strategies for each contaminated site. Typical treatments involve the exca-vation and removal using physical or chemical methods, usually expensive and aggressive. The aim of this study was to evaluate the efficiency of different bioremediation strategies coupling with an oxidation chemical treatment for the TPHs removal in different industrial polluted soils. Four soils with different TPHs concentra-tion (A: 51500 mg/kg; B: 1010 mg/kg; C: 1500 mg/kg; D: 7600 mg/kg) and different physic-chemical properties were tested. Two of them also showed contamination by Cu and Zn (Soil A) and Cu and Pb (Soil D). Soil mesocosms (5 Kg) were treated by bioaug-mentation using a bacteria strain isolated from industrial soils

polluted with TPHs (Acinetobacter junii), and by biostimulation, using nutrients as energy source. The soils were incubated for 4 months in a climatic chamber (26ºC, 60% moisture), analysing the pollutant degradation every month. After bioremediation a chemical oxidation treatment was carried out using two doses of H2O2 (1 and 2%) and Fenton reaction. Among the bioremediation treatments, the highest degradation rate (71%) was observed in soil D treated by biostimulation. Bioaugmentation led to degra-dation percentages between 38-61%. In general, biostimulation led to higher degradation percentages except in soil A where the degradation rate was 51% using biostimulation and 61% using bioaugmentation. The highest degradation rate was observed after three months of incubation in all treatments. The application of chemical oxidation treatments increased the TPHs degradation in percentages lower than 10%. The Fenton reaction led to higher reductions in comparison with the use of H2O2. In general, biore-mediation efficiency was conditioned by soil properties as texture and porosity as well as by the pollutants characteristics. The use of the combined application of bioremediation and chemical oxidation could be an useful strategy for the reduction of this type of recalcitrant organic pollutants.

Acknowledgements: REHABILITA CTM2016-78222-C2-1-R (AEI/FEDER, UE).

Intelligent integration of innovative geotechnical and environmental solutions enables site redevelopment and protects sensitive off-site receptor from petroleum hydrocarbons

Mike Plimmer¹; Gareth Leonard²¹ GEA Ltd; ² REGENESIS

This award-winning remediation project concerning the redevel-opment of a former bus depot in Runcorn, UK, posed unique and complex challenges. Each step in the solution process would have a follow-on effect; therefore a well thought-out, integrated approach was crucial for the project’s success.

The site comprised a mound of industrial waste from the Leblanc process, including several metres of galligu. A bus depot on the site suffered extreme settlement, due to the poor geotechnical properties of the underlying galligu resulting in breakages and leaks from underground storage tanks and pipes.

The leaking fuel migrated through the Galligu into the under-lying ash layer and impacting perched water. The downgradient boundary comprises a steep slope to a canal. Periodically, contami-nated groundwater would egress at ground-level and run over the patios and vegetable patches of the local boat club, into the canal.

The low value of the site prohibited expensive dig and dump. Stabilisation of all of the galligu was not viable due to the thickness and cost . Instead, an integrated solution was used:

• Soil/cement mixed panels were used to support structures, with mixed mattress created under roadways. Installation of these panels altered the groundwater flow; channelling it towards the panel ‘wall’ at the boundary. Here the groundwater would funnel through gaps at a higher velocity and enter the offsite canal.

• An innovative Liquid Activated Carbon (LAC) substrate was used to integrate with the panels. By injecting the LAC into the subsur-face, an activated carbon filter was created in between the soil/cement walls. This barrier intercepted the petroleum hydrocarbons

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and prevented contaminant egress from the site, protecting the canal. The injection was completed from 4-5mBGL using direct push injection on a 3m spacing along a 30m line.

Validation showed that the barrier stopped contaminant egress from the site (98% reduction to the limits of detection). The canal has shown a reduction in hydrocarbon loading and the groundwater break outs on Boat Club land are now devoid of hydrocarbons.

This innovative integrated geoenvironmental solution allowed for highly effective remediation, protection of a public waterway and cost-effective treatment of a busy and difficult site. It allowed site redevelopment to proceed within budget and was delivered on time. Treatment of TPH in the presence of galligu has not been completed previously to our knowledge. This project recently won an award for Best Conceptual Design at the Brownfield Briefing Awards 2018 in London.

Lab scale micro and nano ZVI remediation of groundwater polluted with highly concentrated organochlorides

David Ribas¹; Irene Jubany¹; Vicenç Martí²¹ Fundació CTM, Centre Tecnòlogic; ² Technical University of Catalonia (UPC)

This study was aimed to assess the technical feasibility of using Zero Valent Iron (ZVI) injection to remediate the groundwater (GW) of an industrial site. The major pollutants in GW were: perchloroethylene, trichloroethylene, carbon tetrachloride and chloroform, found at mg·L-1 levels. Other concerning pollutants with concentrations in the range of µg·L-1 were: hexachloroethane, 1,1,2-trichloroethane, c-1,2-dichloroethene, t-1,2-dichloroethene and bromodichloromethane.

Two ZVI were selected for the reactivity study. One was a nano-metric ZVI being the commercial available NANOFER STAR, spherical, with a mean particle size around 100 nm and a surface area of 14.6 m2·g-1. The other was micrometric ZVI (UVR-FIA KKM) which has a flake morphology with lengths about 10 µm and a surface area of 18 m2·g-1.

The study of contaminant depletion at different concentration of ZVI (2, 4, 6, 12 and 18 g·L-1) after 28 days were set in batch mode tests. Due to high concentration of some chlorinated compounds, the reaction with iron would generate large amounts of gases, creating a pressure build up inside the batches. To solve this, a special configuration for gas release was designed which intro-duced a new leaking point in the already complicated volatiles handling. Accordingly, several blanks were included to normalize the results.

NANOFER STAR showed a high performance, already at concen-tration of 2 g·L-1, all major pollutants were eliminated >90%. Furthermore, at 4 g·L-1 all contaminants were eliminated >99%, being all pollutants under the legal intervention values.

Dichloromethane was produced as a by-product in the dechlori-nation of methanes, being the hydrogenolysis pathway dead end. Fortunately, hydrogenolysis is paired with reductive α-elimination which fully accomplishes the methanes dechlorination and was preferred at a ratio of 7 to 1. Regarding dechlorination of ethylenes, this fully took the reductive β-elimination pathway as no by-prod-ucts such as vinyl chloride could be detected.

On the other hand, UVR-FIA KKM had a much poorer performance not reaching similar degradation levels even at the highest ZVI concentration around 18 g·L-1.

Comparing to literature data, NANOFER STAR showed very high reactivity considering the high pollution treated. This means that a complete field remediation at a reasonable cost could be carried out.

To explain the high NANOFER STAR performance, it was hypos-tasized that the high concentrations of the groundwater anions: chloride at 293 and sulphate at 215 mg·L-1 avoided the growing of an impervious passivating oxide layer on the ZVI surface thanks to its corrosive effect. The oxide layer usually blocks the ZVI chemical potential. It can be concluded that a satisfactory remediation could be completed with NANOFER STAR iron using mid-low concentra-tions. These tests also stressed the need to perform lab tests with real waters as their chemical composition has a dramatic effect over ZVI performance.

The removal of PCBs from contaminated water using spent oyster mushroom substrate

Kamila Šrédlová¹; Pavel Mašín²; Alena Filipová¹; Zdena Škrob¹; Tomáš Cajthaml¹¹ Institute of Microbiology, Academy of Sciences of the Czech Republic; ² DEKONTA

Polychlorinated biphenyls (PCBs) are man-made compounds which were widely used during the last century in open and closed applications, e.g. as insulators in transformers and capaci-tors, thermally conductive fluids, plasticizers or additives in paints. Despite being banned around the 1980s, PCBs persist in the envi-ronment due to their chemical stability, lipophilic nature and recalcitrance. Moreover, PCBs exhibit many toxic effects including carcinogenicity, immunotoxicity or endocrine disruption. An envi-ronmentally friendly and inexpensive technique for PCB removal, such as bioremediation, is therefore desirable. A unique ability to degrade PCBs was found within the oyster mushroom species (Pleurotus ostreatus) which is cultivated worldwide for the food industry. Once the growth substrate no longer produces fruit bodies, it’s rendered as “spent” and can be repurposed for myco-remediation applications. In this work the removal of PCBs from water employing a spent substrate-filled bioreactor was optimized. Initially, the degradation was tested at laboratory scale with artifi-cially contaminated tap water (PCB concentration 50 µg/L; 10 L in total) where 97% PCB removal was reached. This process was then scaled up to treat real contaminated water (PCB concentration 0.1–1 µg/L; 4 000 L in total) which originated from a site of a former asphalt concrete producing plant. The fungal bioreactor was able to degrade about 80% of di- and trichlorinated PCBs, 65% of tetra-chlorinated PCBs and about 30–50% of pentachlorinated PCBs, while congeners with more chlorine atoms (present at a minority) were not degraded. Several chlorobenzoic acids were detected as degradation products with 2,4- and 2,5-dichlorobenzoic acids being predominant. Phospholipid fatty acid analysis, performed to monitor the microbial community, showed the presence of living fungal biomass during the whole experiment. The treatment was also evaluated with standard Vibrio fischeri ecotoxicity test and sequencing of bacterial and fungal DNA.

Acknowledgement: This research was funded by the Compe-tence Center TE01020218 of the Technology Agency of the Czech Republic.

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Fixed-bed column studies for the biosorption of methylene blue onto banana, cucumber and potato peels

Anastasia Stavrinou; Christos Aggelopoulos; Christos TsakiroglouFORTH/ICE-HT

The release of dye-containing industrial effluents into the environ-ment has become a major concern during the last decades due to their adverse effects on the ecosystem, water sources and human health. Azo dyes constitute ~70% of all dyes involved in the indus-trial production and their presence in wastewater effluents can cause severe diseases due to their toxicity, carcinogenicity and mutagenicity. Among the methods adopted for water treatment, adsorption process is considered superior due to its convenience, simplicity and effectiveness towards a broad class of dyes. Raw agri-cultural solid wastes are an ideal solution for water treatment, due to their cost effectiveness and abundance in nature (A. Bhatnagar M. Sillanpääet, Chemical Engineering Journal, 157 (2010) 277-296).

In our previous work, banana (BP), cucumber (CP) and potato peels (PP) were used as biosorbents for the removal of both cationic (Methylene blue) and anionic (Orange G) dyes from wastewater in a batch system. Regarding the methylene blue dye, BP, PP and CP revealed high adsorption potential with the corresponding maximum adsorption capacities being 211.9, 107.4 and 179.9 mg/g. Based on our research, all of the abovementioned biosorbents can be used without any modification and could be regarded as very low-cost adsorbents for the effective removal of both anionic and cationic dyes from wastewater (A. Stavrinou, C.A. Aggelopoulos, C.D. Tsakiroglou, Journal of Environmental Chemical Engineering, 6 (2018) 6958-6970).

In this study, the dynamic biosorption of methylene blue onto BP, CP and PP peels was investigated in fixed-bed columns. A PVC column of 10 cm height and 2.5 cm diameter was used for the experiments. Regarding the experimental setup, the inlet of the column was connected in series with a peristaltic pump and the influent wastewater tank whereas the outlet was connected to an effluent wastewater tank. Several continuous flow tests were performed, by varying the initial dye concentration, the column bed height, the flow rate and the initial pH value of the influent aqueous solution. For the determination of the characteristic parameters for the process design, the prediction of the break-through curves and the analysis of the adsorption mechanisms, Thomas model, Bohart and Adams model, Wolboroska model and Yoon and Nelson model, were applied to the experimental data. All models were well fitted to the whole or a part of the breakthrough curve. Based on the findings, BP, CP and PP peels can be used satis-factorily as biosorbents for the industrial dye wastewater treatment under continuous operation.

ACKNOWLEDGMENTS

This work was implemented under the Action “Supporting Enter-prises for Research Projects in the Microelectronics and Advanced Materials” and is co-financed by the European Union and National Resources through the Operational Program “Western Greece 2014-2020” (project title: “Development of materials for energy autonomous water purification units for its safe reuse – YLENDOR; project code: MIS 5029472).

Superoxide radical as a green reagent and an ultimate solution for soil and water contamination

Uri Stoin¹; Yoel Sasson²¹ Alpha Cleantec; ² The Hebrew University of Jerusalem

The contamination of soil and water by organic chemicals remains a significant worldwide problem, even after decades of research. The most common soil pollutants are polychlorinated hydrocarbons (PCHs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorinated solvents, petroleum products, and pharmaceutical leftovers. The contamination of soils and water by persistent organic pollutants (POPs) is an environmental concern because of their high chronic toxicity to both animals and humans, and their long-lasting sorption by soils and sediments.

During the past decades, several new and innovative solutions for efficient contaminant removal from soils and water have been developed and investigated. The methods include excavation and landfilling (for contaminated soil), thermal desorption, incinera-tion, washing, biological remediation, vacuum extraction, chemical extraction, chemical oxidation (AOP’s), photocatalysis and electro-chemical treatment.

Advanced oxidation processes (AOPs) provides an effective means of rapidly treating bio-refractory compounds with efficient process control. Chemical oxidation is a promising process for degrading an extensive variety of hazardous compounds in water and soil remediation. Nevertheless, the biggest challenge of soil remedia-tion industry is the non- homogeneous of the soil, emulsion in water, contact between the pollution and oxidizing agent and the sensitivity of the process.

Superoxide ion is one of the most extensively studied radical species due to its critical role in a wide range of chemical and biochemical processes. However, production and stabilization of superoxide compounds is still a substantial challenge. The high price of manufacturing and required high concentration exclude superoxide radical as economically reasonable advanced oxidation processes. Currently, there is now available methodology for efficient and cost-effective preparation and exploitation of super-oxide radical as soil and water remediation procedures.

In recent years, we developed two different processes (AFA and SOA) for straightforward, efficient and economical superoxide prepara-tion and applying as strong oxidizing agent, under NTP conditions. Under these conditions, superoxide radicals reveal properties of a super nucleophile and super-oxidizing agent which rapidly reacts with a wide range of soil pollutants on concertation up to 100,000 ppm and responsible for the rapid treatment and swiftly mineralization of absorbed and NAPL contaminants. While AFA is based on advanced Fenton and Haber-Weiss reactions activated for superoxide production. SOA is a unique process of alkali super-oxide production from standard and stable shelf products. Both of our patented methodologies applicable for in situ and on-site treatment approaches. The laboratory development phase with dozens of different types of contaminated substances has been accomplished. The technology stability and efficiency have been approved by independent laboratories and first pilot test for PCB and dioxin decontamination have been held. The conversion rate of 65% - 90% was achieved after only two hours of reaction.

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191

Structural insights into how sulfidation of zerovalent iron enhance reactivity and long-term performance

Dominique Tobler¹; Marco Mangayayam¹; Knud Dideriksen¹; Marcel Ceccato²¹ University of Copenhagen; ² Aarhus University

Sulfidation of zero valent iron (sZVI) has emerged as a new tech-nology to create nanosized particles with high reactivity towards common groundwater contaminants (e.g., chlorinated solvents, heavy metals, pesticides) and enhanced stability towards surface oxidation (i.e., passivation) by water. These superior properties are postulated to result from an iron-sulfide-rich shell that surrounds the metallic iron core. However, so far we are lacking clear evidence for this. While such nanoscale structural information may seem of secondary importance compared to rigorous kinetic testing of sZVI, it is indeed the most crucial piece in gaining mechanistic insights into how sZVI outperforms non-sulfidised ZVI (nZVI), and ultimately in predicting their long-term performance once injected into subsurface environments.

In this study, sZVI were synthesised using one-pot synthesis with dithionite, at varying S/Fe ratios, and then aged in artificial ground-waters for up to 30 days. The nanoscale structure of both freshly synthesized and aged sZVI were obtained by synchrotron-based pair distribution function (PDF) analyses combined with high reso-lution electron microscopy and X-ray photoelectron spectroscopy. The reactivities of fresh and aged sZVI were tested in batch reactors with trichloroethene (TCE) and cis-dichloroethene (cis-DCE) to establish the links between sZVI structure and reaction rates. The results showed that freshly synthesised sZVI consists of an Fe0 core with a shell composed dominantly of short-range ordered Fe(OH)2 and FeS. TCE reduction rates increased with increasing sulfida-tion (i.e., shell volume), while cis-DCE reduction rates decreased. The results are consistent with a model where cis-DCE reduction requires access to Fe0 sites, whereas FeS sites promote TCE reduction. The observed contaminant selectivity further suggests that dehalogenation occurs via direct electron transfer. In ageing experiments, sZVI retained >50% of its TCE removal efficiency after 30-day exposure to artificial groundwaters, while the non-sulfidized ZVI were unreactive after only 7 days. Overall, the results show great promise for the use of sZVI for TCE degradation. However they also highlight the materials’ limitation towards reaction with other chlorinated solvents, i.e., their contaminant selectivity.

Sustainability as a key driver in selecting a site remedial strategy: Installing a reactive zone to mitigate off-site migration

Mattias Verbeeck¹; Paulo Valle¹; Cécile Rao¹; Dirk Nuyens²¹ ERM BeNe; ² ERM France

At an operating manufacturing plant, a multi-level remedial strategy has been developed to address chlorinated solvent impacts present in soil and groundwater. The main compounds observed at the Site are Tetrachloroethylene (PCE), Trichloro-ethylene (TCE), 1,1,1-Trichloroethane (TCA) and its breakdown products. The impacts are associated with historical degreasing activities performed at the Site and remediation is required in order to address potential risks to human health and the environment. The Site remedial strategy included remediating the on-site source areas, and installing a Pump & Treat system at the Site border to contain the groundwater plume leaving the Site. This approach had already been discussed and approved by the local regula-

tors. In order to obtain a more sustainable remedial solution for the Site and reducing the long-term project costs associated with the operation and maintenance of the P&T system, an alterna-tive approach considering the installation of an In-Situ Reactive Zone (ISRZ) at the Site border was presented to the regulators. Monitored Natural Attenuation (MNA) results and sustainability factors such as cost-effectiveness in terms of mass recovery, carbon footprint, and waste generation, were used to support the shift in remedial strategy, and a new remedial action plan was submitted to the environmental authorities. This presentation shall focus on the rationale behind the shift in remedial strategy at the Site and the results obtained thru the field pilot test performed at the Site, confirming that the installation of an ISRZ was a viable sustain-able alternative to mitigate off-site migration.The implementation of the MNA program at the Site happened in the early stages of the project, when the first evidences of natural attenuation were identified. In addition to the MNA program, a field pilot test was implemented to confirm whether a significant mass reduction at the site border would be attainable through Enhanced Reductive Dechlorination (ERD). 4 separate field pilot studies were conducted to test different substrates and injection techniques. The selection of substrates for the pilot was based on their estimated effectiveness for the compounds of concern and their applicability considering the local hydrogeological conditions. Only 3 out of the 4 selected substrates were able to be injected and met the established project goals. Both direct-push and vertical injections wells were consid-ered viable options for delivering the substrates, and based on the groundwater monitoring results, a significant bio-stimulation and associated mass reduction were attainable by two out of the four tested substrates. The assessment on preferred substrate and injection technique for full-scale application was based on the contaminant mass reduction achieved by each product, and the associated costs for maintaining the ISRZ in place for a period of 10 to 15 years. The results of the pilot test confirmed that the instal-lation of an ISRZ was a viable sustainable alternative to mitigate off-site migration, and the injection of the reagent 3DME TM via vertical injection wells was selected for full-scale implementation.

Application of combined LDH-biochar derived from waste materials for mine water remediation: A case study from Slovakia

Veronika Veselská1, P. Lacina2, H. Šillerová1, F. Šmat1, B. Hudcová1, L. Trakal1, Ľ. Jurkovič3, P. Šottník4

1Faculty of Environmental Sciences, Department of Environmental Geosci-ences, Czech University of Life Sciences Prague; 2GEOtest; 3Faculty of Natural Sciences, Department of Geochemistry, Comenius University; 4Faculty of Natural Sciences, Department of Mineral Deposits, Comenius University

The mining sites remediation, including mine water cleaning, represents the current issue to be solved in Slovakia. At present, water remediation activities are focused in particular on drinking water resources by applying Fe hydroxides. In the long term, however, it is important to avoid the risk of sediment and ground-water contamination caused by metals and metalloids in mine waters. The purpose of this study, carried out in the project TAČR Zéta TJ01000015, is to produce and optimize a new, efficient and economical adsorbent having a large specific surface area, stability and adsorption capacity for both, cations and anions. The synthesis of layered double hydroxides (LDHs) using Fe sludge as a source of Fe and subsequent biochar modification arises in an innovative remediation tool of specific environmental loads, including mine waters as local sources of sediment and water contamination.

The Mg-Fe LDHs were synthesized by the co-precipitation method

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under alkaline conditions modified by (Hudcová et al. 2017, 2018). The structural characterization of synthesized materials was deter-mined by X-ray diffraction analysis (XRD). The adsorption efficiency of new materials has been verified using batch kinetic experiments as well as column experiments in the continuous flow for As and Sb in mine waters collected in several localities in the Slovakia. The satisfying removal efficiency, reaching up to 100% and 60% for As and Sb, respectively, was observed on all materials. Further-more, they seem to be more effective adsorbents compared to commercially used nano-carbons or granulated activated carbons. Considering natural pH (7-8) of mine waters and buffering effect of Mg-Fe LDHs, adsorption processes were affected by precipitation of carbonates. Column experiments confirmed adsorption capacity of new materials in a range from 0.2-0.5 mg Sb/g of adsorbent. Arsenic was adsorbed completely. In addition, field application of the LDH-biochar using the technology of pressure sorption columns, assisted by the company GEOtest, a.s., is now underway.References:Hudcová, B., Veselská, V., Filip, J., Číhalová, S., & Komárek, M., 2017: Sorption mechanisms of arsenate on Mg-Fe layered double hydroxides: A combination of adsorption modeling and solid state analysis. Chemosphere, 168, 539-548.

New insights into biostimulation of highly dichloro-methane-polluted sites: from the lab to the field

M. Viñas1, M. Guivernau1, F.X. Prenafeta-Boldú1, M.A. Vallecillo²1Institute of Agrifood Research and Technology (IRTA); 2Environmental Re-sources Management Iberia S.A. (ERM)

Dichloromethane (DCM) is a common industrial solvent with high ecotoxicity and carcinogenic potential. Due to the high solubility, volatility and low biodegradability of DCM, extensive plumes of DCM are widely spread in groundwater. In addition, bioremedia-tion of highly DCM polluted sites is a challenge due to its microbial toxicity and bacteriostatic effects on methylotrophic bacteria. New insights to unveil complex DCM-degrading microbial communities in highly DCM-polluted sites, contributing to the identification and monitoring of those best biostimulation conditions to speed up biodegradation are crucial for the implementation of in-situ biore-mediation strategies at field scale.

Here, we present a case study from laboratory scale microcosms and deep microbial assessment, to the field application of a real industrial site close to Barcelona (Spain), harboring highly-polluted ground-water with DCM (>100 mg · L-1). The high chloride concentrations (>2500 mg · L-1), low pH in certain wells (pH ranging 6.5-8), O2 content (0.5-4 mg · L-1), as well as the low concentrations of formaldehyde (FMD) (<1 mg · L-1), revealed that aerobic natural attenuation, linked to the glutathione-dependent dehalogenase pathway, occurred in the polluted site. In addition, microbiome assessment (16S-MiSeq sequencing) of groundwater samples from different wells showed the predominance of bacteria belonging to the Methylophilaceae, Hyphomicrobiaceae and Pseudomonadaceae and Erytrobacteria-ceae which might, therefore, be considered as microbial key-players for the in-situ DCM and FMD biodegradation.

A preliminary microcosm assessment of the target well MW3, revealed that aerobic biodegradation of DCM was feasible (2.4 mg L-1 day-1). However, nutrient amendments were essential both to speed up biodegradation (6.8 mg L-1 day-1) and to achieve the regulatory threshold defined by the Catalan legal authori-ties (<0.75 mg· L-1). 16S-MiSeq sequencing of microcosms under different conditions confirmed the importance of the Erytrobac-teriaceae during natural aerobic attenuation (without nutrient amendment) in the well MW3. Nutrient addition led to a shift of microbial populations being Pseudomonadaceae, Erythrobacte-

riaceae and Methylophillaceae the predominant bacterial families. Interestingly, the addition of chlorate and yeast extract under hypoxic conditions promoted DCM and FMD biodegradation and the growth of Pseudomonas spp. and Silanimonas spp. Species from these genera could utilize chlorate, DCM and FMD under hypoxic conditions and are worth of further research.

In-situ aerobic bioestimulation by means of air injection into the subsurface environment was feasible at field scale (80% of DCM depletion after one year), and confirm the initial results of natural atten-uation achieved in the lab. A diversified approach allows the gathering of more precise data for taking the proper and optimized decisions during remediation projects of highly polluted industrial sites.

Planning of a nano remediation: From mobility and reactivity tests to field application

Anke Wiener, Juergen Braun; Norbert Klaas Universität Stuttgart

The use of nanoparticles for in-situ remediation of contaminated soils and aquifers is an innovative technology. The nanoparticles mostly used consist of zero valent iron (ZVI). Iron is able to degrade a large number of pollutants. Zero valent iron is already known from plume remediation in the form of reactive barriers. Advantages of nano zero valent iron (nZVI) particles are the high reactivity and the possibility of targeted injection in form of aqueous suspensions. Therefore, the focus of an in-situ nZVI remediation is on source remediation. For this purpose, different types of ZVI nanoparticles were designed and tested. The aim is to develop nZVI remediation into a practical, safe and affordable technology. Knowledge of the exact migration and reaction characteristics of the nanoparticles in the contaminated porous medium is a basic prerequisite for the successful application of this remediation method. Control-ling factors for transport and reactivity result mainly from aquifer properties, the type of pollutant and possible aquifer-depen-dent competitive reactions, the properties of the nanoparticles, and the composition of the suspension to be injected. The tests were performed with comercially available nZVI particles. Tetra-chloroethene (PCE) was used as contaminant. The experiments were designed to simulate realistic conditions in the aquifer. The transport and deposition of ZVI in the aquifer were characterized by a combination of special dedicated column experiments in the laboratory. The experiments simulated one-dimensional flow in 0.5 and 2 m columns as well as radial flow in the so called “cascading column experiments”. The goal is a distribution of a defined mass of nZVI particles in a given reaction zone as homogeneous as possible. By modifying the composition of the suspension and by changing the injection conditions the particle distribution could be optimized. The distribution and the change in concentration of the zero-valent iron were measured non-destructively with the aid of a magnetic susceptibility detector. Test results can be used to calculate transport kinetics which is essential to plan an economic and suitable injection grid. For the experimental investigation of the degradation of PCE, special column experiments were carried out. In the experiment, the pH regime were controlled to reduce competitive reactions and the longevity of the particles could be determined. Based on the detected degradation products, reactions were characterized. In addition, the distribution and the change in concentration of the zero-valent iron was measured non-destructively with the aid of a magnetic susceptibility detector. The test results were used to calculate degradation kinetics. In order to design a successful nZVI remediation, it is crucial to combine the complex topic of particle mobility with the equally challenging aspects of particle reactivity. In this poster, the test procedures and results of current research will be presented.

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193

Post-treatment monitoring: an essential tool to highlight and react to unexpected evolution of pollutant concentrations

Samuel Wildemeersch; Maud Le BelSpaque

Active from 1875 to early 1990’s, “UBELL” is a former metal parts factory located in La Louvière (Belgium). Field investigations high-lighted multiple pollution spots in both soil and groundwater with various pollutants including CVOC’s. A two-steps remediation strategy was developed for cleaning up the site: (1) excavation and off-site treatment of pollution spots in soil and (2) enhanced reductive dechlorination (ERD) of CVOC’s spot in groundwater.

ERD was performed using 3DMe® of Regenesis. This product is an injectable liquid material designed to produce a staged-release of its three individual electron donor components. This results in an immediate, mid- and long-term (up to 4 years), controlled-release supply of organic acids to fuel the ERD process. A total mass of 3,200 kg of 3DMe® was injected by direct push in 99 injection points covering a total area of 3,086 m2. This injection was performed in Dec, 2010/Jan, 2011.

Performance of ERD was monitored through frequent sampling campaigns from Oct, 2010. First results were encouraging with a quick and strong increase of TOC combined with a rapid transition to low redox potential indicating that 3DMe® injection induced ideal conditions for reductive dechlorination to occur. The occur-rence of reductive dechlorination was confirmed by a decrease of

TCE concentrations followed by an increase and then decrease of DCE and VC concentrations from Feb, 2011 to Jun, 2012. From then, TCE concentrations quickly and strongly increased to values above those observed before injection. The most likely hypothesis is that this sudden rise in TCE concentrations was related to the construc-tion of a parking lot. Construction work probably disturbed the existing hydrochemical and hydrodynamic equilibriums and induced desorption of TCE adsorbed on the clayey layers. TCE concentrations kept increasing until Aug, 2013 before slowly decreasing. As TCE concentrations were still high in 2016, a second 3DMe® injection was considered. However, through the analysis of DNA and RNA, a feasibility study was first performed in order to ensure that micro-organisms capable of degrading COVC’s were still present and active in the source zone. This analysis, performed by Enoveo, indicated that reductive dechlorination was still active but inefficient due to a lack of TOC and nutrients. Consequently, a second injection of 800 kg of 3DMe® was performed in Dec, 2017 to provide micro-organisms ideal conditions for reductive dechloration. This second injection was performed using the SPIN® technique developed by SODECON. This technique allows injecting with lower pressures, including in low permeable soils, which prevents issues such as substrate outflow onto the soil surface. That was essential to keep the parking lot clean.

“UBELL” case study shows the importance of post-treatment moni-toring of groundwater remediation to spot unexpected evolution in pollutant concentrations related to external factors a priori innocuous such as the construction of a parking lot. When a remedi-ated site has been redeveloped, it also shows that further treatment with very limited impacts on ongoing activities is still possible.

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194

Evaluation of surfactant as useful tool for groundwater remediation

Neda Amanat; Marta M. Rossi; Marco Pertrangeli PapiniUniversity of Rome “La Sapienza”

Site contamination is a global concern due to the potential risks for human health and ecosystem quality. The peculiar physical and chemical characteristics of contaminants make the comprehension and prediction of their distribution in soil and subsoil particularly complex, which make selecting the correct remediation strategy increasingly daunting. As a matter of fact, the traditional remedia-tion systems (like as pump-and-treat) have shown strong limitation especially in the attainment of low regulatory limits. Therefore, a significant regard is paid to the development of technologies able to mobilize contaminants particularly in the areas characterized by very limited permeability. Moreover, remediation processes are negatively affected by the low aqueous solubility of some contami-nants; although, their availability can be enhanced by the addition of surfactants. These compounds are organic molecules that can be chemically and biologically produced. Surfactants contain both hydrophilic and hydrophobic groups, thus reducing surface and interfacial tensions of immiscible fluids and increasing the solubility and sorption of hydrophobic organic and inorganic compounds.

The aim of the study is the experimental evaluation of different commercial surfactants for enhancing the mobilization of sorbed contaminant from solid substrate. In this context, a solution has been contaminated with toluene as a Non-Aqueous Phase Liquid (NAPL); Pine Wood Biochar (PWB) has been selected, as solid substrate, due to its high affinity toward BTEX (Silvani et al., 2017); and a 4% v/v of surfactant in distillated water was prepared as washing/ flushing solution. Preliminarily, kinetic and isothermal tests have been carried out in batch reactors to verify if the surfactant decreases the adsorption capacity of PWB with respect to toluene. The amount of adsorbed contaminant (mg/g) has been reduced to an approxi-mately 50% which confirmed the affinity between surfactant and toluene. Secondly, the test has been run also in column, to simulate secondary source of contamination. The fixed bed column was filled with inert sand mixed with PWB (4% w/w) and saturated with 10 mg/L of toluene. After achieving equilibrium conditions (when the concentration of toluene in the outlet was equal to the inlet), the column has been flushed first with distillated water and then with surfactant. The results for the first investigated surfactant demon-strate that it has a high efficiency to increase mobility of contaminant. Experiments on another surfactant is ongoing.

Sustainable combination heating: An innovative approach for in situ thermal remediation in challenging lithology

James Baldock; Klaus Schnell; Jay DablowERM

At sites impacted by high concentrations of recalcitrant contami-nants, including NAPL accumulations, challenging lithology can be a deciding factor for technology selection. In Situ Thermal Reme-diation (ISTR) is a preferred approach where these conditions make application of physical mobilization and removal or fluid injection approaches problematic. ISTR is typically applied via a single heating methodology (including Thermal Conductive Heating (TCH), Steam Enhanced Extraction (SEE) or Electrical Resistance Heating (ERH)). The preferred approach is usually selected on the basis of subsurface permeability and boiling point of the contami-nants of concern; however the use of dual heating methods at sites

with contrasting permeability is increasing and can enable more sustainable remediation to be carried out.

This paper presents results from two sites, one in California and one in Switzerland, where relatively low permeability silts and clays are underlain by high permeability sands and gravels at both sites and where a combination of ISTR technologies was deployed to mitigate source zone impacts. At the Switzerland site a mixture of high boiling point compounds leached from a landfill was treated via TCH and SEE to achieve stringent concentration based remedial goals. At the California site, a combination of ERH and SEE is being applied at a former manufacturing site impacted by chlorinated solvents.

A Remedial Options Appraisal was undertaken at both sites using a holistic sustainability approach, where site lithologic characteris-tics, environmental, social and economic indicators were evaluated to determine the preferred option. At the Switzerland site, the results combined with a bench scale test showed that ISTR could address the high boiling point compounds and chlorinated solvent DNAPL present, with TCH used to heat shallow silts and clays, in combination with SEE in deeper sands and gravels to address impacts to a depth of 13m below ground level (bgl). In California, a similar approach was designed with treatment extending to a total depth of 18m bgl; in this case the upper 9m of low permeability materials were treated by employing ERH, as the boiling point of the compounds of concern was lower than in Switzerland, paired with SEE for the higher permeability geology.

Construction and implementation of a TCH/SEE approach in Swit-zerland was conducted during 2015. The estimated total mass removed was approximately 6,200kg, of which approximately 75% comprised trichloroethene and 1,2-dichlorobenzene, with the remainder consisting of the high boiling point compounds. Soil and groundwater sampling verified that stringent concentra-tion based remedial goals were achieved. At the California site, following implementation of the combined ERH and SEE remedy, the system achieved asymptotic mass removal, recovered greater than 1,500kg of VOC mass and successfully achieved soil and groundwater remedial criteria.

Lab-scale thermodesorption tests used to estimate the evolution of available aliphatic hydrocarbons in contaminated soils during pilot-scale remediation experiments

Coralie Biache¹; Pierre Faure¹; Catherine Lorgeoux²; Anouk Barrere³; Sébastien Kaskassian³¹ CNRS, Université de Lorraine, UMR7360 - LIEC; ² Université de Lorraine, CNRS, CREGU, GeoRessources, Vandœuvre-lès-Nancy; ³ Tauw France SAS

According to the European Environmental Agency, petroleum contamination affects more than 300,000 sites in Europe. Reme-diation treatments are often required to decrease the contaminant concentration to acceptable levels. The determination of the available fraction of a contamination is a major concern for risk assessment and management of contaminated sites. Indeed, the contaminant availability rules the efficiency of remediation treat-ments and the impact of the contamination on the biota (toxicity).

The aim of this study was to use thermodesorption coupled with molecular analysis for the determination of the available fraction of the contamination. It is based on linking the desorption temper-ature to the binding strength between the contaminant and the soil constituents, i.e. the higher the desorption temperature of a compound, the higher its binding strength with the soil and the lower its availability.

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The method was tested on samples taken from pilot-scale reme-diation of petroleum-contaminated sludge from drilling deep extraction wells. This soil/sludge matrix presents 30,000 mg/kg of average total petroleum hydrocarbon content (TPH) with n-C12 – n-C30 as dominant fraction. The matrix was mixed with compost and top soil in different proportions and a biopile treatment was applied according to different modalities:

- biodegradation only for 18 months, mechanical mixing every 2 months for aeration,

- biodegradation only for 2 to 4 months and vegetation growth (Ray-grass and Alfalfa) afterwards, mixing only occurs every 2 months during the initial biodegradation phase,

- undisturbed, non-amended sludge kept in the dark was used as control sample.

Soil monitoring is performed every 2 months to compare all treatment conditions with time for global in-situ parameters (pH, biogas production, temperature, moisture content), biological (nematodes, bacteria and fungus qPCR) and chemical (contami-nation level, soil enrichment) parameters and vegetation features (biomass production, root development, omega 3 content).

The first months of monitoring showed a limited degradation of contaminant in comparison to previous feedbacks on similar treat-ments. To understand this behavior, a focus was made on the contamination including global and molecular (GC-MS and GC-FID analyses) characterizations in addition to thermodesorption analyses.

Molecular ratio based on compound degradability (n-C17/pristane, n-C18/phytane, LMW/HMW, alkyl-aromatic/parent compounds…) indicated that the biodegradation reached a more advanced stage in the biopile modalities compared to the control sample. Ther-modesorption profiles indicated two distinct behaviors that could correspond to (i) the preferential degradation of the compounds desorbed at lower temperature (available compounds) and (ii) the increase in the content of n-alkanes desorbed at higher temper-ature that could indicate a binding and a stabilization of these compounds during the treatment.

The study is still ongoing and the analyses of the coming samples will be carried out within the next few weeks to evaluate the possible increase of matrix binding effect of TPH with time during the biopile treatment pilot.

Past, current and new application for removal of acid tar pits from contaminated land

Anna Bohers¹; Emília Hroncová²; Jozef Martinka³; Steve Leroi⁴¹ Matej Bel University; ² European Science and Research Institute; ³ Slovak Technical University; ⁴ Independent consultant

Recently a benchmark was made to compare various applications and technologies for the remediation of the 41 acid tar projects in North America and Europe. The benchmark results showed new developments in the European market place. These projects are looking at re-using acid tar instead of considering a disposal option. For re-use, the tar needs to stable and pH neutral (non acidic). Once a stable product is obtained, it can be further processed as a secundary fuel or processed to obtain an oil fraction.

The developments of these “energy recovery“ techniques, are partly due to availability of the European funding linked to the ascession process of these countries into the European Union. The other important reason for implementation of such projects are linked to the drive for cheaper energy. The challenge for cheaper energy and more sustainable alternative to incineration has resulted in some

recovery trials – with and without pretreatment of acid tar in the „energy recovery“ process. For the oil recovery process, a thermal condensation step is implemented, which separates a residual oil from the gas stream. At the same time, the most contaminated charge would remain in the air stream and destroyed in the gas treatment. Pilot scale separation has been achieved and results seem promising in terms of technical and financial feasibility of the full scale application.

This work was supported by the Slovak Research and Development Agency under the contract No. APVV-16-0223 and this work was supported by the KEGA under the contract No. 030UMB-4/2017.

Upscaling in soil remediation: Multi-scale two-phase flow modelling in high permeable aquifers

Maxime Cochennec

The remediation costs of contaminated site projects can be an obstacle to the set-up of conversion projects. In particular, a decrease in the number of pilot tests reduces the cost of the diag-nostic phase. It is expected that such a saving in the number of pilot tests can be achieved through better use of laboratory results, provided that a coherent link can be obtained between laboratory and field scale. In this context, the main objective of this work is to find a link between the hydro-chemical properties of the flow at different scales of a site undergoing remediation. We are interested here in the study of Dense Non-Aqueous Phase Liquid (DNAPL) transport in groundwater. This requires a correct description of multiphase flow in porous media.

A complete understanding of the two-phase flow necessarily requires a detailed knowledge of the structure of the porous medium, which is often difficult to obtain. More often, global measurements and overall distribution of the DNAPL are interesting.

Theoretical and numerical homogenization methods allow obtaining effective parameters that incorporate the influence of heterogeneities at the porous microscale and can be used for the construction of equivalent homogeneous models.

The particularity of the flows in the context of soil remediation is that they can take place in highly permeable porous media. Consequently, the impact of inertia or gravity effects on phase distribution can be significant at the pore scale and requires that the conventional generalized Darcy’s law model be adapted.

While this is largely an open question, experimental and theoretical evidence suggest that, at least, terms representing the drag force between the two phases (DNAPL and water) must be added to the generalized Darcy’s law.

The main aim of this study is to better understand the importance of these terms in the context of soil remediation.

In a first time, we briefly present the results of direct numerical simulations at pore scale that provide valuable insights into the shape and evolution of coupling terms and permeabilities for flows in highly permeable porous media.

In a second step, we present the implementation of the additional coupling terms into the classical two-phase flow Darcy’s law to interpret DNAPL flow experiments results at the laboratory scale. The simulation results are compared with experimental results in 1D column and 2D tank.

Finally, a discussion on the significance of taking these additional terms into account and the prospects for extending models to the field scale is proposed

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Thermal Conductive Heating (TCH): Comparison of power consumption to heat the soil between electrical resistance heating and gas fired burners

Jonathan de GrunneHaemers Technologies

Thermal desorption is an environmental remediation technology that uses heat to increase the volatility of contaminants (organic and/or inorganic) as such that they can be removed from solid matrix (typically soil) to be recycled or destroyed. The subject will focus on two existing in situ TCH techniques: electrical and thermal heating.

The designs and calculations are made considering the injection of power per linear meter of heating element. The method of heat injection with electrical power directly injects 1 kW/m, when the method of heat injection by thermal conduction has a 50-55% effi-ciency, therefore needs to produce 1.8-2 kW/m to inject 1 kW/m. The question here is how is electricity produced?

Current data shows that the needed power in terms of natural gas to produce 1 kW of electricity can vary from 1.6 kW to 2.85 kW depending on the type of thermal plant (conventional or with cogeneration for example). If we take these two extremes of yields, we get to an electrical power consumption in terms of combustion of natural gas between 320 – 640 kWh/m³ of soil for the best case and 570 – 1140 kWh/m³ of soil for the worst case (when the direct natural gas consumption to heat the soil with thermal conduction can vary from 619 to 894 kWh/m³).

The difference between the two techniques in terms of power efficiency and consumption will depend on the type of thermal electricity production. Whether the electricity production is advanced or not, the advantage given to one technique can easily become the advantage of the other depending on the electricity production rates of the countries in which thermal remediation projects will take place. As of now, very few thermal plants can reach a yield of 60% with natural gas. We can globally admit that with the current sources of electricity production, the two tech-niques are very close to each other in terms of consumption and efficiency. Another important factor to consider is the location of remediations sites because of both the electrical power and gas supply availability.

The second part of the article will cover the energy loss related to the interdistance between heating elements. Indeed, energy effi-ciency in heat injection is only a part of total remediation energy efficiency. Interdistance between heating wells drives remediation time and energy losses.

Biochar - from organic waste to resource for treatment of contaminated soil

Anja Enell; Maria Larsson¹; Ludvig Landen²; Peter Flyhammar³; Yvonne Ohlsson³; Sigrun Dahlin⁴; Sara Hallin⁴; Christopher Jones⁴; Cecilia Sundberg⁵; Elias Azzi⁵; Elin Norberg⁴; Dan Berggren Kleja⁶¹ Örebro University; ² NSR-AB; ³ Swedish Geotechnical Institute; ⁴ Swedish University of Agricultural Sciences; ⁵ KTH, Royal Institute of Technology; ⁶ Swedish University of Agricultural Sciences (SLU) / Swedish Geotechnical Institute (SGI)

Biochar-RE:Source is a 2-year research project aiming to develop a remediation technique with biochar to stabilize contaminated soil and increase soil quality to reduce waste and environmental risks. In Sweden, the most common remedial action is still “dig-and-dump”, leading to removal and landfilling of large volumes of soil.

Biochar could here serve as an impressive alternative leading to more sustainable soil management, great socioeconomic savings and several other environmental benefits.

Biochar is the charred solid product resulting from the pyrolysis of biomass under low oxygen environment. It is used as a soil amendment in forestry and farming due to its capacity to increase the soil quality by its ability to conserve water, sequester carbon, prevent nutrient leaching and neutralize soil acidity. Due to its porous structure, large surface area, and many functional groups it can also sorb both inorganic and organic pollutants.

We aim to find biochars produced from local organic waste streams, suitable for remediation of historically contaminated soils. The project will also investigate the conditions for biochar produc-tion from organic waste, the ability to apply the biochar technique in urban environments and quantify the environmental impact of different system alternatives in a life-cycle perspective.

During 2018, a lab study was initiated to test four biochars of different origin (produced from urban garden waste and recycled wood, processed at 500-650℃) and two biochars modified by the addition of clay and miscanthus. Two historical contaminated soils (contaminated by metals and polycyclic aromatic hydrocarbons; PAH) were amended with 3% of each biochar. The bioavailability of PAH is being assessed using polyoxymethylene (POM) and the leachability of metals are studied at different pH using pH-static leaching tests. The soil quality of the biochar-amended soils and the untreated soils is evaluated by measuring CEC, organic carbon content, C/N-ratio, pH and available phosphate, while the charac-teristics of the different tested biochars are analysed by methods regulated by European Biochar Certificate (EBC).

The outcome of the lab-study will serve as the basis for choosing a suitable biochar to test in field experiment during 2019. The purpose of the field study is to determine environmental risks and biological effects under natural conditions (temperature, wind, moisture, rainfall, soil microbes, pH). We will study the impact of biochar addition to different amendment-percentage, and types of soils. The soils will be representative of masses that arise from excavation or demolition in urban environments and contain common pollutants such as PAH and metals, but differ in terms of organic content and permeability (clay content). The cultiva-tion beds (approx. 3 ×3m) will be seeded with a crop and analysed after a growing season (summer 2019) with respect to biomass production and contamination. The bioavailability of pollutants in amended areas and controls will be assessed using leaching and ecotoxicity tests. Impact on soil respiration and effects on soil microorganisms that control the nitrogen cycle will also be studied.

Solubilization of dense non aqueous phase liquids produced as lindane wastes using non-ionic surfactants

Raul Garcia; Arturo Romero; David Lorenzo; Aurora SantosUniversidad Complutense de Madrid

The production of the obsolete pesticide Lindane (g-HCH isomer), included in the Stockholm Convention on Persistent Organic Pollutants (POPs), uses benzene as a starting material. Benzene was photochlorinated by Cl2 and UV light with reaction in series. At each step, the number of chlorine atoms in 6-carbon ring increases. The reaction route includes Chlorobenzene (CB), Dichlorobenzenes (DCB), Trichlorobenzenes (TCB), Tetrachlorobenzenes (TetraCB), Pentachlorocyclohexenes (PentaCX), Hexachlorocyclohexanes (HCHs) and Heptachlorocyclohexanes (HeptaCH)[1]. Since the g-HCH was the only isomer with insecticidal properties, the HCH mixture was purified to produce pure lindane. Among the wastes

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from lindane production, a Dense Non-Aqueous Phase Liquid (DNAPL) composed of HCH isomers, benzene and chlorobenzenes was detected in two landfills of Sabiñanigo (Spain) with an associ-ated polluted groundwater plume[2].

Due to the low solubility of these compounds in the aqueous phase several treatments trains can be considered for the remediation of a site contaminated by NAPLs [3] . Some of them involve the use of surfactants in order to solubilize or mobilize this organic phase in the subsurface and remove it at a higher rate that than achievable with pumped groundwater.

In this work, two ionic surfactants have been tested, Tween 80 from Sigma-Aldrich and E-Mulse 3® from EthicalChem, in order to determine the solubility of each Chlorinated Organic Compound (COCs) identified and quantified in DNAP. Two DNAPL samples were used, obtained at Bailin and Sardas landfills (Sabiñanigo, Spain), at several surfactant concentrations in the aqueous phase. Batch runs have been carried out in closed vials containing a mass of DNAPL and a volume of an aqueous solution with the surfac-tant tested. Analysis of the 28 identified COCs in the remaining organic phase and in the aqueous solution has been carried out. Fingerprint of COCs in the emulsion and in the organic phase were compared. Besides, partition coefficient aqueous/organic phase of each COC was obtained in absence and presence of surfactants. A high increase of the solubility was noticed with the surfactant addition, mainly for the less soluble COCs in water.

Besides, the solubility and stability of the emulsions at neutral and alkaline pH was investigated. It has been proved that at alkaline conditions (pH>12) alkaline dehydrochlorination takes place, with and without surfactants in the aqueous phase [4].

The authors acknowledge financial support from the Comunidad Autonoma of Madrid (Project S2013-MAE-2739 CARESOIL-CM) and from the Spanish MINECO (Project CTM2016-77151-C2-1-R) and the Aragon Government and EMGRISA Company for the supply of samples.

1. Santos, A., et al., Environmental Pollution, 2018.

2. Fernández, J., M. Arjol, and C. Cacho, Environmental Science and Pollution Research, 2013. 20(4): p. 1937-1950.

3. Tsitonaki, A., Treatment trains for the remediation of aquifers contami-nated with MTBE and other xenobiotic compounds, in Department of Environmental Engineering. 2008, Technical University of Denmark: Denmark.

4. Santos, A., et al., Science of the Total Environment, 2018. 615: p. 1070-1077.

Between caravans and boreholes - Challenges of performing in-situ remedia-tion on a camping site in the Black Forest, Germany

Petra Grill¹; Markus Kampschulte¹; Hans-Peter Koschitzky²; Oliver Trötschler²¹ CDM Smith Consult GmbH; ² Universität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung, VEGAS

How do you quickly and inconspicuously extract volatile chlori-nated hydrocarbons (CHCs) on a camping site on the outskirts of a spa town in the northern Black Forest without disturbing the relaxation of the numerous holidaymakers? CDM Smith accept-ed the challenge and supervised the thermal in-situ remediation at a camping site in Bad Liebenzell as consultant and project coordinator.

More than 50 years have passed since the former camera manu-facturer Regula King closed its doors in Bad Liebenzell, in the Black

Forest. But the consequences of the production are still in evidence. The CHCs that Regula King used as degreasing agents until the 1960s contaminated the groundwater in the uppermost aquifer.

The Pump & Treat and Soil Vapour Extraction remediation had not achieved the de-sired success after ten years. The state of Baden-Württemberg / Germany decided to conduct supplemen-tary thermal in-situ remediation of the main contaminated areas (source zone) by means of steam-air-injection.

The contaminated area of approximately 700 m² (contaminated soil volume 4,800 m³) was in the immediate vicinity of a residen-tial area and the local open-air swimming pool and mostly located below a building on the camping site.

To develop the remediation area, 170 boreholes had to be drilled in a narrow grid un-der very difficult site conditions. For removal of the contaminants, a mixture of satu-rated steam and air was injected into the subsoil (500-700 kW steam output) and the vola-tilized compounds were removed by vapour extraction at a rate of approximately 1,000 m³/h.

CDM Smith supervised and coordinated the remediation with all project stakeholders. The remediation was scientifically accompa-nied by VEGAS - Research Facility for Subsurface Remediation, at the University of Stuttgart.

Through the supplementary operation of the steam-air-injection, the former contami-nation centres were successfully remediated at short notice and approximately 730 kg of CHC was removed. The CHC concentrations decreased from 7,700 to 39 µg/L. The thermal in-situ process thus removed within an effective period of just less than 2 years more contaminants than the previous Pump & Treat process over 10.5 years. For the first time, the size of the contami-nated area and the small distance to the groundwater level were factors in the application of the steam-air-injection.

The remediation has been successfully completed in Spring 2017 and for now CDM Smith continues to supervise the project as part of its performance review.

Elimination of threat to one of Scandinavia’s largest groundwater resources

Jesper Holm¹; Niels Ploug¹; Adis Dzafic²; Elin Remstam³; Peter Anderson³; Anders Bank⁴; Hanna Lindvall⁵¹ Krüger A/S; ² Veolia - Sweden; ³ Municipality of Kristianstad; ⁴ Structor Miljö Väst AB; ⁵ Tyréns AB

The site Färgaren 3 in Kristianstad (Skåne, Sweden) formerly housed a dye works and dry cleaners. Releases from these activities have created one of the most contaminated sites in Skåne. The site which sits on top of one the most valuable groundwater resources in Scandinavia. Therefore, this site was prioritized for remediation funded by the Swedish EPA and headed by the Municipality of Kristianstad.

The aim of the remediation was to make the site available for all future land use and to protect the groundwater below the site. This was to be achieved through a combination of digging away the top 2,5 meters of soil on site and implementing thermal treatment from 2,5 meters below ground until 20 meters below ground inside a 900 m2 area. At the end of the digging operation, an extraction layer for the subsequent thermal remediation was installed from 2-2,5 meters below ground to be used for the thermal remediation.

The site was to be remediated down to an average concentra-tion of chlorinated solvents of 1 mg/kg. It was estimated that the

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contaminant mass in the area for thermal treatment was 1.500 kg of chlorinated solvents, primarily PCE. The geology at the site was a combination of clay, sand and sandstone.

Thermal remediation in the form of ISTD was applied on the site. 92 heater elements were installed combined with an extraction and treatment system for treating the evaporated contaminants. Contaminated gas and steam was extracted through the gravel pack along the installed heaters and subsequently through the installed extraction layer.

Operation of the ISTD system commenced in September 2017 and verification sampling was conducted in January/February 2018. Results from this sampling campaign will be available at the time of the presentation.

An estimated contaminant mass of 1.500 kg of chlorinated solvents was extracted over the 4,5 months operating time. Maximum extraction rate was approximately 100 kg/day. Temperature development and extracted mass was monitored on-line over the duration of the remediation to help determine when verification samples should be performed. At the end of the remediation, more than 250 soil samples were taken to validate the remediation. The samples showed a remediation efficiency of app. 99,9 %.

During operation some challenges had to be met. The ground-water level in the area was unusually high during the time of operation, making it difficult to maintain the extraction layer free from water. The water extracted to maintain the extraction layer free for passage of the extracted steam and gas contained micron sized particles making filtration and cleaning of water before release challenging.

The presentation will focus on the design and implementation of the thermal remediation on the challenges met during operation and how they were solved and present the results obtained during the remediation and at the end from the verification samples.

Electrical Resistance Heating (ERH) remediation at an active industrial site

Kenneth Jones¹; Marie Debackere²; Robert Shofstall²; James Baldock³; Martin Ohsé4

¹ ERM nv; ² ERM France; ³ ERM UK; ⁴ ERM BeNe

OBJECTIVES: Reduction of soil and groundwater concentrations within the treatment area, achieved through heating the target zone to 90°C or more if possible, and holding the temperature for the time necessary to reach asymptotic mass removal.

INNOVATIVE NATURE OF THE PROPOSED TOPIC: New remedial in-situ technique for the European market allowing to remediate recalcitrant contaminant in low permeable soil using. Subsurface temperature is increased by electrical resistance heating (ERH). For this site, this technique was the only alternative to excavation and off-site treatment and allowed to remediate the site without impacting the on-site operation.

At an active industrial plant in France, High Resolution Site Character-isation techniques identified an on-site source area associated with historical production activities. Remediation was therefore required to mitigate off-site plume migration and address potential human health risks. Given the low permeability of the soil, the Remedial Option Appraisal identified Electrical Resistance Heating (ERH) as the most appropriate technique to address the soil and groundwater impact from Trichloroethene (TCE), and to a lesser extent Dichloro-methane (DCM), 1,1,1-Trichloroethane (111-TCA) and Toluene, at depths of up to 12,5 meters below ground surface (m bgs). Average VOC concentrations in the source zone was 210 000 µg/l.

The local geology consists of fine grained silty clay soils (alluvium and/or weathered schist) extending to depths in the range of 10 to 13 m bgs where a granitic schist formation is encountered. Ground-water is present at a depth of about 4 m bgs. The main remedial objective was reduction of soil and groundwater concentrations within the treatment area, achieved through heating the target zone to 90°C or more if possible, and holding the temperature for the time necessary to reach asymptotic mass removal. An inter-nationally-recognized ERH contractor was selected for the works following a comprehensive bid phase.

The remedial strategy consisted of heating the impacted treatment zone by applying 3-phase electrical current to achieve 90°c throughout the entire treatment volume, and simultaneously contain and recover contaminated vapours and fluids via a robust Multi-Phase Extraction (MPE) system. Before, during and after the remediation, a monitoring program was implemented to determine contaminant concentrations and natural attenuation extent.

The remedial installation consisted of 28 electrode locations (each location included shallow and deep electrodes). The MPE system consisted of 11 horizontal vapour extraction wells and 11 vertical multiphase extraction wells. The average vapour and groundwater extraction flow rate was 276 m³/hr and 0,9 m³/hr, respectively. The extracted vapour and fluids were treated above ground via a series of process equipment including inlet tanks, heat exchangers and activated carbon. During heating, temperature was monitored via 6 thermocouples distributed within the treatment area. A web-based data monitoring system was used during the works, allowing for regular project team discussions and “real time” system adjustments

Once the electrodes were activated, the target temperature (90°C) was achieved after 120 days. This temperature was maintained for 28 days. At the beginning of the heating process, the daily mass recovery was approximately 4kg per day. Once the average temperature was at 75°C, a peak was measured and the daily mass recovery was approximately 9kg per day. Over time, mass removal decreased to 0,3kg per day, and based on the remedial objectives and monitoring data, the installation was then shut down. Post-remediation groundwater monitoring results showed an average reduction of 95% of total VOC concentrations in the treatment zone. A positive impact on the monitoring wells located down-gradient of the treatment zone was also observed. Further influence of the natural attenuation process as polishing step is currently being evaluated.

Toward the development of photo-reactors for the efficient treatment of water polluted with dyes

Michael Karavasilis¹; Chistos Aggelopoulos¹; Chistos Tsakiroglou¹; Alexandros Barnasas²; Panagiotis Poulopoulos²¹ FORTH/ICE-HT; ² University of Patras

During the last years, much attention has been paid on the decon-tamination of water matrices (e.g. groundwater, effluents of wastewater treatment plants) with advanced oxidation processes like photocatalysis, mainly due to the sustainability of the method associated with the solar energy utilization and the complete mineralization of organic pollutants.

In the present work, a methodology is described for the rational design of a photocatalytic reactor for the treatment of water pol-luted with model organic pollutants (e.g. dyes). On the one hand, immobilized zinc oxide (ZnO) nanorods were grown on Zn foils by treating their surface with various agents (e.g. acids), and annealing

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in an oven at temperatures 300-500 °C. On the other hand, ZnO was immobilized on a variety of supports (e.g. glass spheres, expanded perlite) with hydrothermal synthesis from aqueous solutions of Zn salts in temperatures lower than 100 °C. For assessing the capac-ity of the various types of immobilized photocatalysts to degrade organic pollutants dissolved in water, experimental studies were performed in glass batch reactors illuminated with UV light by treat-ing aqueous solutions of two dyes: methylene blue (cationic dye), and orange G (anionic dye). The residual concentration of dissolved dyes in aqueous solutions was measured with UV-Vis spectroscopy. To assess the effectiveness of the photocatalyst synthesis methods, the nanocrystalline structure of all materials was characterized by a variety of techniques: HRTEM, SEM, EDX, XRD, BET The kinetics of pollutant degradation was coupled with the dynamics of mass-transfer processes, adsorption/desorption in photocatalytic surface, and flow hydrodynamics to develop numerical models of the overall process in continuous flow photo-reactors of varying configuration, and use them as tools to design and construct a lab-scale and continuous-flow photo-reactor. A parametric study was conducted on the continuous flow photo-reactor with respect to tempera-ture, flow rate of the feed solution, and concentration of pollutants to identify the optimal conditions that maximize the process effi-ciency at the minimum power consumption. Finally, guidelines for the development of a pilot-scale photocatalytic unit are given.

ACKNOWLEDGMENTS. This work was implemented under the Action “Supporting Enterprises for Research Projects in the Micro-electronics and Advanced Materials” and is co-financed by the European Union and National Resources through the Operational Program “Western Greece 2014-2020” (project title: “Development of materials for energy autonomous water purification units for its safe reuse – YLENDOR”; project code: MIS 5029472).

Efficiency assessment of immobilization measures for PFAS in soil

Norbert Klaas¹; Juergen Braun¹; Claus Haslauer¹; Sofia Engelmeier¹; Marco Scheurer²; Frank Thomas Lange²¹ University of Stuttgart; ² TZW: DVGW-Technologiezentrum Wasser

Per- and polyfluoroalkyl substances (PFASs) are of increasing concern since they are found in soils and in the ground water. In the middle upper Rhine valley around the municipalities of Rastatt and Baden-Baden soil contamination with PFASs is a huge problem for agriculturally used land. These soils have been treated with compost which was contaminated with residues from the paper production containing PFAS.

Given the large area of the problem, classical remediation tech-niques do not promise to be effective treatment measures. Immobilization rather seems to be an alternative. In order to assess the efficiency of proposed immobilization measures, a combined experimental approach is presented, where batch, column, and lysimeter tests are applied.

The goal of the investigations is to predict the long term efficacy of different immobilisation approaches, which are based upon adding sorption materials like active carbon to the soil. Several of these immobilization agents are tested and compared in a project funded by the federal state of Baden-Württemberg. The project work is distributed between VEGAS and TZW. VEGAS is responsible for the conduction of mobilization tests, such as batch desorption tests, column leaching tests, and lysimeter percolation tests, while TZW is covering most of the PFAS analytics.

The poster will cover the underlying environmental problems, the scientific approaches, and first results of the investigations.

In situ geochemical stabilization (ISGS) for NAPL management

Fayaz Lakhwala; Mike MuellerPeroxyChem Environmental Solutions

In situ geochemical stabilization (ISGS) entails the use of modified sodium permanganate (NaMnO4) designed for in situ manage-ment of non-aqueous phase liquids (NAPL). When added to an impacted aquifer, the ISGS reagents react with organic (and certain inorganic) constituents of interest (COI) present as soil residuals (e.g., NAPL or ganglia). Various reactions associated with ISGS processes serve to physically encrust NAPL and rapidly reduce aquifer permeability, thereby stabilizing NAPL residuals and accel-erating remediation by natural attenuation of dissolved phase COI / plume constituents. COI mass reduction in the range of 10 to 15% is realized via chemical oxidation catalyzed by permanganate whereas COI flux reductions can range from 50 to 90%. In addition, the NAPL is weathered, encrusted and trapped in a lower permea-bility matrix, effectively reducing its mobility. Aquifer permeability can be reduced from 30 to 80% after a single application.

ISGS technology has been applied successfully at wood treatment sites containing creosote, and Gas Works sites containing coal tars. The presentation will discuss the principles on which the tech-nology is based, present laboratory testing procedures to design a field application and show data from successful field applications of the technology.

In situ remediation of PFAS using colloidal activated carbon: A review of multiple case studies

Gareth Leonard¹; Rick McGregor²; Kristen Thoreson³; Maureen Dooley³¹ REGENESIS UK Ltd; ² ISRL; ³ REGENESIS Inc.

This presentation reviews data from multiple field sites where colloidal activated carbon has been utilized to remediate PFAS groundwater contamination in situ. Sites discussed include the Solvents Recovery Service of New England superfund site (US) and a former furniture manufacturing facility (Canada). The talk will also use the latest data from lab and pilot studies at other sites, to explain how the risk of PFAS contamination in soil and groundwater can be contained via in situ remediation, using colloidal activated carbon. This new in-situ containment approach offers a far more cost-effec-tive long term solution to stop and contain risk caused by PFAS plumes, compared to existing methods (hydraulic containment). Further important questions, including the ability to distribute the colloidal activated carbon in the subsurface, the long-term efficacy, and design considerations, will also be addressed.

Multiple field sites were treated with a single application of colloidal activated carbon to address PFAS contamination and other comingled contaminants. Depending on any co-contam-inants present, additional remedial agents were also applied to degrade those contaminants. In each case the amendments were applied under low pressure (non-fracking) conditions using direct-push technology. At one of the sites, groundwater was impacted by petroleum hydrocarbons at concentrations up to 6 mg/L in addition to PFOS and PFOA which were present at baseline concentrations of 300 to 3,300 ng/L. In this case, an oxygen release agent was co-applied to promote the biodegradation of the TPH. At another site, TCE was present in addition to the PFAS contamination and a sulfidated zero-valent iron was co-applied with the colloidal activated carbon. Monitoring at all sites is on-going, with current data ranging from 3 months to over two years, and has included

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analysis of PFOS, PFOA, shorter chain PFASs, and co-contaminant concentrations.For some of the sites to be discussed, laboratory bench tests were performed as an initial step to aid in the field dosing and design considerations. In these cases, site groundwater was treated with varying doses of the colloidal activated carbon to assess for any potential interferences or competition for sorption sites between species present at the site.

Results from field case studies have demonstrated immediate removal of PFAS from the dissolved phase to levels below the US EPA health advisory level when treated with a single application of colloidal activated carbon. The site with the longest monitoring period has maintained its performance with PFOS, PFOA as well as shorter chain species for over two years, with further monitoring ongoing. The colloidal activated carbon treatments, sometimes in conjunction with another remedial agent, were capable of addressing co-contaminants like TPH and TCE. Bench studies also proved helpful in proving efficacy and ruling out the presence of interfering species that would limit performance. Overall, these studies indicate that the in situ application of colloidal activated carbon offers a valid and cost-effect strategy to address the risk associated with PFAS.

ERH experience in Europe, the added value of the consultant

William LeysAECOM

Electrical Resistance Heating (ERH), has been applied for several decades in the United States and, to a limited extent, in Europe. However in recent years, an increase in the number of sites imple-menting ERH in Europe has been observed. In most cases in Europe, ERH remediation is performed by a European contractor in joint venture with one of the larger American or Canadian ERH contrac-tors. This collaboration combines the American ERH knowledge and experience of the technology with the local contractor’s knowledge of the European market and local technical boundary conditions.

The implementation and operational monitoring of in-situ thermal remediation requires a unique approach and vision compared to traditional soil remediation techniques.

ERH technology is applied less frequently and therefore a limited number of contractors and consultants have the knowledge to safely and effectively implement or follow up an ERH remediation. AECOM has acquired valuable ERH experience through involvement with several full-scale ERH remediation projects in Belgium and France. AECOM will present the role and added value of the consultant on ERH projects. Some of these aspects are discussed below.

Since ERH projects are often tendered as lump sum projects, the consultant has the important role of establishing the technical boundary conditions of the ERH-project during the tendering and contracting phase. For example, a detailed monitoring programme must be designed to evaluate the progress and the end of the active remediation (compliance monitoring). In addition, potential migration caused by pressure build-up and the resulting mobiliza-tion of contaminants must also be considered in the monitoring programme and defined in the tendering and contracting phase.

Despite the lump sum character of most ERH projects, intensive monitoring during the operational phase is required to verify if the heating and mass removal processes are according to plan. Significant pollutant mass will be removed in a very short timeframe (typically weeks or months) during the “peak removal period.” Therefore monitoring of an ERH project must be designed

to be prepared for and to detect the peak removal phase during operation. The consultant has to be aware of these rapid processes and can for example impose an in-line gas detection to identify the upcoming peak removal period and other phases of the reme-diation as it progresses. An in-line gas chromatogram (GC) and in-line photoionisation detector (PID) have been deployed and are proven to be effective monitoring techniques. Monitoring of the treatment system, in-situ processes, possible migration issues and the surrounding environment (such as vapour emissions) should be aligned to this peak removal period.

AECOM will emphasize the added value of the consultant for both the client and the contractor during an ERH project, including presentation of case studies, lessons learnt and actual data.

Modelling adsorption of binary mixtures of volatile organic compounds (VOCs) onto activated carbon from contaminated groundwater treatment emissions

Vicenç Martí¹; Elena Piedra¹; Irene Jubany²; Neus Bahí³; Montse Calderer³; Francesco Caridei⁴; Claudia Mosangini⁴¹ Technical University of Catalonia (UPC); ² Fundació CTM, Centre Tecnològic; ³ Fundació CTM, Centre Tecnòlogic; ⁴ Ecosurvey®

Removal of VOCs from groundwater by using methods such as Air Sparging or Soil Vapor Extraction demands the design of a proper gas treatment system able to retain VOCs and avoid impact in air. Adsorption by using fixed bed columns with Activated Carbon (AC) is the most used system for retention of mixtures of VOCs. The competitive adsorption of VOCs in mixtures advances the break-through time (BKTT) in the case of more labile compounds and increases its concentration at the exit.

In the present work the breakthrough curves for VOCs in an AC column as a single components and as components of a binary mixture in air were developed. In the case of single component an equilibrium linear model was considered and in the rest of cases a binary mixture model with first-order kinetics and Langmuir equi-librium has been implemented in a Matlab code.

The isotherms and the breakthrough curves of the models were validated by contrasting with literature results for acetone and xylenes, showing total agreement. The code also showed the total PID signal (Photo Ionization Detector) of the mixture of gases at the exit of the column.

Two case studies were used for the modelling of contaminants.

In the first case study 4 l/min of gas with a mixture of tetrachloro-ethylene (0.48 mg PCE/m3) and trichloroethylene (0.18 mg/m3 TCE) through 350 g of AC was used as a reference. This case study was used to determine de sensitivity of the input parameters (operating conditions and Langmuir curves) on BKTT and maximum concen-tration. By studying the effect of modifying a single parameter at a time, sensitivity ratios for each parameter were obtained. The most influent parameters for BKTT were the flow of gas and the saturation parameters of both components (m1 and m2). The initial concentration of TCE was the main parameter that affected the maximum concentration of TCE during breakthrough.

The second case study considered a setup where 1.52 m3/min of gases from two different extraction wells (A and B) with 1,2-Dichlo-roethylene (1,2DCE), Vinyl Chloride (VC) and PCE as main VOCs were passed through 150 Kg of AC (Carbosorb). At the exit of the setup a PID is placed and detects a concentration equivalent to ppm of isobutylene that informed about the breakthrough.

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Well A has a mixture of 1,2DCE-VC and well B a mixture 1,2DCE-PCE. In both cases 1,2DCE was the more labile compound and compar-ison of single component.

Binary mixture showed that BKTT2 was the same as in the case of single component. 1,2 DCE BKTT was notably affected by the presence of the other VOC strongly adsorbed onto the AC because in the simulation BKTT1 in Well A passed from 126 days in the single compound approach to 94.3 days in binary mixture and BKTT1 in Well B passed from 218.8 days in the single compound approach to 188.1 days in binary mixture. Concentration of 1,2 DCE increased a 32% during the breakthrough in wells A and B.

Concentrations detected with PID and data simulation showed that those measurement could be applied to the breakthrough study of these VOCs.

This research work was performed under the EU Program Eco-Innovation funding (project SMARTSTRIPPING ECO/10/277350/SI.599553)

In situ Stabilization and Solidification (ISS) optimized: benefits of adding sodium persulfate

Mike Mueller; Brant SmithPeroxyChem Environmental Solutions

In situ stabilization and solidification (ISS) is a well-established remedial technology often used to treat highly contaminated sites. ISS decreases the contaminant flux by decreasing the hydraulic conductivity and solidifying site soils. In addition to hydraulic conductivity, ISS is often used to target specific post application unconfined compression strength (UCS) of soils following the appli-cation for purposes such as site redevelopment. Reagent doses can result in displacing 10 to 30 percent of site soils by weight, neces-sitating treatment or disposal of these excess contaminated soils.

Data has shown that both remedial goals can be accomplished using lower overall mass of reagents when adding alkaline activated sodium persulfate in with the ISS reagents during field events.

The objective of these studies was to demonstrate the effect of adding low levels of alkaline activated persulfate during ISS on hydraulic conductivity, contaminant leachate concentration and post application compressive soil strength. Various combina-tions of ISS reagents and alkaline activated sodium persulfate were evaluated on the bench and field scale. In situ soil mixing was utilized in the field and simulated in the laboratory to ensure complete mixing of the contaminated soils with the reagents.

The data show a trend of decreasing hydraulic conductivity and decreasing leachate concentrations with increasing dosages of alkaline activated sodium persulfate. Reagents were balanced to achieve workable post application soils strengths and hydraulic conductivities of 10-6 to 10-9 cm/sec. Site specific dose response curves demonstrating the effect of varied concentrations will be presented.

In-Situ metal precipitation of a nickel groundwater contamination. Results of a comparative lab study on the immobilization of nickel using a carbon source and a permanganate solution

Dirk PaulusTauw Belgium

The aquifer of an industrial site in Tisselt, Belgium has been impacted with heavy metals and fluoride due to former galvaniza-tion activities carried out at the site.

Since high concentrations of heavy metals, mainly Ni, were observed in the local aquifer, there is an obligation according Flemish legislation to remediate for nickel.

A lab test was performed in order to determine the feasibility to immobilize nickel either through precipitation of NiS↓ or through adsorption of Ni on manganese oxides (Birnessite).

Both immobilization mechanisms for nickel were investigated in detail as well as the effect of these reactions on other heavy metals such as Zn and Cr(VI).

Also the influence of high fluoride concentrations on the precipita-tion velocity of Ni was investigated during the lab test as fluoride is believed to act as bactericide inhibiting (or hindering) the biolog-ical reduction of sulfate into sulfide.

The lab test was performed in 2017/2018. The two possible immo-bilization pathways were tested as follows:

1. Immobilization of Ni by adding a carbon source in order to create sulfate reducing conditions in the aquifer leading to the precipitation of Ni as NiS↓.

2. Immobilization of Ni by adding a permanganate solution in order to form manganese oxides on which Ni could adsorb.

Following test conditions were conducted during the lab test:

1. Nickel precipitation as NiS↓

Addition of a 150 mg/l solution of nutrolase and protamylasse to an aquifer sample containing a high fluoride concentration (120 mg/l) and in parallel a similar addition of carbon source to an aquifer sample containing a low fluoride concentration (7,1 mg/l). Samples were shaken during a 6 week period (L/S ratio of 5) with regular measurements of pH, EC, ORP, DOC, Cr, Zn and Ni concentrations.

2. Nickel adsorption on Birnessite

Permanganate was added to aquifer samples in 4 different concentrations. Samples were shaken during a 24h test in a L/S ratio of 5. Test samples were analyzed for pH, EC, ORP, Ni, Zn and Cr concentrations. A second similar test was realized with a pH correction using a 3% CaCO3 solution.

The results of the different tests on Ni, Zn and Cr concentrations are discussed and presented in comprehensive tables and graphs as well as the influence of fluoride on the precipitation velocity of nickel.

Test conditions indicated that a decrease of more than 99% of the initial Ni-concentration could be obtained by both immobilization pathways.

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Results are interesting considering that the material is used without preliminary modification or activation, but further inves-tigations are needed. A fixed-bed reactor in a plexiglass column filled with sand and reactive material is ongoing in order to draw the breakthrough curve and evaluate the material’s performance in continuous conditions.

Can Biochar be used as a cost-effective sorbent for groundwater remediation?

Marta M. Rossi¹; Neda Amanat¹; Gloria Arduini¹; Maria Luisa Astolfi¹; Ida Pettiti¹; Ludovica Silvani²; Marco Petrangeli Papini¹¹ University of Rome «La Sapienza»; ² Norwegian Geotechnical Institute (NGI)

Contaminated sites by mixture of contaminants are diffused worldwide: DNAPLs, VOCs or heavy metals are commonly revealed in the aquifer. Groundwater’s remediation technologies need to be more effective at lowering concentration imposed by local legisla-tion, more sustainable and cost-effective. The “Pump&Treat” remains the most chosen technology combined with “ex situ” treatment, like adsorption onto sorbent materials, such as Activated Carbon. New strategies are interested in low-cost carbonaceous materials, like solid waste obtained by thermal treatment of agricultural waste. In this context lots of research are studying the capacity of “biochar” (BC) in immobilizing different class of compounds from contami-nated solutions (Alhashimi and Aktas, 2017). Some works report the BC’s efficiency in immobilizing nutritional compounds for plants and microorganisms and its eco-friendly being (Zhu et al., 2017). These aspects are interesting for an innovative “in situ” tech-nology, where the BC could be injected directly into the aquifer for selective contaminants immobilization and for supporting natural attenuation carried out by microorganisms. Furthermore, in the majority of papers, laboratory-made BCs were used. In this study pine wood BC (PWBC), obtained in a gasification unit in Germany, a rice husk BC (RHBC), from a pyrolysis small-scale farmers unit in Indonesia, and a BC (from Epatorium sp. shrubs) modified during the pyrolysis process adding oxide-hydroxides of Iron (FeBC), were used (Martisen et al., 2015; Silvani et al.,2017).

SEM and X-ray analysis, meso-, micro-porosity analysis and deter-mination of the surface area (BET) confirmed the morphological difference between these BCs, due to the different feedstock and process conditions (presence/absence of O2; temperature; residence time). Adsorption tests with contaminated solutions by Trichloroethylene (TCE) and Lead (Pb2+) were carried out to inves-tigate the behaviour and the efficiency in contaminants removal by batch and column reactors. Kinetic tests in batch reactors were performed to verify the equilibrium time required to determine the adsorption isotherm. Experimental data were fitted with Langmuir and Freundlich model in order to obtain the optimized param-eters that allow comparing the material behaviour. To simulate real groundwater conditions, fixed-bed reactors were realized in plexi-glass columns packed with a mixture of sand and reactive material and the breakthrough curves are drawn.

The results are very encouraging: at the equilibrium concentration of 5 mg L-1 of TCE, the adsorbed amount is 20 mg g-1 (PWBC), 4 mg g-1 (RHBC) and 5 mg g-1 (FeBC), comparable to adsorption onto a commercial Activated carbon. On the other hand, at 20 mg L-1 of Pb(II) we obtained 5 mg g-1 and 23 mg g-1 for (PWBC) and (RHBC) respectively (texts onto FeBC are ongoing). Columns’ results have shown the potential applicability of these materials in “in situ” treatment (direct material injection) or “ex-situ” treatment (in adsorption columns). Moreover, a fluidized-bed reactor is going to be set up, for optimizing “on-site” treatments.

Analysis of work coil dynamics for induction heating applications

Edwin Reid; David Nyarko; Shiella Delos ReyesMcMillan-McGee Corp.

An analytical model is developed to compute the reflected resis-tance and inductance of a helical conducting work coil placed within a steel pipe. The dependence of inductance on the presence of the pipe is assessed quantitatively and explained on the basis of physical principles, as well as the significance of skin and proximity effects in the work coil. When the pipe and work coil are very close, the inductance of the coil is found to be greatly diminished, a result which is in excellent agreement backed by experimental measurements.

Adsorption of contaminants onto a char obtained by pyrolysis of used tyres and rubber wastes: a possible low-cost alternative in the groundwater technologies

Marta M. Rossi¹; Neda Amanat¹; Violetta S. Kusheeva²; Sergei V. Ostakh²; Anatoly I. Masalevich³; Maria Luisa Astolfi¹; Ludovica Silvani⁴; Marco Petrangeli Papini¹¹ University of Rome «La Sapienza»; ² Gubkin Russian State University of Oil ans Gas; ³ Waste management agency «Mercury safety»; ⁴ Norwegian Geotechnical Institute (NGI)

Soil and groundwater contaminations by mixture of compounds seems to be very diffused worldwide. The watchword in the decision of the remediation technology for each scenario is to select the most sustainable option, among the possible alter-natives. Conventional strategies for dissolved compound in contaminated groundwater provides the use of sorbent materials, but what makes the adsorption technology feasible is the high performance at low concentration revealed in the aquifer and the low cost of the material. Carbonaceous materials are the most used sorbent for this kind of application and Activated Carbon (AC) is usually the sorbent with the highest performances achieved, but it required high costs. In recent years the scientific community has focused on the search of new low-cost materials such as biochars obtained from thermal conversion of agricultural wastes and biomass, or carbon black from waste tyres pyrolysis. The disposal of waste tyres represents a serious problem indeed, hence the pyrolysis of pneumatic tyres and rubbers is advantageous due to their high calorific value and because of the generated products: the oil can be used as fuel, the gases for heating, while the solid waste is studied for gasification, combustion and for activated carbon preparation (Zabaniotou and Stavropoulos 2003; Gupta et al., 2013; Saleh and Gupta 2014;Perondi et al., 2016).

In this study we investigated a carbon black obtained in a pyrolysis plant working in Krasnodar (RU): the feedstock for pyrolysis is composed by used tyres of cars and various waste products of rubber goods, like hoses, high-pressure hoses, drive belts of agricultural machinery and conveyor belts; the temperature setting is 350°C.

The char was characterized by preliminary chemical composition analysis, SEM and X-ray analysis, meso-, micro-pores and surface area (BET) analysis. Secondly, adsorption tests were realized on the raw material: contaminated solutions with Toluene, Trichloroeth-ylene and Lead (Pb2+) were put in contact with different amount of material, therefore kinetic and equilibrium tests in batch reactors were performed. Experimental data of isotherm curves were fitted with Langmuir and Freundlich model and compared with commer-cial activated carbon and biochars performances.

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The scope and some propositions for best-practice application of ISTR were published in a handbook in 2012 (TASK, UFZ Leipzig). For the steam-air injection technique (“Dampf-Luft-Injektion” (DLI), in German) a design software called ‘DLI-ToolV1.1’ was developed and it was published in 2012 (TASK Competence Centre) as Freeware. The relevant input parameters for this software are site- and contaminant-specific parameters of the remediation area, basic hydrogeological information, and the process engineering related parameters (e.g., number of wells, desired temperature). After the necessary calculations are performed, the software suggests plausible remediation steps and estimated timeframes, as well as the major mass flux and heat parameters to design the process engineering of the remediation plant and the remedy.

The DLI-Tool was used to design three different full scale appli-cations to treat CHC contamination in a low permeable soil (2013-2015), fractured bedrock (2012-2016), and fully saturated alluvial sediments (2015-2016). The remediation process was accompanied by VEGAS scientifically, related to mass removal and remediation control aspects. And the tool was subsequently refined with respect to the gained experiences from the field sites. The predicted heat and mass flux remediation targets were met perfectly using the DLI-Tool. However, using the DLI-Tool V1.1, the contaminant removal rates were 20%—50% lower than the software had predicted.

Consequently, the results were implemented in the software tool leading to a basic modification in the determination of the contaminant desorption process. The current version V2.0 (www.iws.uni-stuttgart.de/forschung/DLI-Tool/DLI-ToolV2.0.zip) is now based on a contaminant desorption rate comprising the organic carbon (OC) content of the soil and a contaminant mass transfer for the equilibrium of soil-pore water-soil air.

The presentation will discuss the results and lessons learned of the successfully closed field applications discussed in this abstract and will showcase the related improvements of the DLI-Tool software for remedial design.

Thermally enhanced in-situ remediation using steam-air injection – background and improvement of the “DLI-Design-Tool” software for remedial design

Oliver Trötschler; Wilis Awandu; Florian Boscher; Hans-Peter Koschitz-ky; Claus HaslauerUniversität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung

Thermally enhanced in-situ remediation (ISTR) using steam-air injection is an approved technique to remediate simultaneously the saturated and variably saturated source zone contaminated with chlorinated hydrocarbons (Trötschler et. al. (Aquaconsoil 2017), Koschitzky et. al. (Aquaconsoil 2015)). The scope and some best-practice projects for an application of ISTR were published in a handbook in 2012 (TASK, UFZ Leipzig). For the Steam-Air Injection technique (“Dampf-Luft-Injektion” (DLI), in German), a design software ‘DLI-ToolV1.1’ was published in 2012 on behalf of the TASK Competence Centre.

The relevant input parameters for this software are site- and contaminant-specific parameters of the remediation area, basic hydrogeological information, and the process engineering related parameters (e.g., number of wells, desired temperature). After the necessary calculations are performed, the software suggests plausible remediation steps and estimated timeframes, as well as the major mass flux and heat parameters to design the process engineering of the remediation plant and the remedy.

Sustainable Remediation of Diesel-Contaminated Soil by Low-Temperature Thermal Desorption

Xin Song¹; Jiaqiang Ren²¹ Institute of Soil Science, Chinese Academy of Sciences

Remediation of soils contaminated by petroleum hydrocarbons (TPHs) has been a challenge all over the world. Thermal desorption is a popular remediation technology for TPHs contamination because it is highly effective in removing contaminants of high concen-trations. In this study, artificially contaminated soil samples were prepared using diesel fuel, resulting in the initial TPHs concentration of 6217.00 mg/kg in soil. The effects of temperature and treatment time were investigated using a laboratory-scale apparatus. Low-temperature thermal desorption (LTTD) process was simulated using a quartz boat reactor heated by a tube furnace under a continuous flow of nitrogen (1.5  L/min), at different temperatures (100-350°C) and with different treatment times (10-120 min). Oil content was recovered while the contaminated soil was treated. TPHs content was analyzed using an infrared photometer oil content analyzer. Results showed that desorption efficiency were affected by the temperature and treatment time in the remedial process. A temperature of 250°C and a treatment time of 40 min is sufficient to remediate the diesel-contaminated soil and meet the cleanup goal.

However, thermal treatment also alters many soil properties that affect the functions of soil. Understanding the effects of LTTD on soil properties is vital to the success of remediation and reclama-tion. Therefore, an evaluation on the sustainability of LTTD was conducted to quantify the changes of key soil physicochemical and ecological properties. It was found that heating of soil samples resulted in an overall trend of pH decrease, which might be due to the loss of soil organic matter and changes in the soil mineralogy. In addition, the impact of heating on other key parameters will be evaluated. The ultimate objective of this study is optimize the operational parameters so as to maximize the removal of TPHs and minimize the adverse impact on soil qualities.

Thermally enhanced in-situ remediation using steam-air injection – 20 yeares of remediation experience and improvement of the “DLI-Design-Tool”

Oliver Trötschler¹; Hans-Peter Koschitzky²; Claus Haslauer²¹ University of Stuttgart; ² Universität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung

In the late 1990’s the development of the steam-air driven in-situ thermal remediation (ISTR) was spearheaded by VEGAS on the scale of sandboxes typical for laboratories. In 1998, the first pilot scale remediation using steam injection were operated and successfully at the turn of the century (Plauen, Mühlacker).

Ongoing research activities on a technical scale resulted in the development of a steam-air driven remediation concept. A first pilot study to remediate the saturated zone was finished in 2005 (Albstadt). In 2005, a pilot study in Karlsruhe resulted in the success-fully completed full-scale remediation in 2010. A mobile treatment unit (MOSAM) was developed to conduct pilot studies with the intention to collect site-specific data for remedial planning, as well as to prove the technological application and success (2008). VEGAS performed the necessary work, the German Federal Ministry of Education and Research (BMBF) funded the project via the TASK competence centre at the Helmholtz-Centre for Environmental Research (UFZ) in Leipzig.

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In-situ Zinc precipitation using inorganic sulphides

Dirk Van LookRSK Benelux

In Boechout (Belgium), a new residential development was planned on the site of a former metal processing plant.

The upper soil layers and the groundwater within the first aquifer underneath the site were heavily contaminated with zinc. The groundwater contamination with zinc covers an area of more than 2000 m². It is present to a depth of 37 m and contains zinc concen-trations of more than 1 g/L. The bulk of the zinc can be found in the upper 15 m of the aquifer. The lowest acidity observed was pH 3.5.

Risk assessments showed that remediation was necessary to make the area safe for public and residential use.

Pilot test on zinc precipitation

RSK designed a pilot test to check whether injecting a mixture of sodium sulphide (Na2S), sodium hydrogen sulphide (NaHS) and sodium bicarbonate (Na2CO3) would result in stable precipita-tion of the dissolved zinc in an iron rich aquifer. The mixture was infiltrated in the aquifer at a depth of 11 m below surface and the zinc-sulphide precipitation technique was demonstrated success-fully at this location.

Full-scale remediation

In October 2015, 15 infiltration wells were installed across the zinc plume. The groundwater in these infiltration wells was sampled and analysed to fine-tune the location of the zinc contour.

Then, in 2016, an extra 94 infiltration wells with filter screen at 7–11 m below surface were installed in a 5m by 5m grid. 564 m³ of reagents, 67 m³ of sodium hydroxide and 1,588 m³ of water was infiltrated to treat the contaminated zinc plume covering 2200 m².

In 2017, 40 shallow infiltration wells with filter screen 5–7 m below surface were additionally installed to treat the upper part of the aquifer. 114 m³ of reagents, 6 m³ of sodium hydroxide and 450 m³ of water treated a contaminated zinc plume of 1,100 m².

To restore the original acidity of the aquifer (pH 6.5–7), extra sodium hydroxide was infiltrated, depending on the remaining acidity in the aquifer (above or below pH 5.5).

Environmental soil and groundwater monitoring will continue until 2020, when the residential area is expected to be complete.

The dissolved zinc concentration decreased from a previously high 1 g/L to level below detection limit.

Since 2010, VEGAS used the DLI-Tool to design several pilot tests and full scale remediations in low-permeable soils, fractured bedrock, and fully saturated alluvial sediments. The predicted heat and mass flux remediation points met perfectly the real-world application. The contaminant removal rates were 20%—50% lower than the software had predicted.

Therefore, in the last two years, VEGAS performed remedia-tion experiments to improve the performance of the software: In a box with glass front to monitor contaminant evaporation containing 100 kg of sandy and silty soil, the content of organic matter was varied. The aim of the remediation experiments was to get OC-specific contaminant desorption rates for different soil types. Lab investigations in VEGAS in the framework of a recently completed master thesis indicate an increase of the contaminant desorption (removal) time by 50 – 100% for an OC-content of 1%. For higher OC-contents of 2% the desorption time was increased by a factor of 5 – 8.

The results of the full-scale remedies were implemented leading to an improved determination of the contaminant desorption process in the current version V2.0 (www.iws.uni-stuttgart.de/forschung/DLI-Tool/DLI-ToolV2.0.zip) that is now based on a contaminant desorption rate comprising the organic carbon (OC) content of the soil and a contaminant mass transfer for the equilib-rium of soil-pore water-soil air (Reisinger, C., Grathwohl, P. (1996)). The output is a more accurate estimation of the required timeframe for the designed remediation system.

The poster will focus on the recent investigations and the modifica-tions implemented in the current version of the DLI-Tool software for remedial design.

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Enhanced magnetic separation with Fe-Ni nanoparticles: A novel tool for soil washing

D. Baragaño¹; Juan María Menéndez-Aguado¹; María A. Marina²; Carlos Boente¹; Carlos Sierra³; José Luis R. Gallego¹¹ University of Oviedo; ² ITMA Materials Technology; ³ University of León

Soil washing is a remediation technique based on concentrating pollutants (principally heavy metal(oid)s) into a smaller fraction of soil, thereby generating a considerable volume of “clean” soil. In order to achieve a good separation, the approach followed can focus on one or several physical properties of soil components such as grain-size, density, magnetism or electrical conductivity. In this sense, we hypothesized that an enhanced soil pre-treatment with iron nanoparticles, which adsorb the pollutants on their surface, may facilitate a subsequent magnetic separation thus improving soil washing yields.

In this work, a multi-metal polluted soil with medium-high concentrations of As, Pb and Zn (140, 470 and 5,100 mg/kg respectively) was studied to test its remediation feasibility by means of enhanced magnetic separation by nanoparticles. To this end, bentonite-supported bimetallic Fe-Ni nanoparticles were synthesized and characterised using scanning electron micros-copy (SEM-EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The characterization results suggested nanoparticles treatment feasible due to high magnetic susceptibility and appropriate size of nanoparticles. Subsamples for pilot-scale tests were obtained by grain size fractioning (500-125 and < 125 µm) the original soil. The fractions were pre-treated with Fe-Ni nanoparticles at two doses and subsequently concentrated by Wet High Intensity Magnetic Separation (WHIMS). Three different levels of magnetic intensity were evaluated, and control trials with soil without nanoparticles were performed. The results of the experiments were interpreted using attributive analysis therefore determining a quality index, taking into account threshold levels and soil uses. Moreover, micro-scope techniques were used in order to identify the mineral phases present in the concentrate fractions.

The previous methodology allowed the identification of the most successful assays, as well as more suitable nanoparticles dosages for both magnetic separation and pollutants immobilization. Moreover, it was observed that separation without pre-treatment, even at the lowest magnetic intensity, allowed the recovery of a concentrate with high magnetic susceptibility. This result proved relevant that high magnetic properties differences between both the original soil matrix and the nanoparticles should occur in order to improve the concentration, thus rendering previous magnetic characterization not only advisable but also necessary.

Acknowledgments: NANOBIOWASH CTM2016-75894-P (AEI/FEDER,UE)

In situ and on site bioremediation of MTBE

Leen Bastiaens¹; John Dijk²; Jan van den Boogaart²; Martin Slooijer²¹ VITO NV; ² GreenSoil International B.V.

An industrial site close to Antwerp, Belgium, is contaminated with a variety of contaminants, including Methyl-tert-butylether (MTBE), Monochlorobenzene and other aliphatic and aromatic hydrocar-bons. Most of the contamination is difficult to reach due to the infrastructure and the presence of storage tanks. A field test was conducted to investigate the feasibility of treating the different contaminants in-situ with aerobic bioremediation. Due to the mobile character of MTBE and the size of the plume, also a specific

MTBE-bioreactor designed by VITO, was applied.

The field test consisted of two pilot tests, performed at the site in different areas at the site. Pilot 1 was conducted in an uncon-taminated part of the site to test the radius of influence of the biosparging system. The system consisted of two air infiltration wells and nine monitoring wells. Pilot 2 was conducted in the contaminated part of the site to test the feasibility of stimulated aerobic biodegradation. The system consisted of four extraction wells, five infiltration wells, four monitoring wells and thirteen air infiltration wells. Groundwater was being circulated continuously. A soil vapor extraction system was installed in the vadose zone, mainly to prevent emissions due to the biosparging (i.e. volatiliza-tion). The MTBE bioreactor was fed from groundwater extraction well and the effluent was infiltrated in one of the infiltration wells. Besides the concentrations of the contaminants and methane, the dissolved oxygen concentration, redox potential and nitrogen and phosphorus were carefully monitored.

Due to the high levels of methane that were present, the biosparging system was started up gradually for safety reasons. In the first months the concentration of most contaminants decreased significantly, however, the redox conditions improved only slowly. Additional tests indicated that the soil oxygen demand was extremely high therefore it was decided to install additional air infiltration wells after 9 months. The radius of influence of the air infiltration system appeared to be around 6 m.

The MTBE bioreactor had a removal efficiency up to 98%, however the flow was limited by the high oxygen demand of the ground-water and the rather low influent concentrations (±. 1000 µg/l). A part of the high COD/BOD was caused by a formerly unknown contaminant, that appeared to be a C9-acid. To confirm biological degradation at higher MTBE concentrations, the MTBE reactor was spiked continuously for a short period of time with influent concentrations of ± 4000 µg/. Both MTBE and TBA were degraded with > 99% efficiency in the bioreactor to concentrations below detection limit.

The in-situ MTBE removal efficiency was in the range of 56-76%, with maximum starting concentrations of 15,000 µg/l. It was however remarkable that in-situ MTBE degradation was signifi-cantly higher (93 %) closer to the infiltration well were the effluent from the MTBE reactor was infiltrated than in the wells further away, indicating the additional effect of bioaugmentation.

At the moment a full-scale remediation system is being designed and the lessons learned are implemented.

Remediation of low-permeability soils by an innovative technology-train

Gabriele Beretta; Anna Galbiati; Anna Legnani; Andrea Filippo Mas-torgio; Lisa Pedrali; Sabrina Saponaro; Elena SezennaPolitecnico di Milano

This study deals with an innovative remediation approach for low permeability soils, based on the technology-train In Situ Chemical Oxidation (ISCO) – Electrokinesis (EK) – Electrical Resistance Heating (ERH), where persulfate is used as the oxidant, transported in the soil by EK, and thermally activated by ERH. This approach is promising to overcome the existing difficulties in the transport of the oxidant and offers the advantage of using common electrodes for both EK and ERH. At this stage, the problem was tackled from the modeling point of view, using the COMSOL Multiphysics® modeling software, which highlighted the strengths and weak-nesses of the proposed treatment (ISCO-EK-ERH).

Posters – 4c | Combined treatment technologies and technology trains

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The problem was considered for treating a contaminated site in northern Italy, characterized by significant concentrations of chlorinated organic solvents, among which perchlorethene (PCE) prevails, in clay. Different configurations were simulated, to evaluate the optimal arrangement of the electrodes and persulfate injections, in order to reduce PCE concentration below the table value reported in the Italian Legislative Decree 152/06 for ground-water (1.1 µg/l). Various voltage gradients were taken into account for EK, while ERH was simulated according to the conditions of the national power system (single phase, effective voltage of 230 V, frequency of 50 Hz).

It has been verified that, without the application of an electric field (EK), the transport of the oxidizing agent is almost inexistent. On the contrary, the electrokinetic process allows the persulfate to move in the soil and have a wider spatial margin of action. The increase in soil temperature for the activation of persulphate is to be obtained only in the phase following EK (ERH). The results also show how the electrocinesis process (continuous voltage supply) can be applied for 20-30 d (15-20 V/m); after that, the same elec-trodes can be supplied with alternating voltage (230 V, 50 Hz) for the rapid heating of the soil. The temperatures required for the activation of persulphate (35-40 ° C) throughout the soil can be reached in a few days.

It is more efficient to organize the electrodes in parallel rows, in which the cathode-anode distance is about 3 m, while the distance between a pair of anodes or cathodes is 1.3 m. The persulfate injec-tions are to be carried out along two lines parallel to the electrode rows, between the rows of electrodes, with distance between two adjacent injection points equal to the electrode-injection point distance. This means that if the anode-cathode distance is 3 m, the injection points are 1 m apart from each other and 1 m from the electrode rows. Operating as indicated above, in about 40 d of total treatment the Legislative Decree 152/06 Contamination Threshold Concentration for groundwater is reached, starting from 100 µg /l.

The modeling assessment has to be further investigated in the effects of site-specific characteristics, such as pH, zeta potential and amount of organic matter, which could strongly affect the results. The simulations were in fact conducted using reference values typical of clayey soils

Remediation of TCE contaminated groundwater in low permeability media using Targeted Solids Emplacement at the former “Atlas 12” U.S. Air Force Site

Gordon Bures¹; Jennifer Weidhaas²¹ Sensatec GmbH; ² University of Utah

In situ remediation and the verification of its effectiveness remains a significant challenge in low permeability geologic formations. The objective of this presentation is to introduce and describe TSE® (“Targeted Solids Emplacement”) as an innovative technology for effectively enabling the in situ remediation of contaminants in “impermeable” soils and bedrock.

The presentation showcases innovative, in situ permeability enhancement and amendment emplacement technology to improve subsurface flow characteristics and provide tar-geted distribution of treatment amendments using TSE® (“Targeted Solids Emplacement”) technol-ogy. The TSE approach is a powerful in situ enhancement technology which accelerates and opti-mizes the remediation of virtually any contaminant present in any phase distribution (i.e. unsaturat-ed and saturated zone, soil or bedrock) by:

• Significantly increasing soil/bedrock permeability (up to three orders of magnitude)

• Enabling rapid and targeted emplacement of large quantities of reagents (tonnes/BH)

• Verifying the distribution of treatment amendments in 3D using tiltmeter geophysics

• Treating contaminants to depths of up to100 m biologically, chemically or physically

• Minimizing “rebound effects” from sorbed phase contaminants into groundwater

Using the TSE® approach, a slurry containing highly concentrated remedial amendment is injected under pressure into contaminated zones using drill tooling configured for specific geologic condi-tions. A network of interbedded and hydraulically connected flow pathways is thereby created in individual boreholes over a large radial extent, thus maximizing contact with contaminants and providing long-term “remedial source zones” within contaminant plumes or hot spots.

A case study is presented which illustrates the TSE® approach for remediating TCE- impacted groundwater in bedrock underlying a former military installation in the USA (Journal of Remediation, 2012).

• The TSE® approach was successful for emplacing >100 tonnes of CZVI into bedrock

• Abiotic and biotic degradation processes were observed for the mitigation of TCE

• Drinking water criteria (< 5 ppb) for TCE achieved in areas within hot spot after 18 months

• >90% TCE removal (weighted average) in hot spot after 21 months

• Phase 2 treatment of “distal TCE plume” with additional 40 tons CZVI conducted

• US Army Corps of Engineers approved thIs approach for reme-diation at further sites

Lessons learned:

• Extend of amendment distribution can be controlled, but not its geometric configuration

• Drilling method must be closely coordinated with injection methodology (open hole/packer)

Remediation of a jet fuel contaminated aquifer through enhanced chemical desorption

Paolo Ciampi¹; Carlo Esposito; Paola Goria; Marcello Carboni; Paolo Rizzetto; Marco Petrangeli Papini¹ Sapienza University of Rome

The implementation of a georefereced database provides an inte-grated management, representation and analysis of different data (geological, hydrogeological, hydrogeochemical and geophysical) along with the creation of a 3D Hydrogeophysical model that repre-sents an effective “near real time” Decision Support System able to manage and to release data during the different remediation phases, from the characterization to the technique of implementa-tion, were carried out on a site that consists of a large airport area

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located in central Italy, where about twenty years ago a jet fuel spill occurred. This site is characterized by the alternation of fine and coarse particle size materials with a groundwater depth equal to about 5m showing a high variability throughout the year. The detected contamination, despite being mainly caused by a spill, is quite extensive and has been the subject of years of a Pump & Treat intervention (still operational) that over time has allowed both the reduction of the contaminant mass and a narrowing of the contam-inant plume, that progressively has reached an asymptotic trend. Some portions located immediately downstream of the source show the residual presence of contaminants, which are consid-ered irremovable with the technology being performed, due to the presence of phases adsorbed mainly to the less permeable portions of the aquifer. An in situ enhanced chemical desorption strategy was implemented using the Regenesis PetroCleanze™ product with a main technological function to increase the desorption of hydro-carbons adsorbed to saturated soils or at the capillary fringe, and to increase the recoverability of the product in a separate phase while hydrocarbons are made available in the dissolved phase, allowing a subsequent rapid and effective physical recovery. The interven-tion was carried out during the pilot phase in 3 different areas, by a direct application in the existing wells and reactivating the Pump & Treat system a few days later. The monitoring carried out made it possible to verify a substantial increase in the concentrations in the post-application phase, with a progressive subsequent decrease as a result of the pumping activities. The speciation analyzes carried out made it possible to detect an increase in the shorter hydro-carbon chains, indicating that the prevailing effect of the treatment was probably of a partial oxidative type with the breaking down of the longer chains. The monitoring data obtained during and after the test activities showed that a significant mass of contami-nants was recovered (significantly increasing the efficiency of the system present on the site) and a reduction of the pollutant mass in the area of interest. In addition to the monitoring activities, geophysical tests were performed during the test, which allowed to provide interesting information about the distribution of the reagents in the saturated subsoil. The full-scale project is currently underway. The case study is considered of interest as it illustrates an example of how it is possible to optimize the removal of LNAPL contaminants when they are substantially no longer recoverable by conventional technologies.

Successful closure of a DNAPL site - Lessons learned

Craig CoxCox-Colvin & Associates, Inc.

In 1985, a catastrophic release of 500 gallons of trichloroethene (TCE) occurred inside an industrial site. Initial remedial efforts reduced a small portion of the contaminant mass located in the immediate vicinity of the building. However, it was suspected that the majority of the mass remained trapped beneath the building slab and foundation.

The site was assessed and a long-term groundwater monitoring program ensued under an agreement with the overseeing regula-tory body. A proposed remedy for the site would have required demolition of the facility, which was unacceptable to the site owner. The site owner’s objective was to successfully obtain RCRA closure without the need to demolish the site and abandon its operations.

The released TCE presented itself as a dense non-aqueous phase liquid (DNAPL) beneath the building and in perched water bodies within a glacial till setting. After completing the final two years of groundwater monitoring required by the consent order, a

cooperative approach to site remediation was negotiated with EPA to complete the final investigation and remediation phase on a voluntary basis. Membrane interface probe (MIP) and high-resolution soil sampling techniques were used to refine the understanding of the DNAPL configuration. Remediation consisted of a combination of high vacuum dual phase extraction (HVDPE) followed by potassium permanganate flooding. Mass reduction was assessed using continuously monitored vapor stream concen-trations, recovered fluid concentrations and the results of phased three-dimensional soil sampling efforts.

By 2007, the site was closed under RCRA and had completed the Post-Closure Care and Monitoring period. Using multiple lines of evidence estimates of the mass removal ranged from 89% to 96%. Pre- and post-injection MIP evaluations demonstrated that the DNAPL was forced into new areas ahead of the injectate. Reducing DNAPL through the use of dual-phase SVE, followed by potassium permanganate flooding proved to be effective at reducing the DNAPL mass.

Air treatment methods as possible alternatives to activated carbon

Michela De Camillis; John Dijk; Rogier De Waele; Martin SlooijerGreenSoil International B.V.

During the remediation of soil and groundwater contaminated with organic compounds like hydrocarbons and MTBE, also extracted air needs to be treated. For example, this air can originate from biosparging, SVE, aeration of on-site bioreactors or air extraction of biopiles. Common practice is to use activated carbon to treat the contaminated gas, which is both costly and not very sustainable. In the present paper, three alternative air treatment techniques (compost filter, biopile air filtration technique (BAFT) and Regen-erative Bioscrubber (RBS)) are presented.

Leakages of an old petrol station led to a strong BTEX and TPH soil contamination in the 11m deep unsaturated zone. GreenSoil proposed to combine SVE with a 40ft compost filter equipped with ATEX remediation units to treat high concentrated contaminated air. The compost filter consists of a layers of about 1,5-2 m thickness where the air is circulated with a flow rate of approximately 300 m3/hr.

A former triacetate production site caused soil and groundwater contamination with BTEX (mainly xylene) and Mineral Oil to a depth of 10 m-bgl. The volume of contaminated soil and ground-water is about 18255m³ and 132,417m³ respectively. The approach used in this case of study was excavation and on-site landfarming (unsaturated and smearing zone) combined with in-situ enhanced aerobic degradation of the groundwater contamination. The inno-vative solutions to save active carbon usage proposed by GreenSoil are the recirculation of contaminated air through a BAFT and a RBS.

The compost filter was able to degrade the organic compounds from 1036 ppm to 95,9 ppm within 9 months with an average effi-ciency of about 70%. The degradation rate was considerably fast, with a residence time in the compost filter of few seconds.

The air treatment with the BAFT or RBS are designed as last steps of the landfarming process. After air is extracted from a contaminated biopile, it is driven through the BAFT or the RBS. The air concentra-tions entering these systems ranged from 500 ppm to 2000 ppm xylene.

BAFT consists on turning a completed-clean biopile into an air abatement system, serving as biological filter. This system reached acceptable values within about 70 days, regardless the initial

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contamination concentration. BAFT reduced the contamination with an efficiency up to 60-80% and up to 70% saving on active carbon.

The RBS treated air coming from the contaminated biopile with a flow rate of about 20-40 m3/h. Water is recirculated through the bioscrubber with addition of nutrients in order to stimulate bacteria growth. The efficiency of this system varied with the recir-culated water quality (pH and EC) and provided amount. However, the efficiency of the bioscrubber was in average about 55%.

In general, the presented air treatment methods are able to reduce the contamination concentrations up to 60-80% and are therefore potential alternatives to reduce the amount of active carbon used in the remediation works. However, it is still necessary to employ active carbon as polishing step whether strict concentration limits need to be achieved.

Biological alternatives to conventional activated carbon or catox air treatment

Michela De Camillis; Rogier De Waele; John Dijk; Martin SlooijerGreenSoil International B.V.

Contaminated air, originating from biosparging, soil vapor extrac-tion (SVE) or biopiles, has to be treated before being released into the atmosphere. Common practice is to use activated carbon or catalytic oxidation to treat the contaminated air, which is both costly and not always sustainable. Here, three biological alterna-tives are presented: Automated Compost Filter (ACF), Biopile Air Filtration Technique (BAFT), and Regenerative Bioscrubber (RBS).

1) Large scale SVE system and ACF

Project description: Leakages of an old petrol station led to a strong BTEX and TPH soil contamination in the 11m deep unsaturated zone. GreenSoil installed and operates a large scale SVE system where the highly contaminated soil vapors are treated with a 40ft fully Automated (ATEX) Compost Filter.

Air treatment: The ACF has currently been operating stable for more than a year with a removal efficiency of 60-90% on PID level and 80-95% on BTEX specific level at a flow of 100-300 Nm/h and entering concentrations up to 1500 ppm.

The removal efficiency of the biofilter was high and increasing in time depending on flow rate, air load and process control.

Conclusion: The ACF saved strongly on total O&M cost by reducing activated carbon consumption which was only used as polishing step.

2) Project #2: On site landfarming with BAFT and RBS

Project description: At a former triacetate production site, activities have caused a significant soil and groundwater contamination with BTEX (mainly xylene). In total, about 22.000 m3 of highly impacted soil was present at the site. The soils in the unsaturated and smearing zone have been excavated and treated by on-site land-farming (bioventing through controlled air extraction combined with biostimulation) in a period of 1.5 years. Starting from concen-tration levels up to 10.000 mg/kg, landfarm depots were completed within 70 days with concentrations levels below 50 mg/kg.

Air treatment: The air extracted from the biopiles was treated by two innovative biological air treatment technologies:

a) Biopile Air Filtration Technique (BAFT): when soil standards were met, the completed-clean biopiles were turned into an air abatement system. This system reached an efficiency of

60-90% in treating highly loaded soil vapors (up to 2000 ppm xylene) originating from other active landfarm depots.

b) Regenerative Bioscrubber (RBS). An in-house developed pilot Bioscrubber can treat both contaminated air and groundwater.

Air coming from an active biopile is sent to the RBS at a flow rate of about 20-40 m3/h. Water is continuously recirculated with addition of nutrients to stimulate bacteria growth. The efficiency of the RBS was about 55% showing its high potential for upscaling.

Conclusion: The project is a top-class example of circular soil reme-diation not only cleaning highly impacted soils for on-site re-use but turning them into very cost-efficient air treatment systems. The highly loaded soil vapors at this site were treated with innovative biological techniques like BAFT and RBS which proved to be a very cost-effective alternative in saving up to 90-95% of active carbon consumption saving 100.000’s of € for the client.

The LIFE+ SURFING project: Surfactant enhanced chemical oxidation for remediation DNAPL

Jesús Fernández¹; Aurora Santos²; Klaas Norbert³; John Vijgen⁴; Pedro de Miguel⁵¹ Gobierno de Aragón; ² Universidad Complutense de Madrid; ³ University of Stuttgart; ⁴ IHPA; ⁵ SARGA

The manufacture of lindane during the 70s and 80s of the last century in INQUINOSA (Sabiñánigo, Spain) generated a serious contamination problem with three megasites (INQUINOSA and the landfills of Bailín and Sardas). These spaces should highlight the presence of a dense phase (DNAPL) with chlorinated compounds (aHCH, bHCH, gHCH, pentachlorobenzene and dioxins and furans) included in the Stockholm Convention.

At the Bailín landfill, the DNAPL is located in a fractured aquifer that was extracted by pumping since 2005, and is currently close to being depleted. The result is a residual phase retained in the rock matrix.

On-site technologies such as ISCO; ISCR or bioremediation cannot be applied directly as a first approach when there is a significant residual DNAPL. These methods require that the contaminants be solubilized, but the solubility of DNAPL in the Bailin landfill is quite low.

To proceed with the extraction of the residual DNAPL the Govern-ment of Aragon with the collaboration of SARGA (public company of this Government), the IHPA (International HCH and Pesticides Association), the INPROQUIMA research group of the Complutense University and VEGAS (Research Facility for Subsurface Remedia-tion) at the Stuttgart University, will address the contamination in the SURFING pilot project (SURFactant enhaced Chemical Oxidation for Remediation DNAPL) funded by the LIFE program.

The project comprises:

1. Preparation and detailed knowledge of the pilot area and security barrier.

2. SEAR application, on-site treatment of surfactant recovery and elimination of POPs. After testing different mixtures of surfac-tants, the Emulse® surfactant formulation was selected. For the recovery of the surfactant and the in situ treatment of POPs, the most promising technique is the alkaline hydrolysis of the emulsion, the stripping at 40ºC, the retention of VOCs in the activated carbon and the oxidation of the POPs by sodium persulphate with thermal activation.

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3. SISCO application for the elimination of POPs in situ. In a second phase, the dissolved and absorbed contamination will be treated by the injection of a solution of emulse® in low concentration and sodium persulfate with alkaline activation.

4. Monitoring and treatment of ISCO or SISCO. In this type of fractured media and with this type of pollutants it is common that the contaminants penetrate the rock matrix and hydrau-licly poorly communicating fractures in a relatively short period of time. Thus, an enhancement of the availability is necessary for an effective chemical or biological treatment.

5. Replicability and transferability test, by performing several experiments at laboratory scale (column tests and 2D box dimensions experiments: l * h * w = 1 m * 0.6 m * 0.1 m) for different situations of pollutants and different terrain conditions and large-scale experiment (scale experiment, of dimensions: l * h * w = 6 m * 3 m * 1 m) to verify efficiency under controlled and still realistic conditions, including equilibrium of efficiency and performance.

The presentation will cover the environmental problem, the consortium with the dedicated tasks within the project and the technological approaches.

The LIFE+ SURFING project: On site treatment for recovery surfactant and eliminate COPs in DNAPL remediation

Jesús Fernández¹; Aurora Santos; Jorge Gómez; Elena Cano; Eduardo Calleja¹ Gobierno de Aragón

The manufacture of lindane during the 70s and 80s of the XX in INQUINOSA (Sabiñánigo, Spain) generated a serious contamina-tion problem in three megasites (INQUINOSA and Bailín and Sardas landfills). These spaces have to highlight the presence of a dense phase (DNAPLs) with chlorinated compounds. (aHCH, bHCH, gHCH, Pentachlorobenzene and dioxins and furans) are included in the Stockholm Convention.

In Bailín landfill, DNAPL is located in a fractured aquifer that has been extracted by pumping since 2005, and is currently close to forming a non-pumpable residual phase.

In order to proceed with the extraction of the residual DNAPL the Government of Aragon and other colaborators, within the LIFE programme, will run the SURFING pilot project (SURFactant enhaced chemical oxidation for remediation DNAPL).

One phase of the project involves the injection of surfactant to remove and solubilize DNAPL. After the separation of the decan-table DNAPL, the surfactant emulsion-DNAPL pumped will be treated to recover and reuse the surfactant and eliminate POPs, within a strategy of minimization of external waste management.

To select an on-site treatment methodology to recover the surfac-tant and eliminate contaminants, after laboratory tests, a series of pilot tests have been carried out for the treatment of volumes between 250 and 500 liters of an emulsion formed by Leachate from the aquifer, 10 g/l of surfactant and 5 g/l of DNAPL.

The following tests are being carried out:

1. Fenton oxidation of the emulsion. The kinetics of the process have been established, observing that the surfactant capacity is reduced by 25%, the elimination of POPs reaches 95% and the final precipitate reaches concentrations of 2.5 g/kg of POPs

that will be necessary to manage externally.

2. Alkaline hydrolysis - Stripping - active carbon. The alkaliniza-tion of the surfactant emulsion-DNAPL breaks the emulsion with the separation of an aqueous phase and the formation of a precipitate. The alkaline hydrolysis of HCH, hexachlorohexa-dienes and heptachlororcyclohexanes generates more volatile compounds. After a phase of stripping with and without temperature increase, VOCs are retained in activated carbon. It has been verified that the surfactant capacity is maintained in conditions similar to the previous test and the rate of elimina-tion of contaminants is being assessed.

3. Saturation curve of activated carbon against emulsion and retention rates of POPs and surfactant.

4. Oxidation on coal bed. Active carbon spent in wet or gaseous treatments will be treated by oxidation with persulfate and thermal activation. The objective of the trial is to assess the recovery of activated carbon and the destruction of POPs.

The testing phase will end this year. The assessment of the kinetic aspects, operational difficulties, consumption of reagents, recovery rates of carbon and surfactants, waste minimization rates for external management and POPs elimination rates will allow the selection of a technology for on-site treatment of pumped flows. The easily controllable operating conditions lead us to expect higher yields than those achieved in insitu treatments that are difficult to control.

Surfactant Enhanced Remedation (SER) for in-situ soil and groundwater remediation of petroleum and chlorinated NAPL impacts at brownfield sites in Belgium

Glenn HeernaertTerraCorrec bvba-sprl

The remediation of petroleum and chlorinated solvent impacts at commercial and industrial sites can be a long and costly proposi-tion for most brownfield redevelopers. This presentation describes the application of surfactant enhanced remediation (SER), as a part of a treatment-train remediation strategy, to expedite the removal free phase petroleum hydrocarbons (LNAPL) and free-phase chlo-rinated solvents (DNAPL) mass at two (2) former industrial sites in Belgium, to rapidly achieve the applicable soil and groundwater clean-up standards .

The surfactants were coupled with multi-phase extraction to expedite the NAPL mass removal, and significantly reduce the observed soil and groundwater impacts to less than commercial clean-up standards, and then concluded with the application of chemical REDOX treatment to rapidly achieve the stricter resi-dential clean-up standards for these brownfield redevelopment project sites. A degree of natural biological attenuation was also maintained across the application process.

The result of this novel application strategy was a significant time and project cost saving through the systematic and integrated remediation treatment-train approach strategy for the sites, while minimizing environmental risks, and maintaining internal and external stakeholder consideration and confidence.

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Surfactant enhanced recovery of separate-phase petroleum hydrocarbons

George (Bud) IveyIvey International Inc.

Amtrak Sunnyside Yard in Queens, New York City, historically had the northern portion of the yard served as maintenance facility for electric locomotives and railroad cars. These activi-ties spilled separate-phase petroleum hydrocarbon (SPH), which contains polychlorinated biphenyl (PCB) contamination. In 2007 the NYSDEC issued a Record of Decision for the site, requiring clean up levels of less than 0.1 foot SPH thickness, and ultimately suspending any future railroad expansion. Many remedial actions and Interim Remedial Measures had been completed over the decades, long before the ROD was issued, including the removal of visually-impacted surface soil, the removal of PCB and hot spot soil, and the demolition and removal of old structures, inspection pits, and underground storage tanks. A Dual Phase Vacuum Extrac-tion (DPVE) system was installed in October 2013 to recover SPH. This system consists of 41 extraction wells, and has been opera-tional since startup. To date, the DPVE system has recovered nearly 7,571 L of SPH. SPH recovery using the DPVE system reached an asymptotic state with diminishing mass recovery rates. This was confirmed by completing SPH transmissivity testing and modeling, which found that the remaining SPH onsite has very limited mobility and could not be recovered effectively using the DPVE. Therefore, an amended remedial action(s) was needed to address the remaining SPH plume.

Bench-scale studies were performed using four different tech-nologies geared toward enhancing recovery of SPH while also verifying that PCBs would not be mobilized in groundwater. Testing results showed that Ivey-sol, to be the most optimal technology to enhance recovery of SPH in soils by improving mobility and solu-bility. Ivey-sol did not increase PCB solubility in groundwater nor did it cause any other negative effect on groundwater quality. These findings were sufficient to support field pilot testing.

NYSDEC approved the Surfactant Pilot Study in October 2015 and field work began shortly thereafter. The objectives of the pilot study were to determine feasibility of using a surfactants to enhance mass recovery and treatment of the SPH plume and asso-ciated impacted soils onsite, and to evaluate the potential effects on bioremediation which was previously and concurrently imple-mented. To introduce the surfactant, the Ivey-sol was diluted to 2% with water and then gravity-fed into the extraction wells or injected above the groundwater table via Geoprobe. Multiple test areas were also employed, each utilizing a different configuration of injection and extraction wells. It was concluded from the pilot study that push-pull at single wells as both injection and extraction points was effective removing SPH with an 80% removal average in 1 week of application. Surfactant enhanced remediation can be conducted in areas undergoing bioremediation without depleting the heterotrophic plate count. By conclusion of pilot study in February 2016, the SPH thicknesses was significantly reduced in all wells. The bench-scale and pilot-scale applications realized full scale applications at this 52.5 hectare site in 2017.

Modeling the phosphate dynamics during electro-coagulation process with aluminium electrodes

Ivan Halkijevic; Goran Loncar; Hana Posavcic; Drazen VoukFaculty of Civil Engineering, University of Zagreb

The efficiency of the electrocoagulation (EC) process for the removal of phosphate (PO4-P) was analyzed using a batch pilot device with aluminum electrodes situated within the reactor. The effects of the flow rate through the reactor (0.05 L/s and 0.15 L/s), applied current density at the electrodes (30 and 75 A/m2) and batch mixture volume (90 and 180 L) were the focus of the research. The initial PO4-P concentration was the same in all experiments (3.8 mg PO4-P / L). The concentrations of PO4-P, dissolved oxygen (DO) and aluminum (Al3+), as well as the water temperature and pH, were measured in the batch chamber. The initial PO4-P concentration was reduced by 90 % after 90 min of reactor operation when the flow rate was set to 0.15 L/s when the initial concentration of elec-trolyte (NaCl) were 2 g/L, while the current density is maintained at 75 A/m2. The DO concentration was reduced by 15 %, while pH was increased by 10 % with respect to the initial values.

Additionally, a three-dimensional (3D) numerical model for PO4-P removal via the EC process is developed. By using the 3D numerical model, spatially continuous velocity fields and the PO4-P concen-trations were determined. Numerical model of PO4-P transport includes the processes of phosphate adsorption on flocculent, along with coagulated particles settling. Numerical model parame-terization relies on the measurement results from the experiments made on batch pilot device.

Frac-In: Development and pilot testing of a technology for combined direct push and fracturing of contaminated soil

Jan Kukacka¹; Ondrej Lhotsky¹; Jan Slunsky²; Jan De Vos³; David Simpson⁴; Dries Goorts³; Hans Jacobs⁵¹ DEKONTA, a.s.; ² NANO IRON, s.r.o.; ³ ABO nv; ⁴ AGT nv; ⁵ Geosonda Belgium

A technology for combined direct push injection of remediation agents and combined hydraulic / pneumatic fracturing has been developed within the Frac-In project.

The basic technology used within the framework of the Frac-In technology is the method of high-pressure direct push injection of remediation agents using the top-down injection method. A hollow rod is forced into geological environment formed by soft sediments, using a drilling machine hammer. The end of the rod is equipped with the injection point, mechanically closed during the forcing in, in order to prevent its clogging. After reaching the injection depth, the injection point is opened (by the injection fluid pressure) and a defined volume of the fluid is injected into the geological environment. Subsequently, the injection point is closed again, and it is further forced into deeper horizons. In this way, a number of injections into the geological environment may be carried out within one probe, in various depths.

Within the framework of the high-pressure injection using the direct push method, it is also possible to carry out hydraulic frac-turing of the geological environment, because the pressure used for injecting the remediation agents into the geological envi-ronment is so high in the case of low-permeable sediments that cracks are created in them. The same process takes place within the framework of the Frac-In technology, too. In comparison with the standard high-pressure direct push injection, the process is combined with pressure gas injection, causing also pneumatic

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fracturing, characterised by quicker formation of cracks than in the case of hydraulic fracturing, resulting in influencing higher volume of the geological environment. The cracks newly created by means of hydraulic and pneumatic fracturing are subsequently filled with selected reactive materials, serving simultaneously as the so-called proppant (protecting the formed cracks against closing back) and the remediation agent.

The Frac-In technology was verified by two pilot tests at contami-nated sites in the Czech Republic and Belgium. The sites are characterised by low permeability and heterogeneous geology. While the Czech pilot site is formed by sandy clays contaminated with chlorinated ethenes, the Belgian site consists of loamy sand, sand, and clay, contaminated with Chromium VI.

A number of monitoring approaches may be used for evaluating the efficiency and reach of the Frac-In technology. One of them is installation of monitoring wells with automated loggers, monitoring parameters such as pH, conductivity, and oxidation-reduction potential. A further possibility is to study changes of hydrodynamic parameters of the saturated zone before and after application of the Frac-In technology. Hydrodynamic tests and tracer tests may be used for that. Last but not least, spatial spreading of the injected suspension may be monitored using geophysical methods, such as, for example, Electrical Resistivity Tomography (ERT). Results of such monitoring may be used as input data for modelling processes taking place in the contaminated environment in the case of high-pressure injection using the Frac-In technology.

Successful transition from ex situ to in situ remediation for CVOC-impacted groundwater

Thibault Nodin; Mike Perlmutter; Jim DayJACOBS

From 1983 to 2004, 30 to 40 tons of trichloroethylene (TCE) were used annually in a degreasing steam unit at an industrial site in western France. As a result, groundwater at the site was impacted with chlorinated volatile organic compounds (CVOC) based on findings from subsequent environmental investigations. A Management Plan was prepared in 2010 to outline the corrective action strategy for the site, which focused on the use of ground-water pump and treat (P&T) to achieve CVOC concentration target levels. The P&T system was constructed and began operation in 2013. After three years of modest improvements to groundwater quality, the conceptual site model (CSM) was re-evaluated.

Techniques including the use of passive soil gas samplers, passive diffusion bags, microbials analysis, soil gas sampling using canister and helium leak test, soil sampling using methanol kit and new monitoring wells installation were used to generate a better under-standing of the CSM.

Key findings were as follows:

- Better understanding of vertical extent of CVOC as they were observed deeper than previously thought

- CVOC groundwater concentrations up to 100,000 micrograms per liter were found downgradient of the current waste disposal area

- Better characterization of the hydrogeology: granite bedrock with permeability that is strongly dependent on the existing network of cracks and fractures

- Delineation of the contamination using soil gas results (quali-tative analysis) and offsite human health risk assessment (quantitative analysis) was complete

- Confirmed that natural CVOC biodegradation was occurring in groundwater but at rates that appeared to be limited by the aquifer geochemistry.

Based on the improved understanding of the CSM, site conditions are compatible with the natural processes of reductive dechlo-rination in groundwater. Thus, the corrective action strategy was revised to replace P&T with in situ chemical reduction (ISCR) and in situ bioremediation (ISB).

Once a revised Management Plan was approved by the regulators, the following was implemented:

1) Phase 1: Upgraded and continued to operate the P&T system until the ISB approach was implemented.

2) Phase 2: Installed four injection wells in 2017 to inject zero valent iron, carbon substrate, and water to facilitate ISCR and ISB in the source area (former wash storage area).

3) Phase 3: Installed 20 injection wells in two transects in 2017 to inject a solution of emulsified lecithin substrate, sodium bicarbonate, vitamin B12, and water to establish a biobarrier downgradient of the former wash storage area.

One year after the injection, post-injection results indicate that CVOC groundwater target levels are being met within the source area and within and just downgradient of the bioabarrier. Specifi-cally, CVOC concentrations have decreased by more than 99 percent without significant rebound or daughter product genera-tion. Perhaps most importantly, the effectiveness of the revised approach has enabled the shutdown of the relatively ineffective and expensive P&T system.

The presentation will review the site CSM, remediation objectives, field activities, reagent selection and doses, costs, and results.

Phased remedial approach following the BATNEEC principle to address off-site migration risks

Martin Ohsé¹; Paulo Valle¹; Olga Vounaki²; Olga Vounaki²; Laurent Crucifix¹¹ ERM BeNe; ² ERM

At an active industrial plant in Belgium, a multi-level remedial strategy has been developed to address a complex cocktail of contaminants (chloroethenes, chloroethanes, chloromethanes, chlorobenzenes, chlorophenols, chlorotoluenes and nickel) present in soil and groundwater. High-resolution investigation efforts identified multiple on-site source areas associated with historical production activities. Remediation is required to mitigate off-site migration. The remedial strategy consisted of installing a hydraulic containment barrier at the downgradient Site border to mitigate to the extent possible off-site contaminant migration, and a phased approach to remediate the major sources of pollution, within the limits of the BATNEEC (Best Available Technique Not Entailing Excessive Costs) principle as defined in European Union directives. Pilot tests have been performed at the source areas to evaluate the feasibility of implementing a Soil Vapour Extraction (SVE) system in the vadose zone, and Enhanced Reductive Dechlo-rination (ERD) in the saturated zone. Concurrently, a Monitoring Natural Attenuation (MNA) program was implemented to further characterize the natural attenuation processes occurring in the on- and off-site plumes.

Given the historical nature of the contamination, remedial objec-tives were defined following a risk-based approach. The Biochlor model was used to define the concentrations to be reached in soil and groundwater at the source areas in order to achieve regulatory

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threshold values at the site border. The remedial approach consists of installing a Multi-Phase Extraction (MPE) system in the backfill and upper silty layers, and a recirculation system to enhance the biodegradation of the chlorinated solvents in the deeper and more permeable sandy layer. This approach was defined based on the results of a field pilot test performed at the site to evaluate the best injection technique and carbon substrate. The design of the full-scale remediation approach followed the BATNEEC principles, the potential synergy with the existing P&T system, and the contami-nant mass flux contribution of the different contaminated layers.

The original remediation strategy consisted of addressing the unsaturated zone with a Soil Vapor Extraction (SVE) system and the saturated zone by enhanced bioremediation. Given the local hydro-geological conditions, carbon substrate injections in the shallow layers could not be implemented successfully. Given that extracted groundwater can be treated via the existing P&T installation, it has been decided to address the unsaturated zone and the upper saturated zone by a Multi-Phase Extraction (MPE) system. During the pilot test, enhanced bioremediation was tested in the deep sandy layer via direct push points and via a Push-Pull test. Further, a Step-Drawn test and injection tests were performed to evaluate the possibility of amending the carbon source via a recirculation system. The results of these tests indicated that a network of recirculation wells was the best technique to amend the sandy layer.

Targeting 95% reuse: onsite ex-situ washing of multi-contaminated soils - from pilot testing to full-scale remediation

Thomas Perrier1; Adrien Monso1; Matthew Pannett²1Ramboll France; ² Ramboll Environment & Health

In the context of the closure of a large chemical site in eastern France, a remedial action plan was developed to define the most appropriate management of the contaminated areas. Due to the various contaminants of concern present at distinct site areas and their geographical repartition, excavation was determined to be the sole effective technique to reach the targeted mass removal in the timeframe of the project.

Considering the extension of the contaminated areas (65,000 m3 of impacted materials) and the nature of the subsoil (alluvial deposits), soil washing was chosen after 2 years of pilot testing to maximize onsite soil recycling and prevent offsite disposal to the extent possible and associated prohibitive costs.

Full-scale remedial works have started in end-2017 for 2.5 years. In addition to the high goals targeted for the cleaning of soils to obtain a 80% contaminant mass removal, these works take place in a challenging context with the demolition of more than 10,000 m3 of underground concrete structures, excavation of a total of 190,000 m3 of materials, with more than 70% being performed under large confinement tents to avoid any nuisances to neigh-bourhood and the use of retaining structures for 10-meter deep excavation works, and the management of rain and infiltration water to avoid remobilization of contamination to groundwater.

The treatment train consist of (1) an industrial-scale soil washing unit allowing the reuse as backfill of cleaned materials from 30 cm gravels to 0.1 mm sands (150,000 tons), and (2) a wastewater treatment plant for full recycling of washing waters (total volume 300,000 m3 and flow rate of 200 m3/h) and optimized sludge dewatering performed using the innovative Clariant Invoque® dewatering technology (>80% dryness).

Main achievements to date will be presented.

Remediation of soil and acid tar at a former refinery in Valloy Norway

Stany Pensaert¹; Joke Van De Steene¹; Hendrik Nollet¹ DEME Environmental Contractors

The Valloy peninsula in the south of Norway hosted a refinery. This site was polluted by the activities of the refinery: oil contamina-tions are found in the soil, and a large acid tar dump area has to be removed. At the end of the second world war, this site was heavily bombed which of course worsened the contamination situation.

After the decommissioning of the refinery a few decades ago the acid tar dump was covered with gravel and rocks in order to provide a simple capping. Over the years the cover however slowly sank into the tars, making the situation more complex.

The client, a large petrochemical company, decided to remediate the site and to remove all contaminated materials off-site. A lot of attention was put on the complex acid tar dump. Due to its expe-rience in acid tar remediations DEME Environmental contractors (DEC) were involved in 2011 to carry out several field scale inves-tigations and trials in order to separate gravels from acid tars, and find external disposal routes for the acid tars. In 2013 DEC carried out field pilot trials for the separation, segregation and treatment of the tars as can be found on the site. In addition SO2 emission and its mitigation was investigated. The findings from the various pilot trials formed the basis of the remedial design.

DEC formed a joint venture with the Norwegian company Veidekke, called VeiDec. Veidec has won the contract for this large reme-diation and started full scale work in Autumn 2015. A treatment facility has been set up at the site, where soils and acid tars can be separated, and to treat the acid tars into a secondary fuel that can be used in the cement industry. The contaminated soils from the site are disposed off-site in various disposal facilities in Norway and abroad depending on their degree of contamination. The amount of acid tars to be disposed of is around 20000 ton, and the amount of soils is around 200000 ton.

The remediation is carried out under the most strict safety measures in compliance with the client’s standards. A continuous air moni-toring is carried out in order to avoid or minimize the nuisance to the residential areas around the site.

The Taranto Prpject: Maintenance dredging of discharge canals of a steel mill and innovative in-line processing of run-off sediments

Stany Pensaert¹; Xavier Lepère¹ DEME Environmental Contractors

Three major canals of one of the largest steel mills in Europe are the main discharge routes for run-off and process water from the mill to the Ionic Sea, transporting around 1 million cubic meters of water daily. The canals were designed as a silt trap, which resulted in the siltation of the canals over the last few decades. The client decided to clean up the canals by means of dredging. The dredged sediments had to be dewatered prior to discharge to a landfill.

DEC (DEME Environmental Contractors) surveyed and sampled the canals in 2016 in order to design the most appropriate way of dredging, transport and dewatering of the sediments. In addition various disposal routes were evaluated. It was found that the sediments mainly consist of fine iron oxide particles, with a high content of coal and hydrocarbons, and the particle size distribution ranging from silty to sandy material.

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the restauration of a local biodiversity and the construction of a technosoil. Restoring biodiversity and stimulating soil formation could give a new value to derelict slagheap, as this is directly linked to ecosystem services that a land may deliver. Additionally, HYPASS will have significant economical and societal impacts, as it could reduce the dependence of European countries to SMs importation. Finally, HYPASS could help to create new jobs in the emerging area of high added-value waste treatment and valorization.

Post-treatment of aqueous solution containing surfactant and chlorinated organic compounds from lindane wastes

Aurora Santos¹; Raul Garcia²; Carmen Maria Dominguez²; David Lorenzo²; Arturo Romero²¹ Universidad Complutense de Madrid. VAT Q-2818014-I; ² Universidad Complutense de Madrid

Injection and further extraction of a biodegradable surfactant solution to enhance the removal of DNAPLs (dense non aqueous phase liquid) in the subsurface has received increasing attention in the last years. Among the surfactant types, the non-ionic ones are preferred for soil remediation since they have lower micellar critical concentration and are more readily biodegradable than the ionic ones. Although it has been proved that the soil flushing process using surfactants as extracting agents is an efficient process to remove residual DNAPLs, the pollutants are not destroyed and further treatments are required for this scope.

Therefore, an efficient post-treatment is required for the extracted surfactant flushing solution. This post-treatment can intend the reduction of the volume to discharge/treat and/or the recovery of the surfactant with selective abatement of the pollutants. This topic has been scarcely dealt in the literature and most of these works used synthetic organic phases as a source of contamination or only a single organic compound.

In this study, a DNAPL containing 28 chlorinated organic compoundds (COCs) obtained from Bailin landfill was put in contact with an aqueous solution of a commercial non-ionic surfactant-co-solvent. This DNAPL was a liquid waste produced by an old lindane factory located at Sabiñanigo (Spain). The DNAPL was dumped in unsecured landfills and it migrated by density through the subsur-face, polluting the soil and groundwater.

To simulate the flushing solution extracted, 0.4 g of DNAPL from Bailin landfill was put in contact with 20 mL of an aqueous phase containing 15 g/L of the surfactant. After 24 h of stirring and 72 h of settling, the supernatant was separated and analyzed. Several vials of 15 mL of the supernatant solution, containing the COCs and the surfactant, were prepared by this procedure. The following treat-ments have been applied to these solutions in order to abate the pollutants and recover the surfactant:

- Addition of micro Zero-Valent Iron or nano-Zero Valent Iron

- Addition of Fenton´s Reagent (hydrogen peroxide and ferrous iron)

- Addition of Sodium Persulfate, activated by heat

- Addition of Sodium Persulfate, activated by alkali

In all cases, the COCs reduction and the remaining oxidant and surfactant concentrations were measured. The best results, in relation to the selective abatement of the pollutants, were obtained with the Fenton’s Reagent and the addition of Persulfate activated by alkali.

In spring 2018 the equipment was mobilised consisting of a dredging pontoon with a hydraulic excavator fitted with a centrifugal dredging pump. Between the two largest canals a dewatering facility was set up based on two mobile soil washing plants, combined with a 250 m³/h process water treatment plant consisting of sand and activated carbon filtration. The dredging pontoon and mobile soil washing plants are optimally synchro-nized by means of full automation of the dewatering plants. By continuous measurement of flow rates and densities the dredge makes sure the dewatering plant can always work close to its maximum throughput of 70 tons of dry matter an hour.

The dredging and processing started in summer 2018 and will be finished in spring 2019. Around 100,000 m³ of sediments will have been removed, resulting in 30,000 tons of sand fraction and 50,000 tons of dewatered fines that will have been disposed by the client to a local landfill, and 300,000 m³ of process water that was treated.

The project is unique in its kind as dredging and full scale thorough dewatering at a high throughput were made possible by a high degree of automation of the plant.

HYdrometallurgy and phytomanagement approaches for steel slag management

Fernando PereiraMines Saint-Etienne

Metallurgical slags are major by-products generated by the steel and iron industry. Although they represent potentially important economic resources, as they still often contain significant amounts of “Strategic Metals” (SMs), slags are also considered as industrial waste that may pose public health and environmental concerns. The goal of the HYPASS project is to propose technological innova-tions for both a cost-effective recovery of strategic metals and an eco-friendly management of metallurgical dumps. In this respect, HYPASS will consider the process as a whole, from by-products production to slag valorization and finally rehabilitation of contam-inated landfills, with the ultimate goal of developing economically feasible and environmentally acceptable “zero-waste” processes. The core of the project is the development, assessment and evaluation of two complementary valorization routes using: 1/ hydrometallurgical-based approaches (under alkaline conditions) to recover high SMs amounts, and 2/ phytostabilization approaches [and the beneficial role of “Arbuscular Mycorrhizal Fungi” (AMF)] to promote ecological restauration of slagheaps. Additionally, HYPASS proposes to list and to map existing dumpsites, to perform “Life Cycle Assessments” (LCA) for various processing methods and to develop a “Decision-Support Tool” (DST) to help identi-fying the best treatment options, both from an economical and from an environmental point of view. HYPASS technologies will be implemented at a large slagheap situated at Châteauneuf (Loire, France), which is registered in the SAFIR network. The project involves one industrial (Industeel France ArcelorMittal) and two academic partners (ARMINES/SPIN and BRGM) and is organized into eight complementary “Working Packages” (WPs). Strong and numerous impacts are expected from the project. Technologically, the development of new approaches to recover SMs is in itself very innovative and promising, as this could allow to process large amounts of slags that are currently weakly re-used. This is very important in relation to the ambitious targets set by the “European Union” (EU) for recycling metallurgical by-products and decreasing landfilling practices. Environmentally, using phytostabilization as a capping strategy for slagheap rehabilitation will not only improve visual aspect of degraded lands, but this will also trigger

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The groundwater pollution consists mainly of TCE but reductive dechlorination has occurred in the past given the presence of the less chlorinated daughter products, dichloroethene (DCE) en vinyl chloride (VC). Reducing conditions are established, nitrate as electron acceptor is hardly detected, sulfate is still present and methane is produced. However, TOC concentrations in the aquifer are currently too low (< 10 mg/l) to further drive significant reductive dechlorination. The contaminated formation consists of fine to medium sand containing glauconite and sand stone.

A groundwater model using Modflow coupled with MT3DMS to simulate solute transport was developed. Based on the hydro-geology of the site and the distribution of the pollution 8 model layers were defined. The groundwater model was used to assess the hydraulic performance of a proposed barrier wall to mitigate further migration of the plume.

The constructed hydraulic barrier consists of 7 pumping wells with a screen interval of 30 to 40 m-bgl. In order to prevent further spreading of the plume the hydraulic barrier has to operate at an extraction rate of 1 m³.h-1 per well. The extracted groundwater is than spiked with molasses and re-infiltrated upstream of the hydraulic barrier in 16 biobarriers. No extracted groundwater is being discharged.

The 16 biobarriers are distributed over the contaminated plumes with a inter distance of 20 m. They consist of vertical infiltration filters with a 4 m screen length located at different depths. In total 362 vertical infiltration filters were installed. The shallowest infil-tration depth is 9 m-bgl and the deepest infiltration depth is 40 m-bgl. In the first injection round a volume of 4 m³/m screen of 1%vol molasses solution is being infiltrated into the filters followed by flushing with groundwater at a volume of 0,5 m³/m screen. If pH in the aquifer decreases below 6, sodium bicarbonate will be dosed in line to increase the pH within the optimal interval of 6 to 7.

During the injection extraction flows, groundwater levels, injection pressures and flows and TOC concentrations are monitored. The first injection round takes up 40 days, a volume of 5755 m³ needs to be infiltrated in total. After the injection round the extracted ground-water of the hydraulic barrier will be recirculated to the biobarriers without dosing of molasses. Around 40 wells are being regularly monitored for groundwater levels, concentrations of TOC, chlori-nated ethenes, nitrate, sulfate, iron(II), methane, ethane, ethane.

The presentation focuses on the conceptual site model, the final design and the installation of the full-scale remediation infrastruc-ture. The first infiltration and monitoring results will be presented.

Biological anaerobic degradation of VOCs combined with recirculated groundwater heating

Martin Slooijer; Rogier De Waele; Michela De Camillis; Remi Peters; John DijkGreenSoil International B.V.

The production of barium and strontium salts, followed by past production of ion exchange resins and glues, constituted harmful activities for soil and groundwater. Vertical migration of the con-tamination through the semi permeable unit into the underlying chalk aquifer is a potential hazard. Maximum soil contamination is found between 13,5-13,75 m-bgl with concentrations of 340 mg/kg of 1,2-DCA and 260 mg/kg of DCM. In addition, maximum groundwater contamination is detected at a depth of 8-19 m-bgl with concentrations of 435,000 µg/l of 1,2 DCA, 373,000 µg/l of DCM and 1,700 µg/l of VC. GreenSoil conducted a field test to inves-tigate the feasibility of enhanced reductive dichlorination (ERD) to reduce the risk of spreading.

Besides, to reduce the volume of the COCs solution, ultrafiltration (UF) with membranes of several kDa were tested (from 1 kDa to 5 kDa), finding that UF allowed to reduce the polluted fluid to less than a tenth of the initial volume. However, surfactant was remaining in the concentrate.

The authors acknowledge financial support from the Comunidad Autonoma of Madrid (Project S2013-MAE-2739 CARESOIL-CM) and from the Spanish MINECO (Project CTM2016-77151-C2-1-R) and the Aragon Government for the supply of samples.

Integrated remediation - redevelopment of contami-nated sites: the ISCO-SS soil mixing technology

Vito Schifano; Lorenz San NicolòLadurner Bonifiche S.r.l.

An in-situ remediation project was completed for a site contami-nated by petroleum hydrocarbons using an innovative technology, based on in-situ chemical oxidation, for the destruction of contam-inants, simultaneously with the stabilization of the soil with hydraulic binders, for the restoration of the geotechnical char-acteristics of the soils. Sodium Persulfate was used as a chemical oxidant together with cement to activate the oxidation reactions, promote the pozzolanic reactions that favor high-pH desorption of hydrocarbons from a solid matrix, immobilize residual contamina-tion and any heavy metals, hydraulic isolation of the treatment area and improve the geotechnical properties of the treatment area, in particular increase the strength and bearing capacity, decrease the compressibility and permeability of the ground and thus ensure favorable conditions for the reuse of the site.

The reagent formulation was designed by means of a series of laboratory tests in which the effects of different types and combi-nations of reagents and binders were evaluated. The mechanical distribution of the reagent and of the binder during the execution phase was carried out with the mechanical mixing technology of Bauer “single column soil mixing”.

A reagent-binder slurry was prepared in a batch mixing plant and injected at the tip of the mixing tool. Soils were mixed in-situ to a depth of 8 meters below ground surface. A design concentration of 5000mg/kg of TPH (C5-C12) and of 10.000 mg/kg of TPH (C13-C40) were targeted to be reduced below limit concentration values acceptable in soil and subsoil for commercial and industrial use.

This innovative approach to contaminated sites with a wide range of organic, inorganic and mixed contaminants is designated by the acronym ISCOSS (In-Situ Chemical Oxidation and Soil Stabilization).

Full-scale remediation of a large groundwater pollution of trichloroethene: a combination of biobarriers and hydraulic containment

Sylvie Seurinck¹; Youri Mertens²; Beatrijs Lambié¹¹ ANTEA Belgium; ² OVAM - Flemish Waste Agency

In this paper data from an on-going full-scale remediation of a large groundwater pollution of trichloroethene (TCE) is presented. The pollution originates from a former furniture manufacturer and is located in a partially forested and industrial area.

Two different plumes can be distinguished, each having an aerial extent of around 70 m wide and 400 m long. Plume 1 extends to a depth of 40 m-bgl and plume 2 extends to a depth of 30 m-bgl.

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A former triacetate production site caused a heavy xylene contami-nation up to 27.850mg/kg in soil and 89.000µg/l in groundwater to a depth of 10 m-bgl resulting in a total mass of 90T of Xylene.

RSK in combination with GreenSoil offered a lump sum contract to the client. Within this lump sum contract, a 100% on site and in situ biological remedial approach was proposed being both more sustain-able and economic compared to conventional (off-site) techniques.

The remediation consists of excavation and 100% on-site land-farming for soil (completed) and biosparging for groundwater (ongoing). The excavated soils are placed in biopiles, where dosing of nutrients and bioventing stimulates biodegradation of the contaminants. After soil treatment, the site is levelled and an enhanced in-situ biosparging system is installed below ground level. This in situ system treats residual soil and groundwater contamination.

During the project, innovative techniques like Biopile Air Filtra-tion Technique (BAFT), and Regenerative Bioscrubber (RBS) were successfully developed to reduce costs, especially related to activated carbon consumption.

BAFT. After completion of the soil treatment, biopiles have been redesigned to treat the soil vapors (500-2000 ppm of xylene) origi-nating from new biopiles, as they still contains nutrients and active bacteria called the ‘BAFT technique’.

RBS Soil vapors are also treated by an in house developed bioscrubber (RBS) that can treat both contaminated air and groundwater designed with a continuous regeneration system of carrier material balls.

All 20.500 m3 of heavily impacted soil have been cleaned far below the remedial target values (~400mg/kg) in 1.5 year. Starting from concentration levels up to 10.000 mg/kg, biopiles were reduced within 60-80 days with concentrations levels below 50 mg/kg.to

Both the ‘BAFT process’ and ‘RBS’ reached removal efficiencies between 60-90% in treating highly loaded soil vapors (up to 2000 ppm xylene) originating from other active landfarm depots.

The biological water treatment system worked with high efficien-cies, especially given the high influent concentrations (efficiency rate up to 99-99,9%) and removed the bulk of the incoming groundwater mass, leading to a noticeable reduction of activated carbon as well.

The project showed the power of circular bioremediation in all its aspects and has evidenced that innovation, sustainability and cost can go hand in hand. 99% of the contamination was degraded biologically either in soil, groundwater or air. In addition, 0m3 of soil left the site and cleaned-soil was used as air-treatment. Another remarkable outcome is that the active carbon consumption was reduced with 98% reducing waste.

The main financial costs at risk being (off site) soil treatment, activated carbon consumption and waste processing were managed by the circular bioremediation model allowing to offer a guaranteed outcome by this lump sum contract.

The compounds present are known to be biologically degrad-able under anaerobic conditions. Therefore, a closed system consisting of groundwater circulation and electron donor dosage was proposed and designed for a pilot test. In addition, heating of recirculated groundwater was implemented in the system based on earlier performed degradation tests.

The main purposes of the remediation approach proposed were (a) the stimulation of the biological anaerobic degradation followed by complete degradation of all VOCs with elevated concentrations and (b) the investigation of the effect of recirculated groundwater heating. By circulation of groundwater, dechlorinating bacteria and heated water will be distributed and contaminants will be mobilized and therefore more bioavailable.

The pilot system was installed in a relatively small area (about 50 m2) at one depth (11-15 m below ground level) and consisted of one extraction well and four infiltration wells. The duration of the pilot was about 1 year, including two shut down periods. A fast and clear decrease of high concentrations of DCA and DCM was observed. Concentrations up to 200,000 µg/l were degraded within 3 months. Concentrations of Chloromethane, the degrada-tion product of DCM, were very low and often below detection limit, indicating that it did not accumulate and was likely further degraded to methane. Increased concentrations of the degra-dation products ethene (up to 32,000 µg/l) and methane (up to about 7,000 μg/l), indicated a successful biological degradation. Moreover, the system was able to degrade VC from 300 – 600 µg/l till 29 – 130 µg/l, respectively.

Molecular analysis also confirmed the active presence and increase of the natural bacterial population that are most likely involved in the degradation of DCA and DCM. Dehalococcoides, Dehalobacter and Dehalogenimonas were detected in high numbers up to 1010 cells/l.

Most of the degradation took place before the heating of the groundwater was observed in-situ. Therefore the degradation can be attributed to the dosage of electron donor solely and the heating of groundwater had no significant effect on the degrada-tion during the pilot.

Consequently, these results demonstrated the efficiency of the biological anaerobic remediation approach proposed. Based on these promising results, GreenSoil is currently designing and implementing a full-scale system at the site.

Cyclic bioremediation of a heavily impacted Xylene site in Westerlo (BE) – 100% on site biological treatment of soil, groundwater and soil vapor

Marijke Van Camp¹; Stefan Bangels¹; Michela De Camillis²; Rogier De Waele²; Martin Slooijer²¹ RSK Benelux Bvba; ² GreenSoil International B.V.

This session shows how circular bioremediation was applied at a heavily xylene impacted site in Westerlo, Belgium and how lump sum contracting drives innovation and cost efficiency.

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the reduced efficiency is mainly caused by the saturation with phosphorus of the soils in the constructed wetlands.

The Biocascade offers a natura based solution for this problem. Due to a smart discharge phase, which removes accumulated phos-phorus from the soil, this constructed wetland remains effective in the longer term. In addition, the Biocascade seems to achieve a higher purification efficiency than other constructed wetlands due to use of an innovative combination of several connected ecologically engineered filtering steps: (a) infiltration in iron-rich vertical sand filter followed by (b) a helophyte filter with Phrag-mites australis, Iris pseudacorus and/or Typha angustifolia and finalized by (c) a compartment with underwater vegetation (e.g. Myriophyllum spicatum).

The first pilot of the Biocascade is developed by Research Center B-WARE and the Radboud University. The results of this first pilot are linked to the ecological design knowledge of Witteveen+Bos. During the presentation, results will be shown of this first prototype at the Radboud University and a large-scale (0.8 ha) pilot near Nijmegen-Arnhem. Both nitrogen and phosphorus removal effi-ciencies will be discussed as efficiency of hormones removal.

Global approach to recover rare earth elements from mine tailings by an hyperaccumulating plant

Baptiste Laubie¹; Zeinab Chour¹; Bastien Jally¹; Ye-Tao Tang²; Rongliang Qiu²; Jean Louis Morel³; Laurence Muhr¹; Marie-Odile Simonnot¹¹ CNRS, Université de Lorraine, UMR 7274 - LRGP; ² Sun Yat-Sen University; ³ Université de Lorraine / Laboratoire Sols et Environnement

Agromining is a phytotechnology aiming at producing commer-cial metal compounds from contaminated soils, which can be considered as low-grade ores, thanks to the cultivation of hyperac-cumulating plants. It has been widely developed for the recovery of nickel from serpentine soils and this approach is now extended to rare earth elements (REEs). The potential of the fern called Dicranopteris dichotoma, naturally growing on former mine tailings in South China, has been demonstrated. This plant accumulates up to 0.35% of REEs in its above-ground parts. Several hydrometal-lurgical processes have been developed to recover these elements directly from the biomass or from ashes after combustion.

The global approach will be presented, as well as the main results, in terms of recovery yield and purity. Process optimization, upscaling and other plants potential will be discussed.

Nature based solutions to manage the soil contamination of urban allotment gardens: examples from Nantes (France)

Cécile Le Guern¹; Liliane Jean-Soro²; Béatrice Bechet²; Thierry Lebeau³; Dorine Bouquet³¹ BRGM; ² IFSTTAR -IRSTV; ³ Université de Nantes

Urban allotment gardens (UAG) are important for the provision of foodstuffs, social cohesion, residents’ well-being, and prevention of the formation of local heat islands during summer. The soils of these gardens however may be adversely affected by pollution threats and thus create health risks. In such cases, appropriate management becomes necessary.

For several gardens exhibiting soil contamination (e.g. Pb at 100-400 mg kg-1) in the city of Nantes (France), local actors collabo-

Phytoremediation and mycoremediation of contaminated land at industrial scale: A complete toolkit for nature-based solutions

Olivier Bastin¹; Yann Thomas²¹ NATUREM SOLUTIONS; ² MICROHUMUS

Naturem Solutions is a Belgian company providing bioinspired solutions and ecotechnologies for soil, water and green infrastruc-tures. Microhumus is a French leader in phytoremediation and soil restoration. Both companies started in 2018 a partnership for the Belgian market.

Nature-based solutions is a term more often applied to the water management field. Starting from the definition of the concept and what it entails from a contaminated land remediation viewpoint, the presentation will put in perspective the potential of phytoremedia-tion and mycoremediation in that field, and why these technologies deserve this label as well. Potential interaction and complementa-tion between both approaches will also be discussed, to further multiply the beneficial outcomes. Finally, our approach to increase their widespread application at industrial scale will be outlined.

Definition of nature-based solutions and their multiple expected benefits, in parallel to the concepts of phytoremediation/manage-ment and mycoremediation.

Comparative application fields of both techniques for on-site reme-diation / management (type and concentration of contaminants, type of sites, remediation objectives), based on real case studies, and potential interaction and complementation from an ecological engineering point of view. For this purpose, we will use Microhumus extensive experience in phytoremediation / phytomanagement at industrial scale, to cover different types of previous/current land use (industry, river banks, waste ponds, brownfield, military site), pollution (hydrocarbons, cyanide, heavy metals, PAH, BTEX, mineral N) and objectives (pollution remediation and/or management, land redevelopment, renewable energy production). The results of Naturem Solution R&D program in mycoremediation of soil contami-nated by complex organic pollution using ligninolytic fungi will also be used, as well as a few other documented case studies.

Microhumus working methodology has been developed to address the needs of the industry in a rapid and streamlined process, that has allowed them to work on several full-scale projects: initial diagnosis – laboratory and greenhouse tests – field pilot – full-scale application.

Naturem approach to increase the application of mycoremediation at industrial scale will also be outlined.

Phytoremediation/management provide the different environ-mental, social and economic benefits of nature-based solutions, while mycoremediation still ought to demonstrate its cost-effec-tiveness with full-scale applications. They apply to different cases of contaminated land and hence provide a wide spectrum of potential nature-based solution for land remediation and management. Co-application might be a potential way forward in some cases.

Biocascade: The next generation of sustainable puri-fication of polder water and post-purification of WWTPs

Casper Cusell¹; Piet-Jan Westendorp²¹ Witteveen+Bos; ² Research Centre B-WARE

Existing constructed wetlands, such as the waterharmonica or traditional helophyte filters, often show considerably reduced puri-fication efficiency for phosphorus after a few years. Despite the annual removal of the vegetation in these constructed wetlands,

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217

immobilizing amendment since the combined application of these materials with ratio 1:1 could simultaneously immobilize Pb/Sb in shooting range soil.

Black soil is used as cultivation soil. Contaminated soil and non-contaminated soil were collected at shooting range in Tajimi City, Gifu, Japan. Ferrihydrite + HAp 1:1 were used as amendment. Ferrihydrite was prepared by neutralization and precipitation of Fe(NO3)3 9H2O solution using NaOH. HAp was synthesized through chemical precipitation of (NH4)2HPO4 and Ca(OH)2 at 90 ºC.

The contaminated soil was prepared in different concentrations to evaluate the effect of metal concentration on the efficiency of PSS. Tajimi shooting range contaminated and non-contaminated soil were mixed in appropriate proportions to meet target concentra-tion based on water soluble Pb and Sb (WS-Pb/Sb).

An amount of 100 g, 24.801 g, and 100 g of contaminated soil, amendment, and black soil were added into the experimental box, respectively. A 25μm nylon mesh was put to separate each layer. An appropriate amount of ultra-purewater was added to maintain 50% water holding capacity to each soil. Two guinea grass was grown on black soil. Cultivation process was conducted indoors for 16 weeks with temperature 22 ºC, lighting every 14 h/day, irriga-tion every 2 or 3 days and fertilizing every 30 days.

For all treatments, total Pb/Sb and WS-Pb/Sb concentration in culti-vation soil were not different with the control treatment. These results revealed that cultivation soil was not affected by Pb and Sb from contaminated soil. Total Pb/Sb concentration stabilized by amendment slightly increased with increasing concentration of water soluble metal in contaminated soil. Special attention was put on the results of the amount of Pb and Sb removed on treat-ments which exceeded the amount of WS-Pb/Sb in contaminated soil before the experiment. The removal rate decreased with the increasing total metal concentration. The rate of Sb were tending to be high in comparison with Pb since Sb was transported easily through water migration than Pb. WS-Pb/Sb concentration after cultivation was higher than before in contaminated soil. The increasing of WS-Pb/Sb might be attributed to the metal source of insoluble phase in the soil component.

rated, including: scientists, the municipality’s Parks and Open Space Department, elected officials, sanitary administration, and each site’s gardeners’ association. The soil characterization step was performed along with a sanitary risk evaluation and discussion of management options, based on both the pollution characteristics and local context.

The most frequent option consisted of replacing the polluted soils with clean soils. Managing the excavated polluted soils on-site (e.g. for ornamental purposes) limited the economic and environmental impacts associated with this solution. Alternative solutions, including a combined system of non-accumulative cropping vegetables at the time of phytoextraction, were also employed to maintain gardening uses. In some cases, land use (gardening) was changed into, for example, an orchard, open space or ornamental space. A combina-tion of solutions was introduced in several gardens.

The various options available for managing polluted soils, as implemented in Nantes’ UAGs and based mainly on NBS, can be applied more generally in order to improve soil quality. In addition to enhancing the quality of both residents’ lives and biodiversity, several solutions allow preserving or even restoring soil functions.

Efficiency of Phytosuc-separation System (PSS) for simultaneous removal pb and sb at shooting range soil

Takeshi Sato¹; Uzami Hamzah¹; Wan Zhimin¹; Masahiko Katoh²¹ Gifu University; ² Meiji Univercity

Phytosuc-separation system (PSS) is a new method for soil reme-diation which combines advantages of immobilization and phyto-extraction (PE). This method was built up by four compo-nents, those were contaminated soil, immobilization amendment, cultivated soil, and plant. The immobilization amendment was set up between contaminated soil and cultivated soil. In this study the PSS was applied for simultaneous removal of lead (Pb) and antimony (Sb) in shooting range soil. Lead and antimony were prepared in various concentrations in order to evaluate the effect of metal concentration in contaminated soil on the efficiency of PSS. Ferrihydrite and Hydroxyapatite (HAp) were prepared as

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dilution and the change in the stable isotope signatures can be quantitatively related to the degradation extent via Rayleigh equation. Thus, it can potentially serve as a unique tool that reflects the effectiveness of the pollution control.

In this study, compound-specific stable isotope analysis (CSIA) of the contaminants was carried out at two sites contaminated by trichloroethylene (TCE). Site A had been undergoing bioreme-diation previously. Results showed that its overall extent of TCE degradation and the overall extent of mineralization were less than 20% and insignificant, respectively. Since the overall perfor-mance is a summed effect of bioactivity and source dissolution, it was either the Dehalococcoides were not activated or the mass of source dissolution outcompeted that diminished by the biomass. Site B had intrinsic biodegradation potential. Compared with those of three years ago, both its overall extent of TCE degradation and the overall extent of chlorinated ethenes degradation to ethenes were higher. These indicated that the natural attenuation had been occurring and effective as the mass degraded outcompeted discharge from the source. In addition, the significant extent of mineralization suggested the occurrence of the daughter product, ethene, despite it was not detected in the groundwater. These two cases demonstrated that CSIA can serve as a powerful quantitative diagnostic tool for post-treatment monitoring or long-term site management.

Mass discharge for vapor intrusion site assessmentand vapor intrusion mitigation system analysis

Per LollDMR A/S

It has been suggested that application of a mass discharge test procedure can be used for the determination of when a vapor miti-gation system can be turned off. The presentation will highlight the results of two projects where a mass discharge test has been carried out by application of a vacuum blower based sub-slab vacuum and measuring air flow (m3/h), concentration (µg/m3) and monitoring the differential pressure across the floor. At both sites, previous mitigation systems had failed.

The aim of the first project was to suggest and test a step-wise procedure for determination of mass discharge, and estimation of the necessary mitigation time frame at passive mitigation systems.

The second project was a pilot test for designing a blower driven sub-slab depressurization system. The aim was to design the most cost-effective number of vacuum points, their placement, and the threshold vacuum necessary to create a robust downward pressure gradient. Previous mitigation efforts, based on internal carbon air purifiers, were insufficient for reaching acceptable indoor concentrations.

It is easy and cheap to perform a basic mass discharge test, and used at the right time it can provide critical information for the Conceptual Site Model (CSM).

At both test sites, previous site investigations left an impression of relatively well-established CSMs, with certain “blind spots”. At both sites the mitigation systems had failed in reducing indoor concen-trations to acceptable levels. Performing a mass discharge test at the sites gave valuable information for further development of the CSMs and gave unique new insight into the shortcomings of the mitigation systems.

Based on the results, we propose that a mass discharge test can be a valuable tool, not only at sites with venting/depressurization mitiga-tion systems, but also as a part of site investigations – to refine the CSM.

Demonstration to support approval of monitored natural attenuation remedy for a 1,1-DCE plume in fractured limestone

Melissa Boysun¹; Alicia Fogg²; Kelsey Berger²; Mitch Zimmerman²; Maureen Leahy²¹ ERM Swiss; ² Environmental Resources Management

ERM conducted an evaluation of natural attenuation pathways in primarily a 1,1-dichloroethene (1,1-DCE) plume located at a former manufacturing facility in central Texas, USA. The 1,1-DCE plume is encountered within a fractured limestone water-bearing zone and is approximately 190 meters long by 40 meters wide. Historical pilot study results indicate that active remediation using in-situ chemical oxidation (ISCO) showed limited effectiveness due to back-diffusion from the matrix and 1,1-DCE concentration rebound in all pilot study wells. Based on the limited effectiveness of ISCO, ERM evaluated multiple lines of evidence to assist in understanding the aerobic and anaerobic biodegradation pathways active in groundwater at the site to determine if natural attenuation was a viable long-term strategy. To support this evaluation groundwater samples were analyzed for geochemistry parameters, contaminant concentrations and microbial populations. Rock cores were tested for hydraulic properties, including porosity, and visual observa-tions of fractures and bedding. Downhole testing methods were used to determine in-situ fracture and bedding characteristics and hydraulic conductivity. These test methods included borehole geophysics, acoustic logging and hydraulic conductivity profiling. In addition to new hydrogeologic data, 20 years of historical chemical concentration data was evaluated for degradation of the parent compound 1,1-TCA to 1,1-DCE, groundwater flow direction and velocity, and indications of plume stability.

The Domenico 1987 solution for groundwater flow was used to model flow along the plume centerline in accordance with Texas regulatory guidance. While this solution is not generally ideal for a fractured rock environment, there was a sufficient amount of histor-ical and site-specific hydrogeologic data to calibrate the model and assess plume migration and stability along the centerline. Specifi-cally, ERM used The Domenic 1987 solution method to approximate the degradation rates of 1,1-DCE within the groundwater plume, independent of the aerobic or anaerobic pathway, since there was evidence that both pathways were occurring in different parts of the plume. The degradation rates were used to develop attenua-tion action levels for key monitoring points and points of exposure along the centerline and boundary of the plume. While unconven-tional to use the model in a fractured bedrock setting, this modeling method and the action levels obtained achieved regulatory.

Application of CSIA on evaluating in situ bioremediation effectiveness of chlorinated ethenes

Chia-Pei Li; Hsin-Lan HsuIndustrial Technology Research Institute

Biodegradation or monitored natural attenuation has become a popular option in remediating or managing sites contaminated by chlorinated hydrocarbons. To assess the effectiveness of the remedial option, a tool that can qualitatively and quantitatively evaluate the pollution control is essential. Traditional methods, such as measuring the concentrations of contaminants, are easily affected by dilution or, such as measuring the amount of the Dehalococcoides, are only showing the possibility of undergoing the degradation but not the extent of the degradation. Contrarily, stable isotope signatures of contaminants are not affected by

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of the 18 most abundant taxa were analysed using an AMA-254 Hg analyser. In 2017, 1484 individuals were collected and grouped on 154 taxa identified up to the genus level for 61%. Nine orders were represented with the coleopteran, hemipteran and dipteran accounting for 95% of the total abundance. Different feeding guilds were observed (stinging-sucking insects, defoliators, predators), with a ratio of phytophageous /predatory of 23  ±  6  %. Diversity indexes showed a high taxonomic and functional diversity in the experimental plantation comparable to diversity observed in natural patches of nettles (James et al. 2015). The mean concentra-tions of THg for insects collected from the experimental plantation (387.4 ± 38.4 µg/kg) were significantly higher than those from the control site (24 ± 3.7 µg/kg). Of nettles and insects tissues, the THg concentration follows the order of nettles (21.2 ± 1.0 µg/kg) < primary consumers (27.5 ± 4.3) < predator specialists (43.0 ± 14.1) < predator generalists (617.3 ± 47.2) showing a significant bioaccu-mulation. Moreover, we observed that insects whose spend a part of their life cycle directly in Hg sources (sediment: 5894 ± 111 µg/kg) have a higher THg concentration average (918.4 ± 80.5 µg/kg) than those related to the herbaceous layer of nettles (292.2 ± 17.1 µg/kg). Hence, our study showed a complex network of trophic interactions from the studied nettle-insect food web resulting in a balanced ecosystem on the revegetated sediment landfill. Overall, taxa that contribute the most to the Hg transfer in the highest trophic links are generalist predators and/or those in direct contact with Hg sources. Moreover, in revegetated sediment landfills, plants did not seem to be the primary source of Hg exposure for wildlife.

Transfer of Hg within a sediment-nettle-insect food web at a chlor-alkali landfill

Loïc Yung; Coralie Bertheau; Michel ChalotUMR 6249 Chrono-Environnement

Mercury (Hg) commonly enters ecosystems through anthropo-genic sources such as atmospheric emissions or wastewater from chlor-alkali facilities and landfills. Sediment landfills from chlor-alkali industries require Hg stabilization to prevent air pollution by evaporated Hg. We recently demonstrated the relevance of phyto-management process based on poplar plantations to revegetate and confine the Hg released from the soil in an experimental planta-tion located in a sediment landfill (Assad et al. 2016). Five years after the plantation, biotic and abiotic conditions have promoted the appearance of a spontaneous herbaceous cover highly dominated by stinging nettle (Urtica dioïca L.). In natural conditions, this plant species hosts a diversity of insects (Davis 1989), with strong trophic interactions (Alhmedi et al. 2011). As demonstrated for aquatic ecosystems, Hg is readily biomagnified through food webs, from plants to insects, birds and mammals (Abeysinghe et al. 2017). The present study aimed at evaluating the entomological diversity asso-ciated with stinging nettle in a phytomanagement field trial and its implication for the Hg flux through a sediment-nettle-insect food web system. Insects were collected every month using a sweep net, from April to September 2017 and 2018. Once taxonomically and ecologically characterized, the total Hg (THg) concentrations

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5b | Remediation goals and strategies

Remediation goals and moving goal posts

Jonathan EudallRamboll

Many remediation projects do not go to plan despite best inten-tions. The aim of this lecture is to highlight where remediation can go wrong and that it can be perfectly acceptable to follow a different path. The lecture will be illustrated by a series of case studies that pick out themes such as evolving conceptual site models, site constraints and health and safety.

Remediation should be relatively simple to frame: what is the problem and what are we going to do about it? Often remediation becomes entrenched in a conceptual site model that regulators, clients, consultants accept as a singular model that the site must conform to. Changing your mind or changing the direction of remediation with a regulator or client is difficult. This is why communication at an early stage is crucial to explain why concep-tual site models are not definitive and risk assessments not fixed. Site conditions change as remediation and redevelopment works progress. An adaptive and responsive approach is often needed to the management of contaminated land.

Linked to this is sustainability. Sustainability is viewed by different people in different ways and can be used to avoid remediation activities, which should not be the case. Sustainability is hard to quantify but should bring real value and benefit to the environ-ment and society. Two of the most urgent issues facing the world, global warming and water shortage will create pressures on land and water. Remediation needs to consider tomorrow as well as today.

Understanding of changing remediation and sustainability require-ments will need open and full engagement with stakeholders.

Case studies include:

Where the conceptual site model was wrong: the remediation of a site contaminated with oil due to the overfill of an oil storage tank. Multiple phases of remediation were required linked to the original incident and redevelopment of the site to residential use. The site was in a hydro geologically complex area with three aquifers units and with multiple constraints that acted as pathways for oil transport away from the original spill location. The final phase of remediation work was completed under time pressures and required a last-minute change in remediation approach to meet the regulatory agreed goals;

Where remediation changed: a refueling area contaminated with diesel was subject to source removal and in-situ treatment reme-diation. The earlier characterisation work had identified a need for remediation based on elevated soil and groundwater concentra-tions, but LNAPL was not encountered. However, during the work multiple unexpected finds were encountered along and around constraints including the presence of LNAPL. Remediation goals evolved on a daily basis during the work and constant contact was required between the remediation contractor, environmental consultant and client representatives to agree an acceptable outcome;

Where health and safety became more significant: further examples that discuss remediation activities and health and safety pre-cautions. Health and safety aspects can be overlooked during remediation works.

5a | Legal and economic aspects of the management of contaminated land

Application of environmental forensic investigations to define the allocation of liabilities in insurance claims

Domenico FracchiollaRamboll Italy S.r.l.

The environmental forensic investigation techniques can be applied to identify the responsible of the environmental contami-nation among different subjects who operated at the site. Ramboll was retained by insurance companies to perform forensic investi-gations to understand who was the responsible for the spill event and how and when it occurred, in order to define the allocation of liabilities in environmental claims and provide a suitable reim-bursement for remediation costs.

In the case study n. 1 Ramboll was asked to define who was the responsible for the heavy groundwater contamination detected at a large petrochemical facility, owned by two different subjects, respectively before and after ‘80s. The Compound Specific Isotope Analysis (CSIA) was used to identify the contribution to contamination due to each of the owners, properly allocating the reimbursement of the estimated remediation costs by the insurance companies.

In the case n. 2 CSIA was applied to assess the migration pathway of chlorinated solvents detected offsite to a large chemical facility, where a hydraulic barrier is operating for containment purpose. The isotopic analysis revealed a different fingerprinting of the contami-nants located offsite with respect to the ones located onsite, demonstrating that they were originated by an external landfill, as source of contamination not related to the insured owner.

The case n. 3 is a logistic site, where the insured tenant detected oil products within unknown underground storage tanks, which contaminated the surrounding soil and groundwater. In this case, the analysis of marker additives and chemicals (e.g. Sulphur), considering the maximum concentrations allowed by the regula-tion in the time, was used to estimate the age of the oil products, demonstrating they were date back before 90’s, when the insured subject was not operating at the site. Moreover, the application of chromatographic fingerprinting in the soil samples provided further evidences to confirm the contaminants origin and the spill age dating.

The case n. 4 is a petrochemical facility located in a coastal area, where aromatic hydrocarbons were detected migrating within the harbor located offsite. The site owner is also operating a hydraulic barrier to prevent contaminated groundwater migration toward the sea. A multiple investigation approach (hydrogeolog-ical modelling, chemical fingerprinting and medicinal chemicals markers) was applied to elaborate a complex conceptual site model, defining the contaminants offsite migration pathway. The investigation revealed the existence of a residual historical contam-ination entrapped within the stagnation zone of the hydraulic barrier migrated offsite before its activation.

These case studies show as a scientific approach can be an effective tool for the insurance companies to solve controversies related to definition of liabilities for contamination events and establish if and how much should be reimbursed to the insured subject within the claim.

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ISCR-based remediation of herbicide/pesticide-impacted soils in Canada, China, Colombia, Sweden, and the United States: 22 years of success and surprises

Alan Seech¹; Todd Slater², Mike Mueller1

¹ PeroxyChem Environmental Solutions; ² Retia LLC

Agricultural land is often converted to residential use as urban centers grow. An issue that may be encountered during these changes in land use is the presence of chlorinated pesticides and herbicides at concentrations above regulatory criteria. Over the past two decades, soil at many pesticide/herbicide-impacted sites has been successfully remediated using in situ chemical reduction (ISCR) treatments based on zero valent iron combined with organic carbon. A cycled, anaerobic/aerobic approach is used. This ISCR treatment has enabled attainment of industrial and residential remediation standards and provided an environmentally sustain-able, greener alternative to excavation and off-site disposal. ISCR technology is now considered a proven alternative to excavation and off-site disposal.

Large-scale in situ treatment is usually conducted only after completion of bench-scale testing on a representative soil sample(s) to determine if adequate removal efficiency can be attained. The bench work also provides estimates of the required soil amendment dosage and treatment time. In some cases, bench results indicate that remedial objectives cannot be attained. In cases where bench testing yields positive results, a variety of site-specific scale-up issues must be addressed, and regulatory approval secured before treatment at a site can be initiated. After successful bench-scale testing, a pilot-scale demonstration may be prudent, to ensure successful scale-up under field conditions. Treatment at sites can be conducted in situ or on excavated soil using a variety of soil mixing techniques to incorporate the soil amendments. In most cases, irrigation is also required to achieve a soil water content conducive to reductive dechlorination.

A variety of soils containing chlorinated herbicides and pesticides, including 2,4-D, 2,4,5-T, Metolachlor, Chlordane, DDT, Dieldrin, Aldrin, Lindane, PCP, and Toxaphene, have been treated to appli-cable criteria. In some cases, treatment has been completed rapidly, without difficulty, within the predicted time, and on budget. In others, soil characteristics, weather, and unexpected site conditions (e.g., very high pesticide concentrations) have rendered treatment slower or ineffective due to the need for many treatment cycles. Case studies, both successful and unsuccessful, will be presented. Reasons for observed performance, both good and bad, will be proposed and discussed.

Remediation of chlorinated ethenes via ISCR in a fractured bedrock aquifer at a redevelopment site

Fayaz Lakhwala¹; Mike Merinery²; Ronald Harwood², Daniel Leigh1

¹ PeroxyChem Environmental Solutions; ² Excel Environmental Resources, Inc.

A former dry cleaner facility and surrounding properties were being redeveloped into a retail shopping centre. The dry cleaning operations ended in late 1990s. Discharge of PCE wastes directly onto the ground surface resulted in two source areas at the site. Since the removal of source material in early 2000s, concentrations of PCE, TCE and c-DCE have decrease but still remain significantly above the local regulatory levels (i.e. New Jersey Department of Environmental Protection Ground Water Quality Standards).

The complex sub-surface geology consists of unconsolidated silt and sand, with clay as the overburden unit ranging in thickness

from 1.5 to 7.6 meters. Weathered and fractured rock is encountered underneath the overburden. Groundwater is typically encountered at 4.5 meters below ground surface. Following a comprehensive subsurface investigation to map the site-specific geologic features, hydrogeology, geochemistry and contaminant distribution using state of the art investigation tools, a Conceptual Site Model (CSM) was developed to help understand the contaminant fate and transport. Concentration of PCE in source area monitoring wells ranged from 5,000 to 25,000 ug/L.

Remediation strategy was largely driven by the redevelopment aspects of the site in terms of timing, and that there would be no future access at the site for continued treatment. The CSM indicated that geochemical conditions in the targeted treatment zone supported an in situ chemical reduction (ISCR) approach. ISCR would also provide both short and long-term treatment which was a key consideration. Remediation goals were to achieve a signifi-cant reduction in mass of total CVOCs within three years.

As defined herein, ISCR describes the synergistic effect of combining ZVI (or other reduced metals) with an organic carbon substrate to significantly lower the redox state of an aquifer. EHC is an ISCR amendment consisting of ZVI and organic carbon for treatment of chlorinated solvents. A total of seventeen injection points were installed in the two source areas based on an estimated radius of influence of 7.62 meters. The reagent was injected via pneumatic fracturing by creating 175 fractures through these injection points. Approximately 680 kgs of reagent were injected into each fracture.

Hydraulic fracturing was very effective in achieving a ROI greater than 15 meters. Rapid reduction of PCE accompanied by temporal fluctuations of degradation products TCE, DCE and VC was observed. Complete reduction of PCE to below 1 ug/L was noted at several key well locations. Complete mineralization of CEs was supported by two orders of magnitude increase in Dhc counts and production of ethene/ethane. A second focused application was required around one monitoring well five years later.

Urban soil remediation: In situ thermal desorption under a building, in the centre of Brussels

Hatem SaadaouiHaemers Technologies

Nowadays, urban soil is a natural ressource to preserve. Indeed, the fast urbanization of the recent years led to considerable conse-quences in terms of space and energy consumption as well as water and soil pollution. At the present time, urban areas contain many contaminated sites.

Two main issues can be identified which would need to be addressed through further reflection: first, the space consump-tion. Polluted areas in the centre of the cities are a waste of space. The clean-up of these sites is a necessary requirement to accom-modate housing, parks, schools, etc. Second, some polluted areas are located under existing buildings. Their remediation is often complicated, even sometimes impossible due to stability reasons, environmental impact or access.

HAEMERS Technologies © has conducted an In situ Soil Remedia-tion by Thermal Desorption in the centre of Brussels. The polluted area was located under a building. The origin of the contamination was a fuel tank leaking. The contaminated zone represented 48 m² and 3 meters deep and the contaminants of concern identified at the site were hydrocarbons. The highest concentration detected was 8 000 mg/kg (C10-C40). The aim of this project was to reach the target concentration of 300 mg/kg.

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In Situ Thermal conductive heating is perfectly suited for urban soil remediation for the following reasons:

- Heating is done directly on the ground

- It requires no excavation

- The size of the installation can be adapted according to the size of the polluted area

- No noise is produced

Moreover, In Situ Thermal Desorption has a fast application: the target temperature, fixed at 220°C, was reached in 45 days.

The results of this project showed that the remediation was successful: the target concentration (300 mg/kg) has been reached. Even more, the presence of hydrocarbons in the soil after the treatment was almost non-existent. This project also demonstrated that the technology has a high efficiency and is perfectly suited for urban soil remediation.

The paper addresses the remediation goals that can be imposed today in urban areas thanks to technological improvements which made multifunctional use no longer unaffordable.

The case illustrates the many instances where problem owners have chosen to remediate down to background levels, despite leaving no legal obligation to do so, but mainly because the extra cost was very minor and the benefits were much larger.

TreAting contamination through NanoremedIAtion: the TANIA project

Marie-Odile SIMONNOT¹; Noele Enjelvin²; Carine Vuidel; Kakou KOUMCHANE; Jean Louis MOREL¹ Université de Lorraine - CNRS; ² Université de Lorraine - INRA

Huge areas are contaminated in Europe, the number of potentially contaminated sites in Europe is estimated around 2.5 millions. Site management costs ca 6.5 billions a year. Nanoremediation is an effective strategy for water and soil remediation. However, conven-tional techniques are often preferred because of issues concerning technology novelty and governance models. The objective of the TANIA project is to address these limitations, by using interregional exchanges (involving partners from Italy (coordinator), Finland, France, Greece, Hungary) and participation of stakeholders from environmental and innovation fields.

Nanoremediation involves not only nanosized materials but also nanostructured macro-sized ones, biocompatible nanocontainers able to carry and deliver substances.

The challenges that have been found are: 1) the need for a standardised methodology to evaluate, monitor and control tech-

nologies, as well as an European regulatory framework, 2) pilot applications, 3) patents, 4) incentives for in situ use and 5) awareness.

The objective of this communication is to present a state of the art of projects and pilot applications in Europe, dedicated to soil and groundwater nanoremediation. Examples will be given to illustrate the remediation of sites contaminated by chlorinated solvents by reductive dechlorination using zerovalent (or modified) iron nanoparticules (e.g. case study from Soleo Services company – France, Nanorem project).

The TANIA project is co-funded by the Interreg Europe programme, through ERDF Funding 2014-2020, https://www.interregeurope.eu/tania/. Contact details are available on this web page.

The ISO 18504 standard on sustainable remediation

Jonathan SmithShell Global Solutions (UK) Ltd

Sustainable remediation is the elimination and/or control of unac-ceptable risks in a safe and timely manner while optimizing the environmental, social, and economic value of the work. A new International Organization for Standardization (ISO) Standard on sustainable remediation allows countries without the capacity to develop their own guidance to benefit from work done over the past decade by various Sustainable Remediation fora and groups around the world. The ISO standard was published in 2017 and ‘ligitimized’ the sustainable remediation frameworks previously issued as ‘grey literature’. The risk-based approach to managing the legacy of historically contaminated soil and groundwater has been incorporated into policy, legislation, and practice around the world. It helps determine the need for remediation and the end point of such remediation. Remediation begins with an options appraisal that short lists strategies that could deliver the required reduction in risk. A remediation strategy comprises one or more remediation technologies that will deliver the safe and timely elimination and/or control of unacceptable risks. The ISO standard helps assessors identify the most sustainable among the shortlisted, valid alterna-tive remediation strategies. Practitioners presenting case studies claiming to constitute sustainable remediation should now report how they have aligned their work with the new standard. Indica-tors are used to compare alternative remediation strategies. The simplest metric that allows a characteristic to act as an indicator should be chosen. Weightings indicators can become a contested exercise and should only be undertaken where there is a clear desire for it by stakeholders and a clear need for it in identifying a preferred strategy. The simplest means of ranking alternative reme-diation strategies should be adopted.

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engaged in activities related to sustainable remediation, as well as conducting role-playing games involving various stakeholders with contagious sites as their subjects, frameworks that show basic ideas in Japan. In this paper, we firstly announce the outline of the Japanese framework of sustainable remediation. We then report the role-playing game based on virtual contaminated sites in order to improve the understanding of the concept of sustainable reme-diation as an activity of SuRF-Japan.

This document organizes the framework of Sustainable Reme-diation (SR), including related standards and information, and summarized it for a wide range of readers in Japanese. A reader supposed by this white paper may possibly get the following benefits by tackling SR.

- Share ideas and frameworks of SR with a wide range of readers, including all those involved in soil and groundwater pollution control works. When the countermeasure is required, stakeholders including stakeholders / construction workers, surrounding residents, administrative officials

- Gain an opportunity to consider whether SR is applicable.

- Realize a well-balanced purification work that takes economic, social and environmental considerations by applying SR.

- Through these steps, stakeholders will share equal interests and help the achievement of the “United Nations Sustainable Development Goals (SDGs)” and contribute to the realization of a better society.

Stakeholder engagement: environmental and social impact assessment vs sustainable remediation projects: Comparison and benchmarking from case studies

Andrea IosiaERM Italy

While the stakeholder’s engagement is a common practice and usually requested in the Environmental Site Impact Assessment (ESIA) processes around all geographies, it is not as usual to apply it as part of remediation (REM) projects. The risks associated with poor stakeholder relations – and the opportunities provided by constructive ones – are now better understood by the private sector and financial investors alike. ERM’s experience in working with our clients have significantly advanced our thinking about the centrality of stakeholder engagement to all aspects of environ-mental and social performance.

Many projects show that involving all key stakeholders, establishing clear definitions and practicing intensive communication are the most crucial issues in the process towards a common understanding on sustainable performance and towards the implementation of conceptual frameworks. However, if not properly managed, stake-holder engagement can generate conflicts, mistrust and might delay the project development process. It is important, therefore, to identify the threats of stakeholder engagement so that preven-tive measures can be included in the planning and implementation processes from the start.

This work collects and compares information from case studies in ESIA and REM projects, on how the process of stakeholder’s partici-pation is undertaken and regulated in several different countries in the worldwide arena, and what are the practical advantages and risks of such processes.

Based on a specific information collected, the author attempts to compare aspects like the regulatory framework in several countries, what are the main constraints and challenges in managing stakeholders (both institutional and non-institutional, like local

Posters – 5c | Sustainable and socio-economic evaluation & public perception related to remediationA top-down approach for the development and implementation of GSR in Taiwan: Progress and challenges

Shyh-Wei Chen¹; Kai-Fan Chan²; Chia-Yun Li²; Yo-Ling Tu²; Pin-Han Chen²; Yu-Chen Su²; Bing-Nan Wang²; I-Hsing Chen³; Ya-Ting Wu³¹ Chung Yuan Christian University; ² Sinotech Environmental Technology, Ltd.; ³ Taiwan Environmental Protection Agency

Introduction. Taiwan Environmental Protection Administration (TEPA) has been supporting projects to promote GSR concept, establish the GSR framework, and develop online assessment tools to assist GSR verification and best management practices (BMPs) selection since 2012. In 2016, GSR was added into the Proposal Guideline for Contamination Control or Remediation Projects and local Department of Environmental Protection (DEP) has been looking at these measures during proposal review. However, lack of proper evaluation tools makes it hard for TEPA to assess the efficacy of GSR. In this study, as the first step to devise domestic GSR evaluation indicators, we tracked (1) current status of 6 sites which participated in early GSR projects and (2) recent projects which used GSR assessment tool in order to understand the drivers and obstacles to the implementation of GSR in Taiwan.

Materials and Methods. To confirm that GSR measures were being followed, an inspection system was designed and documented during site visitation twice per year. The inspection team would reviewed the contaminated sites background, remediation plans, and then come up with site-specific assessment sheets. During site visitation, inspection team would examine the actual acts and health and safety issues, and discuss with project contrac-tors regarding the benefits and difficulties they considered while engaging in GSR framework.

Results and Discussion. Information gathered during site visitation suggested that major concerns for remedial projects to adopt GSR measures were the impacts on remediation efficiency and addi-tional cost of time and money. Four of the 6 sites considered GSR assessment tool required additional labor but failed to generate significant benefits. Also the assessment tool was not designed for dynamic project management therefore hindered the use for ongoing projects. One third of the sites (2/6) responded that remedies selection were mostly affected by the project time frame and budget, both set by DEP or TEPA, and the relative importance of GSR was minimized. For the 6 sites, BMPs for project manage-ment which improved overall project efficiency and reduce energy consumption were widely adopted. Two sites were using automated equipment to calculate and control chemical dosage as GSR assessment tool suggested, which reduced chemical consumption and also allowed real time project monitoring and chemical cost reduction. Results from regular inspection indicate that key issues for implementation of GSR in Taiwan remain as to internalize GSR concept during remedy design, establish quan-tifiable GSR evaluation indicators, and create incentives for the adoption of GSR.

A Trial of Sustainable Remediation by SuRF-Japan

Yasuhide Furukawa

“The Sustainable Remediation Consortium” was established as AIST consortium in 2016, and now are also active as SuRF-Japan. This organization is divided into two working groups and one of the working group conducts activities on Green Remediation, especially BMPs (Best Management Practice). The other group is

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Establishment of Stockpiling and Staging AreasSequential excavation/segregation was utilised with material storage in temporary engineered storage area/depots. Excavated materials were visually/manually and mechanically screened using field screening instruments [X-ray fluorescent (XrF), Sudan IV dye shakers and photoionisation detector (PID) units] for waste char-acterisation and H&S monitoring. Confirmatory samples were collected prior to backfilling to verify remediation objectives.

The waste segregation techniques described is resulting in the separation of wastes from the landfill contents summarised below. The project (currently approximately 85% complete) is expected to be completed in January 2019.

Table 1. Excavated Material Mass Balance

Category Approximate Quantity

Waste Excavated 12,500 m3

Recovered materials 8,950 m3

Segregated processed soils (clean backfill)

8,900 m3

Segregated Recyclables 21,178 kg

Segregated Asbestos Containing Materials (ACM)

846 kg

Off-site disposal (non-hazardous waste) 4,680 T

(approx.. 70% recovery) Effective waste segregation/separation techniques is achieving the objective of reducing the volume of materials requiring disposal off-site to an appropriately licensed waste facility. This is being achieved by selective removal technique, dry screening, engaged supply chain for the recycling of anthropogenic materials (plastic, jute, paper, metals etc.) resulting in >70% of the materials being recovered. This is achieving one of the key performance indicator (KPI) along with the H&S approach which will put the labour at an advantage moving forward.

committees), and successful modalities to engage with different parties. Wherever possible, valid behaviors are identified in order to test them in the context of the Site Remediation.

Use of sustainability principles to reduce, reuse and recycle during a landfill excavation project in India

Nin Prakash; Jim Day; Rajat SrivastavJACOBS

Sustainability Principles were applied during Landfill Removal works site in India, consisting of excavation design/implementa-tion, segregation/removal of impacted soils containing hazardous and non-hazardous wastes, and transport/disposal to off-site licensed waste facilities. Waste segregation objectives were to reduce materials transported off-site (reduce truck emissions, H&S concerns, etc.) and maximize reuse of site-won materials.

Landfill characterisation/delineation works defined an average landfill depth of 2.0 meter below ground level (mbgl). The overall process flow for the works is shown in Figure 1 below.

Establish the Works - Baseline Conditions SurveyBaseline conditions were established using topographical and ground penetrating radar (GPR) surveys of the landfill contents, waste sampling/characterisation and detailed list of assets and utilities within the landfill and site access areas.

Protection of Workers Health and Safety (H&S)Social welfare responsibility measures were a focus including tracking potential health impacts and providing H&S training for extended team members. Jacobs ensured that a legacy of H&S awareness via outreach program remained with the local labourers and extended team. Temporary storage facilities, environmental impact monitoring/mitigation measures, allocation of Personal/Respiratory Protective Equipment (R/PPE) and provision of worker welfare facilities.

Posters – 5c | Sustainable and socio-economic evaluation & public perception related to remediation

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From Stand-and-Hold towards Enhanced Bioremediation: Bioremediation and 3D modelling at a former manufactured gas plant in Utrecht, the Netherlands

Suzanne Faber¹; Lisanne Keijzer²; Johan Van Leeuwen³; Jan Gerritse³; Tim Grotenhuis²; Ruud Schotting¹¹ Utrecht University; ² Wageningen University and Research; ³ Deltares

The Griftpark

Between 1840 and 1960 manufactured gas factories were situated at the edge of the city of Utrecht. During the manufac-turing process, coals were heated to produce town gas. This also created waste products, including aromatic compounds (e.g. BTEX, PAH), aliphatic compounds (e.g. mineral oils), as well as inorganic compounds (e.g. cyanide). These products made their way into the soil and groundwater. After the factory was closed, by the 1980s, Utrecht had grown so that the site became situated in the city centre. The neighbourhood pressed to have the site redevel-oped as a park. Much to the frustration of the neighbourhood, the contamination at the site was found to be of such an extent that full remediation was too costly. Instead, to protect neighbouring residents, the municipality used a stand-and-hold management technique, implementing a cement-bentonite wall around the site, to the depth of a 55 meter deep clay layer that divides the first from the second aquifer. A clean top layer was applied and the site transformed into a public park. The clay layer, however, contains ‘holes’ and is therefore not completely confining. This causes a risk of contaminants leaking into the second aquifer that is used as a source for drinking water downstream. Currently, groundwater is pumped from the top aquifer, to create a seepage from the 2nd into the 1st aquifer, aiming to protect the 2nd aquifer from contam-inants that are transported with the groundwater. This measure is costly and does not remediate the soil, so that it needs to be continued eternally.

Bioremediaton and modelling at the Griftpark

In 2006, laboratory experiments showed that soil bacteria are able to degrade organic contaminants, even when high concentrations of pure product are present. Around the same time, biodegradation of organic contaminants was observed in aerated groundwater from the Griftpark. Following these developments, the Municipality of Utrecht has commissioned a consortium (Utrecht University, Wageningen University and Deltares) to sketch scenarios for finite aftercare of the Griftpark. The research comprises a combination of field study, laboratory experiments and computational modelling, with the aim to provide an answer to the question whether (stimu-lated) bioremediation is a feasible method to control groundwater contamination at the Griftpark.

In our poster presentation we will go into detail about the research questions and methods used in this project. We will present the implications of heterogeneity of the subsoil through our 3D hydro-geological model and our understanding of the local natural attenuation processes and opportunities for stimulation. We will explain how these results are integrated into a reactive transport model that will enable us to forecast the feasibility and safety of potential future scenarios at the Griftpark, as well as other similar sites worldwide. Furthermore, we will explain the economic and environmental benefits of transitioning from the stand-and-hold technique to monitored natural attenuation and discuss the social aspects of the redevelopment of a site that is situated in such a central part of town.

Overview of feasible remedial actions to tackle the regional heavy metal soil and groundwater pollution related to former non-ferro industrie in the Campine area (NE Belgium)

Jan Bronders¹; Ilse Van Keer¹; Johan Vos¹; Nele Penninckx²; Dirk Pauwels²; Tim Lieben³; Petra De Clercq³; Allan Vanautenboer⁴¹ VITO; ² Tauw Belgium; ³ OVAM - Flemish Waste Agency; ⁴ Sweco

In the Campine area, located in the north-eastern part of Flanders (Belgium) and the south-eastern part of the Netherlands, the soil and water system is polluted with heavy metals due to the former activities of non-ferro industry smelters. As a result of the studies being carried out in the area since 1995, a good overview is obtained related to the source, the fate and the risks of the pollution. Subsequently, a holistic modelling approach including remedial actions and protective measures has been worked out. Hereby, current pollution risks and future changes in the pollution status of water bodies (groundwater and surface water) were high-lighted. Modelling results indicate that the most effective measure is to clean up the source zones at the industrial sites, which is currently undertaking by the land owner of the different sites.

Although technical features and economical aspects hampers remedial actions on a regional scale, feasible measures were identified by the Flemish Waste Agency in agreement with the stakeholders. One of these measures was the removal of non-ferro waste near schools, private gardens and nature reserves by The Flemish Waste Agency. These waste products were historically used as reinforcements of the parking lots, terraces, playgrounds, etc. Furthermore, measures were taken to protect potential receptors against (infiltrating) polluted groundwater.

Case 1: River Eindergatloop

The erosion of the riverbanks of the Eindergatloop, consisting mainly of zinc ashes, causes surface water pollution with Zn and Cd. In 2018, over a length of 1 km these banks were covered with a geotextile and gabion baskets. This will prevent the erosion of Zn ashes into the stream and will help to reduce surface water concentrations of heavy metals. Downstream a significant influx of polluted groundwater is entering the river. Related to this, potential remediation methods (such as reactive barriers, draining of groundwater)) are evaluated.

Case 2: River Scheppelijke Nete

Polluted groundwater (mainly Zn and Cd) enters the surface water through seepage. It was decided to find a nature-based solution to improve the water quality as the area of concern is very large and traditional remediation techniques would not cover the whole area and would be too costly. Research has been carried out to explore the options of installing reactive material in or on the bottom of the streams or the construction of wetlands. Test have been carried out to define the materials which can be used.

Monitoring network for groundwater quality

To evaluate the status of the groundwater quality the water bodies a groundwater monitoring network has been installed in the affected area. This network consists of a selection of several existing wells (observation network of the Flemish Environmental Agency) and newly installed wells. Twice a year this monitoring network is sampled.

Subsequently, the collected data and modelling results will allow to identify if improvement (positive trend) of the water quality can be observed or if at some places more efforts (actions) are needed.

In the poster these items will be highlighted.

Posters – 5d | Managing large scale industrial and agricultural pollution (water soil energy food nexus)

226

Sustainable redevelopment of brownfields. More than choosing the best soil remediation technology.

Eddy WilleOVAM - Public Waste Agency of Flanders

This paper outlines the results of the policy on brownfield rede-velopment since the mid 1990s in Flanders (Belgium). The revitalization of these brownfield sites is based on the experiences of OVAM gathered during several years of action in the field of soil remediation. On the 22th of February 1995, the Flemish govern-ment enacted the Soil Remediation Decree. The Soil Remediation Decree had an important impact on the transfer of land and the remediation of operational industrial facilities.

Still, abandoned sites were not addressed in an efficient way by this legal framework because there was no sale or ongoing exploitation. Due to the soil contamination, these sites often remain dis-used or under-used and no action related to the above mentioned legis-lation will be taken in the near future unless a changing policy is introduced. Reintegrating those brownfield sites in its environment became a challenging task.

Bringing the stakeholders together and setting up governance structures are basic elements for a successful transition. In December 2000, in line with the Policy Agreement of the new installed Flemish government, the brownfield steering committee was put in place in order to develop a specific policy.

The Brownfield Covenant Act was enacted by Decree on March 22, 2007 and offers developers the opportunity to sign a contract with the Government of Flanders and other private and public stakeholders containing mutual commitments to the realization of a brownfield project. This contract is the result of a process for gaining the (public) support and the cooperation of all the stakeholders involved. Once the contract is concluded, a steering committee monitors the redevelopment of the site. Negotiators appointed by the Government bring the multiple stakeholders together and facilitate the covenant negotiations.

In 2008, the Flemish government launched a first call for proposals and in 2018 the 8th call was published. In total, nearly 200 projects proposals were submitted and 80 projects have already been approved by the Flemish government. All these projects cover an area of 1.400 ha of regenerated brownfields. During the last years, more emphasis on sustainable development was required and also interim use was an important element in bridging the gap between the design phase and the project realization. This paper gives an overview from the perspective of a negotiator.

7a | Circular land use and brownfield regeneration

Opportunities for preparing urban contaminated land for bio-based production

Shaswati Chowdhury; Jenny Norrman; Jaan-Henrik Kain; Marco Adelfio; Yevheniya VolchkoChalmers University of Technology

Circular economy consists of both technical and biological cycles, the former will typically take place in cities while most of the bio-based production is happening outside the cities’ limits. There are however strong arguments for also including urban areas in the biological cycles, such as creating awareness in larger parts of the population regarding advantages of production of food, biomass, biofuel and other bio-based products. Due to urbanization and calls for more compact cities, pressure on urban land resources is high. Here, underused brownfields present opportunities for urban transformation towards a bio-based circular economy. Still, real or perceived soil and/or groundwater contamination is a barrier to redevelopment in terms of investment risks, ownership constraints, risk of future liability claims and public stigma.

The standard solution to remediate those sites for new uses is “dig and dump” as it is quick and easy to communicate with controlling environmental authorities. Even if such remediation is expensive, causes adverse environmental impacts, and consumes non-renewable resources, it is seen as cost-effective and acceptable when the return on investments is high in urban redevelopment projects. Nevertheless, when financial incentives are missing, brownfields risk waiting years for remediation and reuse resulting in an underuse of urban land. There is an international consensus on promoting more gentle remediation methods (e.g. phytoreme-diation) that are low-cost, long-term methods without negative secondary impacts with potential to manage risks and improve soil ecology. While cultivation systems safely can take place on top of remediated soil, bio-based production may also take place directly in contaminated soil. For example, cultivation of bio-energy crops can simultaneously reduce ecological and human health risks, improve soil quality and provide revenue. Brownfields can thus open up cities for circular economy by facilitating temporary or long-term bio-based production.

This paper, stemming from a new PhD project, aims to investigate the possibilities and preconditions for preparing urban brownfields for temporary and long-term urban bio-based production. The specific objectives of the entire PhD work are to: 1) investigate the opportunities in terms of land use functions as well as legal and administrative requirements linked to temporary and long-term land use of former brownfields; 2) develop a method for selecting remediation option, focusing on low-cost and low-impact risk reducing methods; and 3) investigate involved multi-stakeholder planning and governance processes and disentangle the driving forces that hinder or make such processes possible in practice. This paper addresses objective 1, where state of the art of gentle remediation and land use options of brownfields are investigated for various type of bio-based production opportunities. A litera-ture review will be the basis for a framework for understanding the potential of brownfields in urban circular economy. This framework will be tested on selected case study sites in Gothenburg, Sweden and reviewed by a wide range of stakeholders.

Posters – Topic 7 | Land, soil, water and sediment in the circular economy

227

Overview of the challenges regarding topsoil management.

Description of the two different types of applications that we focus on:

1°/ manufactured topsoil production for commercial purposes (to be sold to third parties)

2°/ on-site topsoil production and soil restoration for site develop-ment (using existing material).

Type of materials that can be valorised in both cases.

Description of Microhumus technical expertise, tools and meth-odology applied to both types of applications: laboratory and greenhouses tests, prediction of soil further evolution and improve-ment based on transmission electron microscopy, on-site pilots to demonstrate the concept, agronomic data sheets edition

Description of the overall strategy proposed to manufactured topsoil producers: technical feasibility study, economic feasibility study, product formulation, production and marketing assistance.

Presentation of SubsTer®, manufactured topsoil producer network, currently expanding in France, Belgium and Switzerland and a few industrial examples.

Benefits of both applications in the context of circular economy.

Current concerns of using struvite-based fertilizer in horticulture

Carmen Biel; Marc Viñas; Miriam Guivernau; Maria del Mar Carreras; Rafaela CáceresInstitute of Agrifood Research and Technology (IRTA)

Current issues on the use of products recovered from wastewater treatment plant (WWTP) as a fertilizer source in edible crops are of public concern and need to be further understood.

To this end Life Enrich project (www.life-enrich.eu) is focused on nitrogen and phosphorus recovery technologies from wastewater treatment and their further valorization in the fertilization industry and their use in agriculture as organic fertilizers. The main aim of the present study is to gain a deeper insight into the main bottlenecks identified in the potential utilization of struvite obtained from urban WWTP such its salt solubility, plant nutrient availability, fertilization management (fertigation or mixed in the soil/substrate), and also the presence and effect of heavy metals, emergent contaminants and microorganisms into plant crops and plant-soil microbiome, as well as the potential health risk for consumers.

In this work we present the effect of the utilization of recovered nutrients from WWTP in form of struvite, as organic fertilizers in edible crops conducted at IRTA-Cabrils facilities at pilot scale (Barcelona, Spain).

Preliminary test were conducted to check the availability of the use of struvite in fertigation in lettuce. The struvite product obtained from a WWTP contain 10.7% P, 5.9% N-NH4+, 18.7% Mg and 52.1% organic matter. To improve phosphorus availability, two acidified suspensions were tested (citric and nitric acid), being the citric acid a good acidifying agent; however, the use of citric acid promoted the nitrite formation in the nutrient solution that should be minimized to prevent plant toxicity. Tomato plants growing in soilless system with perlite as a substrate and fertigated with a nutrient solution based on P and N coming from struvite and ammonium salts will be established in spring. A diversified approach including agronomic aspects (macro and micronutrients plant use), microbiome assessment and mobilization of emergent contaminants such as antibiotic resistance genes, in: the nutrient solution tank, plant biomass and leachates will be monitored during the growth cycle.

Posters – Topic 7b | Reuse and upgrading of SSW & products; recov-ery of valuable resources; improving ecological functioningFeasibility project for the remediation and the reuse of sediments resulting from the hydraulic restoration of the infiltration basins of the Arno torrent

Christine Ballarin¹; Stefano Donà¹; Giacomo Donini¹; Carlo Collivignarelli; Luigi Natale¹ AECOM URS Italia S.p.A.

This project deals with the restoration of a system of flood retention and infiltration basins of the Arno torrent of 30 ha of extension, which became highly inefficient because partially or completely occupied by sediments, deposited by the floods of the Arno torrent, contaminated by heavy hydrocarbons.

The design approach favored the choice of interventions that will reduce the contamination to levels acceptable to the environment, maximizing the reuse of sediments and that will be able to improve the quality of water resources and consequently bring benefits to the natural and anthropic systems involved.

Since the majority of hydrocarbon compounds are subject to biodegradation by microorganisms, the intervention strategy for the site foresees the application of in-situ Bioremediation treatment. One of the three basins will be used as a Confined Disposal Facility (CDF) where it will be possible to activate Biore-mediation through oxygenation (Bioventilation) and mechanical mixing of the sediments, in order to be able to reuse the clean sediments for environmental restoration of some quarries located near the reservoirs and a partial reuse of the sediments on site.

The processes of biodegradation of contaminants will be enhanced in situ, before excavation, by increasing the oxygen content both within water and sediments, by: i) a system of oxygenation and movement of water and by ii) a system of mechanical movement/oxygenation of sediments (cutter suction dredgers - CSD).

The project will allow to achieve the environmental quality requirements of the sediments, as required by Italian law, with interventions compatible with the protection of the different systems present in the territory (anthropic, physical, natural), the reuse of the remediated sediments for the environmental restora-tion of quarries located in the immediate vicinity of the infiltration basins with the consequent reduction of the need for disposal, the improvement of water oxygenation conditions and finally the substantial reduction of induced traffic and emissions into the atmosphere for the transport of sediments.

On-site or commercial topsoil manufacture using excavated soils or inert materials: full-scale experience of a pre-European network

Olivier Bastin¹; Yann Thomas²; Lucas Demierbe¹; Gaylord Machinet²¹ NATUREM SOLUTIONS; ² MICROHUMUS

Naturem Solutions is a Belgian company providing bioinspired solutions and ecotechnologies for soil, water and green infrastruc-tures. Microhumus is a French leader in phytoremediation and soil restoration. Both companies started in 2018 a partnership for the Belgian market.

The presentation will describe the strategy successfully applied by Microhumus in France and its partners in Belgium and Switzerland to develop a network of manufactured topsoil producers, as well as providing services for on-site topsoil production and soil restora-tion. As in most of the cases by-products are used (excavated soil and/or inert material from construction industry or quarries), it will also be demonstrated that the activity fits within the circular economy.

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Land mangement issues and mining activities

Jan Bronders¹; Ilse Van Keer¹; Corina Hebestreit²; Petros Maraboutis³; Eberhard Falck⁴¹ VITO; ² Euromines; ³ Ecoefficiency; ⁴ WeFalck

Sustainable land management is important when taking into account mining activities. Next to the activities related to active mining, abandoned mine sites or mine tailings are in many cases a historical heritage for which it is unclear what has to be done and who is responsible when looking at environmental, economic and social aspects. In all cases, active or historical, there is confusion when taking into account the different regulations at EU level or member state level.

To support the mining sector and stakeholders in tackling environ-mental and site reconversion processes, a European consortium/competence centre “the EU Mine Mentor Centre (EMMC)” has been established. The goal is to deliver high quality support on mining operations (as stipulated by EU or related national legisla-tions) including environmental management, water management, material recovery for added-value, mine closure and site remediation.

The EMMC provides sustainable solutions solving mining manage-ment problems in the broad sense, by defining how to implement regulations, improve performance, help to manage liabilities and social aspects, carrying out field audits and finally helps to rehabili-tate properties.

Furthermore the EMMC also focusses on capacity building covering the whole spectrum of activities related to active mining operation but also related to abandoned mine sites, mine closure and site remediation. Not only the technical implementation, but also social and health impacts, safety regulations, specific legislative expertise, etc. are needed to deal with in this complex process.

The poster will give an overview of the approach used by the EMMC.

Phytoextraction capacity of Phragmites australis in constructed wetland to reduce pollutants from industrial wastewater

Amalia García-Valero; Silvia Martínez-Martínez; Martire Angélica Terrero; Ángel Faz; Jose Alberto AcostaTechnical University of Cartagena

Planted constructed wetland can assimilate a large amount of pollutants and play an important role in water purification. Besides, these systems are characterized by low operational and mainte-nance costs. In this study, a phytoremediation system to enhance the treatment of industrial wastewater coming from a standard depuration process was used which can potentially lead to several interesting benefits. Phragmites australis (P. australis), the common reed, was the selected specie due to its ability to adapt to arid and semiarid climate and capacity to pollutant absorption. This research aims to decrease contaminants concentration in indus-trial wastewater using a horizontal subsurface flow constructed wetland (HSFCW) as ecofriendly system. This study was carried out in Lorca, Murcia Region, Spain. The constructed wetland worked in paralell, and it was composed by three cells filled with coarse gravel in the bottom (80 cm) and washed sand in the top (20 cm), and planted with P. australis as phytoextractor specie. It was operated with two hydraulic retention time (HRT = 3 and 7 days) and three cycles by HRT. The Kjeldahl nitrogen (KN), phosphorus (P), boron (B) and chromium (Cr) concentrations were analyzed in water and the

Those tests will give as both fundamental new insights, and a practical and technical data to optimize organic fertigation strate-gies for efficient plant production minimizing their potential risks for health and the environment.

Phytomanagement: towards a reuse of abandoned sites in Wallonia

Elodie Bouhoulle¹; Florian Liénard¹; Laurence Haouche¹; Lucas Gossiaux²; Aricia Evlard²; André Lox³¹ Institut Scientifique de Service Public - ISSeP; ² ValBiom asbl; ³ SPAQuE sa

Some brownfields, former landfills or sediment deposits in Wallonia remain unused or abandoned because of hazardous substances contamination and/or low physical properties.

In October 2017 the Walloon ministry of Environment approved a 3-years convention between the Walloon public scientific institute(ISSeP), the Walloon public society for polluted soils management(SPAQuE sa) and a non-profit organization for the use of biomass(ValBiom asbl) to set up a phytomanagement experiment inunused polluted sites in Wallonia.

The WALLPHY project was born. It has three main goals: to enhance the knowledge on phytotechnologies and in particular on phyto-stabilisation, in order to extend contaminated land management solutions applied in Wallonia; to assess phytostabilisation perfor-mances in stabilizing soil pollutants in the frame of environmental and health risks control; and to assess the potential of produced biomass for recovery within a context of circular economy.

Four field plots have been selected for the experiment, each with different characteristics and raising different issues. One of the field plots is a sediment deposit, mainly contaminated with metallic trace elements and PAHs. Located in a nature protection zone (Natura 2000), the vegetation species that were settled up were selected prioritizing native plant species indigenous to the area, in a vertical structure favouring biodiversity and using set up techniques limiting impact on wild fauna to the maximum extent possible. The phytomangement of the second plot, a former landfill site, has been oriented towards biomass production to reach the most favourable solution for economic purposes. For the two last sites, where formerly steel and charcoal production activi-ties respectively took place, plant species were selected amongst tolerant crops, able to grow on poor-quality soils.

The follow-up of the experiments addresses the transfer of contam-inants to the water compartment and to the vegetative parts of the plant species. Soil micro- and macroflora is also monitored.

Local value chains (energy production or bio-based products) will be identified for the produced biomass. These value chains must be both economically relevant and safe for the environment and for human health. In particular, biomass quality (ie. heavy metal contents) will be evaluated in comparison with existing regula-tions in Wallonia and in neighboring regions and countries. The economic potential will be assessed based on produced biomass yield and on existing local initiatives for biomass use (biomass boiler, fiber industry, green chemistry, etc.).

Phytomanagement may be a way to increase the value of polluted areas but also an opportunity to restore – even partially – soil functions and subsequently enhance biodiversity. Thus, ecological effects including soil quality improvement will be investigated on each experi-mental site in order to provide a global picture of phytomanagement as a solution for contaminated areas management in Wallonia.

Legal and legislatives aspects of phytostabilisation management of contaminated soils and of the potential subsequent use of biomass are addressed within the project.

Posters – Topic 7b | Reuse and upgrading of SSW & products; recov-ery of valuable resources; improving ecological functioning

229

40 °C was pumped. In this way the temperature of the soil matrix increases which has a positive impact on the biodegradation. From literature it is known that the optimal temperature for biodegrada-tion of chloroethenes is around 25 to 30 °C. Moreover increasing the temperature causes the transfer of the contamination and TOC to the aqueous phase and makes it consequently more available for biodegradation. Between the soil heat exchangers multiple injection wells were installed to execute carbon source (VP-1) injec-tions to further stimulate the biodegradation. In source zone 1 only multiple injection wells were installed. In the center of every source zone a deepwell was installed to extract groundwater in order to distribute the injected carbon source in the subsurface.

During the heating phase in source zone 2 the average tempera-ture of the soil matrix increased from 14°C to 28°C while the VOCl concentrations were strongly reduced to the reference value. Compared to source zone 1 and based on the chloride index the biodegradation is 4 times faster when it is thermally enhanced. The results show that biodegradation of contaminated areas with indication of residual product (PCE > 15.000 µg/l) can be remedi-ated faster. Based on these results also a thermal system is installed in source zone 1 to speed up the reductive dechlorination. This expansion is, together with the installation of 25 double injection wells and 7 deepwells in the plume zone, part of the full scale reme-diation which is currently ongoing.

From static waste towards dynamic resources landfill management

Jan Frank Mars¹; Ulrich Stock²; Eddy Wille³¹ Rijkswaterstaat; ² Landesamt für Umwelt, Brandenburg; ³ OVAM - Public Waste Agency of Flanders

Each year in the European Union we throw away 2.7 billion tonnes of waste. On average 25% is going to landfills. The European directive 1999/31 / EC for landfills was an important step in the uniform management of operational landfills. The objective was to prevent or reduce the negative impact of the landfill on the environment (ACS 5a). In addition over 95% of the EU former landfills (>500.000) do not fulfill safety standards of the EU directive. For those landfills we see remarkable differences among the various member states this was reflected in the Interreg EU project COCOON.

The traditional paradigm of the linear economy resulted in landfills as the final waste disposal sites. For both former and new landfills, the risk based approach aiming at an eternal safe situation leads to a static landfill management with often leads not in every case to an eternal solution. Partners in COCOON are calling for a more dynamic and resource driven landfill management (ACS 7a).

Recent developments

Does todays landfill management fulfill the requirements of the 21st century? For example in Flanders and the Netherlands over 50% of landfills are located in flood-prone areas. The risk based model is gradually coming under pressure because maintaining a static situation in a dynamic environment is not easy. In addition, there are various policy demands that with present static landfill approach can currently not provide with a substantiated response (ACS 2c). One of the milestones in the Roadmap to a Resource Efficient Europe states that waste should be managed as a resource.

The spatial pressure is such a typical phenomenon where landfills do not always pose a threat but can also bring a solution. A more active use of the surface was investigated in the interreg Sufalnet project, these examples proof that spatial efficiency can be greatly

removal efficiencies were calculated. Besides, absorption capacity of these elements were analyzed in the aerial and root part of P.austalis. The contaminants levels were reduced for both HRTs, being the most effective for HRT = 3 days with a removal efficiency of 9.8, 78, 13 and 36 % for KN, P, B and Cr, respectively. However, the highest absorption efficiencies of KN, P and B by P. australis in aerial part were at 7 days. In contrast, Cr was significantly retained at 3 days. In the root part, nitrogen absorption was 53 and 80% for 3 and 7 days, respectively. Therefore, P. australis is an ideal phyto-extractor, which combined with constructed wetlands, reduces considerably pollution load of the wastewater.

Reuse of sediments in landscape development: ecotoxicological monitoring of a mound in Wallonia (Belgium)

Florian Liénard¹; Laurence Haouche¹ Institut Scientifique de Service Public - ISSeP

Belgium and nothern France are facing a real management problem with sediments: the dredging of waterways generate significant a mounts o f m aterials d ue t o t he s hallow r elief i n t his geographical area. Waterways operators and public authorities are still waiting for efficient valorization solutions. The VALSE project, funded by the Interreg V program, aims to validate valorization pathways and one of them is focused on landscape development. In this context, a mound made with dredged sediments is ecologi-cally and ecotoxically monitored to determine its impact on the environment over time. An embankment near the studied site was chosen as a reference. The ecological monitoring consists in flora and substrate macro-invertebrates surveys while the ecotoxi-cological monitoring is based on the study of nitrifying bacteria and the reproduction of an earthworm (Eisenia fetida). First results show that the sediments do not seem to have a negative impact on flora and macro-invertebrates nor interfere with natural nitrifica-tion process and E. fetida reproduction. These results tend towards a good integration of the mound in the surrounding environment for the monitored parameters.

Thermally enhanced reductive dechlorination at an industrial site in Nevele, Belgium

Art Lobs¹; Jonas Wittocx¹; Jan Jacobs²¹ Verhoeve Milieu & Water; ² RSK Benelux bvba

As part of a redevelopment project in Nevele a soil remedia-tion project with thermally enhanced reductive dechlorination is executed. The project location is situated in an industrial area. Between 1984 and 2004 a company was present which bought and sold machines for laundry and dry cleaning applications. Before working on the machines they were cleaned in a degreasing space at the site which is determined as the source of the contamination (mainly PCE). Concentrations of PCE were found up to 55.000 µg/l in the groundwater. Although bioremediation was already identified at the location an additional effort was necessary. Since two source zones were present a comparison could be made between source zone 1 (only stimulation by injection of carbon source) and source zone 2 (stimulation by injection of carbon source and heating).

For the thermal enhancement of the biodegradation multiple soil heat exchangers were installed in the contaminated soil at source zone 2 to a depth of 9 m-bgl. A closed circulation system with a heat pump was installed through which heated water of approx.

Posters – Topic 7b | Reuse and upgrading of SSW & products; recov-ery of valuable resources; improving ecological functioning

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Biological Restoration of Soil Function after Smouldering Remediation

Christine Switzer; Neil McCosh; Charles KnappUniversity of Strathclyde

Smouldering remediation is capable of removing 99.9+% of heavy hydrocarbon contamination from soil using self-sustaining flameless combustion. During the course of remediation, smoul-dering subjects soil to temperatures of 500-1200°C for periods of minutes to hours while destroying contaminants in soil pores. Soil experiences physical, chemical, and biologically-relevant changes, including texture, geochemistry, and losses of essential nutrients. Adapting to and overcoming these changes is essential to biolog-ical restoration of soil as well as engineering reuse.

Heating and chemical reactions change soil-surface properties and how soil interacts with water, nutrients, and potentially toxic elements. Nitrogen and total organic carbon become lost around 500°C followed by phosphorus mineral transformations and loss at higher temperatures. Simple clays become fired around 500°C, reducing soil cation exchange capacity and its ability to retain water. Transformations to more complex clay minerals occur at higher temperatures. Because of these changes, nutrient supple-mentation is required to support microbe and plant growth in soils. Amendments derived from natural materials offer some benefit but yield inconsistent results.

A series of laboratory and field experiments involving plants and microbes investigated the potential for soil restoration after smoul-dering. Addition of stoichiometrically-balanced nutrients accelerated microbial colonisation and growth of healthy emergent plants. Further additions became wasteful with no observed improvements in successional development. Phytoremediation plants and microbes capable of bioremediation grew well with balanced nutrients and poorly in nutrient poor conditions. Leguminous plants also grew well but did not develop root nodules while nitrogen was abundant. Limiting nitrogen resulted in some nodule formation, though results were inconsistent. Addition of cultivated, nodule-bearing legumes to decay in the soil during growth of subsequent plants greatly enhanced nodule formation. Decaying plant matter likely intro-duced communities of symbiotic, nitrogen-fixing bacteria as well as nutrients. Further study is needed to determine when further nutrient supplementation can be phased out. In microbe-only experiments, conditions in post-remediation soils favoured gram negative species and fungi colonisation, conditions that will need to be overcome to form healthy, robust soil ecosystems. Similarly, soils in a two-year rooftop field experiment had extensive colonisation by bryophytes and the diversity of species was limited in smouldered soils. In all experiments, soils recovered well in stoichiometrically balanced conditions, but further investigation is needed to support restoration to fully functional ecosystems similar to before contami-nation and remediation.

Real time monitoring and modelling web platform for water reuse optimization in a context of Managed Aquifer Recharge and Soil Aquifer Treatment

Loïc Thomas¹; Axel Aurouet¹; Marie Pettenati²; Géraldine Picot²; Jonathan Durand¹; Charlotte Thierion¹; Aubery Wissocq¹; Hervé Noel¹; Daniel Pierre¹¹ Antea Group; ² BRGM (French Geological Survey)

As part of the H2020 AquaNES project, Antea Group (Géo-Hyd) and BRGM worked on the development of an ICT tool for the opti-mization and monitoring of a managed aquifer recharge and soil aquifer treatment (MAR/SAT). For the demonstration site of Agon-

increased. The demand for housing, recreation or green energy can be filled in at a landfill site (ACS 6c).

In addition, there are also potential threats from climate change. Landfills can become more sensitive to flood risks. On the other hand, a targeted excavation and redevelopment can provide space for water and nature. Landfills are unsorted stocks of raw materials, which are currently not used. The upgrading of this deposited waste brings the end point of the linear economy back into the circular economy.

The long-term management requires a reconsideration of the Isolate, Control and Monitor (ICM) model with an eye for a more dynamic environment. Such management concepts go beyond a traditional risk approach. This requires the input of socio-economic parameters and the link with the sustainable development objec-tives. Half a million dumping locations in the EU cannot simply be written off as lost stock (ACS 7a).

Reconsidering the concept of eternal waste disposal sites in view of a sustainable demand and supply model contributes to an inno-vative land policy. Land(fills) as a resource is in line with current EU-policies on land degradation, soil sealing, climate change and circular economy. COCOON brings EU-partners together to exchange experiences and prepare policy innovation.

Exhausted granulated activated carbon from fresh water production reactivation by use of microwave heating

Marek Svab¹; Martina Svabova²; Barbora Stepanova¹; Pavel Masin¹¹ DEKONTA, a.s.; ² The Institute of Rock Structure and Mechanics, Czech Academy of Sciences

The contribution refers about pilot-scale reactivation of the exhausted granulated activated carbon (GAC) using different heating methods including microwave irradiation. Since water resources are widely contaminated by low concentrations of many artificial trace chemicals (pesticides and PPCP = pharmaceuticals and personal care products), an additional treatments steps have been being installed on fresh water production plants. This final treatment step is based on the GAC adsorption of trace chemicals from the water which passes through the standard technolog-ical lines. The GAC application for fresh water production is the growing field in the Czech Republic and this is why also exhausted GAC processing will be the task of a great importance.

Our regeneration (550 - 600°C) / reactivation (650 - 900°C) process was tested in new pilot-scale facility in batch rotary kiln heated either by electrical furnace or by microwaves. The real sample of exhausted GAC from the fresh water production plant was used for experiments under various conditions. The best results have been achieved in case of microwave heating on 800°C combined with an addition of steam as a reactivation agent (30 minutes). The BET surface area of the reactivated GAC was then 1310 m2/g (new GAC has usually less than 1000 m2/g) with burn-off (loses of the GAC by the process) only about 6 % of dry matter. On the other hand, the reactivation by indirect electrical heating under 700 °C with steam for 60 minutes provided BET of 910 m2/g and burn off 10 %. Together with three times faster heating in comparison with traditional indirect heating systems, the microwaves look to be a promising reactivation heating method. However, suitable opera-tional plant design must be developed.

Posters – Topic 7b | Reuse and upgrading of SSW & products; recov-ery of valuable resources; improving ecological functioning

231

The Long-term Assessment of Rain Garden from the View of Sustainable Land Use

Yasuhide Furukawa; Kazuhiro Mukai; Yuujirou Minomo; Takashi Miwa

The risk of flooding in Japan has been increasing as the meteoro-logical agency showed that the number of heavy rain, which means that the hourly amount of rainfall is over 50 mm/hr, has become larger than it used to be. The average number of the annual occur-rences in the last 10 years (2008 to 2017) was about 238, compared with the average annual number of occurrences, which was about 174 in the first 10 years of the statistical period (1976 to 1985). In addition, the cost to repair the infrastructure stands has been increasing over recent years and the annual cost is estimated to be 5.1 trillion yen in 2023. By considering this situation, the basic plan for water circulation was enforced in 2015, policies such as watershed cooperation, improvement of rainwater storage and recharge functions, sustainable groundwater conservation and preparation for drought were indicated.

One of these countermeasures, rain garden is considered to be effective green infrastructure in reducing peak flow rates and widely accepted. However studies on this bio-retention system are underway and are few examples in Japan. Therefore further exami-nation such as materials to be used and the effective operation is required. In this report, we show the result of column test aimed at practical application of rainwater infiltration system. At the same time, we would report the results of the real-scale pilot tests on water quality and water volume with sustainable aspects.

Coutainville in Normandy (France), this application aims to help the Wastewater Treatment Plant (WWTP) managers to reuse the water for the irrigation of a golf course extracted from the sand dune aquifer in a context of saline intrusion.

Due to the use of SAT system within the water treatment chain, this innovative action requires to combine an advanced hydro-geological expertise and specific set of software to optimize the effectiveness of the system to ensure the quantity and the quality of water that will be reused.

The new tool has been developed with the combination and the interconnection of two specialized software components within a single unified web application.

The first component is the Lyxea® software developed by Antea Group and aims to centralize and control all data collected on the demonstration site. Lyxea® integrates both the data collected during sampling campaigns and the data measured continuously by a sensor network deployed on the site (salinity, piezometry, bacteriology, etc.).

The second component is the 3D Hydrodynamic modelling software Marthe developed by BRGM and aims to model the hydrogeological operation of the hydrosystem of the study site considering all the parameters influencing the natural environ-ment (rainfall, tides, infiltration, artificial recharge...).

Based on these two technical bases, a web platform has been created to allow the site manager i) to consult the measured data (online and offline), ii) to follow the key indicators of the good functioning of the system and iii) to confront the hydrogeological model with predictive scenarios based on the observed conditions (drought, exceptional tides ...).

Posters – Topic 7c | Nature based solutions: Effectiveness for long term ecosystem services for soil & water

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