electrokinetic remediation (erem2014) · techniques for the remediation of soils contaminated with...

ELECTROKINETIC REMEDIATION (EREM2014)

13th

SYMPOSIUM ON ELECTROKINETIC REMEDIATION (EREM 2014) September 7-10, 2014 – Malaga, Spain

Sponsors

University of Malaga

International Society of Electrochemistry

Universidad de Málaga

Campus of International Excellence

Diputación de Málaga

Consorcio Provincial de Residuos Sólidos

Urbanos de Málaga

Consejería de Innovación Ciencia y Empresa

Junta de Andalucía

ELECTROKINETIC REMEDIATION (EREM2014)

Editores

José Miguel Rodríguez Maroto

Rafael García-Delgado

Francisco García-Herruzo

César Gómez-Lahoz

Carlos Vereda-Alonso

María Villén-Guzmán

2014, Málaga, Spain

ISBN - 10: 84-697-0768-X

ISBN - 13: 978-84-697-0768-5

Table of contents

EREM2014 13th Symposium on Electrokinetic Remediation Malaga, Spain

7

Table of contents ............................................................................................................. 5

Welcome ........................................................................................................................ 13

Committees .................................................................................................................... 15

Program ......................................................................................................................... 19

Schedule...................................................................................................................... 21

Oral sessions ............................................................................................................... 22

Poster sessions ............................................................................................................ 26

Author index ................................................................................................................. 33

Key lectures ................................................................................................................... 39

Krishna R. Reddy ....................................................................................................... 41

Manuel Rodrigo .......................................................................................................... 43

Oral Session 1: Metal Removal and transport of inorganics ................................... 45

Nº Ref.: O130 ............................................................................................................. 47

Electrodialytic extraction of phosphorus from ash of low-temperature gasification

of sewage sludge

Nº Ref.: O131 ............................................................................................................. 49

Phosphorus recovery and heavy metal removal during municipal wastewater

treatment

Nº Ref.: O140 ............................................................................................................. 51

Electrochemical detection and electroremediation of polluted soil by mercury

using different removing agents

Nº Ref.: O162 ............................................................................................................. 53

Comparison of two experimental set-ups for electrodialytic removal of heavy

metals and Cl from MSWI APC residues

Nº Ref.: O166 ............................................................................................................. 55

Study of electrokinetic remediation technology at semi-pilot scale. Weak acid

enhancement

Oral Session 2: Fundamentals and Modeling ............................................................ 57

Nº Ref.: O209 ............................................................................................................. 59

Modeling of the direct current assisted transport of zero valent iron nanoparticles

Nº Ref.: O232 ............................................................................................................. 61

Influence of 2D physical heterogeneity on the elcetromigration of nitrate

Nº Ref.: O242 ............................................................................................................. 64

Influence of the electrochemical treatment on humic substances content in the

groundwater from limestone aquifers: Preliminary study

Nº Ref.: O243 ............................................................................................................. 65

Enhancement of electro-osmotic flow during the electrokinetic treatment of

contaminated soils


8

Nº Ref.: O261 ............................................................................................................. 67

Electrokinetics to modify strength characteristics of soft clayey soils: A laboratory

based investigation

Nº Ref.: O268 ............................................................................................................. 70

A continuous multi-scale model for ionic transport through electrically charged

membranes

Oral Session 3: Scaling up and field applications ...................................................... 73

Nº Ref.: O313 ............................................................................................................. 75

Pilot scale electrodialytic treatment of MSWI APC residue to decrease leaching of

toxic metals and salts

Nº Ref.: O325 ............................................................................................................. 77

Multivariate analysis of variable importance in the scaling up of electrodialytic

remediation of heavy metals from harbour sediments

Nº Ref.: O326 ............................................................................................................. 79

Design of a pilot electrokinetic remediation plant for marine sediments

contaminated by heavy metals (PROJECT LIFE12 ENV/IT/442 “SEKRET”)

Nº Ref.: O352 ............................................................................................................. 82

Application of solar cell in electrokinetic remediation of As-contaminated soil in

pilot scale

Oral Session 4: Other uses. Miscellaneous. ................................................................ 85

Nº Ref.: O401 ............................................................................................................. 87

A decontamination of the soil contaminated with cesium using electrokinetic-

electrodialytic technology

Nº Ref.: O439 ............................................................................................................. 91

Electrokinetic driven low-acid IOR in Abu Dhabi tight carbonate reservoirs

Nº Ref.: O453 ............................................................................................................. 94

Selective recovery of dissolved metals from acid mine drainage via

electrochemical method

Nº Ref.: O464 ............................................................................................................. 96

Desalination of granite and sandstones by electrokinetic techniques. Comparison

Oral Session 5: Organic and chlorinated organic compounds remediation ........... 99

Nº Ref.: O520 ........................................................................................................... 101

Electrodialytic process applied for phosphorus recovery and organic contaminants

remediation from sewage sludge

Nº Ref.: O523 ........................................................................................................... 103

Integration of electrokinetic process and nano-Fe3O4/S2O82-

process for

remediation of phthalates in river sediment


9

Oral Session 6: EKR in combination with other techniques .................................. 105

Nº Ref.: O604 ........................................................................................................... 107

Different strategies to enhance bioremediation of diesel-polluted soils using

electro-kinetic processes

Nº Ref.: O606 ........................................................................................................... 109

Feasibility of coupling permeable bio-barriers and electrokinetic soil flushing for

the treatment of organic chemical polluted soils

Nº Ref.: O608 ........................................................................................................... 112

Effect of electrokinetic enhancement on phytoremediation of soils with mixed

contaminants

Nº Ref.: O634 ........................................................................................................... 114

Potential of electrokinetic process to recover phosphorus and remove cyanotoxins

from membrane concentrate

Nº Ref.: O659 ........................................................................................................... 115

Electrodialytic removal of heavy metals from fly ash from co-combustion of wood

and straw – influence from prewash

Poster Session: Metal Removal and transport of inorganics .................................. 117

Nº Ref.: P110 ............................................................................................................ 119

Remediation of cuprum from clay soils

Nº Ref.: P112 ............................................................................................................ 122

Testing of new shifting current electrodialytic treatment setup for efficient

treatment of Cr-contaminated soil fines

Nº Ref.: P116 ............................................................................................................ 124

Electrokinetic remediation with novel electrode configuration

Nº Ref.: P124 ............................................................................................................ 127

Determining variable importance on electrodialytic remediation of heavy metals

from polluted harbour sediments

Nº Ref.: P127 ............................................................................................................ 129

Monitoring electrokinetics by geophysical methods: Preliminary laboratory

investigations

Nº Ref.: P129 ............................................................................................................ 132

Membrane influence on electrodialytic remediation of air pollution control from

municipal incinerated solid waste

Nº Ref.: P133 ............................................................................................................ 134

Study on removal behavior of cesium ion in clay minerals (kaolin and vermiculite)

by using electrokinetic process

Nº Ref.: P137 ............................................................................................................ 137

Optimization of electrokinetic treatment conditions for a metal-contaminated

dredged sediment


10

Nº Ref.: P145 ............................................................................................................ 140

Effects of electrodialytic process on soil phosphorus

Nº Ref.: P149 ............................................................................................................ 142

Comparison of reagent to enhance desorption and mobility of arsenic in electro-

kinetic remediation from contaminated paddy soil

Nº Ref.: P150 ............................................................................................................ 143

Electrokinetic treatment of dewatered soil cake containing flocculants from soil

washing processes

Nº Ref.: P155 ............................................................................................................ 145

Fibers ion exchange for improvement of electrokinetical removal of heavy metals

from polluted sites

Nº Ref.: P160 ............................................................................................................ 147

Electrical behavior of copper mine tailings during EKR with modified electric

fields

Nº Ref.: P165 ............................................................................................................ 150

Study of electrokinetic remediation technology at semi-pilot scale. Strong acid

enhancement

Nº Ref.: P167 ............................................................................................................ 152

A critical study of the use of the BCR speciation for the characterization of

mobilizable metal contamination

Nº Ref.: P169 ............................................................................................................ 154

Study of efficiency in the removal of lead from soil by different treatments

Nº Ref.: P174 ............................................................................................................ 156

Two step electrodialytic remediation of soil suspension for simultaneous removal

of As and Cu

Nº Ref.: P177 ............................................................................................................ 158

The effects of composting, biosurfactant and freezing-thawing on electrokinetic

removal of heavy metals in sewage sludge

Nº Ref.: P178 ............................................................................................................ 159

The use of 2D non-uniform electric field to remediate chromium-contaminated soil

from an abandoned industrial site with permeable reactive composite electrodes

Poster Session: Fundamentals and Modeling .......................................................... 161

Nº Ref.: P217 ............................................................................................................ 163

Numerical analysis of vanadium and water crossover effects in all-vanadium redox

flow batteries

Poster Session: Scaling up and field applications .................................................... 165

Nº Ref.: P305 ............................................................................................................ 167

The scale up of the flushing-fluid-assisted electrokinetic remediation of kaolin soil

polluted with phenanthrene


11

Nº Ref.: P311 ............................................................................................................ 169

Electrokinetic treatment of polluted soil by gasoline at pilot level couple with an

advanced oxidation process of residual water

Poster Session: Other uses. Miscellaneous. .............................................................. 171

Nº Ref.: P418 ............................................................................................................ 173

Effects of porous properties of carbon felt electrodes on the performance of all-

vanadium redox flow batteries (VRFBs)

Nº Ref.: P419 ............................................................................................................ 175

The effects of hybrid catalyst layer design on methanol and water transport in a

direct methanol fuel cell (DMFC)

Nº Ref.: P428 ............................................................................................................ 177

Electrochemical peroxidation using iron nanoparticles to remove arsenic from

copper smelter wastewater

Nº Ref.: P438 ............................................................................................................ 179

Applying EK to achieve SMART (simultaneous modified assisted recovery

techniques) EOR in carbonate reservoirs of Abu Dhabi

Nº Ref.: P444 ............................................................................................................ 182

Electrochemical degradation of chlorobenzene in water using Pd- catalytic

electro-Fenton’s reaction

Nº Ref.: P447 ............................................................................................................ 183

Hydrodechlorination of TCE by Pd and H2 produced from a copper foam cathode

in a circulated electrolytic column at high flow rate

Nº Ref.: P456 ............................................................................................................ 184

Enhancing electro-Fenton chlorobenzene degradation from groundwater,

oxidation technique in the presence of Pd with different catalyst supports

Nº Ref.: P457 ............................................................................................................ 186

Feasibility of modeling by adsorption the magnetic separation of iron

nanoparticles

Nº Ref.: P458 ............................................................................................................ 189

Electrocoagulation reactor design for arsenic treatment

Nº Ref.: P463 ............................................................................................................ 192

Desalination of sandstone with two different setups under an applied electric field

Nº Ref.: P472 ............................................................................................................ 194

Evaluation of microbial communities, growth rates and susbtrate consumption

under electrical field

Poster Session: Organic and chlorinated organic compounds remediation ......... 195

Nº Ref.: P507 ............................................................................................................ 197

Electrokinetic-Fenton process for remediation of PAHs-contaminated railroad soil


12

Nº Ref.: P515 ............................................................................................................ 200

Characterization and regeneration of Pd/Al2O3 catalyst along a three electrodes

column for chlorobenzene remediation.

Nº Ref.: P535 ............................................................................................................ 202

Removal of a thiazine, an azo and a triarylmethane dyes from dyes polluted

kaolinite by electrokinetic remediation

Nº Ref.: P541 ............................................................................................................ 204

Construction and characterization of dimensional stable anodes with iridium and

tantalium by painting, immersion and electrophoretic deposition for the

electrokinetic treatment of polluted soil by hydrocarbon

Nº Ref.: P573 ............................................................................................................ 206

Enhancing solutions for electrokinetic remediation of dredged sediments polluted

with fuel

Nº Ref.: P576 ............................................................................................................ 208

Electrodescontamination of soils contaminated with dyes for industrial use.

Poster Session: EKR in combination with other techniques .................................. 211

Nº Ref.: P646 ............................................................................................................ 213

Electrochemical dechlorination of TCE with mixtures of humic acid, metal ions

and nitrates in a simulated karst groundwater

Nº Ref.: P651 ............................................................................................................ 214

Comparison on electrokinetics and soil flushing for removal of metals after in-situ

soil mixing

Nº Ref.: P675 ............................................................................................................ 215

Soils contaminated with drugs in common use: An attemp to use the

electroremediation, in combination with the adsorptiom, on industrial waste, as a

prevention tool of contamination.


13

Welcome

The symposia on Electrokinetic Remediation have been held for more than a decade.

The first was in Albi (France) in 1997, and was followed by eleven more editions that

have spread all around the world: Lyngby, Denmark (1999), Karlsruhe, Germany

(2001), Mol, Belgium (2003), Ferrara, Italy (2005), Vigo, Spain (2007), Seoul, South

Korea (2008), Lisbon, Portugal (2009), Kaohsiung, Taiwan (2010), Utrecht, The

Netherlands (2011), Sapporo, Japan (2012) and finally Boston, USA (2013). All of

them were attended by a diverse audience representing the engineering and scientific

communities with a well-deserved success of participants. We expect to achieve the

same success with the 13th edition of this conference (EREM 2014) in Málaga (Spain)

and that it will continue in the next edition, expected to be held in Abu Dhabi, United

Arab Emirates (2016).

The first editions of this conference were especially focused on the use of electrokinetic

techniques for the remediation of soils contaminated with heavy metals, organic

compounds, radioactive waste, etc. In recent years, there is a growing interest in the

applicability of the electrokinetic techniques in other areas, especially their use in

production processes: water treatment, waste water treatment, mining, food industry,

etc. So, we hope that this edition in Málaga will provide a venue to present and discuss

new research results concerning electrokinetics, which include but do not limit to:

fundamental aspects of electrokinetics, applied research, environmental remediation,

modelling and simulation, combined techniques, etc.

We welcome you to Málaga

Best wishes

José Miguel Rodríguez Maroto

Conference chair

Professor of the Department of Chemical Engineering

University of Málaga

Committees


17

ORGANIZING COMMITTEE

José M. Rodríguez-Maroto (Chairman)

Rafael García-Delgado

Francisco García-Herruzo

César Gómez-Lahoz

Carlos Vereda-Alonso

María Villén-Guzmán

SCIENTIFIC COMMITTEE

Akram N. Alshawabkeh (Northeastern University, Boston, Ma, USA)

Alexandra B. Ribeiro (New University of Lisbon, Portugal)

Claudio Cameselle-Fernández (University of Vigo, Vigo, Spain)

Gordon C.C. Yang (National Sun Yat-Sen University, Taiwan)

Henrik K. Hansen (Technical University Federico Santa María, Valparaiso, Chile)

José M. Rodríguez-Maroto (University of Málaga, Málaga, Spain)

J. P. Gustav Loch (Utrecht University, Utrecht, The Netherlands)

Juan M. Paz-García (Division of soil mechanics, Lund University, Lund, Sweden)

Kitae Baek (Chonbuk National University, Jeonju, Republic of Korea)

Lisbeth M. Ottosen (Technical University of Denmark, Lyngby, Denmark)

Mohamed Haroun (The Petroleum Institute, The United Arab Emirates)

Sibel Pamucku (Lehigh University, Bethlehem, PA, USA)

Program


21

SCHEDULE

Sunday, September, 7th

19:30 – 20:30 Reception/Welcome cocktail

Monday, September, 8th

9:00 – 9:30 Welcome

9:30 – 10:15 Keynote Lecture

10:15 – 10:55 Oral Session 1 (O140, O130)

10:55 – 11:35 Coffee Break/Poster Session

11:35 – 12:35 Oral Session 1 (O131, O162, O166)

12:35 – 13:20 (Invited Speaker)

13:20 – 15:15 Lunch

15:15 – 16:15 Oral Session 2 (O209, O243, O232)

16:15 – 16:55 Poster Session & Coffee.

16:55 – 17:35 Oral Session 2 (O242-O261)

20:00 –

Dinner

Tuesday, September, 9th

9:30 – 9:50 Oral Session 2 (O268)

9:50 – 11:10 Oral Session 3 (O352, O325, O313, O326)

11:10 – 11:50 Coffe break/Poster Session

11:50 – 13:10 Oral Session 4 (O439, O464, O453, O401)

13:10 – 15:15 Lunch

15:15 – 15:55 Oral Session 5 (O523, O520)

15:55 – 16:15 Oral Session 6 (O659)

16:15 – 16:55 Coffe break/Poster Session

16:55 – 17:55 Oral Session 6 (O606, O608, O634)

17:55 – 18:15 Closing session.

Wednesday, September, 10th

10:00 – 13:30 Tour/drink

13:30 – 15:00 Lunch


22

ORAL SESSIONS

Session 1: Metal Removal and transport of inorganics

Monday morning September 8th

Reference: O140

Title: Electrochemical detection and electroremediation of polluted soil by mercury

using different removing agents

Authors: Robles, I., Garcia, J.A., Bustos, E.

Corresponding author: [email protected]

Reference: O130

Title: Electrodialytic extraction of phosphorus from ash of low-temperature gasification

of sewage sludge

Authors: Parés Viader, R., Jensen, P.E., Ottosen, L.M., Hauggaard-Nielsen, H.,

Ahrenfeldt, J.


Reference: O131

Title: Phosphorus recovery and heavy metal removal during municipal wastewater

treatment

Authors: Ebbers, B., Ottosen, L.M., Jensen, P.E.


Reference: O162

Title: Comparison of two experimental set-ups for electrodialytic removal of heavy

metals and Cl from MSWI APC residues

Authors: Magro, C., Kirkelund, G.M., Guedes, P., Jensen, P.E., Ottosen, L.M., Ribeiro,

A.B.


Reference: O166

Title: Study of electrokinetic remediation technology at semi-pilot scale. Weak acid

enhancement

Authors: Villen-Guzman, M., Amaya-Santos, G., Garcia-Rubio, A., Paz-Garcia, J.M.,

Gomez-Lahoz, C., Vereda-Alonso, C.


Session 2: Fundamentals and Modeling

Monday afternoon September 8th

Reference: O209

Title: Modeling of the direct current assisted transport of zero valent iron nanoparticles

Authors: Gomes, H.I., Rodriguez-Maroto, J.M., Dias-Ferreira, C., Ribeiro, A.B.,

Pamukcu, S.



23

Reference: O243

Title: Enhancement of electro-osmotic flow during the electrokinetic treatment of

contaminated soils

Authors: Cameselle, C., Gouveia, S.


Reference: O232

Title: Influence of 2D physical heterogeneity on the elctromigration of nitrate

Authors:Gill, R.T., Harbottle, M.J., Smith, J.W.N., Thornton, S.F.


Reference: O242

Title: Influence of the electrochemical treatment on humic substances content in the

groundwater from limestone aquifers: Preliminary study

Authors: Rajic, L., Fallahpour, N., Alshawabkeh, A.


Reference: O261

Title: Electrokinetics to modify strength characteristics of soil: A laboratory based

investigation

Authors: Jayasekera, S.


Reference: O268

Title: Modeling of ionic transport through charged membranes

Authors: Paz-Garcia, J.M., Villen-Guzman, M., Ristinmaa, M., Rodriguez-Maroto,

J.M.


Session 3: Scaling up and field applications

Tuesday morning September 9th

Reference: O352

Title: Application of solar cell in electrokinetic remediation of As-contaminated soil in

pilot scale

Authors: Jeon, E.K., Ryu, S.R., Baek, K.


Reference: O325

Title: Multivariate analysis of variable importance in the scaling up of electrodialytic

remediation of heavy metals from harbour sediments

Authors: Pedersen, K.B., Ottosen, L.M., Jensen, P.E., Lejon, T.



24

Reference: O313

Title: Pilot scale electrodialytic treatment of MSWI APC residue to decrease leaching

of toxic metals and salts

Authors: Jensen, P.E., Kirkelund, G.M., Dias-Ferreira, C., Ottosen, L.M.


Reference: O326

Title: Design of a pilot electrokinetic remediation plant for marine sediments

contaminated by heavy metals (project LIFE12 ENV/IT/442 "SEKRET")

Authors: Iannelli, R., Masi, M., Ceccarini, A., Pomi, R., Polettini, A., Marini, A.,

Muntoni, A., De Gioannis, G., Ostuni, M.B., Lageman, R.


Session 4: Other uses. Miscellaneous.

Tuesday morning September 9th

Reference: O439

Title: Electrokinetic driven low-acid IOR in Abu Dhabi tight carbonate reservoirs

Authors: Ansari, A., Haroun, M., Rahman, M.M., Chilingar, G.V.


Reference: O464

Title: Desalination of granite and sandstones by electrokinetic techniques. Comparison

Authors: Feijoo Conde, J., Matyščák, O., Ottosen, L.M, Rivas, T.


Reference: O453

Title: Selective recovery of dissolved metals from acid mine drainage via

electrochemical method

Authors: Park, S.M., Ji, S.W., Baek, K.


Reference: O401

Title: A decontamination of the soil contaminated with cesium using electrokinetic-

electrodialytic technology

Authors: Kim, G.N., Kim, S.S., Moon, J.K.


Session 5: Organic and chlorinated organic compounds remediation

Tuesday afternoon September 9th

Reference: O523

Title: Integration of electrokinetic process and nano-Fe3O4/S2O82-

process for


Authors: Yang, G.C.C., Chiu, Y.H., Wang, C.L. Corresponding author: [email protected]


25

Reference: O520

Title: Electrodialytic process applied for phosphorus recovery and organic

contaminants remediation from sewage sludge

Authors: Guedes, P., Mateus, E.P., Couto, N., Magro, C., Mosca, A., Ribeiro, A.B.


Session 6: EKR in combination with other techniques

Tuesday afternoon September 9th

Reference: O659

Title: Electrodialytic removal of heavy metals from fly ash from co-combustion of

wood and straw - influence from prewash

Authors: Chen, W., Ottosen, L.M., Jensen, P.E., Kirkelund, G.M., Schmidt, J.W.


Reference: O606

Title: Feasibility of coupling permeable bio-barriers and electrokinetic soil flushing for

the treatment of organic chemical polluted soils

Authors: Mena, E., Ruiz, C., Saez, C., Villaseñor, J., Rodrigo, M.A., Cañizares, P.


Reference: O608

Title: Effect of electrokinetic enhancement on phytoremediation of soils with mixed

contaminants

Authors: Chirakkara, R.A., Cameselle, C., Reddy, K. R.


Reference: O634

Title: Potential of electrokinetic process to recover phosphorus and remove cyanotoxins

from membrane concentrate

Authors: Couto, N., Guedes, P., Mateus, E.P., Santos, C., Teixeira, M.R., Ribeiro, A.B.



26

POSTER SESSIONS

Metal Removal and transport of inorganics Reference: P110

Title: Remediation of cuprum from clayey soils

Authors: Romanova, I.V., Korolev, V.A.


Reference: P112

Title: Testing of new shifting current electrodialytic treatment setup for efficient

treatment of Cr-contaminated soil fines

Authors: Jensen, P.E., Ottosen, L.M., Kirkelund, G.M.


Reference: P116

Title: Electrokinetic remediation with novel electrode configuration

Authors: Hassan, I, Mohamedelhassan, E, Yanful, E.K.


Reference: P124

Title: Determining variable importance on electrodialytic remediation of heavy metals

from polluted harbour sediments

Authors: Pedersen, K.B., Ottosen, L.M., Jensen, P.E., Lejon, T.


Reference: P127

Title: Monitoring electrokinetics by geophysical methods: Preliminary laboratory

investigations

Authors: Masi, M., Ceccarini, A., Ostuni, M.B., Lageman, R., Iannelli, R.


Reference: P129

Title: Membrane influence on electrodialytic remediation of air pollution control from

municipal incinerated solid waste

Authors: Parés Viader, R., Jensen, P.E., Ottosen, L.M.


Reference: P133

Title: Study on removal behavior of cesium ion in clay minerals (kaolin and

vermiculite) by using electrokinetic process

Authors: Akemoto, Y., Kitagawa, C., Miyamura, R., Kan, M., Tanaka, S.


Reference: P137

Title: Optimization of electrokinetic treatment conditions for a metal-contaminated

dredged sediment

Authors: De Gioannis, G., Marini, A., Muntoni, A., Polettini, A., Pomi, R.



27

Reference: P145

Title: Effects of electrodialytic process on soil phosphorus

Authors: Salvador, N., Gutiérrez, C., Hansen, H., Nunes, L.M., Teixeira, M.R., Jensen,

P.E., Ribeiro, A.B.


Reference: P149

Title: Comparison of reagent to enhance desorption and mobility of arsenic in electro-

kinetic remediation from contaminated paddy soil

Authors:Ryu, S.R., Jeon, E.K., Baek, K.


Reference: P150

Title: Electrokinetic treatment of dewatered soil cake containing flocculants from soil

washing processes

Authors: Shin, S.Y., Park, S.M., Baek, K.


Reference: P155

Title: Fibers ion exchange for improvement of electrokinetical removal of heavy metals

from polluted site

Authors: Belhadj, B, Akretche, D.E., Cameselle, C.


Reference: P160

Title: Electrical behavior of copper mine tailings during EKR with modified electric

fields

Authors: Rojo, A., Hansen, H., Monárdez, O., Jorquera, C.


Reference: P165

Title: Study of electrokinetic remediation technology at semi-pilot scale. Strong acid

enhancement

Authors: Villen-Guzman, M., Amaya-Santos, G., Garcia-Rubio, A., Vereda-Alonso,

C., Rodriguez-Maroto, J.M., Paz-Garcia, J.M.


Reference: P167

Title: A critical study of the use of the BCR speciation for the characterization of

mobilizable metal contamination


Garcia-Herruzo, F., Gomez-Lahoz, C.


Reference: P169

Title: Study of efficiency in the removal of lead from soil by different treatments.


Rodriguez-Maroto, J.M., Garcia-Herruzo, F.



28

Reference: P174

Title: Two step electrodialytic remediation of soil suspension for simultaneous removal

of As and Cu

Authors: Ottosen, L.M., Jensen, P.E., Kirkelund, G.M.


Reference: P177

Title: The effects of composting, biosurfactant and freezing-thawing on electrokinetic

removal of heavy metals in sewage sludge.

Authors: Luo, Q., Dong, L., Fu, R., Gao, J., Wang, J., Zhang, M..


Reference: P178

Title: The use of 2D non-uniform electric field to remediate chromium-contaminated

soil from an abandoned industrial site with permeable reactive composite electrodes.

Authors: Fu, R., Xu, Z., Luo, Q., Guo, X.


Fundamentals and Modeling Reference: P217

Title: Numerical analysis of vanadium and water crossover effects in all-vanadium

redox flow batteries

Authors: Oh, K., Ju, H.


Scaling up and field applications Reference: P305

Title: The scale up of the flushing-fluid-assisted electrokinetic remediation of kaolin

soil polluted with phenanthrene

Authors: Cañizares, P., López Vizcaíno, R, Risco, C., Saez, C., Rodriguez, L.,

Villaseñor, J., Navarro, V., Rodrigo, M.A.


Reference: P311

Title: Electrokinetic treatment of polluted soil by gasoline at pilot level couple with an

advanced oxidation process of residual water

Authors: Ramos-Huerta, L., Garibay-Cordero, A., Ochoa-Méndez, B., Pérez-Corona,

M., Cárdenas-Mijangos, J., Bustos, E.

Corresponding author: [email protected], [email protected]

Other uses. Miscellaneous. Reference: P418

Title: Effects of porous properties of carbon felt electrodes on the performance of all-

vanadium redox flow batteries (VRFBs)

Authors: Won, S., Oh, K., Ju, H.



29

Reference: P419

Title: The effects of hybrid catalyst layer design on methanol and water transport in a

direct methanol fuel cell (DMFC)

Authors: Lee, K, Ferekh, S., Ju, H.


Reference: P428

Title: Electrochemical peroxidation using iron nanoparticles to remove arsenic from

copper smelter wastewater

Authors: Hansen, H.K., Gutiérrez, C., Rojo, A., Nuñez, P., Valdez, E.


Reference: P438

Title: Applying EK to achieve SMART (Simultaneous Modified Assisted Recovery

Techniques) EOR in carbonate reservoirs of Abu Dhabi

Authors: Al Kindy, N., Haroun, M., Ansari, A., Chilingar, G.V., Sarma, H.


Reference: P444

Title: Electrochemical degradation of chlorobenzene in water using Pd- catalytic

electro-Fenton's reaction

Authors: Ciblak, A., Nazari, R., Mousa, I., Alshawabkeh, A.N.


Reference: P447

Title: Hydrodechlorination of TCE by Pd and H2 Produced from a copper foam cathode

in a circulated electrolytic column at high flow rate

Authors: Fallahpour, N., Yuan, S., Alshawabkeh, A.N.


Reference: P456

Title: Enhancing electro-Fenton chlorobenzene degradation from groundwater,

oxidation technique in the presence of PD with different catalyst supports

Authors: Mousa, I.E., Alshawabkeh, A.N.


Reference: P457

Title: Feasibility of modeling by adsorption the magnetic separation of iron

nanoparticles

Authors: Lancellotti, F., Retamal, F., Nuñez, P., Hansen, H.


Reference: P458

Title: Electrocoagulation reactor design for arsenic treatment

Authors: Pineda, D., Nuñez, P., Hansen, H.



30

Reference: P463

Title: Desalination of sandstone with two different setups under an applied electric field

Authors: Matyščák, O., Feijoo Conde, J., Ottosen, L.M.


Reference: P472

Title: Evaluation of microbial communities, growth rates and susbtrate consumption

under electrical field

Authors: Zeyoudi, M., Hasan, S.W.


Organic and chlorinated organic compounds remediation Reference: P507

Title: Electrokinetic-Fenton Process for Remediation of PAHs-contaminated railroad

soil

Authors: Jung, W.S., Lee, J.Y., Cho, Y.M., Yang, J.W.


Reference: P515

Title: Characterization and regeneration of Pd/Al2O3 catalyst along a three electrodes

column for chlorobenzene remediation.

Authors: Mousa, I.E., Ciblak, A., Nazari, R., Alshawabkeh, A.N.


Reference: P535

Title: Removal of a thiazine, an azo and a triarylmethane dyes from dyes polluted

kaolinite by electrokinetic remediation

Authors: Effendi, Tanaka, S.

Corresponding author: fernando_00id@ yahoo.com

Reference: P541

Title: Construction and characterization of dimensional stable anodes with iridium and

tantalium by painting, immersion and electrophoretic deposition for the electrokinetic

treatment of polluted soil by hydrocarbon

Authors: Herrada, R.A., Medel, A., Manriquez, F., Bustos, E.


Reference: P573

Title: Enhancing solutions for electrokinetic remediation of dredged sediments polluted

with fuel.

Authors: Rozas, F., Castellote, M.


Reference: P576

Title: Electrodescontamination of soils contaminated with dyes for industrial use.

Authors: Hernández-Luis, F., Vázquez, M.V., Rodríguez-Raposo, R., Grandoso, D.,

Pérez, M., Ruiz, G., Arbeló, C.D.



31

EKR in combination with other techniques Reference: P646

Title: Electrochemical dechlorination of TCE with mixtures of humic acid, metal ions

and nitrates in a simulated karst groundwater

Authors: Fallahpour, N., Mao, X, Rajic, L., Yuan, S., Alshawabkeh, A.N.


Reference: P651

Title: Comparison on electrokinetics and soil flushing for removal of metals after in-

situ soil mixing

Authors: Lee, C.D., Lee, S.W., Jeon, E.K., Baek, K.


Reference: P675

Title: Soils contaminated with drugs in common use: An attemp to use

electroremediation, in combination with the adsorptiom, on industrial waste as a

prevention tool of contamination.

Authors: Hernández-Luis, F., Vázquez, M.V., Carvajal, E.G., Dévora, S., Abdalá, S.,

Rodríguez-Raposo, R., Martín-Herrera, D., Arbeló, C.D.


Author index


35

Abdalá, S. .................................. P675

Ahrenfeldt, J. ............................. O130

Akemoto, Y. .............................. P133

Akretche, D.E. ........................... P155

Al Kindy, N. .............................. P438

Alshawabkeh, A.N. ................... P515, O242, P444, P646, P447, P456

Amaya-Santos, G. ..................... P165, O166, P167, P169

Ansari, A. .................................. P438, O439

Arbeló, C.D. .............................. P675, P576

Baek, K. ..................................... P149, P150, P651, O352, O453

Belhadj, B .................................. P155

Bustos, E. .................................. P311, O140, P541

Cameselle, C. ............................ O608, O243, P155

Cañizares, P. .............................. O604, P305, O606

Cárdenas-Mijangos, J. ............... P311

Carvajal, E.G. ............................ P675

Castellote, M. ............................ P573

Ceccarini, A. .............................. O326, P127

Chen, W..................................... O659

Chilingar, G.V. .......................... P438, O439

Chirakkara, R.A. ....................... O608

Chiu, Y.H. ................................. O523

Cho, Y.M. .................................. P507

Ciblak, A. .................................. P515, P444

Couto, N. ................................... O520, O634

De Gioannis, G. ......................... O326, P137

Dévora, S. .................................. P675

Dias-Ferreira, C. ........................ O209, O313

Dong, L. .................................... P177

Ebbers, B. .................................. O131

Effendi ....................................... P535

el Din, M.G. .............................. O536

Fallahpour, N. ............................ O242, P646, P447

Feijoo Conde, J. ......................... P463, O464

Ferekh, S. .................................. P419

Fu, R. ......................................... P177, P178

Gao, J......................................... P177

Garcia, J.A. ................................ O140

Garcia-Herruzo, F. .................... P167, P169

Garcia-Rubio, A. ....................... P165, O166, P167, P169

Garibay-Cordero, A. .................. P311

Gill, R.T. ................................... O232

Gomes, H.I. ............................... O209

Gomez-Lahoz, C. ...................... O166, P167

Gouveia, S. ................................ O243

Grandoso, D. ............................. P576

Guedes, P................................... O520, O634, O162

Guo, X. ...................................... P178

Gutiérrez, C. .............................. P428, P145

Hansen, H.K. ............................. P428, P145, P457, P458, P160

Harbottle, M.J. ........................... O232

Harms, H. .................................. O536

Haroun, M. ................................ P438, O439

Hasan, S.W. .............................. P472

Hassan, I .................................... P116


36

Hauggaard-Nielsen, H. .............. O130

Hernández-Luis, F. .................... P675, P576

Herrada, R.A. ............................ P541

Iannelli, R. ................................. O326, P127

Jayasekera, S. ............................ O261

Jensen, P.E. ............................... P112, O313, P124, O325, P129, O130, O131, P145, O659,

O162, P174

Jeon, E.K. .................................. P149, P651, O352

Ji, S.W. ...................................... O453

Jorquera, C. ............................... P160

Ju, H. ......................................... P217, P418, P419

Jung, W.S. ................................. P507

Kan, M....................................... P133

Kim, G.N. .................................. O401

Kim, S.S. ................................... O401

Kirkelund, G.M. ........................ P112, O313, O659, O162, P174

Kitagawa, C. .............................. P133

Korolev, V.A. ............................ P110

Lageman, R. .............................. O326, P127

Lancellotti, F. ............................ P457

Lee, C.D. ................................... P651

Lee, J.Y. .................................... P507

Lee, K ........................................ P419

Lee, S.W. ................................... P651

Lejon, T. .................................... P124, O325

López Vizcaíno, R ..................... P305

Luo, Q. ...................................... P177, P178

Magro, C. .................................. O520, O162

Manriquez, F. ............................ P541

Mao, X....................................... P646

Marini, A. .................................. O326, P137

Martín-Herrera, D. .................... P675

Masi, M. .................................... O326, P127

Mateus, E.P. .............................. O520, O634

Matyščák, O. ............................. P463, O464

Medel, A. ................................... P541

Mena, E. .................................... O604, O606

Miyamura, R. ............................ P133

Mohamedelhassan, E ................. P116

Monárdez, O. ............................. P160

Moon, J.K. ................................. O401

Mosca, A. .................................. O520

Mousa, I.E. ................................ P515, P444, P456

Moustafa, A. .............................. O536

Muntoni, A. ............................... O326, P137

Navarro, V. ................................ P305

Nazari, R. .................................. P515, P444

Nunes, L.M. ............................... P145

Nuñez, P. ................................... P428, P457, P458

Ochoa-Méndez, B. .................... P311

Oh, K. ........................................ P217, P418

Ostuni, M.B. .............................. O326, P127

Ottosen, L.M. ............................ P112, O313, P124, O325, P129, O130, O131, O659, O162,

P463, O464, P174

Pamukcu, S. ............................... O209


37

Parés Viader, R. ......................... P129, O130

Park, S.M. .................................. P150, O453

Paz-Garcia, J.M. ........................ P165, O166, P167, O268, P169

Pedersen, K.B. ........................... P124, O325

Pérez, M. ................................... P576

Pérez-Corona, M. ...................... P311

Pineda, D. .................................. P458

Polettini, A. ............................... O326, P137

Pomi, R. ..................................... O326, P137

Qin, J. ........................................ O536

Rahman, M.M. .......................... O439

Rajic, L. ..................................... O242, P646

Ramos-Huerta, L. ...................... P311

Reddy, K. R. .............................. O608

Retamal, F. ................................ P457

Ribeiro, A.B. ............................. O209, O520, O634, P145, O162

Risco, C. .................................... P305

Ristinmaa, M. ............................ O268

Rivas, T. .................................... O464

Robles, I. ................................... O140

Rodrigo, M.A. ........................... O604, P305, O606

Rodriguez, L. ............................. P305

Rodriguez-Maroto, J.M. ............ O209, P165, O268, P169

Rodríguez-Raposo, R. .............. P675, P576

Rojo, A. ..................................... P428, P160

Romanova, I.V. ......................... P110

Rozas, F. .................................... P573

Ruiz, C....................................... O604, O606

Ruiz, G. ..................................... P576

Ryu, S.R. ................................... P149, O352

Saez, C....................................... O604, P305, O606

Salvador, N. ............................... P145

Santos, C. .................................. O634

Sarma, H. ................................... P438

Schmidt, J.W. ............................ O659

Shin, S.Y. .................................. P150

Smith, J.W.N. ............................ O232

Tanaka, S. .................................. P133, P535

Teixeira, M.R. ........................... O634, P145

Thornton, S.F. ........................... O232

Valdez, E. .................................. P428

Vázquez, M.V. .......................... P675, P576

Vereda-Alonso, C. ..................... P165, O166

Villaseñor, J. .............................. O604, P305, O606

Villen-Guzman, M. ................... P165, O166, P167, O268, P169

Wang, C.L. ................................ O523

Wang, J. ..................................... P177

Won, S. ...................................... P418

Xu, Z. ........................................ P178

Yanful, E.K. .............................. P116

Yang, G.C.C. ............................. O523

Yang, J.W. ................................. P507

Yuan, S. ..................................... P646, P447

Zeyoudi, M. ............................... P472

Zhang, M. .................................. P177


38

Key lectures


41

KRISHNA R. REDDY

Future Directions for Electrokinetic Remediation Research

Abstract

In-situ electrokinetic remediation is a

promising technology for the remediation of

difficult subsurface conditions. It is

particularly useful in soils with low

permeability and heterogeneous subsurface

environments where other common

remediation technologies typically fail.

Electrokinetic remediation technology may

also be used to remediate diverse and mixed

contaminants, even when they are non-

uniformly distributed within the subsurface.

The standard electrokinetic remediation method is essentially an electrokinetically

enhanced flushing process. However, electrokinetic remediation may be enhanced or

optimized when integrated or coupled with other proven remediation technologies.

Recently, several successful bench-scale projects have been reported where

electrokinetic remediation was integrated with other technologies. Nevertheless, the

success of electrokinetic remediation technology is dependent on several factors,

including: (1) reliability of the technology; (2) costs of application; (3) practicality of

implementation; (4) application of and ability to meet risk-based remediation goals; (5)

anticipated remediation time; (6) acceptability to project stakeholders; (7) necessity of

special permits; (8) implications on end-use of the site; (9) sustainability considerations,

including triple bottom line parameters; and (10) remediation versus management

paradigm for complex sites. In this presentation, these aspects will be addressed with

respect to future technological innovation and application, the benefits and drawbacks

of its use will be reviewed, and the urgent need for translation of basic research into

actual field applications will be emphasized.

About Dr. Reddy

Krishna Reddy is a Professor of Civil and Environmental Engineering and also the

Director of the Geotechnical and Geoenvironmental Engineering Laboratory (GAGEL)

at the University of Illinois, Chicago, USA. He has over 25 years of teaching,

consulting and research experience focused on contaminated site remediation, waste

management, and sustainable engineering. His research includes laboratory studies,

field experiments, and computer modeling. He has been conducting electrokinetic

remediation for over 18 years. Dr. Reddy is the author of well-known book titled

“Geoenvironmental Engineering: Site Remediation, Waste Containment, and Emerging

Waste Management Technologies” published by John Wiley in 2004. He is also author

of 160 journal papers (with h-index of 35), 10 edited books, 9 book chapters, and over

150 full conference papers. Dr. Reddy has given 129 invited presentations in the U.S.

and 15 other countries (Canada, U.K., Germany, France, Spain, Italy, India, Sri Lanka,

China, Hong Kong, Thailand, South Korea, Japan, Brazil and Colombia). He has served

or currently serves on editorial boards of over 10 different journals. Currently, he is the

Chair of the Geoenvironmental Engineering Committee of Geo-Institute/American


42

Society of Civil Engineers and a member of the Environmental Geotechnics Committee

of International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE).

Dr. Reddy has received several awards for excellence in research and teaching,

including the ASTM Hogentogler Award, the University of Illinois Scholar Award, and

the University of Illinois Award for Excellence in Teaching.


43

MANUEL RODRIGO

Different strategies to enhance bioremediation of diesel-polluted soils

using electro-kinetic processes

Abstract

In this lecture, different strategies for the

remediation of spiked soils combining

biological processes with electro-kinetic soil

flushing and permeable reactive barriers are

assessed at bench scale in clay and sandy soils

using two-week long treatment tests.

Strategies applied are: 1) Direct combination

of bioremediation with electrokinetic soil

flushing using bicarbonate solution as

flushing fluid 2) single electro-bioremediation

processes with periodic polarity reversal 3)

electrokinetic soil flushing with permeable

reactive bio-barriers using surfactant solutions

as flushing fluids.

Results obtained depend strongly on the type of soil and, as expected, combinations are

only worth for clay soils. In this case, results show that efficiencies obtained with

classical bioremediation are not improved but worsen with the direct combination of

EKSF. These unexpected results are explained in terms of the difficult regulation of pH

and also because of the high temperatures reached at high electric fields (due to the

huge ohmic drops). Both parameters influence negatively on the viability of the

biological culture and finally cause its depletion. In this strategy, temperature also plays

a very important role on results because it favors volatilization of the pollutant. On the

contrary, efficiencies are greatly improved respect to single bioremediation using

permeable reactive bio-barriers consisting of either fixed cultures of acclimated

microorganisms or beds of soil mixed with suspended cultures. In this case, pH

regulation effect is not as dramatic as in the strategy 1 and microorganisms degrade very

efficiently the diesel pollutant. Electro-bioremediation with periodic polarity reversal

also shows good efficiencies avoiding the problems caused by acidic and basic fronts on

microorganisms, although the rates obtained are far below those obtained by bio-

barriers. Changes in the concentration of nutrients, pH, conductivity and temperature are

also analyzed in this work giving light about the ways in which these processes can be

applied at the full scale in a synergistic fashion.

About Dr. Rodrigo

Manuel Rodrigo was born in Plasencia (Spain) in 1970. He studied Industrial Chemistry

at the University of Valencia (1993) and obtained the PhD degree in Chemical

Engineering in the same university in 1997, with a research focused on the development

of automation systems for biological nutrient removal processes. In 1997, he joined the

University of Castilla La Mancha (UCLM), starting a new research line in

Electrochemical Engineering at the Department of Chemical Engineering. In this first

electrochemical stage, his research was focused on the electrolyses of wastewaters


44

polluted with organics. After a postdoctoral training in the EPFL (Switzerland), he

started working on electrocoagulation, high temperature PEM fuel cells, oxidants

production, microbial fuel cells and, nowadays, soil electro-remediation (including

bioprocesses). In 2009, he got the position of Full Professor of Chemical Engineering at

the UCLM. He maintains strong consultant collaboration with many companies in

energy and environmental engineering. He is author of more than 200 papers (H=37) in

referenced journal and books, more than 70 technical reports for companies, five

patents, and he has supervised ten doctoral theses. He also has been invited professor in

the Université Paris Est - Marne la Vallée. At present, he is the vice-dean of Chemical

Engineering in the Faculty of Chemical Sciences & Technologies of the University of

Castilla La Mancha and he serves as the Chairman of the Working Party of

Electrochemical Engineering of the European Federation of Chemical Engineering and

Vice-chair of Division 5 Electrochemical Process Engineering and Technology of the

International Society of Electrochemistry.

Oral Session 1: Metal Removal and transport of inorganics

Session Chair:

Alexandra B. Ribeiro


47

Nº REF.: O130

Electrodialytic extraction of phosphorus from ash of low-temperature gasification of sewage sludge

Raimon Parés Viadera*

, Pernille Erland Jensena, Lisbeth M. Ottosen

a,

Henrik Hauggaard-Nielsenb, Jesper Ahrenfeldt

b

a Department of Civil Engineering, Technical University of Denmark, 2800 Kongens

Lyngby, Denmark b Department of Chemical and Biochemical Engineering, Technical University of

Denmark, 4000 Roskilde, Denmark

*Corresponding author: [email protected]

Recirculation of nutrients to agricultural soils is especially important for those produced

from non-renewable resources, such as phosphorous (P) obtained from phosphate rocks.

The reserves of this mineral, mostly located outside the European Union (EU), are

foreseen to be depleted in a range of 100-400 years [1]. In 2012 EU imported 88% of

the phosphate rock consumed. Since only about one fourth of the P applied to

agricultural fields is actually recycled today [2], innovative recycling and re-use

concepts need to be developed and adopted. Low-temperature gasification allows an

energy production from biomass resources with high contents of low melting ash

compounds – often shown to be a source of boiler operational problems in more

traditional incineration. Materials like sludge, have a high P content, which should

preferentially be recycled back to agricultural soils after this thermal process. However,

major concerns are its heavy metal content and the low plant availability of P; hence, a

separation of phosphorus from the bulk bioashes and heavy metals would be beneficial.

P separation can be achieved by acidifying the bioashes in a water solution;

nevertheless, heavy metals will also be released (Figure 1).

Figure 1. pH-desorption of P and Heavy metals in gasified sludge bioashes

In contrast, Electrodialysis (ED) is a technology that allows the mobilization of P from

sewage sludge based bioash materials to aqueous solutions, ensuring its plant

availability as well as separating it from heavy metals. ED was applied to a gasified

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

0 1 2 3 4 5 6 7 8 9

% d

eso

rpti

on

pH

%P

%Cd

%Cr

%Cu

%Ni

%Pb


48

sludge with low Fe content, allowing a recovery of around an 80% of the P in a water

solution. Similar experiments were run to a gasified sludge with high Fe content,

showing less encouraging results as the recovery of P was found to be around 30%. For

both ashes, the mass ratio heavy metals/P in the aqueous solution was considerably

lower than in the original material, showing a potential in heavy metals reduction.

References

[1] C.J. Dawson, J. Hilton, Food Policy 36 (2011) S14-S22

[2] D.L. Childers, J. Corman, M. Edwards, J.J. Elser, Bioscience 61 (2011) 117-124


49

Nº REF.: O131

Phosphorus recovery and heavy metal removal during municipal wastewater treatment

Benjamin Ebbersa,*

, Lisbeth M. Ottosena, Pernille E. Jenssen

a

a DTU-Byg, Kgs. Lyngby, 2800 Denmark


With current and projected consumption rates, primary sources of phosphorus will

rapidly dwindle in the near future and the need for secondary sources will significantly

increase [1]. A high potential secondary resource is sewage sludge; however,

fertilization of agricultural soil using sewage sludge is often impeded by insoluble

phosphorus complexes and hazardous compounds [2], both organic and inorganic of

nature.

The formation of insoluble phosphorus complexes is the result of chemical coagulation,

a common wastewater treatment method. Iron- or aluminum salts are used to precipitate

aqueous phosphorus, mainly present as ortho-phosphates, decreasing phosphorus

mobility and significantly restricting recovery from the sludge at a later stage.

Electrodialysis (ED) has the potential to extract the fraction of aqueous phosphorus,

normally precipitated, during wastewater treatment. Application of ED in a wastewater

treatment plant (WWTP) could eliminate the usage of chemical coagulants altogether.

Furthermore, without chemical coagulation and after incineration, the remaining

phosphorus in the resulting sludge ash will be more readily available for recovery [3].

Whenever heavy metal concentrations exceed legislative standards, for application on

agricultural soil for example, ED can be used to bring heavy metal concentrations below

these limits, allowing the sludge to be applied again.

During preliminary research, the removal rates of both phosphorus and heavy metals in

relationship to general characteristics of wastewater (sludge) using a 3-compartment

(3C) ED cell (figure 1a) was investigated. Samples were obtained from a wastewater

treatment plant in Roskilde during different steps in the treatment process.

The results showed that optimal conditions for extraction of phosphorus or heavy metals

using ED were found at different locations throughout the wastewater treatment process.

Changes in phosphorus removal were mostly influenced by the pH (change) of the

sludge; which in turn was related to the buffer capacity. The removal of heavy metals

depended significantly on the presence of organic matter (OM); where the removal of

heavy metals increased when the amount of OM decreased. Most of the aqueous

phosphorus (present as ortho-phosphate’s) was effectively recovered.

The goal of this study is to continue the development of ED as treatment method to

complement existing wastewater treatment methods and replace chemical coagulation.

In order to create an efficient method, the most important characteristics of wastewater

that influence ED efficiency are investigated. This will be done by subjecting

wastewater and sewage sludge to ED treatment. The wastewater and sludge will be


50

obtained during different stages of wastewater treatment from various WWTP’s in

Denmark, employing a variety of wastewater treatment methods, such as oxidative

digestion and enhanced biological phosphorus removal.

Lab experiments are performed using a 2-compartment (2C) ED treatment cell where

the wastewater sludge is separated from the electrode compartments with ion-exchange

membranes. The 2C-setup has shown to significantly improve the heavy metal removal

from iron-rich sewage sludge ashes compared to the 3C-setup [4]. For extraction of

heavy metals, the sewage sludge will be in contact with the anode and the cathode

compartment will be separated by a cation-exchange membrane (figure 1b) while during

extraction of phosphorus the sludge will be in contact with the cathode while the anode

is separated by an anion-exchange membrane (figure 1c).

Figure 1. ED cell setup for (a) 3C setup, (b) 2C extraction of HM’s and (c) 2C extraction of P, with

CAT and AN representing the cation- and anion-exchange membranes, respectively.

The obtained data from this study can be used to asses an optimal placement of ED as

technique to recover phosphorus or remove heavy metals in combination with existing

wastewater treatment methods. Furthermore, correlating ED extraction of phosphorus or

heavy metals against important parameters in the sludge, e.g. organic matter content and

pH, will provide important information for improvement of using ED in these

situations.

References

[1] Cordell, D., Drangert, J.O., White, S.. The story of phosphorus: Global food

security and food for thought. Global Environmental Change, 19, (2009) 292-305.

[2] Miljøministeriet (2012), Miljøstyrelsen, Undersøgelse af PCB, dioxin og

tungmetaller i eksporteret slam til Tyskland, Miljøprojekt nr. 1433, 2012, ISBN

nr. 978-87-92903-32-7.

[3] Matsuo, Y., Release of phosphorus from ash produced by incinerating waste

activated sludge from enhanced biological phosphorus removal. Wat. Sc. Tech.

34, issues 1-2, (1996) 407-415.

[4] Ebbers, B., Ottosen, L.M., Jenssen, P.E., Comparison of two different

Electrodialytic cells for separation of phosphorus and heavy metals from sewage

sludge ash. Chemosphere, submitted (2014).


51

Nº REF.: O140

Electrochemical detection and electroremediation of polluted soil by mercury using different removing agents

I. Robles, J. A. García, E. Bustos*

Centro de Investigación y Desarrollo Tecnológico en Electroquímica S. C. Parque

Tecnológico Querétaro Sanfandila, Pedro Escobedo, Qro. C.P. 76703.


Heavy metals are a large group of elements which are industrially and biologically

important; in consequence they are defined as the group of elements with an atomic

density greater than 6 g cm-3

. Some of these heavy metals are toxic to living organisms

in high concentrations. Heavy metals of greatest concern in terms of human health,

agriculture and ecotoxicology are arsenic (As), cadmium (Cd), lead (Pb), tallium (Tl),

uranium (U) and mercury (Hg). Mercury is one of the most toxic elements to human

health and ecosystem; because of all mercury species are toxic. A wide variety of

mercury species exist in the environment and its various chemical forms can differ in

bioavailability, transport, persistence, and toxicity. Due to high bioaccumulation,

mercury is found on many levels of the food chain. Due to these processes and the high

mobility of mercury species, a good understanding of how mercury species transform

and accurate monitoring are essential for assessing the risk of mercury in the

environment 1.

For the determination of Hg2+

in low concentrations a number of techniques can be

applied, in particular colorimetry and atomic absorption spectrometry. Electrochemistry

provides analytical techniques characterized by instrumental simplicity, moderate cost

and portability; some as stripping methods use a variety of electrochemical procedures

which all share a characteristic initial stage. In Anodic Stripping Voltammetry (ASV),

the electrode behaves as a cathode during deposition and as an anode during

redissolution, where it is oxidized by the analyte again and returns to its original form.

This technique is advantageous to other analytical techniques is its simplicity of use,

low cost of instrumentation, and being monodestructive 1. On other hand, there are

different treatments of polluted soil by mercury as electroremediation, which has been

successfully applied in a variety of soil restoration studies, this methodology having the

advantage of exhibiting simultaneous chemical, hydraulic and electrical gradients.

Indeed, for efficient mercury removal from a saturated soil with electroremediation,

application of either an electric field or direct current through two electrodes (anode and

cathode) is required. These are usually inserted in wells containing a supporting

electrolyte made from inert salts, leading to improved electric field conductive

properties. Specifically, for mercury polluted soil electroremediation, the use of

complexing agents like ethylendiaminetetraacetic acid (EDTA), KI, and NaCl under a

constant potential gradient has been reported 2. Based on the above precedents, the

electroremediation was developed aided by extracting agents for mercury removal from

San Joaquin’s Sierra Gorda soil samples (Figure 1) 3.


52

Figure 1. Electroremediation process in batch reactor assisted by EDTA (A), and its

corresponding removal percentage of Hg2+ followed during 13 h of treatment, close to anode and cathode.

Electroremediation of mercury polluted soil, facilitated by the use of complexing

agents, proved to be an attractive alternative treatment for the removal of mercury from

polluted soil in mining areas located at Sierra Gorda in Queretaro, Mexico.

Implementation of this remediation protocol is expected to improve the living

conditions and general health of the population in the Mine “El Rincón” in San Joaquin.

Experimental observations suggest that it is possible to remove up to 75 % of metal

contaminants in mercury polluted soil samples by wetting them with 0.1M EDTA,

placing them in an experimental cell equipped with Ti electrodes, and then applying a 5

V electric field for 6 hours. When we followed the electrochemical removal of mercury

in a batch reactor, it was removed around 87% of Hg2+

in a time of 9 hours close to the

anode side by the presence of EDTA. The pH remains nearly constant at 4 and

conductivity showed values close to 10 mS cm-1

by the ionic species. All the mercury

measures were obtained using ASV with a pre-concentration potential –0.6 V vs.

Ag/AgCl, deposition time 6 min, quiet time 30 s, scan rate 20 mV s-1

, obtaining a

detection and quantification limit of 1.47 and 4.89 g L-1

respectively 3.

Finally, the efficient removal of mercury contaminants observed under these conditions

is attributed to electromigration of the coordination complexes that form between the

terminal hydroxyl groups in EDTA and divalent mercury (Hg+2

), which is probably

strengthened by supramolecular interactions between unshared electrons at EDTA’s

tertiary amino nitrogens and Hg+2

. These interactions are particularly effective with the

presence of potassium ions. This observation is supported by molecular modeling of

several possible interactions in the proposed complex using the Density Functional

Theory method (B3LYP LANL2DZ) 1.

References

[1] I. Robles, Luis A. Godínez, J. Manríquez, F. Rodríguez, A. Rodríguez, E. Bustos.

13rd

Chapter from the Book “Soil Pollution”. Ed. In Tech (2014) 379 – 396.

[2] I. Robles, J. Lakatos, P. Scharek, Z. Planck, G. Hernández, S. Solís, E. Bustos.

29th

Chapter from the book “Soil Pollution”. Ed. InTech (2014) 827 – 850.

3 I. Robles, M. G. García, S. Solís, G. Hernández, Y. Bandala, E. Juaristi, E.

Bustos. Intern. J. Electrochem. Sci. 7 (2012) 2276 – 2287.


53

Nº REF.: O162

Comparison of two experimental set-ups for electrodialytic removal of heavy metals and Cl from MSWI APC residues

Cátia Magroab1

, Gunvor M. Kirkelundb*

, Paula Guedesa, Pernille E. Jensen

b,

Lisbeth M. Ottosenb, Alexandra B. Ribeiro

a

a CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de

Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica,2829-516

Caparica, Portugal b Department of Civil Engineering, Technical University of Denmark, DK-2800 Kgs.

Lyngby, Denmark


Air pollution control (APC) residues from municipal solid waste incineration (MSWI) is

classified as hazardous waste and disposed of, although it contains potential resources.

Due to the different flue gas cleaning system designs (wet or semi-dry), APC residues

present distinct chemical and physical characteristics that can influence the remediation

success and their possible reuse [1, 2]. The most problematic elements in MSWI APC

residues are leachable heavy metals and salts. Studies have been made to optimise the

removal of heavy metals from the highly alkaline MSWI APC residues by

electrodialytic remediation in the stirred three compartment set-up (Fig. 1). To obtain

high metal removal assisting agents or long remediation times to acidify the APC

residues are needed [3, 4]. However, assisting agents and significant acidification of the

APC residues drastically changes the properties of the matrix [5]. For reuse purposes,

the aim for remediation should instead be reducing the heavy metal leaching and at the

same time keeping the material characteristics, i.e. keeping the alkaline pH. This is a

new approach for remediating APC residues.

A new two compartment electrodialytic set-up was recently filed for patenting [6]. The

traditional three compartment electrodialytic cell and the new two compartment

electrodialytic cell for treatment of particulate material suspensions are seen in Figure 1.

Figure 1. The experimental set-up of the three and two compartment electrodialytic cell. AN-anion

exchange membrane, CAT-cation exchange membrane.

One of the advantages of the two compartment cell is the insertion of the anode directly

into the suspension that should be treated, leading to faster acidification of the

suspension by the electrode process than the acidification by water splitting at the anion

exchange membrane in the three compartment cell. This would help reduce the

remediation time of the treated material. This work presents a comparison of

mailto:[email protected]


54

electrodialytic treatment in the two cell set-ups under different experimental conditions,

with the aim of reducing leaching of Cd, Cu, Cr, Pb, Zn and Cl from APC residues, to

facilitate reuse of the APC residues.

Two APC residues were collected from wet and semi-dry flue gas cleaning systems

from Danish waste incineration plants. Sixteen continuously stirred electrodialytic

experiments were made, eight experiments in each cell type. In compartment II and I of

the three and two compartment cell respectively, 100 g APC residue was mixed with

350 ml distilled water, keeping a fixed liquid to solid ratio of L/S 3.5 in all experiments.

Experiments differed in the applied current density (0.1 or 1.0 mA/cm2) and duration (3

or 14 days). Electrical conductivity and pH was measured in the APC residue

suspension daily.

The results show that the pH development in the APC residue suspension was

dependent on the type of APC residue and the experimental cell type, where the

acidification of the suspension occurred earlier when using the two compartment setup

and the acidification of the wet APC residue occurred earlier than for the semi-dry APC

residue. The lowest final pH for the wet and semi-dry APC residues was 6.4 and 10.9,

respectively. To obtain a high net removal of heavy metals from APC residues, lower

pH are needed, however, this is very time consuming [3, 4].

On the other hand, the results obtained from this study showed that the leaching of Cd,

Cu, Pb and Zn were reduced compared to the initial heavy metal leaching from the

untreated residues, except when the pH was reduced to a level below 8 for the wet APC

residues. Cr leaching increased after the electrodialytic treatment. Cl leaching from the

APC residues was less dependent on experimental conditions and was reduced in all

experiments compared to the initial levels.

The results further indicate that the new two compartment cell would be beneficial to

reduce the remediation time for electrodialytic treatment of APC residues prior to

possible reuse.

Acknowledgements

The project FP7-PEOPLE-2010-IRSES-269289-ELECTROACROSS - Electrokinetics

across disciplines and continents: an integrated approach to finding new strategies for

sustainable development and GAP funding from DTU are acknowledged for financing

the study.

References

[1] M.J. Quina, J.C. Bordado, R.M. Quinta-Ferreira, Waste Manage 28 (2008) 2097.

[2] C. Ferreira, A. Ribeiro, L. Ottosen, J Hazard Mater B96 (2003) 201.

[3] A.J. Pedersen, L.M. Ottosen, A. Villumsen, J Hazard Mater B122 (2005) 103.

[4] L.M. Ottosen, A.T. Lima, A.J. Pedersen, A.B. Ribeiro, J Chem Technol

Biotechnol 81 (2006) 553.

[5] A.J. Pedersen, K.H. Gardner, J de Physic IV France, 107 (2003) 1029

[6] L.M. Ottosen, P.E. Jensen, G.M. Kirkelund, B. Ebbers, European patent

application no. 13183278.4 (2013)


55

Nº REF.: O166

Study of electrokinetic remediation technology at semi-pilot scale. Weak acid enhancement

M. Villen-Guzmana,*

, G. Amaya-Santosa, A. Garcia-Rubio

a, J.M. Paz-Garcia

b, C.

Gomez-Lahoza, C. Vereda-Alonso

a

a Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain

b Division of soil mechanics, Lund University, Lund, 22363, Sweden


In another work presented at this conference, titled "Study of electrokinetic remediation

technology at semi-pilot scale. Strong acid enhancement", the results obtained for the

remediation of a soil contaminated by heavy metals are presented. In this case the

enhancement agent is a weak acid solution (acetic acid).

It is well-known that using weak acid presents, besides other advantages, the following:

organic acids are environmentally safe and biodegradable, posses certain buffer

capacities, can behave as complexing agents, and induce small increases in the soil

conductivity [1, 2].

The experimental setup and procedure is the same described in the other paper. The

parameters studied were pH, water content, total metal concentrations (Ca, Cu, Fe, Mg,

Mn, Pb) and BCR fractionation. Besides that, the results obtained in this work were

compared with those obtained from batch extraction experiments together with their

mathematical models.

The experimental results for the acetic acid enhanced experiment at the target values of

pH 4 and 5 are quite similar. Figure 1 shows the percentage of Pb obtained by the BCR

speciation after the soil treatment and for the initial soil. As can be seen the lead related

to the weak acid soluble (WAS) and to the reducible fractions (RED) has been

mobilized in soil close toward the anode compartment by the acid-enhanced technique.


56

Figure 1. BCR results for the weak acid enhancement of EKR (pH-5)

The results obtained in this work put forward the need of studying lab experiments,

together with mathematics models in order to better understand and predict the behavior

of the remediation techniques at the field-scale.

References

[1] A.T. Yeung, Y.Y Gu. J. Hazard. Mater. 195 (2011) 11.

[2] M. Pazos, S. Gouveia, M.A. Sanromán, C. Cameselle. J. Environ. Sci. Heal. A43

(8) (2008) 823.

Acknowledgements

Authors acknowledge the financial support provided by the Spanish Ministry of

Innovation and the FEDER fund of the EU through the Research Project ERHMES,

CTM2010-16824 and the UE project Electroacross IRSES-GA-2010 269289. Villen-

Guzman also acknowledges the FPU grant obtained from the Spanish Ministry of

Education, Culture and Sport. We also appreciate very much the help of Prof. Carmen

Hidalgo Estevez from the University of Jaen for her advice in the selection and

sampling of the contaminated soils.

0%

20%

40%

60%

80%

100%

120%

140%

160%

180%

Initial 1 2 3 4 5 6 7 8 9 10

% P

b

RES OXI RED WAS

Oral Session 2: Fundamentals and Modeling

Session Chair:

J.P. Gustav Loch


59

Nº REF.: O209

Modeling of the direct current assisted transport of zero valent iron nanoparticles

Helena I. Gomesa,b

*, J.M. Rodríguez-Marotoc, Celia Dias-Ferreira

b, Alexandra B.

Ribeiroa, SibelPamukcu

d

aCENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências

e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal

bCERNAS – Research Center for Natural Resources, Environment and Society, Escola

Superior Agraria de Coimbra, Instituto Politecnico de Coimbra, Bencanta, 3045-601

Coimbra, Portugal c Department of Chemical Engineering, University of Málaga, Campus de Teatinos,

29071-Málaga, Spain dDepartment of Civil and Environmental Engineering, Fritz Engineering Laboratory, 13

E. Packer Avenue, Lehigh University, Bethlehem, PA 18015-4729, USA


Zero valent iron was used successfully, for more than 20 years, for soil and groundwater

remediation in permeable reactive barriers [1, 2]. Since the late nineties, with the

nanotechnology boom, zero valent iron nanoparticles (nZVI) were considered a

promising step forward due to the possibility of inject them in the contaminated area,

especially for targeting organochlorines in groundwaters [3-7]. However, iron

nanoparticles quickly aggregate and settle, primarily due to magnetic attractive forces

[8]. Results from field scale applications confirm this limited mobility, ranging from

1 m [9] to 6-10 m [10].

One of the methods tested to overcome this poor nZVI mobility was the use of direct

current (DC) [11-15], using the same principles of electrokinetic remediation (EK). In

this method, low-level direct current induces several transport mechanisms and

electrochemical reactions.

In this work, a generalized physicochemical and numerical model has been developed to

describe the nZVI transport through different porousmedia under electric fields. The

model aims to be sufficiently detailed to describe the main processes and also a

predictive tool for the nZVI transport.The model consists in the Nernst–Planck coupled

system of equations, which accounts for the mass balance equation of ionic species in a

fluid medium when diffusion and electromigration are considered in the ions transport

process. In the case of charged particles of nzVI, diffusion and electrophoretic terms

have been taken into account. In both cases, also the electroosmotic flow has included in

the equation. Therefore, the flux of any chemical species or charged particles imoving

from a volume element of the system can be expressed as:

iei*ii

*ii ckcUcDN

(1)

whereci is the molar concentration, *iD is the effective diffusioncoefficient, is the

electrical potential, keis the electroosmoticpermeability coefficient and *iU , is the


60

effective electrophoretic mobilityfor nzVI charged particles or ionicmobility, estimated

by the Einstein–Nernst relation for ions.

Two kinds of reactions,electrochemical and chemical, are also included.The rate of

generationterm is not included in the continuity equation for the porous mediumcells

sincewe assume that usually the only electrochemical reactions which need to be taken

into account in the system are the reduction and oxidation of water on the

electrodes.The model has permitted to detect that, in some cases; an important fraction

of the nZVI particles tends to aggregate when their concentration is high relative to the

available pore volume, becoming an immobile iron cake, but the results also indicate

that aggregated mass diminishes clearly in the presence of direct current.

Experimental data using different porosity matrices –ranging from glass beads (with

diameter less than 1 mm, previously sieved) to white Georgia kaolinite clay

(> 2 μm) –, and different electrolytes (10-3

M NaCl, 10-3

M NaOH, 10-1

M Na2SO3 and

0.05 M CaCl2) were used to validate the model.

Acknowledgments

This work has been funded by the European Regional Development Fund (ERDF)

through COMPETE – Operational Programme for Competitiveness Factors (OPCF), by

Portuguese National funds through “FCT - Fundaçãopara a Ciência e a Tecnologia”

under project «PTDC/AGR AAM/101-643/2008 NanoDC», by FP7-PEOPLE-IRSES-

2010-269289-ELECTROACROSS and by the research grant SFRH/BD/76070/2011.

References

[1] USEPA, Permeable Reactive Barrier Technologies for Contaminant Remediation,

National Risk Management Research Laboratory Office of Research and

Development, U. S. Environmental Protection Agency Cincinnati, Ohio 1998.

[2] S. Comba, A. Di Molfetta, R. Sethi, Water Air Soil Poll., 215 (2011) 595-607.

[3] C.B. Wang, W. Zhang, Environ. Sci. Technol, 31 (1997) 2154-2156.

[4] W. Zhang, C.B. Wang, H.L. Lien, Catal. Today, 40 (1998) 387-395.

[5] J. Dries, L. Bastiaens, D. Springael, S.N. Agathos, L. Diels, Environ. Sci.

Technol, 39 (2005) 8460-8465.

[6] Y. Liu, H. Choi, D. Dionysiou, G.V. Lowry, Chem. Mat., 17 (2005) 5315-5322.

[7] H. Song, E.R. Carraway, Environ. Sci. Technol39 (2005) 6237-6245.

[8] T. Phenrat, N. Saleh, K. Sirk, R.D. Tilton, G.V. Lowry, Environ. Sci. Technol, 41

(2007) 284-290.

[9] C.M. Kocur, A.I. Chowdhury, N. Sakulchaicharoen, et al., Environ. Sci. Technol,

(2014) DOI: 10.1021/es4044209.

[10] W. Zhang, D.W. Elliott, Remediation, (2006) 7-21.

[11] H.I. Gomes, C. Dias-Ferreira, A. Ribeiro, S. Pamukcu, Water Air Soil Poll., 224

(2013) 1-12.

[12] H.I. Gomes, C. Dias-Ferreira, A.B. Ribeiro, S. Pamukcu, Chemosphere, 99 (2014)

171-179.

[13] S. Pamukcu, L. Hannum, J.K. Wittle, J. Environ. Sci. Heal. A, 43 (2008) 934-944.

[14] E.H. Jones, D.A. Reynolds, A.L. Wood, D.G. Thomas, Ground Water, 49 (2010)

172-183.

[15] G.C.C. Yang, H.C. Tu, C.H. Hung, Sep. Purif. Technol. 58 (2007) 166-172.


61

Nº REF.: O232

Influence of 2D physical heterogeneity on the elcetromigration of nitrate

R. T. Gill a,

*, M. J. Harbottle b, J. W. N. Smith

c,a& S. F. Thornton

a

a.Groundwater Protection and Restoration Group, University of Sheffield, Department

of Civil & Structural Engineering, Kroto Research Institute, Sheffield, S3 7HQ, UK b.

Cardiff University, School of Engineering, Queen's Buildings, The Parade. Cardiff,

CF24 3AA, UK c.Shell Global Solutions, Lange Kleiweg 40, 2288 GK Rijswijk, The Netherlands

* Corresponding author: [email protected]

Physical heterogeneity in the subsurface poses significant problems for the

bioremediation of contaminants, these include: (1) delivery of biological amendments to

stimulate bioremediation by hydraulic techniques is limited to soils and sediments with

hydraulic conductivities abovearound 10-7

m s-1

[1]; and (2) physical heterogeneity

imparts controls on the distribution and microscale mixing of microbes and solutes thus

hindering biodegradation [2]. Electrokinetics (EK) is effective at initiating a number of

different transport phenomena in materials with low hydraulic conductivities such as 10-

10m s

-1 [3]. The technique may therefore be suitable at delivering amendments under

physically heterogeneous conditions[4].

The aim of this research is to determine the influence of 2D heterogeneity on the

electromigration of nitrate. The objectives are: (1) to identify whether 2D heterogeneity

imparts controls on the voltage gradient based on differences in the effective ionic

mobility and subsequently the effective electrical conductivity; (2) whether these

voltage gradient differences contribute to enhanced migration between sections of the

2D heterogeneous system; and (3) identify these phenomena in both idealised and

natural sediments.

Electromigration theory indicates that changes in permeability can potentially have an

effect on the mass flux. The description of 1D electromigration mass flux of ionic

species, i is given [5]:

(1)

Where Ji, electromigration mass flux (kg m-2

s-1

); Ci, solute concentration (kg m-3

); uj*,

effective ionic mobility (m2

V-1

s-1

);ke, electroosmotic permeability (m2

V-1

s-1

); E,

electrical potential (V); x, distance (L). The ionic mobility is analogous with the

diffusion coefficient:

(2)

Where ui, ionicmobility (m2

V-1

s-1

); n, porosity (-); τ, tortuosity (-); F, Faraday’s

constant (C mol-1

); zi, valence of ion; Di*, effective diffusion coefficient (L2T

-1); R,

universal gas constant (J K-1

mol-1

); T, absolute temperature (K). The diffusion

coefficient has been shown to decrease with permeability due to an increase in the

tortuosity of the migration path length [6]

. Therefore if the ionic mobility varies spatially

there will also be subsequent variations in the electromigration rate. Similarly, there will


62

also bevariation in the voltage gradient based on the relationship between the effective

ionic mobility and the effective electrical conductivity [7]

:

∑

(3)

∑

(4)

Where I, current density (C s-1

m-2

); σ*, effective electrical conductivity (S m-1

). Thus,

in a physically heterogeneous setting where concentration of chemical species is

uniform, the voltage gradient should increase in material with a low effective ionic

mobility (i.e. low permeability material) relative to material with a high effective ionic

mobility (i.e. high permeability material).

Experiments will be conducted in an experimental setup similar to Figure 1. There are

three elements to the experimental design each with associated outcomes:

1. Homogenous vs heterogeneous comparison: homogeneous controls will be run

using the same material type representing the low permeability section in the

heterogeneous experiments. Differences in values for nitrate concentration and

voltage gradient will be used to determine whether nitrate migration between

layers is occurring.

2. Varying nitrate inlet concentration between experiments: this is to increase the

proportionof the amendment in the total electrical conductivity of the electrolyte.

It is expected that the high permeability section will have a higher associated

effective ionic mobility, therefore, the higher the nitrate inlet concentration the

greater the difference in electrical conductivity and voltage gradient between

layers potentially leading to increased migration.

3. Glass beads vs natural sediment: selected homogenous and heterogeneous

experiments will be repeated with natural sediment to observe whether this

phenomena occurs in conditions more representative of the natural environment.

Figure 1. Reactor vessel schematic. Dark and light areas in the sediment chamber show the

zones of low and high permeability X and O represent sampling and voltage probe ports.

References

[1] R.E. Saichek, K.R. Reddy, Surfactant-enhanced electrokinetic remediation of

polycyclic aromatic hydrocarbons in heterogeneous subsurface environments, J.

Environ. Eng. Sci. 4 (2005) 327–339. doi:10.1139/s04-064.


63

[2] X. Song, E.A. Seagren, In Situ Bioremediation in Heterogeneous Porous Media:

Dispersion-Limited Scenario, Environ. Sci. Technol. 42 (2008) 6131–6140.

doi:10.1021/es0713227.

[3] K.R. Reddy, R.E. Saichek, Effect of soil type on electrokinetic removal of

phenanthrene using surfactants and cosolvents, J. Environ. Eng. 129 (2003) 336–

346. doi:10.1061/(ASCE)0733-9372(2003)129:4(336).

[4] R.T. Gill, M.J. Harbottle, J.W.N. Smith, S.F. Thornton, Electrokinetic-enhanced

bioremediation of organic contaminants: A review of processes and

environmental applications, Chemosphere. 107 (2014) 31–42.

doi:10.1016/j.chemosphere.2014.03.019.

[5] Y.B. Acar, A.N. Alshawabkeh, Principles of electrokinetic remediation, Environ.

Sci. Technol. 27 (1993) 2638–2647. doi:10.1021/es00049a002.

[6] R.K. Rowe, K. Badv, Chloride migration through clayey silt underlain by fine

sand or silt, J. Geotech. Eng. 122 (1996) 60–68. doi:10.1061/(ASCE)0733-

9410(1996)122:1(60).

[7] A.N. Alshawabkeh, Y.B. Acar, Electrokinetic remediation. II: Theoretical model,

J. Geotech. Eng. 122 (1996) 186–196. doi:10.1061/(ASCE)0733-

9410(1996)122:3(186).


64

Nº REF.: O242

Influence of the electrochemical treatment on humic substances content in the groundwater from limestone aquifers: Preliminary study

Ljiljana Rajic*, Noushin Fallahpour, Akram Alshawabkeh

Civil and Environmental Engineering Department, Northeastern University, Boston,

MA, 02115, USA


Groundwater natural organic matter (NOM), and its interactions with carbonate aquifer

constituents, may play an important role in controlling subsurface processes by acting as

a proton donor and acceptor and as a pH buffer, by influencing mineral precipitation

and dissolution, and by affecting the transport and degradation of pollutants [1]. In this

study we investigated the influence of electrochemical treatment on humic substances

(HS) content in the simulated groundwater from limestone aquifers. The treatment was

conducted by cathode→anode electrode arrangement in electrochemical flow-through

reactor column filled with limestone gravel. Total organic carbon (TOC) and dissolved

organic carbon (DOC) decreased 50.2% and 44.7%, respectively, after the simulated

groundwater flow through column reactor without current application. This indicates

HS adsorption on the limestone gravel under the tested conditions. After

electrochemical treatment there was a significant TOC (92.8%) and DOC (58.0%)

decrease which indicates the electrochemical transformation of HS. We also

investigated an impact of HS presence on the electrochemical trichloroethylene (TCE)

degradation. TCE electrochemical removal efficiencies were: 31.9% in the absence of

HS and 33.6%, 31.9% and 32.5% in the presence of 1 ppm, 5 ppm and 10 ppm TOC

from HS, respectively. The results indicate that electrochemical treatment affects HS

content in groundwater but there is no influence of HS on the electrochemical TCE

removal efficiency.

References

[1] J. Jin, A.R. Zimmerman, Appl. Geochem. 25 (2010) 472


65

Nº REF.: O243

Enhancement of electro-osmotic flow during the electrokinetic treatment of contaminated soils

Claudio Cameselle*, Susana Gouveia

Department of Chemical Engineering, University of Vigo. 36310-Vigo (Spain)


Electro-osmosis is one of the main transportation mechanisms for contaminant removal

in the electrokinetic remediation of contaminated soils. Electro-osmosis can be defined

as the net flux of water towards one of the electrodes induced by the electric field. The

electro-osmosis flow depends on fluid characteristics (dielectric constant and viscosity)

and soil surface characteristics represented by the Zeta potential, as well as the voltage

gradient. Zeta potential is a function of many parameters including the chemical nature

of the soil particles, pH, temperature and ionic strength of the interstitial fluid. Some of

these parameters are affected by the electrokinetic treatment itself. The soil pH and the

type and concentration of ions in the interstitial fluid change during the electrokinetic

treatment of a contaminated soil due to the chemical reactions and the transportation

induced by the electric field. Those changes clearly affect the development and the

maintenance of a high electro-osmotic flow.

The aim of this work is to determine the influence of electrochemical variables in the

development and maintenance of electro-osmotic flow with the objective to determine

the best operating conditions for the treatment of soil contaminated with mixtures of

organic and inorganic contaminants.

An agricultural soil with a high content of organic matter was used in this study. The

soil was contaminated with heavy metals (Cd, Co, Cr, Cu, Pb, Zn) and PAH

(Anthracene and Phenanthrene). Six experiments were carried out in a cylindrical

electrokinetic cell to determine the influence in the electro-osmotic flow of the pH,

voltage gradient, and the use of facilitating agents on anolyte and catholyte. Three

organic acids: citric, oxalic and tartaric acid were used as facilitating agents to improve

metal removal, but at the same time, to improve the electro-osmotic flow and control

the pH on the electrode chambers.

Figure 1. Accumulated electro-osmotic flow as a function of the applied voltage in the

electrokinetic treatment of an agricultural soil.


66

Figure 1 shows the influence of the voltage on the electro-osmotic flow (EOF) of a

sample of the agricultural soil. Tap water was used in both electrode chambers and no

pH control was used during the first 27 days of operation. After the first week, where a

minor electro-osmotic flow was collected at the cathode, a very different behavior was

observed based on the applied voltage. A voltage of 20 V, which corresponds with

1 V/cm, resulted in a continuous EOF whereas the experiment at 30 V showed no EOF.

The experiment at 10 V showed an intermediate value. After 27 d of operation, the pH

on the anode was kept alkaline with periodic addition of NaOH and the catholyte was

acidify with periodic addition of sulfuric acid. Surprisingly, the experiments at 20 and

10 V did not showed any variation in the EOF after the pH shift, but an increasing EOF

was detected in the experiment at 30 V. These results can be related to the pH into the

soil due to the control of pH in the catholyte and anolyte.

Figure 2 shows the accumulated electro-osmotic flow when citric, oxalic and tartaric

acid where used in the anolyte in the electrokinetic treatment of a soil sample at

constant voltage: 20 V. These acids may enter the soil transported by electro-osmosis,

but this transportation is limited by the electromigration of the anions in the opposite

direction, towards the anode. Despite of the opposite transportation of citrate, oxalate

and tartrate by electromigration and electro-osmosis, very different EOF was observed

when organic acids were used compared to the results of experiment at 20 V in figure 1.

Moreover, the effect of each organic acid in the EOF was very different. Citric and

tartaric acid resulted in a continuous EOF, whereas oxalic acid showed a very fast flow

in the very beginning and then the flow stopped. During the first 27 days, the pH in the

anode tend to be very acidic and on the cathode very alkaline. On day 27th

NaOH and

the corresponding organic acid were used to acidify the cathode and to increase the pH

on the anode. After the pH shift the behavior was even more surprising. The EOF in the

experiments with citric and tartaric acid stopped and a significant EOF was detected on

the anode. The experiment with oxalic acid showed a significant EOF towards the

cathode. This results can be related with the soil pH affected by the pH in the electrode

chambers, and what is more important, the EOF is affected by the interaction of citrate,

oxalate and tartrate with the soil particles, changing the surface characteristics, the zeta

potential, and therefore the EOF.

Figure 2. Accumulated electro-osmotic flow using citric, oxalic and tartaric acid in anolyte and

catholyte in the electrokinetic treatment of an agricultural soil.

References

[1] C. Cameselle, K.R. Reddy, Electrochim. Acta 86 (2012) 10.


67

Nº REF.: O261

Electrokinetics to modify strength characteristics of soft clayey soils: A laboratory based investigation

Samudra Jayasekeraa*

a Faculty of Science, School of Science, Information Technology & Engineering,

Federation University of Australia, Ballarat 3350, Australia


The use of electrokinetic (EK) methods is a viable in situ soil remediation and treatment

technique that is being researched in many parts of the world and currently being

practised successfully in some parts of the Europe and US. EK processing significantly

alters many physicochemical properties of soil porous media. Although there is a

considerable amount of literature available reporting the changes in chemistry of porous

media with EK processing, only limited studies have investigated changes in soil

physical properties, particularly strength characteristics with EK processing.

In this study, the effects of EK processing on compressive strength characteristics of

two types of soils were investigated using laboratory experimental models. Soils were

collected from soft alluvial soil deposit (Soil S1) and basaltic soil deposit (Soil S2) in

central Victoria, Australia. A layer of soil was placed in glass tanks (900mm×350mm

plan area) and compacted to a known density and water content typical of field

conditions. Using electrodes inserted into the soil, a direct current was passed across the

soil under various voltage gradients (0.5, 1, 2V/cm) for period of 7, 14 and 30 days.

Unconfined compression (UC) tests and pocket penetrometer tests were conducted on

original soils and EK processed soils.

From the UC and penetration test results (Table 1) it is noted that, soil compressive

strength increases with the increasing processing time and increasing voltage gradients,

at various rates. Under certain voltage gradients and processing times, around 175% and

200% strength increases are observed. In general, stress increases of at least 30% or

more are reported for both soils under all test conditions.

It is apparent that the variation in strength can be attributed to several complex and

interrelated processes that become active under EK processing [1, 2, 3]. These may

include, (i) Electroosmotic advection - When a soil is subjected to EK processing with

an open electrode configuration, the water content of the soil varies predominantly due

to the electroosmotic advection while natural drying and evaporation could also add to

the decrease in water content to some extent, depending on the time and environmental

conditions such as temperature and humidity [2, 3]. The test results show that with the

decrease in water content, there is a corresponding increase in the strength. (ii)

Electromigration - The electromigration of charged ions and their interaction with clay

minerals can also affect the soil strength due to the variations in the DDL ionic

concentration and subsequent modifications in the soil structure [1]. (iii) Ionic Diffusion

and Aging - After the complete termination of EK processes, the ionic concentrations

still continued to modify at a slower rate. This is considered to be due to the ionic

diffusion. In this phase too, cementation bonds may continue to develop that could

contribute to the increase in soil strength. During this period, two other processes, i.e.


68

natural drying of soil and aging [4] may continue that can also affect the variation of

soil strength.

Table 1. Variation of maximum axial stress at cathode and anode positions for soil S1 and S2 with increasing voltage gradients and EK processing time durations

Soil

type

Treatment

duration

(days)

Voltage

Gradient

(V/cm)

Cathode Anode

Stress

kN/m2

Stress

increase

%

Stress

kN/m2

Stress

increase

%

S1

Untreated 37- 42

7

0 40 5.3 33 -13.2

0.5 50 31.6 44 15.8

1 59 55.3 54 42.1

2 63 65.8 51 34.2

14

0 44 15.8 34 -10.5

0.5 65 71.1 47 23.7

1 72 89.5 56 47.4

2 82 115.8 52 36.8

30

0 47 23.7 41 7.9

0.5 70 84.2 56 47.4

1 81 113.2 58 52.6

2 104 173.7 60 57.9

S2

Untreated 95 - 104

7

0 106 9.3 88 -9.3

0.5 105 8.2 151 55.7

1 178 83.5 166 71.1

2 208 114.4 192 97.9

14

0 116 19.6 88 -9.3

0.5 163 68.0 213 119.6

1 124 27.8 246 153.6

2 246 153.6 287 195.9

30

0 141 45.4 105 8.2

0.5 185 90.7 222 128.9

1 164 69.1 262 170.1

2 264 172.2 303 212.4

References

[1] Acar, Y. B., Hamed, J. T., Alshawabkeh, A. N., and Gale, R. J. (1994). "Removal

of cadmium (ii) from saturated kaolinite by the application of electrical current."

Geotechnique, 44 (2), 239-254.

[2] Lo, K. Y., Micic, S., Shang, J. Q., Lee, Y. N., and Lee, S. W. (2000).

"Electrokinetic strengthening of a soft marine sediment." International journal of

offshore and polar engineering, 10 (2).

[3] Micic, S., Shang, J. Q., and Lo, K. Y. (2002). "Electrokinetic strengthening of

marine clay adjacent to offshore foundations." International journal of offshore

and polar engineering, 12 (1).


69

[4] Lo, K. Y., and Hinchberger, S. D. (2006) "Stability analysis accounting for

macroscopic and microscopic structures in clays." Fourth International

Conference on Soft Soil Engineering, Vancouver, Canada, 3-34.


70

Nº REF.: O268

A continuous multi-scale model for ionic transport through electrically charged membranes

J.M. Paz-Garciaa, M. Villen-Guzman

b, M. Ristinmaa

a, J.M. Rodriguez-Maroto

b

a Division of soil mechanics, Lund University, Lund, 22363, Sweden

b Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain


Electrically charged (ion-exchange) membranes (IEMs) are used in several technologies

for separation and energy production [1, 2]. In electrokinetic remediation (EKR), IEMs

are receiving considerable attention, as they produce selective separation with low

energy consumption. IEMs are the base for electrodialytic soil remediation processes

[3]. In this context, the membranes are used for the design of these enhanced

techniques; e.g. to control the pH of the media by hindering the acidic or alkaline fronts,

to create electrolyte compartments between the treated sample and the electrode

chambers for the selective recuperation of the contaminants, or to avoid contaminants to

reach the electrodes surface producing competitive electrochemical reactions.

Synthetic IEMs are normally organic polymers layers (homogenous films of 50-200 μm

thick) containing a certain amount of fixed (not mobile) of either positive or negative

charge (typically in a concentration of at least 3-4 mol g-1

). The fixed charge is

electrically counteracted by ions of the opposite sign (counterions). IEMs allow the

passage of the counterions but exclude ions with the same charge (coions). In IEMs, the

transport number, t, (defined as the fraction of the total current carried by a particular

ion) of the excluded ions is very small, t ~ 0.05, as the current is mainly transported by

the counterions. The sum of the transport number of the counterions is a measure of the

relative permeability or permselectivity of the membrane.

Figure 1. Depiction of the electric potential in the membrane and the adjoining electrolytes for the

two models compared: (a) discontinuous Donnan potential; (b) surface potential.

Traditionally, two different approaches are used for modelling the transport of ions

through electrically charged membranes: (1) the discontinuous Donnan model, and (2)

the continuous surface potential (or Gouy-Chapman double-layer potential) model [4,5].

, , exp ; 1,2,...,i m i i Dc c z i N (1)


71

(2)

The Donnan model is based on the Donnan equilibrium equation, Eq. 1, for each of the

N species in the system, and the electroneutrality condition, Eq. 2, [5], where

(mol m-3

) is the concentration, the subscript m and refer to the membrane and the

bulk electrolyte respectively, (-), is the ionic charge, (-) is the dimensionless

potential drop between the membrane and the electrolyte, (C mol-1

) is the Faraday

constant, and (C m-3

) is the concentration of the membrane fixed charge (referred

to the volume of electrolyte assuming the membrane as a porous material).

The Donnan model is practical for cases in which the electrolytes are continuously

flowed, and the concentration can be considered constant in the perpendicular direction

of the membrane surface, therefore a value for the parameter is identified. In EKR

treatments, however, significant concentration gradients are formed in that direction

making the use of the Donnan model unfeasible or inaccurate.

The continuous surface model describes the interface between the membranes and the

electrolytes based on the Gouy-Chapman double layer model [6], which is:

(3)

(4)

Which is derived from the continuity equations, Eq. 3, coupled with the Poisson’s

equation of electrostatic, Eq. 4; where (mol m-2

s-1

) is the flux term (defined using

the Nernst-Planck equation, (mol m-3

s-1

) is chemical reaction term, (V) is the

electrical potential, and (C V-1

m-1

) is the permittivity of the media.

In the present work, we present a continuous multi-scale model for the transport of ions

through charged membranes. We consider a general multi-species and asymmetric

electrolyte case as an example of an electrodialytic remediation treatment, including

chemical reaction effects are included.

References

[1] R.F. Probstein, Physicochemical Hydrodynamics; an introduction. 2nd

ed. (1994),

John Wiley & Sons, Inc.

[2] A.H. Galama, J.W. Post, M.A. Cohen Stuart, and P.M. Biesheuvel, J. Memb. Sci.

442 (2013) 131.

[3] T.R. Sun, L.M. Ottosen, J. Mortensen, Chemosphere 90 (2013) 1520.

[4] V.M. Volgin, A.D. Davydov, J. Memb. Sci. 259 (2005) 110.

[5] F.G. Donnan, Z. Elektrochem. 17 (1911) 572.

[6] J.M. Paz-Garcia, B. Johannesson, L.M. Ottosen, A.N. Ribeiro, J.M. Rodriguez-

Maroto (Submitted)

, 0i i m

i

X F z c

ic

iz D

F

X

,ic

; 1,2,...,ii i

cG i N

t

J

2 0i i

i

F z c

iJ

iG


72

Acknowledgements



CTM2010-16824 and the UE project Electroacross IRSES-GA-2010 269289.

Oral Session 3: Scaling up and field applications

Session Chair:

Lisbeth M. Ottosen


75

Nº REF.: O313

Pilot scale electrodialytic treatment of MSWI APC residue to decrease leaching of toxic metals and salts

Pernille Erland Jensena,*

, Gunvor Kirkelunda, Celia Dias-Ferreira

b, Lisbeth M.

Ottosena

aTechnial University of Denmark, 2800 Lyngby, Denmark.

bCERNAS, Escola Superior Agrária, 3040-316 COIMBRA, Portugal.


A major challenge of municipal solid waste incineration (MSWI) technology is the

residue generated during the burning, and especially the air pollution control (APC)

residue. In Denmark, incineration with energy recovery is the chosen strategy for

handling municipal solid waste except for a few fractions like glass, paper, cardboard,

metal and hazardous waste which is sorted out at the source. Around 100,000 ton of

APC residue is produced annually and exported as hazardous waste to Norway and

Germany. The hazard arises from high amounts of mobile toxic elements, salts as well

as trace quantities of very toxic organic compounds and the highly alkaline pH.

Electrodialysis of semidry APC residue has shown potential for reduction of leaching of

toxic elements and salts [1,2] to produce a material feasible for substitution of cement in

mortar [3]. During the electrodialytic process, elements of potential value are

concentrated in the concentrate stream which implies a reduction in the volume of

hazardous material and a potential for regeneration.

Figure 1 Experimental setup

APC residue suspension

Concentrate

Electrolyte

ED stack


76

In this work, results of 23 pilot-scale treatments in an electrodialytic stack setup (figure

1) are reported. The experimental span is described in table 1. In all the experiments L/S

10 was kept for the suspension (5.3 or8kg APC residue and 53 or 80 l water were

mixed), and the suspension continuously treatedfor up to 24 hours in an electrodialytic

stack. Experiments were made with APC residues from dry, semidry and wet fluegas

cleaning system, as well as carbonated and pre-washed semidry APC residue.Sampling

was made regularly (every or every secondhour) during treatment.Current density(0 –

11.3 mA/cm2), different batch samples and aeration were varied to reveal optimal

treatment conditions and stability of the process.

Table 1. List of experiments

APC residue No. experiments Investigated parameters

Dry 2 Current density

Semidry 15 Current density, batch influence,

aeration

Semidry- carbonated 2 Carbonation pretreatment

Semidry-washed 1 Washing pretreatment

Wet 3 Current density, batch influence

Significant reduction in leaching of the critical elements Pb, Zn and Cl was obtained.

Leaching reduction depended somewhat on current density and treatment time, as a high

current density and long residence time gave operational problems in the set-up. Type of

pretreatment and type of APC residue also influence the remediation potential.

References

[1] P.E. Jensen, C.M.D. Ferreira, H.K. Hansen, J.U. Rype, L.M. Ottosen, A.

Villumsen, Journal of Applied Electrochemistry 40 (2010) 1173.

[2] G.M. Kirkelund, P.E. Jensen, A. Villumsen, L.M. Ottosen, Journal of Applied

Electrochemistry 40 (2010) 1049.

[3] G.M. Kirkelund, M.R. Geiker, P.E. Jensen, Nordic Concrete Research, Submitted.


77

Nº REF.: O325

Multivariate analysis of variable importance in the scaling up of electrodialytic remediation of heavy metals from harbour sediments

Kristine B. Pedersena,*

, Lisbeth M. Ottosenb, Pernille E. Jensen

b, Tore Lejon

a,

a Department of Chemistry, The Arctic University of Norway, 9019 Tromsø, Norway

b Arctic Engineering and Sustainable Solutions, Technical University of Denmark, 2800

Kgs Lyngby, Denmark


Large amounts of polluted sediments are annually dredged around the world in order to

meet the demands of harbour development and/or to meet governmental acts to improve

the aquatic environment of harbours. The most common way of dealing with dredged

contaminated sediments is disposal at licensed landfills (land/deep sea), and in some

cases solidification/stabilisation of the sediments, e.g. in new harbour constructions.

The focus on treatment possibilities of the dredged polluted sediments prior to potential

re-use has been limited. With the general focus of developing sustainable societies in

which the amount of waste is reduced considerably, a bigger emphasis on identifying

and developing methods for removing pollutants from dredged polluted sediments prior

to recycling these, e.g. in construction materials, may be expected in the future.

Electrodialytic remediation (EDR) provides a method that has been proven to

successfully remove heavy metals from polluted harbour sediments in laboratory scale –

removing up to 98% of the initial heavy metal concentration and meeting international

recommendations from OSPAR [1-7].

The focus of this study was to contribute in the further development of the EDR method

for future scaling up. Three different set-ups were tested – two on laboratory scale and

one on bench-scale. The EDR set-ups in laboratory scale were the traditional three

compartment cells and the newly developed two compartment cells. In the three

compartment cells ion exchange membranes separate the sediment in suspension in the

middle compartment from the electrodes and circulating electrolytes at the end

compartments to prevent the produced proton and hydroxyl ions produced at the

electrodes from entering the compartment with the suspension. Water splitting at the

anion exchange membrane ensures the acidification of the sediment [8]. In the two

compartment cells the anode is placed directly into the compartment with the sediment

in suspension and the separated cathode compartment is maintained to prevent hydroxyl

ions produced at the cathode from disturbing the remediation process in the

compartment with the sediment in suspension. The EDR set-up on bench scale was

based on separating the sediment suspension from the electrodes and circulating

electrolytes. The sediment suspension was continually circulated through a system of

consecutive compartments separated by anion and cation exchange membranes; the

electrodes were placed at each end of the stack.

The targeted heavy metals in the study were chromium, copper, nickel, lead and zinc,

since elevated concentrations of these heavy metals were found in the sediments. A

preliminary laboratory scale screening of the experimental variables showed a relative

variable importance in the order remediation time>current density>cell set-up>>stirring

rate>liquid-solid ratio>light. Based on these results a multivariate experimental design


78

was applied to determine the relative importance of the variables: remediation time,

current density, type of sediment and type of EDR equipment (2-compartment cell, 3-

compartment cell, stack). Two types of polluted harbour sediments were used – one

from Hammerfest harbour in the Arctic region of Norway and one from Sisimiut

harbour in Greenland. Measurements of the metals aluminium, barium, calcium, iron,

potassium, magnesium, manganese, sodium and vanadium were made as indications of

the changes EDR may have on the sediment matrix.

Multivariate analysis of the results revealed the variable importance in the experimental

space. This was done by performing projection to latent structures (PLS) in which

relations between two matrices; X consisting of the experimental variables and Y

consisting of the responses, i.e. the remediation levels of the targeted heavy metals and

metals naturally occurring in the sediments were determined. The PLS analysis

determines whether the variation in the experimental variables are related to the

variation in the remediation levels.

The PLS analysis showed that the relative importance of remediation time, current

density, EDR equipment and type of sediment were similar in magnitude hence having

a similar affect on the remediation process. The highest remediation levels were found

when using the two compartment cell set-up. The measurements of naturally occurring

metals in the sediments indicated that the 2-compartment cell induced the biggest

disturbance to the sediment matrix. Comparing the laboratory scale set-ups with the

bench scale set-up showed that more heavy metals per mass of sediment were removed

in the EDR cells, however the EDR stack can contain and remediate larger volumes of

sediment. The results can be used as basis for future optimisation of the scaling up of

the EDR method.

References

[1] G. Nystroem, L. Ottosen, A. Villumsen, Sep. Sci. Technol., 40 (2005) 2245-2264.

[2] G.M. Nystroem, L.M. Ottosen, A. Villumsen, Environ. Sci. Technol., 39 (2005)

2906-2911.

[3] G.M. Nystroem, A.J. Pedersen, L.M. Ottosen, A. Villumsen, Sci. Total Environ.,

357 (2006) 25-37.

[4] K.H. Gardner, G.M. Nystroem, D.A. Aulisio, Environ. Eng. Sci., 24 (2007) 424-

433.

[5] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, J. Hazard. Mater., 169 (2009) 685-

690.

[6] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, Chemosphere, 79 (2010) 997-1002.

[7] L.M. Ottosen, G.M. Nystrom, P.E. Jensen, A. Villumsen, J. Hazard. Mater., 140

(2007) 271-279.

[8] H.K. Hansen, L.M. Ottosen, B.K. Kliem, A. Villumsen, J. Chem. Technol.

Biotechnol., 70 (1997) 67-73.


79

Nº REF.: O326

Design of a pilot electrokinetic remediation plant for marine sediments contaminated by heavy metals

(PROJECT LIFE12 ENV/IT/442 “SEKRET”)

Renato Iannellia,*

, Matteo Masia, Alessio Ceccarini

b, Raffaella Pomi

c, Alessandra

Polettinic, Angelo Marini

c, Aldo Muntoni

d, Giorgia De Gioannis

d, Maria Beatrice

Ostunia and Reinout Lageman

e

a University of Pisa, Department of Energy Engineering, Systems, Land and

Construction, Via Gabba 22, 56122 Pisa, Italy. b University of Pisa, Department of Chemistry and Industrial Chemistry, Pisa, Italy

c “La Sapienza” University of Rome, Dept. of Civil and Environmental Engineering,

Roma, Italy d University of Cagliari, Department of Civil and Environmental Engineering and

Architecture, Cagliari, Italy e Lambda Consult, Schuylenburgh 3, 2631 CN Nootdorp, Netherlands


Dredged sediments are often severely contaminated by a variety of hazardous

pollutants, mostly heavy metals and hydrocarbons originated from different sources

such as ship transport, harbour activities, industry, agriculture, municipal sewage and

others [1]. Polluted sediments cannot be dumped offshore or reused, and the most

common options are landfilling or disposal in confined basins. Due to the large amounts

of contaminated material dredged worldwide, these choices generally exhibit high costs

and environmental impact; therefore, effective decontamination techniques are required.

For finely grained matrices, most of the traditional treatment technologies have proved

to be ineffective [2]. Unlike the majority of techniques, Electrokinetic remediation

(EKR) is effective for fine grained, low-permeability soils and sediments. This

technique employs a low-intensity electric field which induces the mobilization of

contaminants and water through the porous media toward the electrodes, due to three

main transport mechanisms [3-5]: electromigration, electroosmosis and electrophoresis.

The suitability of electrokinetic remediation for removing heavy metals from dredged

marine sediments is under investigation within the SEKRET Life+ project (“Sediment

ElectroKinetic Remediation Technology for heavy metal pollution removal”), by means

of a demonstrative 150 m3 treatment basin to be built in an area of the port of Livorno

(Italy). In the port of Livorno almost 100000 m3/year of sediments are dredged on a

regular basis. An environmental seabed assessment performed in 2005 detected the

presence of sediments polluted by significant concentrations of Cd, Cr, Cu, Ni, Pb and

Zn. In order to design the treatment plant, several calculations and estimations have

been carried out based on data from laboratory tests. The methods and the parameters

used for the design of the plant are discussed below.

The installation will consist of the following elements (Figure 1): i) an electric power

supply section, ii) a treatment basin, iii) semi-permeable electrolyte wells (slotted pipes)

placed in the contaminated medium and connected to an electrolyte management

system, iv) an electrolyte management system for the conditioning of the electrolytes, to

maintain the pH to a desired level, v) an electrolyte treatment system comprising ion


80

exchange and reverse osmosis filtration, vi) a gas treatment unit (scrubber system) for

the abatement of Cl2 gas emissions, vii) a monitoring and control system (PLC).

The design of the plant involved the evaluation of several operational parameters. The

most critical parameters for the electrokinetic process are: i) the speciation and mobility

of the contaminants, ii) pH of the sediment and of the electrolytes, iii) the cation and

anion exchange capacity, iv) the buffer capacity and v) the resistivity. These parameters

were obtained from laboratory tests and used to calculate the design parameters.

The size of the basin will be 6x18x1.3 m. The electrode will be placed along array

arrangements, with 6 electrodes each row. The distance between anodes and cathodes

will be about 1 m. The wells will be about 1.3 m deep and their diameter will be 9 cm.

The anode wells will be sealed and connected to a venting circuit that will collect the

gases produced during plant operation (e.g. chlorine) and treat them with a scrubber.

The electrical power will be applied to the electrode arrays via 8 power supplies (50kW

total power), delivering up to 30V. The applied current density will vary as a function of

the resistivity of the sediments, with a maximum design value of 5 A/m2 to prevent

electrolyte overheating. The number of electrodes will be 108 and each one will deliver

max. 14 A. The electrode material will be titanium with an iridium oxide coating. The

design electrolyte flow rate was estimated by imposing an optimal pH level inside the

wells. This allowed us to calculate the rate of reagent dosage needed to control the pH

to the desired level, and an electrolyte flow rate which minimizes the pH range between

the inflow and outflow from each row of electrodes. The treatment duration and metal

migration were determined by a simplified model (which neglects geochemical

reactions). According to these estimates, the remediation will be completed within 18

months of operation.

Figure 1. “SEKRET” electrokinetic treatment plant layout.

References

[1] Peng, J., et al., The remediation of heavy metals contaminated sediment. Journal

of Hazardous Materials, 2009. 161(2-3): p. 633-640.

[2] Mulligan, C.N., R.N. Yong, and B.F. Gibbs, Remediation technologies for metal-

contaminated soils and groundwater: an evaluation. Engineering Geology, 2001.

60(1–4): p. 193-207.

[3] Acar, Y.B. and A.N. Alshawabkeh, Principles of electrokinetic remediation.

1993. 27(13): p. 2638-2647.


81

[4] Reddy, K.R. and C. Cameselle, Electrochemical remediation technologies for

polluted soils, sediments and groundwater. 2009: Wiley & Sons Ltd. 732-732 p.

[5] Lageman, R., Electroreclamation: application in the Netherlands. Environmental

Science and Technology, 1993. 27(13): p. 2648-2650.


82

Nº REF.: O352

Application of solar cell in electrokinetic remediation of As-contaminated soil in pilot scale

Eun-Ki Jeona, So-Ri Ryu

a, Kitae Baek

a,b,*

aDepartment of Environmental Engineering, Chonbuk National University, 567 Baekje-

daero, Deokjin, Jeonju, Jeollabuk 561-756, Republic of Korea bDepartment of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-

daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea

* Corresponding author (K.Baek) : Tel.:+82-63-270-2437; Fax:+82-63-270-2449; E-

mail: [email protected]

Abstract

Electrokinetic remediation has been applied to remove a wide range of contaminants

including heavy-metals, organic pollutants, and radioactive materials from contaminated

soil, sediments and sludge. Contaminants in the soil are removed by the application of

an electric current across the contaminated soil [1, 2]. In general, the cost of electrical

energy increases the total remediation costs in the electrokinetic technique, which is

approximately 25% of total operation cost [1, 3]. Recently, solar cell has attracted for

electrokinetic remediation because it generates direct current (DC) [3, 4]. Direct current

generated by solar cell can be suitable for electrokinetic remediation for contaminated

soils [4].

In this study, we evaluated the feasibility of solar cell for pilot scale electrokinetic

remediation. Soil was sampled from a real contaminated site nearby refinery plant and

classified as a clay loam. Initial arsenic (As) level was higher than Korean regulation

concentration. Two different power sources, solar panel and normal power supply, were

applied for the comparison. The open circuit voltage of solar cell is 20V and two solar

cell panels were connected in series. We used oxalic acid as an electrolyte based on the

previous experimental results. Figure 1 shows the EKR system schematic diagram used

in this study.

Figure 2. EKR system schematic diagram


83

Acknowledgement

This research was supported by Korea Environment Industry & Technology Institute

(KEITI)

References

[1] A.N. Alshawabkeh, A.T. Yeung, M.R. Bricka, J. Environ. Eng.-ASCE 125 (1999)

27-35.

[2] D.H. Kim, J.M. Jung, S.U. Jo, W.S. Kim, K. Baek, Sep. Sci. Technol.47 (2012)

2235-2240.

[3] S. Yuan, Z. Zheng, J. Chen, X. Lu, J. Hazard. Mater. 162 (2009) 1583-1587

[4] Y.H. Kim, D.H. Kim, H.B. Jung, B.R. Hwang, S.H. Ko, K. Baek., Sep. Sci.

Technol. 47 (2012) 2230-2234

Oral Session 4: Other uses. Miscellaneous.

Session Chair:

Gordon C.C. Yang


87

Nº REF.: O401

A decontamination of the soil contaminated with cesium using electrokinetic-electrodialytic technology

Gye-Nam Kim*, Seung-Soo Kim, Jei-Kwon Moon

Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-gu, Daejeon,

305-353, Korea

[email protected]

1. Introduction

The radioactive soil at the KAERI radioactive waste storage facility has a slightly high

hydro-conductivity, and was mainly contaminated with 137

Cs 30-35 years ago. Recently,

a soil washing method was applied to remove 137

Cs from the radioactive soil, but it

appeared that the removal efficiency of 137

Cs was low, and a lot of waste solution was

generated. Meanwhile, an electrokinetic decontamination method provides a high

removal efficiency of 137

Cs and generates little waste effluent. Thus, it was suggested

that an electrokinetic decontamination method is a suitable technology in consideration

of the soil characteristics near South Korean nuclear facilities. The electrokinetic

process holds great promise for the decontamination of contaminated soil as it has a

high removal efficiency and is time-effective for a low permeability. The soil

contaminated with cesium was sampled at an area near a nuclear facility in Korea. The

electrokinetic decontamination equipment and electrokinetic-elctrodialytic

decontamination equipment were manufactured to decontaminate the contaminated soil.

The removal efficiency according to the lapsed time by the electrokinetic

decontamination equipment and the electrokinetic-elctrodialytic decontamination

equipment was investigated through several experiments. The difference between the

removal efficiency of the electrokinetic-elctrodialytic decontamination without anion

exchange membrane and that of with anion exchange membrane was investigated

through several experiments. In addition, the removal efficiency trend according to

different cesium radioactivity of soil was drawn out through several experiments.

2. Manufacturing of decontamination equipment

Electokinetic equipment decontamination was manufactured for the experiments. The

electrokinetic decontamination equipment consists of horizontal soil cells, two electrode

compartments (anode/cathode rooms), a reagent reservoir, an effluent reservoir, and a

power supply, and 480 g of contaminated soil was placed into a horizontal soil cell of

4.5x5.9x14.5 cm for Experiment 1. In Experiment 1, a paper filter was inserted between

the electrode compartment and the contaminated soil to protect against an influx of soil.

A pump supplies a reagent to the reagent reservoir at 0.5-1 ml/min, and the reagent

reservoir supplies a chemical solution to the anode room. The electric current between

electrodes is 0.6A, and the electric voltage between electrodes is 4.5-5.2 V. The

temperature in the cathode room was below 65 C. Experiments 1and 2 used a different

soil sample radioactivity, and the electrokintic decontamination period was 21 days

without exception.

In experiment 2, an anion exchange membrane was inserted between the anode room

and the contaminated soil to protect against an influx of cesium ions, and a paper filter

was inserted between the cathode room and the contaminated soil. 200g of


88

contaminated soil was placed into a horizontal soil cell, namely, the ratio of liquid (mg)/

soil (g) is 0.5. Experiments 3 and 4 used soil samples with a different radioactivity, and

the electrokintic decontamination period was 21 days without exception. Also, 200g of

contaminated soil was placed into a horizontal soil cell, namely, at a ratio of liquid

(mg)/soil (g) of 0.5. In Experiment 4, an anion exchange membrane was inserted

between the anode room and the contaminated soil to protect against an influx of

cesium ions, and a paper filter was inserted between the cathode room and the

contaminated soil. 200g of contaminated soil was placed into a horizontal soil cell,

namely, at a ratio of liquid (mg)/soil(g) of 0.5. Fig. 1 shows schematic diagram of the

electrokinetic-electrodialytic decontamination equipment.

Fig. 1. A schematic diagram of the electrokinetic-electrodialytic decontamination equipment

3. Electrokinetic-electrodialytic decontamination results

Cesium (137Cs+) in the contaminated soil in the electrokinetic-electrodialytic

decontamination equipment was removed by electro-osmosis, electro-migration, and a

hydraulic pressure flow. The experimental electrokinetic-electrodialytic conditions were

as follows. When the decontamination period of 0.3 days, 2 days, and 7 days elapsed,

137Cs+ in the soil was removed by about 10%, 37%, and 68%. However, the removal

efficiency of 137Cs+ was reduced after 7 days, because the 137Cs+ on the surface of

the soil particle had almost been removed for 7 days. However, the removal efficiency

of Experiment 3 was increased more than Experiments 1 and 2, because Experiment 3

used an impellor to increase the surface area of soil particles making contact with

electrolyte in the horizontal soil cell. In addition, when the decontamination period of

10 days, 14 days, and 21 days elapsed, the 137Cs+ in soil was removed by about 75%,

78%, and 81%. The removal efficiency of Experiment 3 was increased more than

Experiment 1 and 2 owing to the impellor.


89

An anion exchange membrane was inserted between the anode room and the

contaminated soil to protect against an influx of cesium ions in the electrolyte

occupying an upper part of a horizontal soil cell. When the decontamination period of

0.3 days, 2 days, and 7 days elapsed, 137Cs+ in the soil was removed by about 12%,

38%, and 83%. However, the removal efficiency of 137Cs+ was reduced after 7 days,

because the 137Cs+ on the surface of the soil particles had almost been removed for 7

days. The removal efficiency of Experiment 4 was increased more than that of

Experiment 3 because Experiment 3 used the anion exchange membrane to prevent the

contamination of 137Cs+ in the anode room. When the decontamination period of 10

days, 14 days, and 21 days elapsed, the 137Cs+ in soil was removed by about 91%,

93%, and 97%. Meanwhile, the more the origin radioactivity of soil decreased, the more

the removal efficiency of 137Cs+ was reduced. Table 1 shows removal efficiency

according to the lapsed time by electrokinetic-electrodailtic decontamination with an

anion exchange membrane (Experiment 4).

Conclusively, the removal efficiency of 137Cs+ from soil by electrokinetic-

electrodialytic decontamination technology was higher than that of 137Cs+ from soil by

electrokinetic decontamination technology. In addition, the anion exchange membrane

in electrokinetic-electrodialytic decontamination increased the removal efficiency of

137Cs+ from soil owing to the interception of an infiltration of 137Cs+ in the anode

room.

Table 2. Removal efficiency according to the lapsed time by electrokinetic-electrodailtic decontamination with an anion exchange membrane(Experiment 4)

OriginRed. 0.3

(days)

2

(days)

7

(days)

10

(days)

14

(days)

21

(days)

Removal

Eff. 1

20.5

(Bq/g) 14.0% 40.7% 86.5% 92.3% 95.1% 98.2%0.37

Removal

Eff. 2

12.4

(Bq/g) 12.7% 38.1% 83.9% 91.1% 93.5% 97.2% 0.35

Removal

Eff. 3

5.8

(Bq/g) 11.9% 36.7% 81.4% 87.5% 91.3% 95.4% 0.27

Removal

Eff. 4

1.7

(Bq/g) 11.1% 35.3% 79.5% 85.3 % 89.2% 94.1% 0.1

4. Conclusions

The difference between the removal efficiency of the electrokinetic-elctrodialytic

decontamination without an anion exchange membrane and that with an anion exchange

membrane was investigated through several experiments. The removal efficiency of 137

Cs+ from soil by electrokinetic-electrodialytic decontamination technology was

higher than that of 137

Cs+ from soil by electrokinetic decontamination technology. In

addition, the anion exchange membrane in electrokinetic-electrodialytic

decontamination increased the removal efficiency of 137

Cs+ from soil

owing to the

interception of an infiltration of 137

Cs+ in the anode room. Meanwhile, the more the

origin radioactivity of soil decreased, the more the removal efficiency of 137

Cs+ reduced.

When the electrokinetic-electrodialytic decontamination period of 0.3 days, 2 days, and

7 days elapsed, 137

Cs+ in the soil was removed by about 12%, 38%, and 83%. However,

the removal efficiency of 137

Cs+ was reduced after 7 days because the

137Cs

+ on the

surface of soil particles had almost been removed for 7 days. When the decontamination


90

period of 10 days, 14 days, and 21 days elapsed, the 137

Cs+ in soil was removed by

about 91%, 93%, and 97%.

References

[1] G. N. Kim, W. K. Choi, C. H. Bung, J. K. Moon, J. Ind. Eng. Chem. 13 (2007)

406-413.

[2] G.N. Kim, Y.H. Jung, J.J. Lee, J.K. Moon, Journal of the Korean Radioactive

Waste Society. 25(2)(2008) 146-153.

[3] K. Reddy, C.Y. Xu, S. Chinthamreddy, J. Hazard. Mater. B84 (2001) 279-296.

[4] S. Pamukcu, J.K. Wittle, Environ. Prog. 11(3) (1992) 241-270.

[5] K. Reddy and S. Chinthamreddy, J. Geotech. Geoenviron. Eng., March. (2003)

263-277.


91

Nº REF.: O439

Electrokinetic driven low-acid IOR in Abu Dhabi tight carbonate reservoirs

Arsalan Ansaria Mohamed Haroun

b,*, Mohammed Motiur Rahman

c, George V.

Chilingard

a, b, c The Petroleum Institute, Abu Dhabi, P.O. Box: 2533, U.A.E.

bUniversity of Southern California, Los Angeles, CA 90089, USA

*Mohamed Haroun: [email protected]

Abstract

Conventional acidizing, though useful in increasing the effective permeability in the

near well-bore region, has compatibility and operational issues such as limitation in

depth of penetration and HSE issues to handle, transport and injection ofhigh

concentration of acid into the well. On the other hand, the application of electrokinetics

(EK) has a number of economic and environmental advantages such as reduced oil

viscosity, reduced water-cut, and no depth limitation [1]. This study presents recent

research that demonstrates the impact of EK on matrix acid stimulation in Abu Dhabi

carbonate reservoirs with varying acid concentrations and voltage gradients [2].

Core-flood tests were conducted by saturating core-plugs retrieved from Abu Dhabi

oilfields with medium and light crude oil in a specially designed HTHP EEOR core-

flood setup[3]. Initially, EK was applied using acids of varying concentrations from

0.125 to 1.2% HCl injected at the anode to cathode (producer) at 0.25ml/min.

Experiments were also repeated with low concentration HClstimulation without the

application of EK.

Several correlations related to acid concentration, displacement efficiency and

permeability enhancement are presented here at ambient and reservoir conditions as

shown in Fig.1 and Fig.2. The experimental results have shown that upon the

application of waterflooding on the carbonate cores yields an average oil recovery of

60%. An additional 17-29% oil recovery was enhanced by the application of EK-

assisted low concentration HCl IOR (EK LA-IOR) at Abu Dhabi reservoir conditions.In

addition, EK LA-IOR was shown to enhance the reservoir’s permeability by

approximately 11-53% across the tested core-plugs.


92

Fig. 1. Effect of EK LA IOR on permeability enhancement using 0.5, 1, and 2 V/cm.

Fig. 2. Effect of EK LA IOR on oil displacement efficiency using 0.5, 1, and 2 V/cm.

Fig. 3. EK LA IOR at elevated reservoir temperature and pressure(formation water composition

270k ppm TDS) 30% increased oil displacement and more than 50% reduced water injected.

It was observed that low acid concentration with application of low voltage EK,

recorded a maximum oil displacement of 89% at reservoir conditions as shown in Fig.

3. Furthermore, this technique can be engineered to be a sustainableprocessin the

presence of EKas the concentration and voltage gradient can be optimized to reduce the


93

amount of acid injected and power consumption by 20-41% further improving

economic feasibility.

References

[1] Amba, S.A., Chilingar, G.V. and Beeson, C.M., 1964. Use of direct electrical

current for increasing the flow rate of reservoir fluids during petroleum recovery.

J. Canad. Petrol. Technol., 3 (1):8-14.

[2] Ansari A., Haroun M., Rahman M., Chilingar G., Wittle J.K. “Electrokinetics

Assisted Acidizing for Enhancing Oil Recovery in Abu Dhabi Carbonate

Reservoirs”. Electrokinetic Remediation Conference, EREM 2013, June 23-26,

2013.

[3] Haroun M., Wittle J.K. and Chilingar G.V., 2012. Publication No.

WO/2012/074510. Title of the invention: "Method for Enhanced Oil recovery

from Carbonate Reservoirs." Applicants: ELECTRO-PETROLEUM, INC. (US).

Inventors: Mohammed Haroun (AE), J. Kenneth Wittle (US) and George

Chilingar (US), June 12.


94

Nº REF.: O453

Selective recovery of dissolved metals from acid mine drainage via electrochemical method

S.M. Parka, S.W. Ji

b, K. Baek

a, c*


daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea bEnvironmental Hazardous Group, Korea Institute of Geoscience and Mineral

Resources, Daejeon 305-350, Republic of Korea cDepartment of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-


*Corresponding author: Tel.:+82-63-270-2437; Fax:+82-63-270-2449; E-mail:

[email protected]

In Korea, heavy metals contamination by abandoned mines has been a serious

environmental problem. Especially, acid mine drainage (AMD) contaminates the down-

stream of mines because that contains various toxic heavy metals as well as dissolved

iron and aluminum [1]. Recently, several researchers investigated to solve the

environmental problem related to AMD in points of recovery of metals instead of

removal in AMD. In the previous study, we reported that it is possible to recover

dissolved Fe, Al, Cu, and Zn/Ni from AMD by selective precipitation [2]. However, the

recovery consumed too much neutralizing chemicals such as neutralizing and oxidizing

agents. In this study, we produced oxidizing and neutralizing agent by electrochemical

reactions to reduce the usage of chemicals. The experimental conditions are shown in

the Table 1.

Table 1. Experimental conditions

Exp. Current (mA) Electrode Electrolyte

Membrane Anode Cathode Anolyte Catholyte

1 0 - -

200mg

Fe(II)/L

0.3M

NaHCO3

Nafion

N117

2 30 Graphite

Titanium

3 60 Titanium

4 60 BDD

5 60 Graphite

6 80 Graphite

7 Solar-cell Graphite

We hypothesized that ferrous was oxidized into ferric at the anode surface or in the

anolyte, and the cathodic reaction generated high concentration of hydroxide, a

neutralizing agent in the selective precipitation. We investigated the oxidation rate

constants, which were highly dependent on the anode materials (Fig.1(a)). Graphite

anode shows the highest oxidation rate, and the catholyte pH was independent on the

electrode material. Additionally, higher current enhanced the oxidation rate (Fig.2(b)).



95

Based on the result, ferrous can be oxidized to ferric iron via directive oxidation on the

anode surface, and it is potentially possible to produce neutralizing agent and to be used

for selective recovery of dissolved metals from AMD.

Time (hr)

0 1 2 3 4 5

0mA (Graphite)

30mA (Graphite)

60mA (Graphite)

80mA (Graphite)

Time (hr)

0 1 2 3 4 5

Ferr

ou

s iro

n c

on

cen

trati

on

(m

g/L

)

0

50

100

150

200

60mA (Titanium)

60mA (BDD)

60mA (Graphite)

(b)(a)

Figure 1. Concentration of ferrous iron in anolyte, (a) electrode types, (b) currents

Acknowledgement

This work was supported by Korea Institute of Geoscience and Mineral Resources

(KIGAM).

References

[1] D. Mohan and S. Chander, Removal and recovery of metal ions from acid mine

drainage using lignite – A low cost sorbent, J. Hazard. Mater. 137 (2006) 1545-

1553.

[2] S.M. Park, J.C. Yoo, S.W. Ji, J.S. Yang, and K. Baek, Selective recovery of Cu,

Zn, and Ni from acid mine drainage, Envrion. Geochem. Health 35 (2013) 735-

734.


96

Nº REF.: O464

Desalination of granite and sandstones by electrokinetic techniques. Comparison

Jorge Feijoo Condea*

, Ondrej Matyščákb, Lisbeth M. Ottosen

c, T. Rivas

aDept. of Natural resources and environmental. University of Vigo Campus Lagoas,

36310 Vigo-Spain bDepartment of Civil Engineering, Brno University of Technology, 602 00 Brno, Czech

Republic cDepartment of Civil Engineering, Technical University of Denmark, 2800 Kgs. Lyngby,

Denmark

* [email protected]

Soluble salts are considered as a main reason for damage of porous building materials

such as rocks, bricks, granites which are used in the building constructions of the

architectural and archaeological heritage. Soluble salts are also responsible for various

forms of deterioration such as sand disaggregation and superficial detachments [1-3].

These problems can be solved by conservation technologies which are aimed at

decreasing the salt concentration in the rocks (desalination).

The present study aims to investigate the efficiency of electrokinetic techniques for

desalination of two different kinds of rocks such as granite and sandstone in which this

technique had already been shown to be effective [4, 5]. These rocks were contaminated

with NaCl solution and the thickness of the samples used in the tests was 6 cm. This

study compares the percentage removal of salts at different depths (efficacy) and the

time needed to get this percentage removal (effectiveness) achieved in both stones.

From the results obtained, it was possible to find those inherent factors to each stone

which could have an influence on the efficacy of the treatment.

As the results, this technique reduced the salt concentration in the granite almost to 100

%, however, in the sandstone samples the decreases were not so high mainly at the

intermediate levels (Figure 1) where slight enrichments were observed. The obtained

results indicate that although the used technique is efficient for the salt removal

regardless of porosimetric distribution of the rock, the better interconnection between

the pores (the granite used in this research had a better interconnection) favored that the

desalination process in the material happened faster.


97

Figure 1.: a) chloride content (%Cl- g/g referred to the dry weight of the stone) by depth inside the

stones (granite; sandstone) before and after desalination test (seven application); b) efficacy (%Cl-) achieved in each rock

References

[1] Charola, A.E. Salts in the deterioration of porous materials: an overview. Journal

of America Institute of Conservation 39 (2000) 327-343.

[2] Doehne, E. Salt weathering: a selective review. Segesmund S., Weiss T. and

Vollbrecht A. Natural stone weathering phenomena, conservation strategies and

case studies. Geological Society. London. Special publications, 205, 51-64

(2002).

[3] Silva, B.; Rivas, T.; Prieto, B. (2003).- “Soluble salts in granitic monuments:

origin and decay effects. Applied Study of Cultural Heritage and Clays.J.L. Pérez

(Ed.), pp 113-130.

[4] Feijoo. J.; Nóvoa. X.R.; Rivas. T.; Mosquera. M.J.; Taboada. J.; Montojo. C.;

Carrera. F. (2012).- “Granite desalination using electromigration. Influence of

type of granite and saline contaminant”. Journal of Cultural Heritage.

[5] Ottosen, L.M.; Christensen, I. (2012) Electrokinetic desalination of sandstones for

NaCl removal – Test of different clay poultices at the electrodes. Electrochimica

Acta

Acknowledgements

J. Feijoo research was funded by a FPU-predoctoral grant by the Ministerio de

Educación of Spain.

Oral Session 5: Organic and chlorinated organic compounds remediation

Session Chair:

Claudio Cameselle-Fernández


101

Nº REF.: O520

Electrodialytic process applied for phosphorus recovery and organic contaminants remediation from sewage sludge

P. Guedes*, E. P. Mateus, N. Couto, C. Magro, A. Mosca, A. B. Ribeiro

CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências

e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal


In Europe, contamination by organics and inorganics is a concerning problem. Waste

material streams such as sewage sludge contribute for it. However, this waste stream,

considered as deleterious material, can be a source of important secondary resources

that nowadays are lost. In fact, sewage sludge from waste water treatment plants may

contain contaminants or unwanted elements regarding specific applications, but it also

contains secondary resources of high value like phosphorus that is one of the essential

nutrients in nature. Phosphate rock, the world main source phosphorus, is a non-

renewable resource, and it is expected to last 100 years becoming important to find new

strategies for phosphorus recovery. The electrodialytic process can be an option to

recover phosphorus from sewage sludge.

The present work discusses the efficiency of the electrodialytic process applied to

sewage sludge aiming phosphorus recovery and organic contaminants removal. Eight

organic contaminants, that are known to be endocrine disruptors, were studied: caffeine

(CAF), 17β-oestradiol (E2), 17α-ethinyloestradiol (EE2), triclosan (TCS), bisphenol A

(BPA), nonylphenol (NP), octylphenol (OP) and Oxybenzone (MBPh) in sewage sludge

in a laboratory cell.

Sewage sludge samples were spiked with all studied contaminants subjected to a low

level direct current. The laboratory cell was divided in two compartments where the

electrodes were placed [1]. Experiments were carried out with and without pH control in

the electrolyte compartment.

Due to water electrolysis, hydroxyl radicals (•OH, oxidation potential of 2.8 V NHE-1

)

are continuously being generated and can oxidize organic contaminants unselectively at

a diffusion-controlled rate. For this, degradation of the organic contaminants due to

water electrolysis was also studied.

Results show that remediation of organic contaminants and simultaneous phosphorus

recovery seems to be feasible through an integrated approach with different

remediation/removal mechanisms (electrokinetic transport, electro- and photo-

degradation).

Acknowledgements

Financial support was provided by FP7-PEOPLE-2010-IRSES-269289-

ELECTROACROSS - Electrokinetics across disciplines and continents: an integrated

approach to finding new strategies for sustainable development,

PTDC/ECM/111860/2009 - Electrokinetic treatment of sewage sludge and membrane


102

concentrate: Phosphorus recovery and dewatering. N. Couto acknowledges Fundação

para a Ciência e a Tecnologia for Post-Doc fellowship (SFRH/BPD/81122/2011).

References

[1] Ottosen, L.M., Jensen, P.E., Kirkelund, G.M., Ebbers, B. (2014). Electrodialytic

recovery and purification of phosphorous from sewage sludge ash, sewage sludge

and wastewater. Filed in 2013, Denmark.


103

Nº REF.: O523

Integration of electrokinetic process and nano-Fe3O4/S2O82- process for


Gordon C. C. Yang a, b, *

, Yu-Han Chiua, Chih-Lung Wanga

a Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung

80424, Taiwan b Center for Emerging Contaminants Research, National Sun Yat-Sen University,

Kaohsiung 80424, Taiwan


In this work the injection of nanoscale Fe3O4 slurry and sodium persulfate solution

coupled with electrokinetic (EK) process was tested for remediation of phthalate esters

(PAEs) in river sediment. The electrokinetic-assisted nano-Fe3O4/S2O82-

process has

been reported for remediation of soils contaminated by trichloroethylene and nitrate [1,

2]. The same process was employed in this work for remediation of river sediments

contaminated by di-n-butyl phthalate (DnBP; 1,909 μg/kg), di-(2-ethylhexyl) phthalate

(DEHP; 2,049 μg/kg), and di-iso-nonyl phthalate (DiNP; 929 μg/kg). First, nanoscale

Fe3O4 and its slurry were prepared in the laboratory. Then, several tests with different

reaction time (0-28 d) were carried out using the electrokinetic-assisted nano-

Fe3O4/S2O82-

process for PAEs degradation. In all EK tests, the anolyte and catholyte

were the river water obtained from the sampling site of river sediment of concern.

Nanoscale Fe3O4 slurry and sodium persulfate solution were injected into the same

electrode reservoir simultaneously or different electrode reservoirs separately on a daily

basis. Major research findings are given as follows: (1) under the optimal operating

conditions (i.e., titanium electrodes, electric potential gradient of 2 V/cm, reaction time

of 14 d, and daily injection of 3.14 g Na2S2O8 and 0.63 g nano-Fe3O4 into the anode

reservoir), overall removal efficiencies of 93.62%, 51.73%, and 98.92% were obtained

for DnBP, DEHP, and DiNP, respectively; (2) when nano-Fe3O4 slurry and Na2S2O8

solution were injected into the anode reservoir and cathode reservoir separately, a

serious electrochemical corrosion of titanium anode occurred because of the presence of

an electron acceptor (i.e., nano-Fe3O4) in the anode reservoir; (3) DEHP, reported by

others as a refractory organic contaminants, was the most persistent phthalate to degrade

in this work; and (4) more than 10 intermediate products due to PAEs degradation by

the nano-Fe3O4/S2O82-

process could be determined. In conclusion, the electrokinetic-

assisted nano-Fe3O4/S2O82-

process employed in this study is a viable technology for

river sediment contaminated by phthalate esters.

References

[1] G.C.C. Yang, C.F. Yeh, Sep. Purif. Technol. 79 (2011) 264.

[2] G.C.C. Yang, M.Y. Wu, Sep. Purif. Technol. 79 (2011) 272.


Oral Session 6: EKR in combination with other techniques

Session Chair:

Juan M. Paz García


107

Nº REF.: O604

Different strategies to enhance bioremediation of diesel-polluted soils using electro-kinetic processes

M.A. Rodrigo*, E. Mena, C. Ruiz, C. Saez, J. Villaseñor, P. Cañizares

Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies

& Institute of Chemical and Environmental Technology, Ciudad Real, 13071 SPAIN


In this lecture, different strategies for the remediation of spiked soils combining

biological processes with electro-kinetic soil flushing and permeable reactive barriers

are assessed at bench scale in clay and sandy soils using two-week long treatment tests.

Strategies applied are: 1) Direct combination of bioremediation with electrokinetic soil

flushing using bicarbonate solution as flushing fluid 2) single electro-bioremediation

processes with periodic polarity reversal 3) electrokinetic soil flushing with permeable

reactive bio-barriers using surfactant solutions as flushing fluids.

Results obtained depend strongly on the type of soil and, as expected, combinations are

only worth for clay soils. In this case, results show that efficiencies obtained with

classical bioremediation are not improved but worsen with the direct combination of

EKSF. These unexpected results are explained in terms of the difficult regulation of pH

and also because of the high temperatures reached under high electric fields (due to the

huge ohmic drops). Both parameters influence negatively on the viability of the

biological culture and finally cause its depletion. In this strategy, temperature also plays

a very important role on results because it favors volatilization of the pollutant.

On the contrary, efficiencies are greatly improved respect to single bioremediation using

permeable reactive bio-barriers consisting of either fixed cultures of acclimated

microorganisms or beds of soil mixed with suspended cultures. In this case, pH

regulation effect is not as dramatic as in the strategy 1 and microorganisms degrade very

efficiently the diesel pollutant.

Electro-bioremediation with periodic polarity reversal also shows good efficiencies

avoiding the problems caused by acidic and basic fronts on microorganisms, although

the rates obtained are far below those obtained by bio-barriers.

Changes in the concentration of nutrients, pH, conductivity and temperature are also

analyzed in this work giving light about the ways in which these processes can be

applied at the full scale in a synergistic way. Table 1 shows a summary of the main

results obtained in the three strategies discussed in this lecture

Table 1. Results of the different strategies after 14-days long remediation tests

Single

Bioremediation

Alternative 1

(single EBR)

Alternative 2

(reversal EBR)

Alternative 3

(EBR with PRB)

% COD Removed 11.79 11.36 18.12 26.78

Power Consumption (kW·h/TmSoil) -- 1238.5 145.3 90.3


108

At this point, matters related with scale up in soil remediation processes are discussed,

pointing out the difficulties of obtaining the same controlling mechanisms in setups at

different scales and hence the uncertainness of the reproducibility of results at different

scales [1,2].

Acknowledgements

Financial support from the Spanish government through project CTM2013-45612-R

and Innocampus (Procesos de electrorremediación, biorremediación y electro-

biorremediación de suelos contaminados) is gratefully acknowledged.

References

[1] E.Mena, J.Villasenor, P. Cañizares, M.A. Rodrigo, Journal of Environmental

Science and Health Part a 46 (2011), 914

[2] R. Lopez-Vizcaino, J. Alonso, P Cañizares, M.J. Leon, V. Navarro, M.A.

Rodrigo, C. Saez, Journal of Hazardous Materials 265 (2014) 142


109

Nº REF.: O606

Feasibility of coupling permeable bio-barriers and electrokinetic soil flushing for the treatment of organic chemical polluted soils

E. Menaa, C. Ruiz

a, C. Sáez

b, J. Villaseñor

a,*, M.A. Rodrigo

b, P. Cañizares

b

a Chemical Engineering Department. Research Institute for Chemical and

Environmental Technology (ITQUIMA). University of Castilla La Mancha, 13071,

Ciudad Real, Spain. b Chemical Engineering Department. Faculty of Chemical Sciences and Technology.

University of Castilla La Mancha, 13071, Ciudad Real, Spain.


This work presents the results obtained in the application of a novelty technique for the

treatment of polluted soils, which combines two previously well known technologies:

(1) Electrokinetic soil flusing (EKSF), consisting on applying an electric field to the

polluted soil for the drag of species through different mass transport processes [1, 2],

and (2) Biological permeable reactive barriers (Bio-PRB), which are based on

mobilizing the polluted groundwater through a barrier on which a supported microbial

consortia degrades the pollutants [3, 4]. Two experiments have been performed using

organic chemical-polluted clay soils in order to study the feasibility of the proposed

combined technology. We used two well-differenced organic compounds: the first one

was glucose, which is a highly biodegradable organic substrate and it was used with the

purpose of checking the viability of the treatment proposed; the second one was diesel,

which is a pollutant itself and its occurrence in the environment is unfortunately very

widespread. The bench-scale setup used in the tests in this work is schematized in the

Figure 1.

Figure 1: Bench-scale setup.

The setup was made in transparent methacrylate. The Bio-PRB with the attached

microbial consortia was located in the central part of the polluted soil section. As long

as the soil treatment was performed, the biological barrier was flooded in an inorganic

nutrients solution. Synthetic low permeability soil was used in all the experiments

(kaolinite). All the experiments were performed in a potentiostatic way, setting a

constant voltage gradient (1 V cm-1

). Different parameters directly related with the

biological degradation process were daily monitored during the experiments (e.g.

Cathodic Compartment

Power Supply

Graphite electrode CathodeGraphite electrode Anode

VA

Anodic Compartment

Collector Compartment

Collector Compartment

20 cm.

10cm

.

Polluted Soil BB Polluted Soil

Level

Control

Electrolite:

Syntethic

tap water

E.O.

volume

Multimeter

mA


110

electrical current, temperature, pH and inorganic nutrient concentrations). At the end of

the experiments, an in-depth sectioned analysis of the complete soil section was done.

Figure 2. a) Glucose test conditions in the Bio-PRB medium: temperature (), dissolved oxygen

(), pH (); b) Diesel test conditions in the Bio-PRB medium: temperature (), dissolved oxygen (), pH (). c) Relation between pH and microbial population in the soil at the end of the tests: pH () and microbial concentration () in the glucose-test; pH () and microbial

concentration () in de diesel-test. d) Pollutants removal: diesel and glucose concentration at the beginning of the tests (), diesel concentration at the end of the test (), glucose concentration

at the end of the test ().

Temperature, dissolved oxygen and pH were between optimal values for the biological

degradation process during all the experiments (Figure 2.a and b), which confirmed that

the position of the barrier in the middle point of the soil section was adequate for the

proposed technology. As it was expected, values of pH obtained in the nearness of the

anode were acid, and, in the same way, values obtained in the nearness of the cathode

were basic (Figure 2.c). Because these pH conditions, activity of the microorganisms in

these areas was inhibited. Microbial concentrations were higher in the central areas

where the pH values were around the neutral value. Regarding the organics removal,

glucose was completely removed from the soil because its high water solubility and

biodegradability (Figure 2.d). On the other hand, a diesel oil removal efficiency near to

the 27% was obtained.

From the results presented in this work it can be concluded that the combination of

EKSF with Bio-PRB technologies could be an efficient alternative for the removal of

organic pollution from low permeability soils. Most of the important parameters

influencing on the biodegradation process were successfully controlled and the

biological removal of pollutant was possible, with different efficiencies depending on

their biodegradability and solubility.

Acknowledgments

The financial support of the Spanish Government through projects CTM2010-18833

and CTM2013-45612-R and INNOCAMPUS is gratefully acknowledged.

0

5

10

15

20

25

0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200 250 300 350

Tem

per

atu

re (

ºC)

D.O

. (p

pm

) //

pH

Time (h)

0

5

10

15

20

25

0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200 250 300 350

Tem

per

atu

re (

ºC)

D.O

. (p

pm

) //

pH

Time (h)

a

b

1

10

100

1000

10000

100000

0

1

2

3

4

5

6

7

8

9

10

1 2 3 4

CF

U/g

So

il

pH

Position

0

2000

4000

6000

8000

10000

12000

1 2 3 4m

g(G

luco

se/D

iese

l)/k

gS

oil

Position

Anode CathodeBio-PRB

c

d


111

References

[1] R. López-Vizcaíno, C. Sáez, E. Mena, J. Villaseñor, P. Cañizares, M.A. Rodrigo,

J. Environ. Sci. Heal. A. 46 (2011) 1549

[2] R. López-Vizcaíno, C. Sáez, P. Cañizares, V. Navarro, M.A. Rodrigo, Sep. Sci.

Technol. 46 (2011) 2148

[3] S. Saponaro, A. Careghini, L. Romele, E. Sezenna, A. Franzetti, I. Gandolfi, M.

Daghio, G. Bestetti, WIT Trans. Ecol. Envir. 164 (2012) 439

[4] S. Saponaro, M. Negri, E. Sezenna, L. Bonomo, C. Sorlini, J. Hazard. Mater. 167

(2009) 545


112

Nº REF.: O608

Effect of electrokinetic enhancement on phytoremediation of soils with mixed contaminants

Reshma A. Chirakkaraa, Claudio Cameselle

b,*, Krishna R. Reddy

c

a Graduate Research Assistant, Department of Civil and Materials Engineering,

University of Illinois at Chicago, Chicago, Illinois 60607, USA b Associate Professor, Chemical Engineering Dept., University of Vigo, Vigo, Spain

c Professor, Department of Civil and Materials Engineering, University of Illinois at

Chicago, Chicago, Illinois 60607, USA


Soils contaminated with mixed contaminants are a major environmental problem

worldwide not only for their negatives effects for living organisms but also for the

complexity of their remediation. Many of the contaminated sites contain both organic

and inorganic (e.g. heavy metals) contaminants and their remediation is even more

complex due to the very different physic-chemical properties of both kinds of

contaminants. There are very few methods that can remediate both heavy metals and

organic contaminants in soils. Most of these methods, however, are energy intensive,

time consuming and expensive; and the remediation results largely depend on site

characteristics. In this context, phytoremediation is proposed as a promising method for

remediation of sites with contamination mixtures.

Phytoremediation is a green and sustainable remedial strategy, most appropriate for

large sites with low contamination levels [1]. This technology is based on the growing

of selected plants in the contaminated site to extract, stabilize or degrade the

contaminants in the soil around the plant roots [2]. Several mechanisms

(phytoextraction, rhizofiltration, phytostimulation and phytodegradation) have been

identified for the removal/degradation of contaminants in soil remediation due to the

plant activity. One of the major limiting factors in phytoremediation is the low

bioavailability of contaminants in the soil pore fluid. This limitation can be overcome

by the application of a low electric potential in the vicinity of the growing plant to

mobilize the contaminants in the soil [3]. Very few studies combining electrokinetics

and phytoremediation have been published [3], and they were all done on soils

contaminated only with heavy metals. The potential of the combined phytoremediation-

electrokinetics technology for mixed contaminated soils have not been explored.

This study aims in enhancing the bioavailability of contaminants for phytoremediation

by the application of a low voltage electric potential to the soil. Alternating current was

applied instead of DC, since the main objective is to increase the mobility and

bioavailability of the contaminants, but not their transport in a specific direction. Based

on their capability to survive and remediate in mixed contaminated soils, Avena sativa

(oat plant) and Helianthus annuus (sunflower) were selected for the study [4]. Mixed

contaminated soil was prepared by spiking silty clay soil, typical of the Chicago area,

with naphthalene, phenanthrene, lead, cadmium and chromium. Contaminated soil was

mixed with 200 g/kg of compost to improve plant growth [5]. The contaminated soil

was filled in five electrokinetic cells. Two cells were seeded with twenty seeds of Avena

sativa and two cells were seeded with twenty seeds of Helianthus annuus. One cell was


113

kept unseeded to study the effect of electric potential application without plant growth.

The cells were placed under metal halide grow lights of average photosynthetic photon

density of 400 µmols/m2 s. Grow lights were timed for 16 hours of light period per day.

After 30 days of plant growth, 25 V (alternate electric current) was applied 3h/day to

one cell with Avena sativa, one cell with Helianthus annuus and to the unplanted cell.

The plants were harvested after 61 days of seeding. The root and shoot biomass were

dried separately at 60°C for 6 days. Heavy metal content was determined in soil samples

by acid digestion (EPA method 3050B) followed by Flame Atomic Absorption

Spectroscopy (FLAA). The exchangeable fraction of metals in soil was determined by

extraction with sodium acetate followed by FLAA [2]. PAH analysis was done

following EPA method SW8270C with gas chromatography, after solvent extraction.

The experimental results revealed that Avena sativa had higher germination rate

compared to Helianthus annuus, which can be interpreted as an effect of the

contaminants in soil. The electric field did not seem to affect germination and survival

rates of the plants or the final maximum plant heights of both plants. However, total

biomass of both plants was found to be higher for plants in cells with electric potential

application. Avena sativa did not show any significant reduction (p>0.05) in Pb or Cd,

but in cells with Helianthus annuus, there was an approximate reduction of 23% Pb and

17% Cd. Exchangeable Pb was found to be zero in all cells whereas planted pots did not

show any significant difference in exchangeable Cd content compared to control.

Unplanted cell with electric potential application had higher exchangeable Cd compared

to control. Chromium concentration in soil was reduced significantly in all planted pots.

Approximate Cr reduction was 23% by Avena sativa and 18% by Helianthus annuus.

All the cells had lesser exchangeable Cr concentrations compared to the control. All the

planted cells had significantly lesser exchangeable Cr concentrations compared to the

cells with electric potential application only.

Naphthalene concentration was found to be zero in all the samples suggesting microbial

degradation and volatilization. There was no considerable difference in phenanthrene

concentration of different cells. This shows that the applied voltage and duration of the

electric potential may not be sufficient to increase the availability of contaminants for

plant uptake or plant promoted degradation. It is suggested to increase the application

time of the electric potential and the frequency of its application in order to enhance the

effect of the electric current on the bioavailability of contaminants.

References

[1] K. R. Reddy & R. A. Chirakkara, Geotech. Geol. Eng. 31 (2013) 1653.

[2] H. D. Sharma, K. R. Reddy, Geoenvironmental engineering: site remediation,

waste containment, and emerging waste management technologies. John Wiley &

Sons, New York. (2004).

[3] C. Cameselle, R. A. Chirakkara, K. R. Reddy, Chemosphere 93(2013) 626.

[4] R. A. Chirakkara, K. R. Reddy, Proc. 106th

Annual Conference & Exhibition, Air

& Waste Management Association, Pittsburgh, PA, (2013) 1.

[5] N. Karami, R. Clemente, E. Moreno-Jiménez, N.W. Lepp, L. Beesley, J. Hazard.

Mater. 191 (2011) 41.


114

Nº REF.: O634

Potential of electrokinetic process to recover phosphorus and remove cyanotoxins from membrane concentrate

Nazaré Coutoa,*

, Paula Guedesa, Eduardo P. Mateus

a, Cristele Santos

b, Margarida

R. Teixeirab, Alexandra Ribeiro

a

a CENSE, Departamento de Ciências e Engenharia do Ambiente, Faculdade de

Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. b

CENSE, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de

Gambelas, 8005-139 Faro, Portugal.


Water treatment technologies, like membranes, can be used to guarantee safe levels of

contaminants in water. Nanofiltration (NF) is a viable option for drinking water

treatment that effectively removes cyanobacteria and cyanotoxins from algal blooms, a

phenomenon found worldwide in water reservoirs. The use of NF produces a clean

stream (permeate) but also a concentrate stream (membrane concentrate) that contains

all the compounds removed by the membrane. The presence of phosphorus (P) in

membrane concentrate suggests the possibility of nutrient recover for further re-use.

In this study NF was applied to produce membrane concentrates using water from two

portuguese Dam reservoirs as feed water. The purpose was to combine NF to

concentrate P existent in the concentrate stream followed by its recovering using the

electrodialytic process (ED). Contaminants from the concentrate stream were also

removed by ED. This is the case of microcystins (toxins produced by Microcystis

aeruginosa MC-LR), a high molecular weight compound, slightly negative and

hydrophilic that may cause severe health due to their acute and sublethal toxicity.

Applying a low level direct current the electrokinetic movement of ions is combined

with electrodialysis, promoting analytes movement towards one of the electrode

compartments, where they are concentrated and may be removed.

Electrodialytic process seems to be a feasible option for P recovery but its recovery

percentage depends on the characteristics of the waste streams. Complementary

experiments were also conducted to evaluate microcystins removal, MC-LR variant,

effectively purifying P from other contaminants.

Acknowledgements

Financial support for the work is provided by projects FP7-PEOPLE-2010-IRSES-

269289* ELECTROACROSS - Electrokinetics across disciplines and continents: an

integrated approach to finding new strategies for sustainable development and

PTDC/ECM/111860/2009 - Electrokinetic treatment of sewage sludge and membrane

concentrate: Phosphorus recovery and dewatering. N. Couto acknowledges Fundação

para a Ciência e a Tecnologia for her Post-Doc fellowship (SFRH/BPD/81122/2011).


115

Nº REF.: O659

Electrodialytic removal of heavy metals from fly ash from co-combustion of wood and straw – influence from prewash

Wan Chen*, Lisbeth M. Ottosen, Pernille E. Jensen, Gunvor M. Kirkelund, Jacob

W. Schmidt

Department of Civil Engineering, Technical University of Denmark, Brovej, Building

118, DK-2800 Lyngby, Denmark


The heavy metal content in the fly ash from biomass combustion, such as straw, wood

and sludge, often needs to be lowered before the ash can be used as fertilizer at

agricultural land or in construction materials. In this study, fly ash from a boiler fueled

with wood chips and straw was either treated directly by electrodialytic remediation

(EDR) or a combination of prewash in water and EDR to lower the heavy metal content

(Figure 1). Different experimental set-ups (Figure 2 under different experimental

conditions in Table 1) were tested for treatment of the ash suspended in distilled water

in order to investigate the heavy metal removal. The investigation focuses on Cd and Pb

removal as these are the major problems in relation to the limiting values, but also other

heavy metals are reported: As, Cr, Cu, Ni and Zn.

Prewashing caused an increase in total concentrations of most heavy metals compared

to the ash before wash. This is because the high soluble fraction (around 80 %) is

removed and thus the heavy metals are concentrated in the ash as these are generally

little soluble in water.

After prewash, the limiting concentration of Pb (120 mg/kg) was exceeded. The

concentration in the washed ash was not lowered sufficiently during EDR in a 3

compartment cell (Figure 2-a), but after treatment in the EDR cell with 2 compartments

(Figure 2-b) the concentration met the requirement. The two compartment cell was

probably better (Table 2) due to the fast acidification process. However, this fast

acidification may in turn affect the leaching property of the treated ash, which has As,

Se and Ni exceeding the limiting concentrations. Ni needs attention in the ashes treated

in 3-compartment cell. The Cd concentration was reduced to below 2 mg/kg, no matter

how high the concentration was before the treatment.

Figure 1. Experimental design.


116

Figure 2. The schematic drawing of the types of EDR cells used in the experiments: (a) 3-

compartment, and (b) 2-compartment. (AN: anion exchange membrane; CAT: cation exchange membrane).

Table 1. The experimental conditions.

No. Sample Current

(mA)

EDR cell

(compartment no.)

L/S

(L/kg)

Duration

(days)

Charge

(Coulombs)

E1 EFA-1 50 3 7 14 60480

E2 WEFA-1 50 (Day 1)1 to 10 3 7 ~ 67 60480

E3 WEFA-2 10 3 7 70 60480

E4 EFA-2 50 3 7 10 43200

E5 WEFA-2 40 3 7 10 34560

E6 WEFA-2 40 2 7 10 34560 1The voltage between the two working electrodes went up to the maximum voltage of the power

supply on Day 1, so the current was changed to 10 mA from Day 2.

Table 2. Cd and Pb removal from the EDR experiments.

E1 E2 E3 E4 E5 E6

Cd Removal

efficiency1,%

98

96

96

98

94

98

Mass

balance2, %

91

102

100

106

105

93

Pb

Removal

efficiency,%

Mass

balance, %

67

94

18

96

25

91

48

122

12

94

47

83 1The removal efficiency was calculated from the mass difference of the element in the ash

before and after treatment divided by the initial mass in the ash.

2Mass balance was defined as the percentage of the total final mass of the element, found in all

parts of the cell (electrodes, electrolyte, membranes, ash suspension), in its initial mass input

from the ash.

Poster Session: Metal Removal and transport of inorganics


119

Nº REF.: P110

Remediation of cuprum from clay soils

Romanova I.V.a, Korolev V.A.

b

aStudent of Geological Faculty of MSU named M.V. Lomonosov, Moscow, 119991,

Russia; e-mail address: [email protected] b Professor of Geological Faculty of MSU named M.V. Lomonosov, Moscow, 119991,

Russia; e-mail address: [email protected]

The cleaning of clay soils from various heavy metals (HM) is the important issue, and it

is the great ecological value. Among the heavy metals cuprum is one of the major sites

as a contaminant of soil and other environmental components. Now, the electrokinetic

method is one of the effective methods of cleaning soil from cuprum. The complex

electrochemical and electro kinetic processes occurring in soils in the field of direct

electric current is at its core.

The study of electrosurface and electrokinetic soil processes conducted at the

Department of Engineering and Ecological Geology, Geological Faculty of Moscow

State University(MSU)since the 1960's, and their using for cleaning soils from various

toxic components(heavy metals, hydrocarbons, radionuclides, organic toxicants etc.) is

studied since 1995 [2].

Many patterns of electrochemical migration of heavy metals (including cuprum) are still

unexplained, despite a lot of work carried out in this area [1-4].Therefore, in this paper

we present the results of studies of this process and analyzes of the main factors

affecting on the remediation of cuprum from clay soils.

The laboratory investigation was performed in the electroosmotic cells of two types:

type one (type 1) envisaged a staic version of the experiment, and type two (type 2)

envisaged a flowing version simulating sample washing and electrochemical leaching

out the pollutant.

Cuprum as the toxicant, belong to the second class of hazard substances. Therefore, the

study of factors affecting on its electrochemical remediation is important for the

environment. The analysis of the main factors is described below.

1. The influence of mineral composition was studied on the non-flowing mode (type

1). It manifests itself through the features of the double electric layer (DEL) parameters,

which is formed around the particles of different mineral composition and in the pore

volume occupied by the DEL in the soil. This makes the different physicochemical

and electrochemical activity clay soils. We studied monomineral clay (smectite, illite

and kaolinite) as well aspolymineral glacial clay soils. It was found that the

electrochemical activity of the clay soil decreases in the series: “smectite clays> illite

clays> kaolinite clays = polymineral clays”.

2. The influence of granulometric composition. The effect of granulometric

composition of soil on remediation of cuprum from clay soils was studied in call of type

1.The clay soil, which dispersion increased from sandy loam to light and medium loam,


120

was investigated. It was found that with increasing of dispersion the degree of cleaning

clay soils in the anode zone increases.

3. The influence of initial moisture. Experiments were performed on kaolinite clay at

the same initial concentration of cuprum in the samples- 12g /kg(i.e., related to a very

high degree of contamination).It has been found that in non-flowing variant (type

1),with increasing initial moisture the degree of cleaning soil from the cuprum in the

anode zone increases. This is due to the fact that magnitude of electroosmotic transport

increasing with the moisture increases because the thickness of the double electrical

layer (DEL) around the particles also increases.

4. The influence of the test. We have studied the cuprum removal efficiency by

comparing the results cleaning the same soil in the flowing and non-flowing cells.

Experiments have shown that the degree of purification of the soil in the anode area in

the flow variant (type 2) is greater than in non-flowing variant (type1). Electrochemical

leaching is more effective for cleaning. At the same time, the longer the flushing

process, the more copper is removed from the clay soil.

5. The influence of anolyte. Purpose fully selecting the composition of the anolyte, we

can increase the degree of purification of soil cuprum. The composition of the anolyte

may affect on the acidity of the pore solution environment (pH), as well as desorption of

cuprum from the cation exchange complex of the clay soil. In this way the

electrochemical mobility of cuprum may increase. Therefore, the degree of soil

decontamination increases in the mode of electrochemical leaching (type 2).

Experiments have shown that this can be used for the acidification of the aqueous

solutions.

6. The influence of cuprum forms in the soil. The cuprum, like many other heavy

metals in the soil is located in the different forms and ionic complexes. Each of them is

different will be exposed to an electric field and will exhibit different electrochemical

activity. There are different adsorption sites of cuprum in the clay soils; they have

different effects on the electrochemical mobility of cuprum. Usually to the determine

modes of occurrence of heavy metals use the method of successive extracts, for example

by the method of Tessier [1]. We confirmed that the greatest contribution to the removal

of cuprum from the clay soils makes cuprum, located in the soil cation exchange

complex, i.e.within the DEL. Consequently, all factors affecting on the characteristics of

DEL in the clay soil, will have impact on the electrochemical removal of cuprum from

them. Further, a smaller contribution to the removal of cuprum contributes the cuprum

adsorbed onto carbonates and oxides of Fe and Mn, an even smaller contribution is the

cuprum sorbed on organic substances. I.e. the cuprum humates most difficult to remove

from the soils. This is explained by the special forms of physical and chemical

interactions of cuprum with humic substances, including - with fulvic acids. Therefore,

the grounds containing humus, including soils and peats, it will be harder to clean from

cuprum than not humus soils.

7. The influence of impurities other HM. Also, the presence of other heavy metal

ions, such as ions Cd, Zn, Hg, Ni, Mo, etc. influenced on the electrochemical migration

of cuprum in the clay soils. And there are conflicting information in the press on this

factor [1].In our opinion these differences are explained by the different composition of

cations in the clay soil exchange complex, and consequently –by the different mutual

influence on the processes of adsorption and desorption.


121

Conclusion. Thus, the results of research showed that the electrochemical remediation

of cuprum from clay soils is the quite effective method for the purify of clay soils from

cuprum to the required environmental levels.

References

[1] V.A. Korolev, E.N. Samarin, Y.V. Shumkina, Engineering Research, 12 (2012)

72-78 (in Russian)

[2] V.A. Korolev. Cleaning of soils from pollutions. Moscow, MAIK

Nauka/Interperiodika, 2001, 365 p. (in Russian)

[3] L.M. Ottosen, I.V. Christensen, I.Rӧring-Dalgard, P.E. Jensen, J. of Environ. Sci.

and Heath, Part A. Toxic/Hazardous Substances & Environ. Engineering. 43(8)

(2008), 795-809

[4] A. Ribero, J.T. Mexia, J. Hazard. Mater. 56 (3) (1998) 257-277


122

Nº REF.: P112

Testing of new shifting current electrodialytic treatment setup for efficient treatment of Cr-contaminated soil fines

Pernille Erland Jensena,*

, Lisbeth M. Ottosena, Gunvor Kirkelund

a

a Technial University of Denmark, 2800 Lyngby, Denmark.


Cr contamination is regularly encountered in surface soil and poses a risk towards

human health and the environment. Cr is particularly mobile and toxic in its oxidized

form: Cr(VI). Previous investigations of the influence of Cr-speciation on electrokinetic

remediation (EKR) in stationary setups showed that removal of Cr(III) occurred only

under highly acidic conditions [1], and Cr (III) removal from industrially contaminated

soils is slow compared to removal of other heavy metals [2]. It was shown that Cr(VI) is

much faster remediated by EKR than Cr(III) [3]. Indeed, Cr(VI) was observed to be

faster remediated than both Cd and and Ni under acidic conditions [1] and removal of

Cr(VI) was observed to increase at neutral/alkaline conditions from spiked soil [1].

Reduction of Cr(VI) to Cr(III) during stationary EKR was documented [1]. In general,

however, Cr was recovered in the anolyte when soils were spiked with Cr(VI) [1, 4, 5,

6] and in the catholyte when soils were spiked with Cr(III) [7, 8, 9]. When treating soil-

fines in a suspended setup as reported in [10], as much as 53% Cr was, however,

transferred to the catholyte as Cr(III) from a CCA-impregnation contaminated soil

within 10 days. But Cr(III) remained the slowest contaminant to remove compared to

both As, Cd, Cu, Ni, Pb and Zn; and from two other soils less than 20% Cr was

removed by identical treatment [10]. Thus development proper enhancement method is

needed to be able to remediate Cr(III)-contaminated soil efficiently.

In the present work, a new treatment concept is tested for its feasibility on Cr-

remediation. In the new setup, soil fines are treated in suspension with alternating

current between two anodes at different frequencies. One anode is placed in the anode-

compartment and the other anode is placed directly into the middle compartment

containing the soil fines suspension (figure 1) with the aim to oxidize Cr(III) to Cr(VI)

by direct contact between electrode and contaminant.

Figure 1. Experimental setup

+


123

All experiments were made with soil from the Collstrop-site in Hillerød, Denmark,

contaminated by CCA-impregnation activity. Thus contaminated by Cu, Cr and As.

Experiments were made according to the plan listed in table 1.

Table 1. List of experiments

Exp. No of compartments (fig. 1) Frequency of alternating current

2C 2 (only II and III) 0 (i.e. only anode in middle compartment on)

3C 3 0 (i.e. only anode in anode compartment on)

3C-min 3 Every minute

3C-hour 3 Every hour

3C-day 3 Every 24 hours

The results show that direct contact between the contaminated soil fines and the anode

significantly enhances remediation efficiency of Cr.

References

[1] K.R. Reddy, S. Chinthamreddy, Journal of Geotechnical and Geoenvironmental

Engineering 129 (2003) 263.

[2] H.K. Hansen, L.M. Ottosen, B.K. Kliem, A. Villumsen, Journal of Chemical

Technology and Biotechnology 70 (1997) 67.

[3] S. Li, T. Li, F. Li, L. Liang, G. Li; S. Guo, Proceedings of 5th International

Conference on Bioinformatics and Biomedical Engineering (2011).

[4] K.R. Reddy, U.S. Parupudi, S.N. Devulapalli, C.Y. Xu, Journal of Hazardous

Materials 55 (1997) 135.

[5] K. Sanjay, A. Arora, R. Shekhar, R.P. Das, Colloids and Surfaces A -

Physicochemical and Engineering Aspects 222 (2003) 253.

[6] A. Sawada, S. Tanaka, M. Fukushima, K. Tatsumi, Journal of Hazardous

Materials 96 (2003) 145.

[7] Z.M. Li, J.W. Yu, I. Neretnieks, Journal of Hazardous Materials 55 (1997) 295.

[8] Z.M. Li, J.W. Yu, I. Neretnieks, Journal of Environmental Science and Health

Part A-Toxic/Hazardous Substances & Environmental Engineering 32 (1997)

1293.

[9] C.H. Weng, C. Yuan, Environmental Geochemistry and Health 23 (2001) 281.

[10] P.E. Jensen, L.M. Ottosen, B. Allard, Electrochimica Acta 86 (2012) 115.


124

Nº REF.: P116

Electrokinetic remediation with novel electrode configuration

Ikrema Hassana, Eltayeb Mohamedelhassan

b*, Ernest K. Yanful

a

a Dept. of Civil & Env. Eng., Western University, London, ON, N6A 5B9, Canada

b Dept. of Civil Eng., Lakehead University, Thunder Bay, ON, P7B 5E1, Canada


Introduction

In electrokinetic process, electrolysis reactions at the electrodes create an acid front near

the anode and a base front at the cathode. The two fronts then move toward each other

by electroosmosis and/or electromigration creating two soil zones with opposite pH

characteristics. The impact from the advancement of the acid and base fronts in the soil

is dependent on the intended use of electrokinetics. For instance, in electrokinetic

bioremediation, the low pH in the acid front zone is detrimental to the existence of

bacteria and subsequently decreases the effectiveness of the process [1]. The acidic

medium causes the dissolution of heavy metal compounds in the soil which facilitates

the removal of the metals by electroosmsois and/or electromigration. On the other hand,

the base front on its path towards the anode reacts with the cations in the pore fluid

before they reach the cathode causing premature precipitation of the heavy metal(s) in

the soil. The premature precipitation of the heavy metals is a major drawback for

electrokinetic remediation [2]. Extensive research has aimed to hinder the advancement

of the base front and the premature precipitation of ionic species. Researchers have

investigated conventional and innovative techniques to overcome the limitation of the

premature precipitation. The most popular conventional approaches are the addition of

enhancement fluids to depolarize the cathode reaction [3-5]. The innovative techniques

include stepwise moving anode [6] and polarity exchange [2]. The field applications for

conventional approaches or innovative techniques need either the use of of chemicals

compounds or an extra field work or both. Thus, the overall cost of the remediation

process increases regardless of the improvement in the efficiency.

This study proposed a novel approach, Two Anode Technique (TAT), to hinder the base

front advancement and enhance electrokinetic remediation of soil contaminated with

heavy metal(s). Compared to conventional anode configuration (CAC) and innovative

approaches, TAT can significantly decrease the advancement of the base front without

adding a chemical compound or an extra field work.

(a) (b)

Figure 1. (a) Conventional anode configuration (CAC); (b) Two anode technique (TAT)

OH

H

Cathode

DC Power supplyMain electric circuit

Primary anode

OH

H

H

Cathode

DC Power supplyMain electric circuit

DC Power supply

Secondaryelectric circuit

Primary anode Secondary anode


125

Procedure

In this study, one-dimensional electrokinetic remediation was performed using an EK

cell with inner dimensions of 385×125×250 mm (lengthwidthheight). Copper(II)

chloride dehydrate was used to artificially contaminate a lean clay and simulate

common heavy metals pollution. Graphite electrodes with dimensions 200x15x6 mm

(length width × thickness), served as pair of anodes and pair of cathodes, were placed

in direct contact with the soil specimen in the electrokinetic cell. The two anodes were

placed 30 mm apart and likewise the pair of the cathodes. One DC power supply was

connected to the anode and cathode in the elctrokinetic testing cell with CAC

(Figure 1a). Two DC power supplies were connected to the graphite electrodes in the

electrokinetic testing cell with TAT (Figure 1b). ADC power supply with applied

voltage of 40V (2 V/cm) was connected to the pair of primary anodes and the pair of

cathodes (outer electric circuit) in both cells. In addition to the aforementioned power

supply, a second power supply with applied voltage of 15 V (3 V/cm) was connected to

the pair of secondary anodes and the pair of cathodes to form the secondary electric

circuit in the TAT cell as shown in Figure 1b.

Results

After the test, the soil specimen was divided into four equal sections (S1 to S4). The pH

in the soil sections after the CAC test at S1, S2, S3, and S4 are 2.0, 2.2, 7.2, and 8.5,

respectively. The pH at the end of TAT test at S1, S2, S3, and S4 are 2.2, 2.2, 2.5, and

3.5, respectively. Thus, while CAC lowered the pH of the soil to acidic levels in two

sections, TAT was effective in lowering the pH of the soil to acidic levels in all

sections. Figure 2 shows the ratio (%) of copper concentration (C/Co) in soil sections

after CAC and TAT tests with power consumption of 1250 Whr. As seen in Figure 2, in

the CAC test, 94%, 89%, and 35% of initial copper was removed from S1, S2 and S3,

respectively. In the cell with TAT configuration, 93%, 87%, and 81% of the initial

copper was removed from S1, S2, and S3, respectively. In both tests, approximately all

of the removed copper accumulated in S4.

(a) (b)

Figure 2. (a) Conventional anode configuration (CAC); (b) Two anode technique (TAT)

Conclusions

The purpose of the study was to investigate an innovative approach to hinder the

advancement of the basic front and enhance the efficiency of removing heavy metals

from contaminated soil. In CAC and TAT tests, most of the copper was removed from

sections S1 and S2. However, TAT test was successful in removing 81% of the copper

from S3 compared to 35% in CAC test. The effectiveness in removal from S3 in TAT

test resulted from the success of the technique in preventing the base front from

Soil sections (S1-S4)

Co

pp

er

C/C

o (

%)

0

50

100

150

200

250

300

Total copper in soil

Copper in soil solids

Copper in water

S1 S2 S3 S4

An

od

e

Ca

tho

de

Soil sections (S1-S4)

Co

pp

er

C/C

o (

%)

0

50

100

150

200

250

300Total copper in soil

Copper in soil solids

Copper in water

S1 S2 S3

An

od

e

S4

Se

co

nd

ary

an

od

e

Ca

tho

de


126

reaching S4. The success of TAT in removing the copper from 75% of the contaminated

soil compared to 50% in the CAC tests is significant to the progress of elecrokinetic

remediation of contaminated soils. More research is needed to optimize TAT configuration for electric current and location of secondary anode.

References

[1] E.K. Nyer. In situ treatment technology. Boca Raton, Fla., Lewis Publishers

(2001)

[2] M.Pazos, M.A. Sanroman, Chemosphere 62 (2006) 817

[3] Y.B. Acar, A.N. Alshawabkeh, Environ. Sci. Technol. 27 (1993) 2638

[4] Y.B. Acar, Hamed J. T., A.N. Alshawabkeh, R.J. Gale. Geotechnique

44(1994)239

[5] A.T. Yeung, C. Hsu, Journal of Hazardous Materials 55(1997) 221

[6] X.J. Chen, Z. M. Shen, T. Yuan, S.S. Zheng, B.X. Ju, W.H. Wang, J. of Environ.

Sci. and Heal. Part a-Toxic/Hazardous Substances & Environ. Eng. 41(2006)

2517


127

Nº REF.: P124

Determining variable importance on electrodialytic remediation of heavy metals from polluted harbour sediments

Kristine B. Pedersena,*

, Lisbeth M. Ottosenb, Pernille E. Jensenb, Tore Lejon

a

a Department of Chemistry, The Arctic University of Norway, 9019 Tromsø, Norway

b Arctic Engineering and Sustainable Solutions, Technical University of Denmark, 2800

Kgs Lyngby, Denmark


Harbour sediments have been exposed to a wide variety of pollutants caused by decades

of human activities in the harbours as well as on adjacent land. The need for

management of polluted harbour sediments arises either through governmental acts to

decrease the hazardous risk for human health and the environment; or through the

development of harbours in which contact with or removal of polluted sediments is

inevitable; e.g. when increasing navigational depths. The most common way of dealing

with dredged contaminated sediments is disposal at licensed landfills (on land or at deep

sea), and in some cases solidification/stabilisation of the sediments, e.g. in new harbour

constructions. In order to increase the recycling potential of contaminated sediments

there is a need to develop more cost-efficient methods for remediating to levels at which

the sediments are made available for reuse. Electrodialytic remediation (EDR) has been

proven a good method for removing heavy metals from polluted harbour sediments to

levels assessed as not posing a hazardous risk for human health and the environment

according to international recommended values from OSPAR [1-7].

The focus of this study was to contribute to the further development and optimisation of

the EDR methods in remediating harbour sediments, applying the newly developed two

compartment cells as opposed to the traditional three compartment EDR cells. In the

traditional three compartment cells ion exchange membranes separate the sediment in

suspension from the electrodes and the circulating electrolytes to prevent proton and

hydroxyl ions produced at the electrodes from entering the polluted material[8]. Water

splitting at the anion exchange membrane ensures acidification of the polluted material.

In the two compartment cells the anode is placed directly in the polluted material

compartment; maintaining the separation of the cathode from the sediment in

suspension by a cathode exchange membrane thus preventing the hydroxyl ions

produced at the cathode from disturbing the remediation process in the sediment

compartment.

The influence and relative importance of the experimental variables (current density,

remediation time, stirring rate of the sediment in suspension, liquid-solid ratio of the

suspended sediment and light/no light) on the remediation of the heavy metals

cadmium, chromium, nickel, copper, lead and zinc from polluted harbour sediments

from Sisimiut in Greenland was tested. Measurements of the metals aluminium, barium,

calcium, iron, potassium, magnesium, manganese, sodium and vanadium were made as

indicators of the changes EDR may have on the sediment matrix.

A multivariate statistical experimental design was applied ensuring that as much as the

experimental space was covered in the 8 experiments and in addition enabled the


128

multivariate analysis of the results for assessing the relative variable importance. This

was done by performing projection to latent structures (PLS) in which relations between

two matrices; a X matrix with independent experimental variables and a Y matrix with

the responses (i.e. remediation levels) was determined. The PLS analysis hence assess

the possible relation between the variation in the experimental variables and the

variation in the remediation levels. Results of the PLS analysis indicate the order of

relative variable importance as time>current density>>stirring rate>liquid-solid

ratio>light. For the given experimental design the most important variables for the

remediation process is time and current density.

References

[1] G. Nystroem, L. Ottosen, A. Villumsen, Sep. Sci. Technol., 40 (2005) 2245-2264.

[2] G.M. Nystroem, L.M. Ottosen, A. Villumsen, Environ. Sci. Technol., 39 (2005)

2906-2911.

[3] G.M. Nystroem, A.J. Pedersen, L.M. Ottosen, A. Villumsen, Sci. Total Environ.,

357 (2006) 25-37.

[4] K.H. Gardner, G.M. Nystroem, D.A. Aulisio, Environ. Eng. Sci., 24 (2007) 424-

433.

[5] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, J. Hazard. Mater., 169 (2009) 685-

690.

[6] G.M. Kirkelund, L.M. Ottosen, A. Villumsen, Chemosphere, 79 (2010) 997-1002.

[7] L.M. Ottosen, G.M. Nystrom, P.E. Jensen, A. Villumsen, J. Hazard. Mater., 140

(2007) 271-279.

[8] H.K. Hansen, L.M. Ottosen, B.K. Kliem, A. Villumsen, J. Chem. Technol.

Biotechnol., 70 (1997) 67-73.


129

Nº REF.: P127

Monitoring electrokinetics by geophysical methods: Preliminary laboratory investigations

Matteo Masia, Alessio Ceccarini

b, Maria Beatrice Ostuni

a, Reinout Lageman

c and

Renato Iannellia*

a University of Pisa, Department of Energy Engineering, Systems, Land and

Construction, Via Gabba 22, 56122 Pisa, Italy b University of Pisa, Department of Chemistry and Industrial Chemistry, Pisa, Italy

c Lambda Consult, Schuylenburgh 3, 2631 CN Nootdorp, Netherlands


Monitoring of electrokinetic processes [1] both in laboratory and in field is usually

carried out by point measurements and sample collection from discrete locations.

Geophysical methods can be very effective in obtaining high space and time resolution

mapping for an adequate control of the electrokinetic processes. This study investigates

the possibility of using geophysical methods to monitor electrokinetic remediation

processes. Among several geophysical methods, we selected the induced polarization

(IP) technique because of its capability to provide qualitative and quantitative

information about the physico-chemical characteristics of the porous medium [2].

We carried out laboratory-scale electrokinetic remediation experiments on marine

sediments contaminated by heavy metals, in a prismatic acrylic cell (50x15x15 cm).

Four experiments (EXP1 to EXP4) were performed by changing the intensity of the

applied electric field and the type of conditioning agent circulated within the system to

enhance the extraction process. Tap water was used as the process fluid in EXP1 and

EXP2. To promote metal removal, a 0.1M solution of citric acid and 0.1M EDTA

solution were used in EXP3 and EXP4, respectively. The applied voltage gradients were

50 V/m (EXP1 and EXP3) and 80 V/m (EXP2 and EXP4). The treatment duration was

10 days. At the end of each experiment, the material was sampled from 5 locations and

analyzed for pH, total metal content and IP response, measured in the frequency domain

in the range 10-3

-103 Hz and deconvolved using the Debye decomposition method [3].

A linear relationship between the sample chargeability m (mV/V) and pH was found

(Figure 1). This relation can be interpreted taking into account the electrical double

layer (EDL) polarization mechanism. According to the EDL theory, a pH variation is

responsible for a change in the zeta potential of the sediment, which is proportional to

the amount of electric charge at the EDL. A variation of chargeability is thus directly

associated with an alteration of electric charge at the EDL. Such a relationship has

potential value for the interpretation of IP data during electrokinetic remediation.

Furthermore, we performed numerical simulations to assess the feasibility of measuring

the IP response with a multi-electrode tomography system (Figure 2). We developed a

synthetic model which reproduces the tomographic IP response based on the true values

measured at the end of EXP2, assuming that they only change along the x-direction

(horizontal) and they are constant along the z-direction (vertical). An array of 24

electrodes, with 2 boreholes and 1 surface array was used. We simulated 780 dipole-

dipole measurements with 2% RMS Gaussian noise, added to the data before the

inversion procedure (Levenberg-Marquardt method). The empirical linear model


130

coupled with the tomographic inversion procedure are able to predict the pH values of

the sediment with a RMSE error below 0.55 (at 3.5 cm depth) and 0.8 (at 9 cm depth).

These results strongly encourage the field-scale engineering implementation of the IP

method for monitoring electrokinetic processes.

Figure 1. Variation of chargeability with pH. Symbols show measured data. The line is determined

by linear regression. The fitting quality is indicated by the determination coefficient R2

Figure 2. Numerical simulations. i) Synthetic model based on data measured in EXP2, ii)

reconstruction of the synthetic model by tomographic inversion and iii) resistivity/chargeability profiles along two arbitrary horizontal lines (located at 3.5 cm and 9 cm depth, respectively).

References

[1] Acar, Y.B. and A.N. Alshawabkeh, Principles of electrokinetic remediation.

1993. 27(13): p. 2638-2647.

[2] Kemna, A., et al., An overview of the spectral induced polarization method for

near-surface applications. Near surface geophysics, 2012. 10(6): p. 453-468.


131

[3] Nordsiek, S. and A. Weller, A new approach to fitting induced-polarization

spectra. Geophysics, 2008. 73(6): p. F235-F245.


132

Nº REF.: P129

Membrane influence on electrodialytic remediation of air pollution control from municipal incinerated solid waste

Raimon Parés Viadera*

, Pernille Erland Jensena, Lisbeth M. Ottosen

a

a Department of Civil Engineering, Technical University of Denmark, 2800 Kongens

Lyngby, Denmark


Electrodialysis (ED) has been widely investigated as a technology to reduce the

leaching of metals and salts in some polluted materials, such as Municipal Solid Waste

Incineration (MSWI) Air Pollution Control (APC) [1]. Important parameters of ED like

the intensity, the remediation time or the membrane brand used have been studied on

different materials [2, 3]. However, no previous research has been done on the impact of

the membranes used when treating APC residues. This is a crucial criterion when

scaling up, because the costs of the membranes change dramatically from one brand to

another.

In the present work, four different brand membranes were used in the same

electrodialytic cell set up (Figure 1) and at the same operating conditions, treating two

different kinds of MSWI APC; one of a dry flue-gas cleaning system and another of a

wet flue-gas cleaning system.

Figure 1. Schematic view of a cell used for the ED treatment of both APC residues. AN: anion-

exchange membrane; CAT1 /CAT2: cation-exchange membranes.

The targeted metals were Al, As, Ba, Ca, Cd, Cr, Cu, Mn, Mo, Na, Ni, Pb, V, Zn,

whereas the targeted salts were chloride and sulfate. The results show that the leaching

of metals and salt from the APC residues was generally reduced for all membranes after

ED remediation. However, with a confidence limit of a 95%, the leaching of the

following elements was found to be different after ED treatment depending on the

membrane used:


133

- For the APC residue from the dry flue-gas cleaning system: Ca, Cr, Cu, Na, Ni, Pb,

Zn, Cl, SO4.

- For the APC residue from the wet flue-gas cleaning system: Al, Ba, Cr, Cu, Mn,

Mo, Na, Ni, V, Zn, Cl, SO4.

For some elements and membranes, the final leaching values were below the Danish

law thresholds in the reuse of waste materials in the construction industry.

References

[1] G.M. Kirkelund, P.E. Jensen, A. Villumsen, L.M. Ottosen, J. Appl. Electrochem.

40 (2010): 1049-1060

[2] P. E. Jensen, L. M. Ottosen, C. Ferreira, Electrochimica Acta, 52 (2007), 3412-

3419

[3] L.-G. Ulises, A.-L. René, O. German, T.-G. Julieta, C. Federico, Journal of Water

Resource and Protection, 3 (2011), 387-397


134

Nº REF.: P133

Study on removal behavior of cesium ion in clay minerals (kaolin and vermiculite) by using electrokinetic process

Yasuhiro Akemotoa, Chihiro Kitagawa

a, Ryosuke Miyamura

a, Masahiko Kan

b,

Shunitz Tanakaa,*

a Graduate School of Environmental Science, Hokkaido University, Sapporo, 060-0810,

Japan b Hokkaido University of Education Sapporo, Sapporo, 002-8502, Japan

*Corresponding author: [email protected] (Shunitz Tanaka)

Introduction

On March 11th 2011, the mega earthquake happened in Japan. This earthquake caused

the big tsunami which attacked the east coast of Tohoku area. Consequently, large

amount of radionuclides were released in environment from nuclear reactor of

Fukushima Daiichi Nuclear Power Plant (FDNPP) exploded [1]. Japan now faced to the

severe pollution in water and soil. Since 137

Cs, which is one of the radionuclides, has a

long half-time of 30 years, the effect of 137

Cs on human and environment will continue

for a long term. However, the removal of Cs ion from soil is not easy because Cs ion

might be bound strongly in the layer of some kinds of clay minerals. Especially, it is

said that vermiculite has the specific binding sites such as frayed-edge sites (FES) [2].

Electrokinetic process has a potential to remove Cs ion from contaminated soil without

destructing soil structure [3]. In this study, we investigated the removal behavior of Cs

ion in model soil by using electrokinetic process and analyzing the chemical forms of

Cs ion in model soil before and after electrokinetic process.

Experimental

Kaolin and vermiculite purchased from Wako Pure Chemical Co. (Tokyo, Japan) and

Kenis Ltd. (Osaka, Japan), respectively, were used as the model soil. In this study, an

EK cell made from acrylic resin was used as a migration chamber (3.0 cm in diameter

and 10 cm length). This EK equipment was depicted in the Figure 1. Two meshed Ti

electrodes coated with Pt were used as the electrode. The concentration of Cs in soil was

measured by AAS.

Figure 1 Schematic diagram of EKR equipment

Additionally, sequential extraction analysis was used as a fractionation method to

analyze chemical forms of Cs in soil before and after experiment. Since this method is

originally used for the fractionation of heavy metals [4], some parts of the method were



135

improved for analysis of Cs. Table 1 shows some fractions and chemicals used for

extraction in this study.

Table 1 Sequential extraction analysis for cesium from clay minerals

Fraction Chemical form Chemicals for fractionation

0 Water-soluble Distilled water

1 Exchangeable 1 M ammonium acetate (pH 7.0)

2 Bound to carbonates 1 M ammonium acetate (pH 5.0)

3 Bound to Fe and Mn oxides 0.04 M hydroxylammonium chloride

(25% acetic acid)

4 Bound to organic matter 30% hydrogen peroxide (pH 2.0)

3.2 M ammonium acetate (20% nitric acid)

5 Residual 0.5 M oxalic acid

Results and discussion

Figure 2-4 shows the distribution of Cs ion after EK process for 72 hours, when 0.1 M

KCl was used as an electrolyte and 10 V as the applied voltage. Vermiculite used in the

study included some organic matters, because this was for gardening. When kaolin and

vermiculite were used as a model soil, the removal efficiencies were 27.2% and 0.0%,

respectively. The removal of Cs ion was not easy from vermiculite than from kaolin. It

is said that vermiculite have a FES by drying which adsorbing and fixing Cs selectively.

But this results of EK experiments showed Cs chemical form in soil was translated from

fraction 5 (residual) into fraction 4 (bound to organic matter). It means that Cs can be

extracted from the residual part of vermiculite by applying electric potential. Figure 4

shows that the distribution of Cs ion after EK process when the vermiculite, whose

organic matters was degraded by heating at 600℃ before experiment, was used as a

model soil. In this condition, the removal efficiency was 14.7%. The chemical form of

Cs in soil can be changed by heating soil, under such condition EK method can be

appied to remove Cs from soil.

Figure 2 Distribution of Cs ions in kaolin before and after EK process

Figure 3 Distribution of Cs ions in vermiculite before and after EK process

Figure 4 Distribution of Cs ions in vermiculite which preprocessed


136

References

[1] T. Sato, J. Clay Sci. Soc. Japan 50 (2011) 26 (in Japanese)

[2] A. Cremers, A. Elsen, P. De Preter, A. Maes, Nature 388 (1988) 247


[4] A. Tessier, P. G. C. Campbell, M. Bisson, Anal. Chem. 51 (1979) 844


137

Nº REF.: P137

Optimization of electrokinetic treatment conditions for a metal-contaminated dredged sediment

Giorgia De Gioannisa, Angelo Marini

b,*, Aldo Muntoni

a, Alessandra Polettini

b,

Raffaella Pomib

a University of Cagliari, Department of Civil and Environmental Engineering and

Architecture, Cagliari, 09123, Italy b University of Rome “La Sapienza”, Department of Civil and Environmental

Engineering, Rome, 00184, Italy

*[email protected]

Sediments accumulated at the bottom of rivers, lakes and seabed may become a sink of

contaminants deriving from the contribution of surface waters that receive discharges of

various liquid and solid wastes often containing hazardous compounds. Contaminants of

both organic and inorganic nature are often concomitantly present in sediments, and

have the potential of re-dissolving or migrating into the water column depending on the

prevalent chemical conditions. The decontamination processes for polluted sediments,

which typically derive from technologies developed for contaminated soils, in most

cases display poor remediation performance owing to the peculiar characteristics of

sediments (high water, salt and organic contents, significant amounts of fine materials).

For this reason, sediment remediation has not been extensively practiced until now,

therefore very few proved sediment cleanup cases and defined performance standards

are currently available. Electrokinetic (EK) remediation deserves particular attention in

the case of contaminated sediments due to its potential advantages, including the

capability of treating fine and low-permeability materials, and achieving consolidation,

dewatering and removal of salts and inorganic contaminants in a single stage.

Furthermore, the process can be applied in situ, and may thus be adopted where

decontamination is required but dredging is not.

The suitability of EK remediation to remove hazardous metals from dredged marine

sediments is currently being investigated in the Life+ SEKRET project (“Sediment

ElectroKinetic REmediation Technology for heavy metal pollution removal”). A

preliminary sediment characterization campaign was conducted during the initial stages

of the project in the study area, namely the Livorno harbor site (located in western

central Italy), where the harbor authority has to deal with ~100,000 m3 of dredged

sediments per year. The results of the characterization campaign are reported in Figure 1

in terms of total content of major elements and minor constituents in sediment.

Considering the threshold concentrations established by the Italian regulation for soil in

residential areas 0, the critical contaminants were found to include Cu, Cd and Zn; Cr

was present in sediment at concentrations slightly below the limit value. Adopting the

informal criteria defined by the Italian Ministry for the Environment 0, Ni should also

be included among the contaminants of concerns. The grain size distribution of

sediment was as follows: 18.1% coarse sand, 35.2% fine sand, 46.7% fine fraction (silt

+ clay), confirming the potential suitability of the material for the EK treatment.

The aim of the SEKRET project is testing the performance of EK remediation of

sediment at the pilot scale. To this purpose, a 150 m3 demonstration EK reactor will be


138

built and operated. A number of preliminary lab-scale tests are being conducted in order

to assess the feasibility of metal removal from sediment using the EK process and to

evaluate the optimal operating conditions required for the pilot-scale process. In order to

explore a wide range of process parameters, a large number of lab-scale experiments is

currently underway making use of small electrokinetic cells (5158 cm Perspex

prisms, comprising three compartments of equal volume for the electrode chambers and

sediment core) operated at constant electric current intensity. The experimental

campaign has been arranged according to a number of electrokinetic tests where

different conditions in terms of composition of the electrode solutions, applied current

density and treatment duration are investigated (see Table 1). Additional EK tests will

also be conducted in which the opportunity of a sediment pre-treatment stage (e.g.,

washing, size separation) will be evaluated, with the aim of improving the remediation

yield and/or reduce energy consumption. The EK process is monitored by

measurements of the time evolution of voltage gradient along the sediment core, pH and

metal concentrations in the electrode chambers, as well as final distribution of pH and

metal content in the solid sample at different distances from the electrodes. The analysis

of the mentioned parameters will be used as a means to investigate the underlying

mechanisms responsible for metal detachment from the solid particles and migration

along the EK cell. The contrasting effects of undesired side reactions (including

oxidation/reduction of the circulating solution, electrodeposition of metals onto the

electrode surfaces, metal precipitation within the sediment cell and change in metal

speciation during the process) will be investigated in detail, and the optimal

combination of process conditions to overcome the mentioned negative phenomena will

be evaluated.

Table 1. Summary of the experimental conditions tested

Run no.

Anodic solution

Cathodic solution

Current density (A/m2)

Duration (d)

1 H2O H2O 20 7 2 H2O HNO3 20 7 3 H2O HCl 20 7 4 H2O CH3COOH 20 7 5 H2O H2O 10 7 6 H2O H2O 10 14 7 H2O HCl 10 7 8 H2O HCl 10 14 9 H2O CH3COOH 10 7

10 H2O CH3COOH 10 14 11 H2O EDTA 20 7 12 H2O EDTA 10 7 13 H2O EDTA 10 14 14 CH3COOH CH3COOH 20 7 15 CH3COOH HCl 20 7

Figure 1. Elemental composition of the investigated dredged sediment

References

[1] Decreto Legislativo 3 aprile 2006, n. 152, Norme in materia ambientale, G.U. n.

88 14/04/2006, Supplemento Ordinario n. 96 (Italian regulatory framework on

environmental protection).


139

[2] APAT, ICRAM, Manuale per la movimentazione dei sedimenti marini

(Guidelines for marine sediments handling), 2007.


140

Nº REF.: P145

Effects of electrodialytic process on soil phosphorus

Núria Salvadora, Cláudia Gutierrez

b, Herink Hansen

b, Luís M. Nunes

a, Margarida

Ribau Teixeirac,

*,Pernille E. Jensend, Alexandra Ribeiro

e

aCTA, Faculty of Sciences and Technology, University of Algarve, 8005-139 Faro,

Portugal bDepartamento de Ingeniería Química y Ambiental, Universidad Técnica Federico

Santa María, Valparaíso, Chile cCENSE, Faculty of Sciences and Technology, University of Algarve, 8005-139 Faro,

Portugal dDepartment of Civil Engineering, Technical University of Denmark

eCENSE, Faculty of Sciences and Technology, New University of Lisbon, Campus de

Caparica, 2829-516 Caparica, Portugal

* Corresponding author:[email protected].

Abstract

Phosphorus (P) is an essential element for all life forms, assuming a key role in crop

growth and food production. Phosphorus has no substitute in fertilizer crops and the

main source of P applied in agriculture comes from non-renewable phosphate rocks.

Therefore, there is a global concern that P resources could be depleted in the next 50–

100 years, related to the increasing P demand to satisfy consumption rates of an

increasing global population. Eventually long-term phosphorus reserves will become

scarce, thus the challenge is to introduce alternatives to manage the P cycle before it

becomes seriously scarce. In this sense recovering, recycling and reuse phosphorus will

have to be adopted as integral parts of P management responses. Phosphorus is not

widely circulated on the globe, there is a flux from land to water but the reverse flux is

extremely limited. As a result, excessive amount of P can accumulate in water bodies

and can contribute to eutrophication. Eutrophication is caused by the overenrichment of

aquatic ecosystems with nutrients, principally phosphorus, leading to algal blooms and

anoxic environments. This event is a persistent condition of surface waters and a

widespread environmental problem, which can lead to decreases on ecosystems

services, such as losses on fish, wildlife production, and recreational amenities, and

increases in costs of water purification for human uses. To mitigate such algal blooms

much effort has been made to implement measures to reduce external loading of

phosphorus decreasing phosphorus concentrations in lake waters. However, such

approaches do not consider the roll of internal phosphorus release from sediments. In

lakes where phosphorus internal loading constitutes a considerable part of total loading,

the success of management actions requires an integrated approach of both external and

internal phosphorus loads. Reduction in internal phosphorus loading for control of algal

biomass can be achieved by various restoration approaches, either physical or chemical,

such as the removal of phosphorus-rich surface layers or by the addition of iron or alum

to increase the sediment’s sorption capacity, or by a combination of different

approaches.

This study was developed in order to evaluate the feasibility of electrodialytic

remediation (EDR) to remove and recover phosphorus from soils. Phosphorus removal

and recovery results were not as higher as expected from unpublished results, not



141

exceeding 2% for both removal and recovery for all experiments. Although more

research is needed, as many different mechanisms may be involved in soil phosphorus

release, this approach when combined with other remediation techniques may be useful

in controlling nutrient loading to surface waters.

Acknowledgements

Financial support for the work is provided by project FP7-PEOPLE-2010-IRSES-

269289 ELECTROACROSS - Electrokinetics across disciplines and continents: an

integrated approach to finding new strategies for sustainable development.


142

Nº REF.: P149

Comparison of reagent to enhance desorption and mobility of arsenic in electro-kinetic remediation from contaminated paddy soil

So-Ri Ryua, Eun-Ki Jeon

a, Kitae Baeka

,b,*


daero, Deokjin, Jeonju, Jeollabuk 561-756, Republic of Korea bDepartment of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-


*Corresponding author (K.Baek) Tel.:+82-63-270-2437; Fax:+82-63-270-244 E-mail:

[email protected]

Abstract

Arsenic (As) is one of toxic contaminants in the soil and groundwater, and

electrokinetic remediation has been applied to treat the As-contaminated soil. The main

mechanisms for the removal of As in the electrokinetic remediation (EKR) are electro-

migration and electro-osmotic flow [1]. In EKR system, anode generates hydrogen ions,

which acidifies the anodic region, the acidification of soil changed the surface charge

from negatively to positively. As exists as oxyanionic forms, arsenate (As(V)) and

arsenite (As(III)), in the nature, and it is well known that As(V) is adsorbed onto the soil

surface but As(III) is hardly done. In the EKR for As-contaminated soil, As(V)

desorbed into pore water will be transported toward anode because it is an anion. As(V)

transported by electro-migration will be adsorbed onto the positively charged soil

surface, which causes the decrease in As mobility. Therefore, change in the surface

charge as well as desorption of As(V) should be simultaneously considered in the EKR.

The reduction of As(V) to As(III) is one solution to solve the adsorption problem onto

soil surface because the adsorption of As(III) is much less than that of As(V). The pH

increase could change the surface charge, and As(V) and As(III) could be ion-

exchanged with hydroxyl ions [2, 3]. In this study, we investigated various enhancing

agents including extracting agents, chelating agents, and reducing agents to increase

desorption and mobility of As in the EKR of As.

Acknowledgement

This work was supported by KEITI through GAIA project.

References

[1] T. Suzuki, M. Moribe, Y. Okabe, M. Ninae, A mechanistic study of arsenate

removal from artificially contaminated clay soil by electrokinetic remediation, J.

Hazard. Mater. 254-255 (2013) 310-317.

[2] M. Jang, J.S. Hwang, S.I. Choi, Sequential soil washing techniques using

hydrochloric acid and sodium hydroxide for remediating arsenic-contaminated

soils in abandoned iron-ore mines, Chemosphere 66 (2007) 8-17.

[3] K. Baek, D.H. Kim, S.W. Park, B.G. Ryu, T. Batjargal, Electrolyte conditioning-

enhanced electrokinetic remediation of arsenic-contaminated mine tailing, J.

Hazard. Mater. 161 (2009) 457-462.


143

Nº REF.: P150

Electrokinetic treatment of dewatered soil cake containing flocculants from soil washing processes

Su-Yeon Shin1, Sang-Min Park

1, and Kitae Baek

1, 2*

1 Department of Environmental Engineering, Chonbuk National University, 567 Baekje-

daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea 2 Department of Bioactive Material Sciences, Chonbuk National University, 567

Baekje-daero, Deokjin-gu, Jeonju, Jeollabuk-do 561-756, Republic of Korea

*Corresponding author : Tel.:+82-63-270-2437; Fax:+82-63-270-2449; E-mail:

[email protected]

Abstract

Soil washing is the most common choice to remediate metals-contaminated site in

Korea [1]. In the soil washing process, the fine grained soil containing silts and clay

should be separated from the washing effluent, and flocculants is generally used in

coagulative separation for recycling of washing solution. Negatively charged soil

particles could form flocs when the cationic flocculants is used. However, the flocculent

(positive charged polymer) could produce a stable complex with arsenate(AsO45-

) and

arsenite(AsO33-

) when the soil washing process is applied to remediate As-contaminated

soil. Oxyanionic forms of As adsorbed onto the clay surfaces diffuse into internal pores

of the clay aggregates [2]. Even though enhancing agents desorb As from the residual

soil after washing process, the transport of As is retarded by the interaction between As

and cationic flocculants.

Therefore, in this study, we carried out electrokinetic remediation of dewatered soil

cake containing flocculants and arsenic in laboratory scale. The soil samples were

collected from the actual washing plant to remediate As-contaminated site, Jang-Hang,

Republic of Korea, and the dual hydrocyclone discharged three different sizes of soi

particles: 2~0.075mm, 0.075~0.005mm, and < 0.005mm. Table 1 shows the

concentration of metals and other physicochemical properties. We evaluated the

influence of cationic flocculants on the EKR of residual soil after soil washing proesses.

Table 1. Initial concentrations and characteristics of soil sample.

As

(mg/kg)

Cu

(mg/kg)

Pb

(mg/kg) pH

Water

Contents(%)

EC

(uS/cm)

CEC

(mg/100g)

Sample1

(2~0.075mm) 4.8 7.5 10.4 6.4 15.9 107.2 0.8

Sample2

(0.075~0.005mm) 90.7 119.8 253.9 6.5 34.3 245.1 21.9

Sample3

(0.005mm under) 52.7 124.3 147.9 6.5 37.7 442.0 25.6

Acknowledgement

This work was supported by KEITI through GAIA project.



144

References

[1] C.S. Jeon, J.S. Yang, K.J. Kim, K. Baek, Electrokinetic removal of petroleum

hydrocarbon from residual clayey soil following a washing process, Clean-Soil

Air Water 38 (2010) 189-193.

[2] Z. Lin, R.W. Puls, Adsorption, desorption and oxidation of arsenic affected by

clay minerals and aging process, Environmental Geology 39 (2000) 753-759


145

Nº REF.: P155

Fibers ion exchange for improvement of electrokinetical removal of heavy metals from polluted sites

B. Belhadj 1, D.E.Akretche

1*, C.Cameselle

2

1Laboratory of Hydrometallurgy and Molecular Inorganic Chemistry, Faculty of

Chemistry, University of Science and Technology Houari Boumediene,USTHB, B.P. 32

El – Alia, 16111 Bab – Ezzouar, Algeria 2Department of Chemical Engineering, University of Vigo.Rua Maxwell s/n, Building

Fundicion. 36310 - Vigo. Spain

*corresponding author : email [email protected] and [email protected]

In a previous work, [1] it has been shown that fibers ion exchange can be used in

electroremediation processes with success regarding the ion to be removed. Fibers ions

exchange have been tested playing the same role of ion exchange membranes. However,

they are based on a cellulosic structure which induces hydrophilic properties. Thus, they

have shown a good mechanical structure and they have enhanced the osmosis flux with

a better selectivity against ions less hydrated as lead. Polluting products such as heavy

metals are very difficult to eliminate completely and usually, low metal concentration

remains in the effluents. In effect, electrokinetic remediation is one of in situ processes

that was been developed for metal removal. Depending on the nature and the

concentration of the heavy metals, different processes were reported to improve the

efficiency of the electrokinetic treatment. The use of anion and/or cation exchange

membranes allows controlling the transport of ions in and out of the solid of fluid to be

treated. Thus, several authors [2-6] reported the advantages of using ion-exchange

membranes in the electrokinetic treatment of soils and wastes. To improve the process,

other materials can be tested in this field. Ion-exchange fibers have been used first as a

suppressor of the packed material in columns for ion exchange chromatography,

improving the baseline stability and decreasing ion-exclusion effects and chemical

reactions [6]. The use of fibers was favored by their high separation capacity, fast ion

exchange rates and good electrical conductivity [7].

In this work, the behavior of FIBAN ion-exchange textiles was tested for the

transportation under the effect of a constant DC electric current for two heavy metals:

lead and zinc. Detailed characterization of fibers has been carried out in order to

determine the effect of their structure on heavy metal transport. Ion-exchange fibers

structure was studied by electronic scan microscopy (SEM), X-ray fluorescence (XRF),

spectrogammametric analysis and FTIR Spectroscopy/Attenuated Total Reflectance.

HITTORF model was used to determine the transport number of Pb2+

and Zn2+

during

the electrokinetic treatment. fibers ion exchange are studied to examine their role as an

alternative to the membranes. Fibers ion exchange have better mechanical properties

than membranes and they have an ion-exchange capacity more interesting with the

particular characteristic of being hydrophilic materials which permit the mobility of ions

inside them, and that mobility is comparable to that in aqueous solutions.

A plexiglass cell for the determination of the transport number is used for these tests. It

is divided in three compartments of equal volume (0.1 L each compartment). Fibers ion

exchange were inserted between compartments: anionic exchange textile on the



146

cathodic side and cationic exchange textile on the anodic side. The main electrodes

(anode and cathode) are located on both sides of the cell. The distance between the

electrodes is 20 cm. A graphite sheet of 3.14 cm2 was used for the anode and the

cathode. The cell compartments were filled with lead(II) or zinc(II) nitrate solution at

the concentration of 10-3

or 10-4

M. A DC power supply was used to apply a constant

DC electric current in each experiment for 4 h. The selected values were: 10, 20, 30 and

40 mA. Experiments were carried out at room temperature which is around 298 K. A

conventional cell is used for electroremediation tests. Ion concentration in solution was

determined by a Unicam 929 Atomic Absorption Spectrophotometer.

Results obtained have shown that a classical electroremediation of soils polluted by

heavy metals can be improved by using fibers ion exchange in comparison to ion

exchange membranes. In this case, the osmotic flow is also favoured regarding the

hydrophilic properties of these materials.

References

[1] L.M.Ottosen, H.K.Hansen, S.Laursen, A.Villumsen, Environ. Sci.Technol.,

(1997),31(6),1711.

[2] A.B.Ribeiro, J.T.Mexia., J Hazard Mater, (1997), 56, 257.

[3] H.K.Hansen, L.M.Ottosen, K.B.Kliem, A.Villumsen, J.

Chem.Technol.Biotechnol., (1997),70, 67.

[4] L.M.Ottosen, H.K.Hansen, C.B.Hansen, J Appl.Electrochem, (2000), 30, 1199.

[5] A.B.Ribeiro, E.P.Mateus, L.M.Ottosen, G.B.Nielsen, Environ.Sci.Technol.,

(2000), 34(5), 784.

[6] M. Vuorioa, J.A. Manzanares, L. Murtomakia, J. Hirvonen, T. Kankkunen, K.

Kontturi, J. of Controlled Release 91 (2003) 439.

[7] L. Chen, G.Yang, J. Zhang, React. Funct.Polym. 29 (1996) 139.


147

Nº REF.: P160

Electrical behavior of copper mine tailings during EKR with modified electric fields

Adrian Rojoa*

, Henrik K. Hansena,

,Omara Monárdeza, Carlos Jorquera

a

aUniversidad Técnica Federico Santa María, Valparaíso, casilla 110-V Chile


Introduction

Electrokinetic remediation (EKR) is an in-situ treatment technology for restoration of

contaminated hazardous waste sites [1].The conventional application of this alternative

treatment uses direct current (DC) applied across electrodes inserted in the soil to

generate an electric field for the mobilisation and extraction of contaminants [2]. In the

case of waste from copper mining, previous work [3] has shown that the conventional

DC system was limited with regard to metal removal efficiency and had very high

electrical energy consumption.Under this scenario sinusoidal EKR was applied by an

electric field through the simultaneous application of DC and AC voltages [4,5].

In general, experiments have shown that the use of a sinusoidal electric field favoured

overall copper removaland specific energy consumption in the EKR cell [6],and

particularly good results were observed when this type of electric field produce

periodical polarity reversal inthe electrodes. However, special phenomena have been

observed associated with high frequency of the AC voltage, which require better

understanding of the electrical behaviorof the tailing when EKR with a sinusoidal

electric field of the type mentioned above is applied.

Experimental

Six EKR experiments results with a remediation time of 7 days were analyzed. In this

case, a synthetic waste was prepared with fine sand, copper concentrate (chalcopyrite)

and copper sulfate pentahydrate, to obtain a mixture containing 1000 ppm of total

copper from which 400 ppm are soluble. In all experiments, a sample of approximately

1.6 kg solid dry weight of the above synthetic waste was adjusted to an initial humidity

of 20%, using sulfuric acid solution. The modified electric field in pulses was obtained

by applying simultaneously continuous-alternating (DC-AC) voltages with an external

power supply. The EKR experimental setup is shown on Figure 1 and the experimental

originals conditions are given in Table 1.


148

Figure 1. Experimental setup

Table 1 Summary of the experimental conditions.

Exp. Applied potential V (V) Frequency fVAC (Hz) Pulses ON/OFF (s)

DC AC Veffective Vmaximun Vminimun

1 20 -- 20 20 20 -- --

2 10 15 14.6 25 -5 50 25 (2500/100)

3 10 15 14.6 25 -5 500 25 (2500/100)

4 10 15 14.6 25 -5 1000 25 (2500/100)

5 20 25 26.7 45 -5 1000 25 (2500/100)

6 20 15 22.6 35 5 1000 25 (2500/100)

7 10 15 14.6 25 -5 2000 25 (2500/100)

8 20 25 26.7 45 -5 2000 25 (2500/100)

9 10 15 14.6 25 -5 1000 20 (2000/100)

Results and Discussion

Sinusoidal EKR with voltages in Volts, VDC/VAC= 10/15, producing an effective voltage

of 14.6 [V], show a steady increase inthe removal ofcopper (total and soluble) if the

frequency of the AC voltage increases from 0.05 to1 kHz, but increased to 2 kHz

removal was negligible.The same effect was observed for the experiments with

VDC/VAC = 20/25, Veffective = 26.4 [V], in terms of getting a negligible removal going

from 1 to 2 kHz. Table 2 shows he results associated with this observation.

Table 2. Overall removals of total and soluble copper, frequency AC Voltage effects, for Veffective 14.6 and 26.4 (V). Pulses time ratio 25.

Exp. Frequency fVAC (kHz) Veffective (V) Overall removal (%)

Total copper Soluble copper

2 0.05 14.6 3.1 5.8

3 0.5 18.0 31.9

4 1 24.5 47.9

7 2 0.4 1.0

5 1 26.4 21.5 55.3

8 2 -0.5 -1.3

Conclusions

For the conditions selected in this discussion, in sinusoidal EKR experiments with

simultaneous application of DC and AC voltages, the conclusions are:


149

When the frequency of the AC voltage reaches 2 kHz, tailings sample behaves

as a frequency filter. For this application could give 2 types of filters: a low pass

and a high pass.

In this case it is a high pass filter, which removes or attenuates all frequency

components bellow a frequency threshold. So in the experiments 7 and 8, the

removed DC voltage (zero frequency) does not produce thenetchargeto promote

electrokinetic phenomenafor remediation, and only the AC voltage was applied

to the sample, and for this reason the removal process was negligible.

References


[2] R.F. Probstein, R.E. Hicks, Science 260 (1993) 498

[3] A. Rojo, H. K. Hansen, L. M. Ottosen, Minerals Engineering, 19(2006) 500

[4] A. Rojo, H. K. Hansen, M. Agramonte, Sep. and Pur.Technology, 79(2011) 139

[5] A. Rojo, H. K. Hansen, M. Cubillos, Electrochimica Acta, 86(2012), 124

[6] A. Rojo, H. K. Hansen, O. Monárdez, Minerals Engineering, 55(2014), 52


150

Nº REF.: P165

Study of electrokinetic remediation technology at semi-pilot scale. Strong acid enhancement

M. Villen-Guzmana,*

, G. Amaya-Santosa, A. García-Rubio

a, C. Vereda-Alonso

a,

J.M. Rodriguez-Marotoa, J.M. Paz-García

b




In this work acid-enhanced EKR experiments at semi-pilot scale were carried out. The

soil, collected from the ceased mining district of Linares (Spain), is a clay-loam soil

with low permeability. In these cases, in which soils are clayey, the application of

electrokinetic remediation should be considered. It is also widely accepted that EKR

requires the use of some kind of enhancement. The most typical enhancement method

consists in the neutralization of the alkaline front generated at the cathode by the

addition of an acid to the catholyte [1, 2].

We have chosen the BCR (Bureau Commuautaire de Référence) as a speciation analysis

[3, 4]. This procedure consists in a sequential extraction procedure (SEP) that divides

the total metal content into several fractions. The used of this SEP in a “before and

after” way, provides information not only about the total concentration of the target

contaminants, but also about the changes on the mobility of the contaminants due to the

applied treatment.

Figure 1 schematically shows the experimental system. The experiments were

performed in two methacrylate columns holding, about 2000 g of saturated soil, each.

The catholyte and anolyte solutions were continuously pumped from independent

vessels of about 500 ml into the corresponding electrode compartment and allowed to

flow back to the vessels, without pressure gradient between the two compartments. The

pH value of the catholyte vessel was kept constant, at the target values 4 and 5 by

addition of nitric acid. At selected time steps, samples were obtained for metal analysis.

The columns were electrically connected in series in order to assure that the same

electrical charge flows through them. At the end of the experiments the soil of each

column was divided into ten slices. The pH, water content, metal concentrations (Ca,

Cu, Fe, Mg, Mn, Pb) and BCR speciation were determined for each of these slices.

Figure 1. Outline of the experimental system.


151

In general, results reveal that the concentration of metals in the soil close to the anode

compartment decrease during the experiment. Figure 2 shows the percentage of Mn

obtained by the BCR speciation after the soil treatment and for the initial soil. As it can

be seen the Mn associated with the two more bioavailable BCR fractions (WAS and

Reducible) has been removed in the soil close to the anode compartment. This is in

agreement with the fact that when the concentration of Mn decreased in the soil, the

concentration of lead in the RED fraction also decreased, since this fraction is related to

the metal adsorbed onto Fe/Mn oxides.

Figure 2. BCR results for the strong acid enhancement (pH-4)

The metal concentration analysis of each fraction obtained following the BCR method

is of great importance to better understand the behaviour of the main contaminant, lead.

References


[2] A.T Yeung, Y.Y Gu. . J. Hazard. Mater. 11 (2011)195

[3] G. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, R. Rubio, C. Davidson, A. Ure, Ph.

Quevauviller. J. Environ. Monit. 1 (1999) 57

[4] G. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, E. Barahona, M. Lachica, C.

Davidson, A. Ure, A. Gomez, D. Lück, J. Bacon, M. Yli-Halla, H. Muntau, Ph.

Quevauviller. J. Environ. Monit. 2 (2000) 228.

Acknowledgements








0%

20%

40%

60%

80%

100%

120%

140%

160%

Initial 1 2 3 4 5 6 7 8 9 10

% M

n

RES OXI RED WAS


152

Nº REF.: P167

A critical study of the use of the BCR speciation for the characterization of mobilizable metal contamination

Villen-Guzman, M.a*

, Amaya-Santos, G.a, Garcia-Rubio, A.

a, Paz-Garcia, J.M.

b,

Garcia-Herruzo, F.a, Gomez-Lahoz, C.

a




The sequential extraction procedures (SEPs) for heavy metals speciation in

contaminated soils are obtaining increasing attention. These analytical procedures are

performed as a tool for the risk assessment and the feasibility studies of the recovery

techniques. The need of this kind of tool arises from a balance between two facts: First,

the use of analytical techniques that obtain the total concentration implies that all forms

of a heavy metal have an equal impact on the environment and this supposition is

clearly refuted. On the other hand, soil contamination usually involves such a

complexity that it would be impossible to establish each species with detail. SEPs study

the behaviour of all the species present upon the addition of specific extracting agents.

In this work, it has been studied the BCR (Bureau Communautaire de Référence) [1] as

a SEP to determine the mobility of lead and other heavy metals in the contaminated soil

from the mining district of Linares (Spain). In addition to that, the simulation of the

experimental results was performed using the freeware chemical equilibrium speciation

software Visual MINTEQ. In brief, the BCR uses three sequential steps: The sample is

first treated with acetic acid to release the exchangeable and the acid-extractable metals;

this step is denominated the weak-acid soluble fraction (WAS). Then, the remaining

solid phase is separated by centrifugation and a solution of hydroxylamine

hydrochloride is used to solubilize the metals associated with the reducible fraction. In

the third sequential step, the second step residue is treated with hydrogen peroxide, to

obtain the oxidizable fraction. Usually a fourth step is also performed in which the

residue of step three is digested with aqua regia, to obtain the residual fraction. This

fourth step allows the comparison of the results obtained in each step with the

pseudototal content of each metal in the soil that can be obtained by the digestion of the

original soil. On the other hand, the simulation procedure, considers the possible

different lead species according to the main cations and anions present in the soil (Ca,

Mg, Fe, Mn, carbonates, etc), and then reproduces the BCR fractionation of the lead in

the soil by the chemical software.

As can be seen in Figure 1, which shows experimental and simulation results for the

conventional BCR (BCRx1) and modified BCR (BCRx2) of the original soil, the

simulation adequately predicts the distribution of Pb between the BCR fractions.

According to the model, if the WAS fraction of the BCR is repeated, a significant

additional amount of Pb will be extracted. The simulation results for this modified

procedure predict a 20% increase of the WAS fraction relative to the one obtained in the

simulation of the conventional BCR method. This behaviour is also confirmed by the

experimental model results which show that the relative amount of Pb associated with

the WAS fraction increases from (63% ± 4%) in the conventional BCR procedure to


153

(75% ± 4%) in the modified BCR procedure with the repetition of the WAS extraction.

Besides that, experiments with a modified version of BCR in which the first step (Weak

Acid Soluble, WAS) was repeated until the pH value of the extractant was similar to

that of the initial extracting solution, showed that when the pH value after the extraction

is not close to that of the acid acetic solution, the WAS fraction, as defined by BCR,

undervalues the amount extractable by acid, and this additional acid-soluble amount is

recovered in the following fractions.

Figure 1. Experimental and simulation results for the conventional (BCRx1) and modified

(BCRx2) sequential extraction of the initial soil

The information obtained is relevant to the studies of electrokinetic remediation

technologies. The good agreement between the experimental and simulation results

indicates that the chemical system selected for the description of equilibrium process in

which Pb is involved is correct.

References

[1] G. Rauret, J.F. Lopez-Sanchez, A. Sahuquillo, E. Barahona, M. Lachica, C.

Davidson, A. Ure, A. Gomez, D. Lück, J. Bacon, M. Yli-Halla, H. Muntau,Ph

Quevauviller. J. Environ. Monit. 2 (2000) 228.

Acknowledgements








0%

20%

40%

60%

80%

100%

Pb WAS RED OXI RES

Model

Experimental

BCR x1

Model

Experimental

BCR x2


154

Nº REF.: P169

Study of efficiency in the removal of lead from soil by different treatments

M. Villen-Guzmana, G. Amaya-Santos

a, A. Garcia-Rubio

a,*, J.M. Paz-Garcia

b,

J.M. Rodriguez-Marotoa, and F. Garcia-Herruzo

a

a Chemical Engineering Department, University of Málaga, Málaga, 29071, Spain.

b Division of Solid Mechanics, Lund University. Lund, 223 63 Sweden


In this work, different extractant agents are evaluated to establish their efficiency in the

removal of the total Pb concentration of different soils from the mining district of

Linares (Spain). Furthermore, a speciation analysis is used to compare the mobility of

lead before and after the use of each extractant.

The possible application for soil electrowashing was explored, after the kinetic study of

these extractant agents.

Four samples of soils were treated:

o Soil with a very high lead concentration ([Pb]=45000 ppm), called “SC”

o Soil with a less concentration of lead ([Pb]=2700 ± 400 ppm), called “SL”

o Spiked soil. This is SL soil spiked to amount a similar concentration to SC. This

soil is stored in containers; some of them are closed (“SLC T”, [Pb]=41500 ±

3300 ppm) and the others without cover (“SLC ST”). A cylinder of SLC ST is

obtained and this cylinder is divided into three sections:

o the deepest section, width of 1 cm, that is denominated here “SLC ST1”

o the middle section, width of 1,5 cm, that is denominated here “SLC ST2”

o the most superficial section, width of 1.5 cm, that it is denominated here

“SLC ST3” ([Pb]=111800 ± 11000 ppm). Only SLC ST3 was treated in

this experimental procedure.

The first assays to remove lead consist of the mixture of 8 g of the dry soil with 24 mL

of an extraction solution (EDTA 0.1M or Citric Acid 0.1M). This mixture is agitated for

24 hours (equilibrium time). Then, the remaining solid phase is separated by

centrifugation and the solutions mentioned above are added again to solubilize the

remaining metals in the soils. The whole procedure is repeated until five extractions are

obtained. The metal concentration of each supernatant is determined by AAS.

The results are shown in the following figure:


155

Figure 1. Results of extraction assays.

After that it was proved that EDTA solution and Citric Acid solution remove 100 % of

Pb from the soils, several batch extraction tests were performed in order to know the

kinetics of the processes [1]. Besides, several electrowashing experiments were

performed to compare the efficiency and leaching rate with and without current.

The washing and electrodialytic washing experiments are achieved in agitated tank,

where 400 g of dry soil are mixed with 1200 mL of solution (EDTA 0.1 M). At selected

times samples are taken from the tank for Pb concentration measurements in the

supernatant liquid. The difference between both experiments is the installation of

electrodes in the tank to create an electrical potential difference. Also, a cationic

exchange membrane (CEM) is placed around the cathode.

References

[1] J.D. Subirés-Muñoz, A. García-Rubio, C. Vereda-Alonso, C. Gómez-Lahoz, J.M.

Rodríguez-Maroto, F. García-Herruzo, J.M. Paz-García. Separation and

Purification Technology, 79 (2011) 151.

Acknowledgements









156

Nº REF.: P174

Two step electrodialytic remediation of soil suspension for simultaneous removal of As and Cu

Lisbeth M. Ottosena,*

, Pernille E. Jensena, Gunvor M. Kirkelund

a

aARTEK, Department of Civil Engineering, Technical University of Denmark, 2800

Lyngby

*[email protected]

Introduction

Simultaneous removal of As and Cu from soil during electrochemical treatment is not

straightforward. To have successful, simultaneous removal As and Cu they must desorb

during the remediation process and be present in ionic form in the soil solution. Cu is in

ionic form in an acidic environment regardless oxidation status of the soil. As is also

desorbed under acidic conditions [1,2], but the redox status is highly important for the

As speciation. Table 1 shows a generalized pattern for Cu and As being charged and

mobile for electromigration under different pH and redox conditions.

Table 1. Generalized pattern for Cu and As speciation

pH Redox Cu As

Acidic Low Ionic form As(III) uncharged

Alkaline High Precipitated As(V) charged

Acidic High Ionic form As(V) uncharged highly acidic, charged moderately acidic

Alkaline Low Precipitated As(III) uncharged moderately until slightly alkaline, charged

highly alkaline

Without use of assisting agents it is not possible to remove Cu from the soil. Under

acidic conditions it is only possible to remove As at in an environment with high redox

potential at a moderately low pH as (H2AsO4-). The present work is focused on

obtaining such optimal condition for electroremediation by a two-step electrodialytic

method. Figure 1 shows the two steps tested in the present investigation.

Figure 1. The two steps for simultaneous As and Cu removal. The anode is first placed directly in

the soil suspension (I) and after a period of time a separate anode compartment is added.

In the first step (2C) the anode is placed directly into the soil suspension. The anode

process H2O → 2H+ + ½ O2 (g) + 2e

- will result in an acidic environment with a high

redox potential just as needed for the simultaneous removal of As and Cu. Cu is

removed into the catholyte in setup (I), but As remains dissolved in the suspension in

2C, thus the second step (2C-3C) is needed for a separation of As into the anolyte.


157

In the preliminary test of the two-step electrodialytic remediation two experiments were

conducted with soil sampled at a wood preservation site. Initial concentrations were 710

mg As/kg and 1500 mg Cu/kg. The experiments were:

2C; Cell (I) for 2 days

2C-3C; Cell (I) for 2 days and cell (II) for 7 days

The experimental cells were cylindrical (internal diameter 8 cm, length of electrode

compartments 5 cm and compartment with ash suspension 10 cm) The ion exchange

membranes were from Ionics. The platinum coated electrodes from Permascand. A

constant current of 10 mA was applied. Circulating in the electrode compartments 500

mL adjusted to pH 2 with HNO3. The soil was kept suspended by an overhead stirrer.

During the experiments, the pH was adjusted manually in the cathode compartment to

between 1 and 2 once a day with 1 M HNO3. A constant current of 10 mA was applied.

Figure 2. (a) pH of the soil suspension in the experiments and (b) Distribution of Cu and As in the

system after the two experiments.

Overall results from the experiments are in figure 2. During two days in 2C pH

decreases from 6 to 3 and after adding the anode compartment to the cell (2C-3C) pH

remains rather stabile at 3.5 (fig. 2a). The distribution of As and Cu at the end of

experiments (fig. 2b) shows that after two days in 2C, the major fraction of As is still

adsorbed, whereas already after 2 days 80% Cu was removed into the catholyte, and the

Cu remediation was actually sufficient to reach the Danish limiting value. When

combining 2C and 2C-3C As desorption continued during the 3C period, and almost all

desorbed As was transported into the anolyte. However, 64% As remained in the soil.

This initial result is encouraging. The Cu remediation already finished after 2 days in

2C. Too little As was desorbed, but the separation of dissolved As into the anolyte was

very efficient. As desorption is only sufficient (90-100%) at pH of about 1 in a

suspension [1, 2] so in coming experiments the period in 2C will be longer to reach this

pH. In the following 3C the aim is then first to remove H+ into the catholyte in the

applied electric field, so suspension pH increases to a level, where As is mobile.

References

[1] L.M. Ottosen, P.E. Jensen, H.K. Hansen, A.B. Ribeiro, B. Allard, B. Sep. Sci.

Technol. 44(10) (2009) 2245

[2] T.R. Sun, L.M. Ottosen, P.E. Jensen, G.M. Kirkelund, G.M. J. Haz. Mat. 203-204

(2012) 229

0

1

2

3

4

5

6

7

0 5 10

pH

in s

usp

en

sio

n

Time (d)

2C

2C-3C

0

10

20

30

40

50

60

70

80

90

100

As (2C) Cu (2C) As (2C-3C) Cu (2C-3C)

Dis

trib

uti

on

(%

)

Cathode

Soil

Liquid

Anode (3C)


158

Nº REF.: P177

The effects of composting, biosurfactant and freezing-thawing on electrokinetic removal of heavy metals in sewage sludge

Qishi Luoa,*

, Lei Dongb, Rongbing Fu

a, Jie Gao

a, Jing Wang

a, Ming Zhang

b

a State Environmental Protection Engineering Center for Urban Soil Contamination

Control and Remediation, Shanghai Academy of Environmental Sciences, Shanghai,

200233, P R China b College of resource and environmental Science, East China Normal University,

Shanghai, 200062, P R China


It is quite necessary to remove the heavy metals in sewage sludge before being reused

as a resource. Electrokinetics has been proven to be an effective way to remove the

heavy metals in sludge when it is properly applied. Sludge pre-treatment is always

needed for a higher electrokinetic treatment of sludge. Three pre-treatment techniques

including composting, bio-surfactant treatment, and freezing-thawing were adapted to

explore their effects on electrokinetic removal of heavy metals from sewage in present

work. The bench scale tests showed that: (1) Pre-treatment of sludge through

alternatively freezing and thawing increased the potential availability of heavy metals in

sludge, and raised the electrokinetic removal of Cu、Zn、Cd and Ni, with an efficiency

of 62%, 80%, 44% and 39%, respectively; (2) Sludge pre-treatment with a bio-

surfactant saponin raised the desorption of heavy metals, and produced a higher

electrokinetic removal efficiency of Cu、Zn、Cd and Ni in sludge, 115%, 167%, 134%

and 113%, respectively; (3) However, composting of sludge, as a whole, reduced the

efficiency of electrokinetic treatment, due to the induced stabilization of heavy metals in

sewage sludge; (4) Furthermore, the electric consumption was raised by 76%, 287%,

28% during the test period of 6 days, for the electrokinetic system of sludge pre-treated

with freezing-thawing, saponin, and composting, respectively. The above findings

demonstrated that freezing-thawing might be a preferable pre-treatment technique for

enhanced electrokinetic treatment of sewage sludge.


159

Nº REF.: P178

The use of 2D non-uniform electric field to remediate chromium-contaminated soil from an abandoned industrial site with permeable

reactive composite electrodes

Rongbing Fu*, Zhen Xu, Qishi Luo, Xiaopin Guo

Shanghai Academy of Environmental Sciences, Shanghai, 200233 and P. R. China

*Rongbin Fu: [email protected]

Electrokinetic remediation has shown the potential for effective removal of heavy

metals from soil [1]. However, traditional one-dimensional electrode systems limited

their widespread application because of a large part of ineffective electric field in the

system [2]. This study was conducted to improve chromium removal from contaminated

soil from an abandoned industrial site in a bench-scale electrokinetic (EK) system with

permeable reactive composite electrodes (PRCEs) in a hexagonal configuration. The

experiments were performed under a constant voltage gradient of 1.5v/cm in an EK

reactor. (diameter:1 m, depth:20 cm) over 60 days(Figure 1). The initial concentrations

of Cr (VI) and Cr (III) were 816.05 and 4352.12 mg/kg, respectively.

The pH, removal efficiencies, speciation of Cr and ineffective area in the EK reactor

were investigated. Results shows that, EK treatment led to 67.82~91.23% Cr (VI) and

89.72% of Cr(III) removals over 60 days. The ineffective area was approximately

0.1875 m2 and it accounted for 12.5 % of the total soil area which was much lower than

that of the traditional one-dimensional system (~50%) [3]. The changes of pH and

concentrations of Cr followed similar trends with the electric field strength. PRCEs

played an important role in soil pH control (3.5~4.7, after 60 days of remediation). In

addition, the composite anode transformed Cr (VI) into less toxic Cr(III) by the reaction

of Fe(0) with Cr(VI) [4].

This remediation system has three major advantages: (i) The hexagonal two-

dimensional electrode configuration enhanced the removal efficiency by minimization

of the inactive area of the electric field. (ii) Composite electrodes effectively controlled

soil pH. Moreover, heavy metal could be removed by unplugging these electrodes from

the soil. (iii) Additional chemicals and complex equipment were not required.



160

Figure 1. Schematic illustration of experimental set-up(a) and sampling points (b)

References


[2] A.N. Alshawabkeh, R.J. Gale, E. Ozsu-Acar, R.M. Bricka, J. Soil Contam. 8

(1999) 617

[3] W. Kim, G. Park, D. Kim, H. Jung, S. Ko, K. Baek, Electrochimica Acta, 86

(2012) 89

[4] R. Fu, F. Liu, C. Zhang, J. Ma, Environ. Eng. Sci, 30 (2013) 17

Poster Session: Fundamentals and Modeling


163

Nº REF.: P217

Numerical analysis of vanadium and water crossover effects in all-vanadium redox flow batteries

Kyeongmin Oh and Hyunchul Ju*

Department of Mechanical Engineering, Inha University, 100 Inha-ro, Nam-Gu,

Incheon, 402-751, Republic of Korea


Recently, all-vanadium redox flow batteries (VRFBs) using different oxidation states of

vanadium ions as both negative and positive electrolytes have received considerable

attention for large-scale energy storage system. The main electrochemical reactions and

species transport are schematically shown in Fig. 1.

Figure 1. A schematic of vanadium redox flow battery structures and reactions in each electrode.

However, crossover of vanadium ions and resultant side reactions still hinders the

commercialization of VRFB. The capacity loss during charging and discharging process

due to vanadium ion crossover is continuously reported [1-3], implying the periodical

electrolyte rebalancing and system maintenance are inevitably required for long-term

VRFB operations.

Figure 2. Vanadium ion crossover and resultant side reactions in VRFB

As shown in Fig. 2, vanadium ions move through the membrane to opposite electrodes

and reacts with originally existent species by side reactions reducing the concentration

of charged species. Once the vanadium ions in the negative electrode, V2+

, V3+

transport

across the membrane, the following side reactions can occur in the positive electrode:


164

(1)

(2)

On the other hand, the crossover of VO2+

and VO2+ from the positive to negative

electrodes results in the following side reactions in the negative electrode, i.e.

(3)

(4)

It is evident that the crossover of vanadium ions through the membrane and resultant

side reactions cause an imbalance in vanadium ions between the negative and positive

electrodes, which gives rise to loss of capacity. Consequently, consumption of charged

species slows down the rate of charging process and accelerates the discharging process.

In this work, a crossover model is newly developed to account the crossover of

vanadium ions through the membrane and resultant side reactions occurring in both

positive and negative electrodes. The crossover model is then numerically coupled with

previously developed three-dimensional (3-D), transient, thermal VRFB model [4].

Using the comprehensive VRFB model, we investigate the effects of vanadium

crossover between the negative and positive electrodes during a single

charge/discharging cycle. Numerical simulations successfully capture the capacity loss

related to vanadium crossover, clearly showing the difference in species distributions

due to side reactions. The result shows that more charging time and less discharging

time have been achieved due to effect of vanadium ion crossover.

Figure 3. Voltage curves during charging and discharging process.

References

[1] E. Wiedemann, A. Heintz, R.N. Lichtenthaler, J. Membrane Science 141 (1998)

215

[2] C. Sun, J. Chen, H. Zhang, X. Han, Q. Luo, J. Power Sources 195 (2010) 890

[3] K.W. Knehr, E. Agar, C.R. Dennison, A.R. Kalidindi, E.C. Kumbur, J.

Electrochem. Soc. 159 (2012) A1446

[4] K. Oh, H. Yoo, J. Ko, S. Won, H. Ju, Energy, accepted.

2 2

2 2V 2VO 2H 3VO H O 3 2

2V VO 2VO

2 2 3

22 2VO V H V H O 2 3

2 2VO 2V 4H 3V 2H O

Poster Session: Scaling up and field applications


167

Nº REF.: P305

The scale up of the flushing-fluid-assisted electrokinetic remediation of kaolin soil polluted with phenanthrene

P. Cañizares 1,

*, R. López-Vizcaíno1, C. Risco

1, C. Saez, L. Rodriguez

1, J.

Villaseñor1, V. Navarro

2, M.A. Rodrigo

1

1 Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies

& Institute of Chemical and Environmental Technology, Ciudad Real, 13071 SPAIN 2

Geoenvironmental Group, Civil Engineering School, University of Castilla-La

Mancha, Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain


In this work, the scale up of the flushing-fluid-assisted electrokinetic remediation of

kaolin soil polluted with phenanthrene was studied. Three different scales ranging from

lab to pilot scale plants were used to compare the significance of the different

mechanisms of removal of pollutant and to point out the significance of the scaling

factors on the results obtained in electrochemically assisted remediation studies. Figure

1 shows an scheme of the three electrokinetic remediation plants used in this work.

Figure 1. Experimental setups of electrorremediation processes: lab scale (25 cm3), bench scale

(28 x103 cm3) and pilot scale (175 x103 cm3).

Results show that electrokinetic fluxes, removals of PHE and pollutant distribution in

soil were very different in the three setups in spite of being the same soil, pollutant and

operation conditions. Electroosmotic fluxes were much bigger in the case of the lab

scale setup and very similar in the bench scale plant and in the pilot mock up, just as

expected according to the PHE fluxes and to the distribution of PHE removal.

Moreover, in the pilot scale plant used, hydraulic flux produced by gravity and

evaporation flux by electric heating of the soil should be taken considered. This variety

of results suggests a very complex process with many factors influencing on results [1].

In the lab scale plant, the main mechanisms involved in the removal of PHE are

Anodic well Surfactant wellCathodic well

Pilot Scale

Bench Scale

Lab scale

25

cm

50

cm

68

cm

48 cm

16 cm8 cm30 cm

45 cm

25

cm

10 cm


168

dragging with electro-osmotic flow in the cathodic wells and electrophoresis after

interaction of surfactant with phenanthrene in the anodic wells. Just on the contrary,

desorption of PHE promoted by the electric heating seems to be a very significant

removal mechanism in the bench scale plant and in the pilot mock-up. Figure 2 shows

the comparison of the removals of PHE obtained in the three setups.

Figure 2. PHE balance in the electroremediation of a clay soil polluted with phenanthrene in lab (), bench () and pilot (▲) scale mock-up. Operation condition: Ez = 1 VDC/cm, initial

pollution: 500 mg PHE kg-1 of soil.

Acknowledgements

Financial support from the Spanish government through project CTM2013-45612-R

and Innocampus (Procesos de electrorremediación, biorremediación y

electrobiorremediación de suelos contaminados) is gratefully acknowledged.

References

[1] R. Lopez-Vizcaino, J. Alonso, P Cañizares, M.J. Leon, V. Navarro, M.A.

Rodrigo, C. Saez, Journal of Hazardous Materials 265 (2014) 142.

0

10

20

30

40

50

60

70

80

90

100

remaining in soil

after treatment

removed in the

anodic well

removed in the

cathodic well

removed by

desorption

mechanism of removal

PH

E (

% P

HE

0)

0.01

0.1

1

10

100

removed in the

anodic well

removed in the

cathodic well

removed by

desorption

mechanism of removalP

HE

(%

PH

E0)


169

Nº REF.: P311

Electrokinetic treatment of polluted soil by gasoline at pilot level couple with an advanced oxidation process of residual water

L. Ramos-Huerta, A. Garibay-Cordero, B. Ochoa-Méndez, M. Pérez-Corona, J.

Cárdenas-Mijangos and E. Bustosa,*

aParque Tecnológico Querétaro s/n, San Fandila, Pedro Escobedo, Querétaro, México.

C.P. 76730.

[email protected].

Productive activities in Mexico such as mining, extraction and refining of oil, have

caused serious environmental problems. Among them, the generation of large amounts

of waste and hazardous waste, which represents a risk to health and ecosystems. The

remediation of soils contaminated with hydrocarbons using the technique called electro-

remediation (ER) has shown good results at level laboratory and field 1.On the other

hand it is necessary to consider the treatment of wastewater with the contaminant due

electrolyte extracted contains contaminants that were dragged mainly by electroosmosis

process, in consequence it is necessary to implement some treatment of wastewater, as

Fenton treatment which is an advanced oxidation process (AOP) by the hydroxyl

radicals close to anodes 2.

The pilot system consisted of contaminate 3.3 m3 of soil type basalt of the State of

Queretaro to a concentration of 1126 ppm by gasoline, value that is for over the

permissible limits of the mexican law NOM-138-SEMARNAT/SS-2003.

The hydrate soil was added 60L of 6.7x10-4

M NaOH, which was extracted daily after

applying the treatment ER consisted in applying a potential of 20 V for 4.5 hours by a

period of 20 days, across this time the soil treated by ER was characterized. Figure 1

shows the circle arrangement of electrodes with six IrO2-Ta2O5│Ti as anodes around

the central titanium cathode.

Figure 1.-Picture of pilot system with 3.3 m3 with an arrangement of six IrO2-Ta2O5│ Ti anodes

and a central titanium cathode.

The quantification of fats and oils (F&O), was done for the method Soxhlet following

the NMX-AA-005-SCFI-2000, the extract obtained by Soxhlet was dissolves using



170

CH2Cl2 and was semi-quantitatively analyzed by Gas Chromatography-Mass

Spectrometry (GC-MS).

In the case of the treatment of polluted water 50% H2SO4, 40% FeSO4, 30% H2O2 and

50% NaOH were used for the Fenton oxidation system. Chemical oxidation demand

(COD), pH and electrical conductivity of the solution were evaluated during Fenton

reaction.

Figure 2 shows presents the results obtained for COD of the extracted solution after

applying electrochemical treatment, which decreased from 50% in the first week to 67%

in the second week. This behavior indicates that organic pollutants were destroyed after

two weeks by ER treatment with electroosmosis process using Fenton treatment.

Finally, with the best quality of treated water after the Fenton reaction, this was re-used

in the ER treatment of polluted soil by gasoline to continue the electroremediation.

Figure 2. Graphical of behavior of COD evaluated during two weeks of ER treatment.

The electroremediation of polluted soils from Mexico is an alternative technology for

cleaning up contaminated soils generated by the oil industry, as well as coupling of an

advanced oxidation process as Fenton reaction for the treatment of polluted solution by

gasoline. This coupling is interesting by the integral process of treatment of polluted

soil and water, which is a competitive advantage with respect to biological systems

widely used in the country.

References

[1] M.P. Corona, E. Beltrán, Sustentable Environmental Research. 2013, 285 –

288. ISSN: 1022-7630.

[2] R. Méndez, J. Pietrogiovanna, Rev. Int. Contam. Ambien. 26 (2010), 211– 220.

276

89

140

48

1 2

CO

D (

mg/

L)

Week

Initial End

Poster Session: Other uses. Miscellaneous.


173

Nº REF.: P418

Effects of porous properties of carbon felt electrodes on the performance of all-vanadium redox flow batteries (VRFBs)

Seongyeon Won, Kyeongmin Oh, Hyunchul Ju*

Department of Mechanical Engineering, Inha University, 100 Inharo, Namgu, Incheon

402-751, Republic of Korea

*[email protected]

The porous structure of electrodes of all-vanadium redox flow batteries (VRFBs) has a

substantial influence on transport characteristics and cell performance during VRFB

charging and discharging processes. A carbon felt has been recognized as the favored

porous-electrode substrate for VRFBs due to several advanced features over other

electrode materials such as low cost and high permeability of liquid electrolyte [1,2].

Desired porous structure and properties of carbon-felt electrodes can be achieved via

optimizing assembly clamping pressure. Chang et al. [3] experimentally showed that as

the clamping pressure increases, the thickness and porosity of the carbon felt electrode

(F1-75P4) decrease whereas its electronic conductivity is improved (see Table 1), which

significantly affects electrolyte and electron transport through the electrodes.

Table 1. Properties of carbon felt electrode under various levels of compression

Carbon felt electrode : F1-75P4

Percentage of

compressions (%) Change on

thickness Compression

(Mpa) Conductivity

(S/m) Porosity

(%) 0 4 →4.0mm 0 31.4 89.5 10 4 →3.6mm 0.139 53.9 88.1 40 4 →2.4mm 0.336 281.2 84.3

In this study, we numerically investigate the effects of porous properties of carbon felt

electrodes on the operation of VRFBs, using a three-dimensional (3-D), transient VRFB

model developed in the previous study [4]. Based on the empirical data of Chang et al.

[3], we precisely account for the relation between the electronic conductivity, porosity,

and thickness of the electrode as a function of electrode compression level. In addition,

the correlation of electronic contact resistance between the porous electrode and current

collector is newly developed as a function of electrode porosity. The modified model is

then applied to a simple VRFB geometry shown in Fig. 1a and charging and discharging

simulations are carried out under different levels of electrode compression. The

calculated cell voltage and state of charge (SOC) evolution curves are presented in Fig.

1b wherein different charging and discharging performances were predicted due mainly

to different degrees of electronic and ionic charge transport losses through the

electrodes. The present study contributes to identifying the optimal design and

compression of carbon felt electrode in VRFBs.


174

(a)

(b)

Figure 1. (a) Computational domain and mesh configuration of a simple VRFB geometry. and (b) cell voltage and SOC evolution curves under different levels of electrode

compression.

References

[1] A. Di Blasi, O. Di Blasi, N. Briguglio, A.S. Arico, D. Sebastian, M.J. Lazaro, G.

Monforte, V. Antonucci, J. Power Sources, 227 (2013) 15-23

[2] Se-Kook Park, Joonmok Shim, Jung Hoon Yang, Chang-Soo Jin, Bum Suk Lee,

Young-Seak Lee, Kyoung-Hee Shin, Jae-Deok Jeon, Electrochimica Acta, 116

(2014) 447-452

[3] Tien-Chan Chang, Jun-Pu Zhang, Yiin-Kuen Fuh, J. Power Sources, 245 (2014)

66-75

[4] K.Oh, H. Yoo, J, Ko, S, Won, H. Ju, Energy, accepted.


175

Nº REF.: P419

The effects of hybrid catalyst layer design on methanol and water transport in a direct methanol fuel cell (DMFC)

Kise Lee, Saad Ferekh, Hyunchul Ju*

School of Mechanical Engineering, Inha University,100, Inha-ro, Nam-gu, Incheon

402-752, Republic of Korea

* [email protected]

According to the capillary transport theory in porous materials, the rate of liquid

transport can be effectively controlled by the spatial wettability variation of porous

electrode [1-4]. Therefore, in the research field of direct methanol fuel cell (DMFCs),

many researchers have focused on multi-layered electrode designs, using additional

hydrophobic layers [5-8] and/or PTFE-treated anode backing layers (BLs) [9-11], which

successfully reduced methanol crossover and/or water flooding inside a DMFC. In this

study, we propose new catalyst layer (CL) designs based on double-layered structure;

one is coated on the backing layer side whereas the other is on the membrane side.

These two CLs are designed to exhibit different wetting characteristics. The hydrophilic

CL can be fabricated with conventional Nafion binder whereas both Nafion and PTFE

binders are used to design relatively hydrophobic CL. Combining two layers for the

anode or cathode CL enables to effectively control methanol transport in the anode side,

water transport in the cathode, water and methanol crossover through the membrane. To

examine its influence, four different membrane electrode assemblies (MEAs) with

different combinations of anode and cathode CLs are fabricated and tested under

different methanol feed concentrations. Fig. 1 schematically depicts the four MEA

designs, namely MEA-1, MEA-2, MEA-3, and MEA-4.

Figure1. The schematic diagram of four MEA designs with different anode and cathode CLs.

A comparison of polarization curves in Fig. 2 clearly demonstrates a substantial

influence of double-layered CL structure on methanol and water transport, and resultant

overall cell performance. In addition to the experimental observation, a one-dimensional

hybrid CL model is newly developed and simulated in order to theoretically analyze

methanol and water transport characteristics through the double-layered (hydrophobic +


176

hydrophilic) CL structures. This study emphasizes that controlling wetting

characteristics of CLs is effective to obtain favorable methanol and water profiles inside

a DMFC.

Figure 2. Polarization curves of MEAs measured at different methanol-feed concentrations (3M,

4M). The cell was operated at 60℃ and an anode/cathode stoichiometry of 3/3 at 200mA/cm².

References

[1] H.C. Ju, J. Power Sources. 185 (2008) 55

[2] K.M. Kang, K.M. Oh, S.H. Park, A.R. Jo, H.C. Ju, J. Power Sources. 212 (2012)

93

[3] A. Pablo, G. Salaberri, M. Vera, I. Iglesias, J. Power Sources. 246 (2014) 239

[4] C.E. Shaffer, C.Y. Wang, Electrochimica Acta. 54 (2009) 5761

[5] K.M. Kang, G.Y. Lee, G.H. Gwak, Y.J. Choi, H.C. Ju, Int. J. Hydrogen Energy.

37 (2012) 6285

[6] Y.C. Park, D.H. Kim, S.Y. Lim, S.K. Kim, D.H. Peck, D.H. Jung, Int. J.

Hydrogen Energy. 37 (2012) 4717

[7] C.G. Suo, X.W. Liu, X.C. Tang, Y.F. Zhang, B. Zhang, P. Zhang,

Electrochemistry commun. 10 (2008) 1606

[8] J.Y. Cao, M. Chen, J. Chen, S.J. Wang, Z.Q. Zou, Z.L. Lin, D. L. Akins, H. Yang,

Int. J. Hydrogen Energy. 35 (2010) 4622

[9] C. Xu, T.S. Zhao, Q. Ye, Electrochim. Acta. 51 (2006) 5524

[10] K.M. Kang, S.H. Park, G.H. Gwak, A.R. Jo, M.S. Kim, Y.D. Lim, W.H. Kim,

T.W. Hong, D.M. Kim, H.C. Ju, Int. J. Hydrogen Energy. 39 (2014) 1564

[11] C.M. Hwang, M. Ishida, H. Ito, T. Maeda, A. Nakano, A. Kato, T. Yoshida, J. Int.

Cou. Electrical Engineering. 2 (2012) 171


177

Nº REF.: P428

Electrochemical peroxidation using iron nanoparticles to remove arsenic from copper smelter wastewater

Henrik K. Hansena*

, Claudia Gutiérreza, Adrián Rojo

a, Patricio Nuñez

a, Erica

Valdezb

a Departamento de Ingeniería Química y Ambiental, Universidad Técnica Federico

Santa María, Avenida España 1680, Valparaíso, V Region, Chile b Departamento de Química, Universidad Técnica Federico Santa María, Avenida

España 1680, Valparaíso, V Region, Chile


Chile is one of the main copper manufacturers in the world. During the processing of

sulfide minerals, the smelter process, gases that contain sulfur dioxide and arsenic

among others are produced: These gases must be cleaned before discharge in the

environment. In the copper smelter gas cleaning process a wastewater is produced and it

contains high concentrations of arsenic and others heavy metals that are far over the

Chilean threshold value for discharge in the aquatic environment. At present the

wastewaters are treated with Ca(OH)2, to increase the pH to approximately a value of

10, which favors the precipitation of heavy metals as hydroxides but also precipitates

calcium sulfate. Large amounts of arsenic remain soluble in the wastewater and the

Ca(OH)2 addition produces a great volume of sludge, owing to the fact that initial pH of

the wastewater is too acid (pH <1.0). This methodology has the disadvantage that great

quantity of sludge is produced and requires a subsequent treatment. There are several

technologies based on the use of ferric oxides and hydroxides (HFO) that are used to

remove heavy metals from wastewaters. This technologies present an alternative to the

treatment with Ca(OH)2, that at the moment is been applied. The HFO are highly

insoluble precipitates (Ksp ≈ 10-38

) with a large surface area (around 600 m2 g

-1). This

precipitates are brown –orange colored and have a high affinity to adsorb several heavy

metals, because of this, are used in wastewaters treatments.

The Electrochemical Peroxidation process (ECP) is one of the methods that use the

HFO to remove heavy metals. Until now this process has used steel electrodes and a DC

electrical current between them to dissolve the anode and provide the Fe+2

that react

with the hydrogen peroxide to produce the Fe+3

that subsequently results in the HFO

production. In this work it is proposed to use inert electrodes such as carbon electrodes

and iron nanoparticle addition to provide the Fe+2

when the Fe0 is oxidized by the anode

process. This could be advantageous over the ECP process when the iron electrodes are

dissolved, because from the operational point of view, an electrode renewal would not

be necessary since the carbon electrodes are not sacrificial.

Iron nanoparticles (NZVI), are highly reactive, they have large surface area and small

particle size, which allow them to remain in suspension. The iron nanoparticles possess

dual properties, because of the dense metallic center enclosed by a thin layer of iron

oxide material (FeOOH). The thickness of the outer layer varies from 10 to 20 nm. The

oxide layer is an inherent part of the nanoparticles formed instantaneously during their

synthesis to passivize the metallic center. The oxide layer allows electron passage,

conserving the reducing properties of Fe0, owing to the fact that the layer is extremely


178

thin and disordered. Besides iron oxides formed from Fe0

corrosion are able to oxidize

As (III) to As (V). Therefore iron nanoparticles are able to oxidize and reduce As (III).

This work proposes the HFO formation through the ECP process by the iron

nanoparticles oxidation at the anode and later the oxidation of ferrous ions to ferric ions

by hydrogen peroxide. The metals removal occurs due to the formation of the HFO

followed by an adsorption and/or co-precipitation.

In the present work a study of the ECP process was made by using carbon electrodes

and iron nanoparticles. The arsenic removals from synthetic and real wastewaters from

copper pyro metallurgical industry were evaluated. The experiments were carried out in

a batch reactor at laboratory scale, of 2 L of volume, with agitation by air injection; the

airflow was approximately 5 L min-1

. A fixed current density of 171.7 A m-2

was used

and a dosage of hydrogen peroxide 30 % w/w was supplied to the solution drop wise to

around 0.5 - 1 mL min-1

. The parameters analyzed were the initial pH of the wastewater,

that was in the range of 2.0 to 6.5 and the treatment time, that was done from 30 to 180

min. The results when the ECP process, with carbon electrodes and iron nanoparticles

was applied for 1 h, in the pH range of 2.0 to 6.5, to treat As (III) synthetic wastewater,

showed that the As maximum removal was 62.4 % at a pH of 6.5; being approximately

constant when more treatment time was applied. When treating As (V) wastewater, the

maximum removal was 99.7 % at a pH of 5.0. When working with real wastewaters in

the pH range of 3.5 to 6.5; the arsenic maximum removal was 96 % at pH 6.5; this last

removal was approximately constant when more treatment time was applied. The ECP

process showed to be a capable technology to remove high concentrations of arsenic

(1000 to 3000 mg L-1

) when carbon electrodes and iron nanoparticles are used.


179

Nº REF.: P438

Applying EK to achieve SMART (simultaneous modified assisted recovery techniques) EOR in carbonate reservoirs of Abu Dhabi

Nabeela Al Kindya, Mohamed Haroun

b,*, Arsalan Ansari

c, George V. Chilingar

d,

Hemanta Sarmae

a, b, c, e The Petroleum Institute, Abu Dhabi, P.O. Box: 2533, U.A.E.

d University of Southern California, Los Angeles, CA 90089, USA

*Mohamed Haroun: [email protected]

Among the emerging EOR technologies in carbonate reservoirs are Nano-EOR and

surfactant-EOR in conjunction with the application of Electrically Enhanced Oil

Recovery (EEOR) [2-6]. This is gaining increased attention due to a number of

reservoir-related advantages such as reduction in fluid viscosity, water-cut and

increased reservoir permeability.

The concept of SMART EORtakes advantage of the high transport phenomena of EK

coupled with chemical flooding to enhance depth of penetration[3-6]. The main

objective of this research is to target unswept oil efficiently while reducing HSE

concerns of handling and transporting the nano and surfactant particles. Experiments

were conducted on 1.5-inch. carbonate reservoir core-plugs from Abu Dhabi producing

oilfields with porosity and permeability ranging from 0.01 to 21% and 0.007 to 24.4

mD, respectively. Several nano particles including CuO and NiO of 50nm size range

were tested and compared for ultimate recovery factors against the injection of a non-

ionic alkyl polyglucoside (APG) with C10/12 chain structure, a blend of nonionic-

anionic APG surfactant and a cationic fatty amine based betaine surfactant were

evaluated for this study. These surfactants were selected based on the fact that they are

synthesized from renewable resources such as starch and coco derivatives, easily bio-

degradable and have very low ecotoxicity.

Fig. 1. SMART EOR at ambient conditions. Ansari et al., 2012 [3]

The experimental results at ambient conditions show that the application of

waterflooding on the water-wet carbonate core-plugs yields a recovery of approximately

46-72%, whereas SMARTEOR enhanced the recovery by an additional 7-14%. An

additional 6-11% improvement in recovery was achieved by the application of EK.

Essentially, SMART EOR produced an average of 79-81% displacement efficiency


180

from all the carbonate reservoir cores tested at ambient conditions as can be seen in Fig.

1 [Ansari et al., 2012].

The results to Abu Dhabi reservoir conditions (high temperature, pressure and

formation water composition) yielded another 6-10% increase in ultimate recovery.

Overall, SMART EOR produced an average of 85-88% displacement efficiency from all

the carbonate reservoir cores tested at Abu Dhabi reservoir conditions (formation water

composition 270k ppm TDS) 10% increased oil displacement and more than 50%

reduced water injected [Haroun et al., 2013 and 2014] as can be seen in Fig. 2.

Fig. 2 a and b. EEOR vs SMART EOR at ambient conditions (a) vs. elevated reservoir conditions

(b) in carbonate reservoir core-plugs

Furthermore, this process can be engineered to be a sustainable approach as the water

requirement can be reduced by more than 50% on application of electrokinetics, while

power consumption can be optimized at $4/Bbl, thus improving environomics[1].

References

[1] Al Kindy N., Haroun M., Ansari A. and Sarma H., 2013. Application of

Electrokinetics to achieve Smart Nano-Surfactant EOR in Abu Dhabi Carbonate

Reservoirs. ADIPEC.

[2] Amba, S.A., Chilingar, G.V. and Beeson, C.M., 1964. Use of direct electrical

current for increasing the flow rate of reservoir fluids during petroleum recovery.

J. Canad. Petrol. Technol., 3 (1):8-14.

[3] Ansari, A., Haroun, M., Abou Sayed N., Al Kindy, N., Ali, B., Shrestha, R., and

Sarma, H., 2012. A new approach optimizing mature waterfloods with

electrokinetics-assisted surfactant flooding in Abu Dhabi carbonate reservoirs.


181

SPE 163379 SPE Kuwait International Petroleum Conference and Exhibition,

Kuwait, 10-12 Dec.

[4] Haroun, M., Ansari, A. and Al Kindy, N., 2014. Applying EK to achieve SMART

(simultaneous assisted recovery techniques) EOR in conventional and tight

carbonate reservoirs of Abu Dhabi. Electrochemistry Gordon Research

Conference, Ventura, CA.

[5] Haroun, M., Ansari, A., Al Kindy, N., Abou Sayed, N., Ali, B., Shrestha, R., and

Sarma, H., 2013. Application of electrokinetics to achieve smart EOR in Abu

Dhabi oil-wet carbonate reservoirs. Presented at the Electrokinetic Remediation

Conference, June 23-26.

[6] Haroun M., Wittle J.K. and Chilingar G.V., 2012. Publication No.

WO/2012/074510. Title of the invention: "Method for Enhanced Oil recovery

from Carbonate Reservoirs." Applicants: ELECTRO-PETROLEUM, INC. (US).

Inventors: Mohammed Haroun (AE), J. Kenneth Wittle (US) and George

Chilingar (US), June 12.


182

Nº REF.: P444

Electrochemical degradation of chlorobenzene in water using Pd- catalytic electro-Fenton’s reaction

Ali Ciblak, RoyaNazari*, Ibrahim Mousa, Akram Alshawabkeh*

Department of Civil and Environmental Engineering, Northeastern University, 400

Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, United States

Presenter: [email protected]

In this study, a three electrode flow system is proposed for Pd-catalytic oxidation of

chlorobenzene (CB) in groundwater. The system is consisted of sequentially arranged

electrodes, one mixed metal oxide (MMO) anode and two MMO cathodes. Applied

current is divided between cathodes to develop acidic vicinity around the first cathode.

Two grams of Pd/Al2O3 is packed at the top of the first cathode to catalyze

electrochemically generation of H2O2. Column experiments are conducted to investigate

the system variables. Their performance for CB removal was evaluated in open flow

column at room temperature. The results indicate that three electrodes system with

supported Pd/Al2O3 on the surface of cathode can be used for the removal of CB

pollution and their capacity does not depend on the nature of the CB concentration.

Also, the three MMO electrodes provide more acidic conditions comparing two

electrode systems for better oxidation. Compared with the dehalogenation with a total

CB removal of 44% in 2 h with Pd/Al2O3, the CB removal reached 56-64% with

Pd/Al2O3 supported with ferrous salts under the same operate condition. With the

proposed treatment, the electrochemical process supported with Pd keep the degradation

of CB for long time without replacement.



183

Nº REF.: P447

Hydrodechlorination of TCE by Pd and H2 produced from a copper foam cathode in a circulated electrolytic column at high flow rate

Noushin Fallahpoura, SonghuYuan

a,b, Akram N. Alshawabkeh

a,*

aCivil and Environmental Engineering Department, Northeastern University, Boston,

MA, 02115, USA. bState Key Lab of Biogeology and Environmental Geology, China University of

Geosciences, Wuhan, 430074, P. R. China.

*Corresponding author: E-mail: [email protected]

Abstract

Pd-catalytic hydrodechlorination of trichloroethylene (TCE) using cathodicH2in situ

produced from water electrolysis has been reported. For a field in-well application, the

flow rate is generally high. In this study, the performance of Pd-catalytic

hydrodechlorination of TCE using cathodic H2 is evaluated under high flow rate (1

L/min) in a circulated column system. An iron anode and a copper foam cathode are

used to enhance TCE hydrodechlorination because iron anode improves reducing

conditions and copper foam cathode can hydrodechlorinate TCE directly in addition to

H2 production. Under the conditions of 1 L/min flow rate, 500 mA current, and 5 mg/L

initial concentration, TCE removal efficacy using iron anode (96%) is significantly

higher than using mixed metal oxide (MMO) anode (66%). Two sets of experiments

with iron anode and two types of cathodes (MMO and copper foam) in the presence of

Pd/ Al2O3 catalyst under various current intensities were conducted to evaluate the

effect of cathode materials. The removal efficienciesare almost the same for both

cathodes under the same conditions, with more precipitation generated using copper

foam cathode. Packing Pd pellets into a column with iron anode and copper foam

cathode improves the removal rate to 90% for all the currents applied except 62 mA,

with production of less precipitates. For the potential field application, a cost-effective

and sustainable in situelectrochemical process is proposed using asolar panel as power

supply.



184

Nº REF.: P456

Enhancing electro-Fenton chlorobenzene degradation from groundwater, oxidation technique in the presence of Pd with different catalyst supports

Ibrahim Mousa1*, Akram Alshawabkeh

2

1Department of Environmental biotechnology, Genetic engineering and biotechnology

institute (GEBRI), University of Sadat city, Minoufia 22857, Egypt. 2Department of Civil and Environmental Engineering, Northeastern University, 400

Snell Engineering, 360 Huntington Avenue, Boston, Massachusetts 02115, United States

Presenter email : [email protected]

ABSTRACT

The study of the electrochemical degradation of Chlorobenzene is becoming

increasingly an important issue in environmental electrochemistry. Oxidation of CB

using Pd/A2O3 and Pd/AC as catalysts at mild conditions (20±1 0C, 1 atm) was carried

out in three electrodes column with Na2SO4 and FeSO4 as supporting electrolyte at

different pH. The highest reaction rate was achieved when the process was carried out at

a solution of pH= 3. The Pd/AC showed an appreciable loss of activity upon time on

stream, which was associated with the adsorption capacity. However, a residual activity

remained practically stable, reaching very similar CB conversion (62 and 72%) in

presence of Pd/A2O3 and Pd/AC, respectively. The Pd/AC catalyst maintained a

constant activity at a 72% CB conversion once the steady state was reached. This

suggests that the AC supported catalyst is less susceptible to the chloride poisoning

produced during the reaction with high adsorption capacity.

Background

Chlorobenzenes are intermediates in the industrial production of drugs, scents, dyestuff,

herbicides, and insecticides. They are also used as additives to oils, lubricants, and dye-

carriers, and are employed in heat exchange systems and for dielectric insulation

(Adrian and Gorisch, 2002). Large quantities of chlorobenzenes have been released to

the environment as a consequence of the wide use during the last decades (Lee and

Fang, 1997). Chlorobenzenes are hydrophobic, persistent, and some of them are chronic

to animals and humans (Lee and Fang, 1997). They are typically associated with soils

through hydrophobic bonding (Song-hu et al., 2007).

Table 1 Variation of element composition for Pd/Al2O3and Pd/AC pellets after catalysis process.

Element Pd/Al2O3 Pd/AC

C K 6.16 75.36

O K 35.01 18.92

AlK 56.15

PdL 3.74 2.54

NaK 0.41

K K 3.18



185

Fig. Microstructure of Pd/Al2O3 pellets and Pd/AC catalysts with FESEM images and EDAX analysis.


186

Nº REF.: P457

Feasibility of modeling by adsorption the magnetic separation of iron nanoparticles

Fiona Lancellottia, Francisco Retamal

a, Patricio Núñez

a, Henrik Hansen

a*.

aUniversidad Técnica Federico Santa María, Valparaíso, Chile.


High and low magnetic field separation systems considering the competing forces and

the probability of a particle to be captured have been modeled extensively by numerous

authors. Although models have demonstrated accuracy with respect to the experimental

data, their point of view has always been from physicals or electric engineering. This

work proposes the modeling of magnetic separation from the point of view of a well-

known chemical engineering process, the adsorption process.

The modeling consisted in looking a low magnetic separation system for removing iron

nanoparticles as a fixed-bed adsorber where the steel wool inside was considered to be

the porous media where nanoparticles were adsorbed in its surface. The resulting model

was a typical 1D advection-dispersion model with Danckwerts’ boundary conditions.

The model was solved in COMSOL Multiphysics version 4.3 and validated

theoretically and experimentally. Theoretical validation showed high representativeness

using other papers parameters and data. Contrasting the model with experimental data

for two magnetic filters made experimental validation. The magnetic filters were

stainless steel tubes filled with stainless steel wool and rounded by a coil which

produced the magnetic field. The filters were operated as continual systems.

The magnetic separation process of iron nanoparticles could be represented by an

adsorption model, only in early stages of operation, this is, few time after saturation of

the filters. It was found that the greater impact in both model and operation of magnetic

filters were volumetric flow, maximum adsorbent capacity and, principally, inlet

concentration.



187

Oxidation

1st Precipitation

2nd Precipitation

Filtration

Drying and calcination

Raw wastewater from copper smelter gas cleaningpH: <1As: 4.000 – 15.000 [mg/L]

Oxidized raw wastewaterpH: <1As: 4.000 – 15.000 [mg/L]

Wastewater after 1st PrecipitationpH: ≈1As: 100 – 1.000 [mg/L]

H2O2

Ca(OH)2

Floculant

Fe2(SO4)3/FeCl3

HCl/H2SO4

Floculant

Treated wastewaterpH: ≈7As: 0,1 – 5 [mg/L]

Wet solids

Stabilized solid residue with arsenic and

heavy metals

Sludge

Sludge

CaCO3

Filtrate

Figure 1- Copper smelter gas cleaning wastewater treatment scheme

Nanoparticles tank

Wastewater AirElectrocoagulator

Clarifier

ValvePinch

Timer

Clean water

DC

Clean Water

DC DC

Nanoparticlesto tratament

Nanoparticlesto tratament

Nanoparticles recovery

Arsenic disposal

Figure 2 - Pilot plant proposal for arsenic removal with iron nanoparticles.

The filters achieved high filtration efficiencies, being 99,8% and 98,5% the lowest

values for the bigger and smaller filters, respectively. The maximum retention capacity

for bigger filter was 1,52 [g iron nanoparticles/ g steel wool] under 0,07 [T] and for

smaller filter, 1,23 [g iron nanoparticles/ g steel wool] under 0,08 [T]. The optimum

operation times until saturation for bigger and smaller filters were round 20 [min] and 8

[min], respectively. After these times, the increment in coil temperature could be

affecting the retention capacity of the filter. It was observed that highest utilization

capacity for both filters (near to 95,5%) were obtained with highest inlet concentration.

The higher equivalent mass retained gave the higher utilization capacity. For similar

utilization capacity (≈95%), a smaller volume filter produced a bigger utilization of the

adsorbent because the space velocity was bigger. Figure 3 shows the actual filtration

efficiency at different flow rates.

Figure 3. Iron Nano particle filtration Efficiency

The following equation was used to model the process of magnetic filter, assuming that

is analogous to an adsorption process.

(

) |


188

The results of this equation is plotted on Figure 4,that shows a good agreement among

the data points and the model prediction.

Figure 5 - Experimental setup of the smaller magnetic filtration system


189

Nº REF.: P458

Electrocoagulation reactor design for arsenic treatment

Diego Pinedaa, Patricio Núñez

a, Henrik Hansen

a*.

aUniversidad Técnica Federico Santa María, Valparaíso, Chile.


Chile is the main producer of copper in the world with 32,7% of the world production in

the 2010, by the 2012 there were produced 5.455.000[ton] of this mineral. Most of the

industrial wastewater generated in the mineral processing carries heavy metals and

sulfates in high concentrations, which ones are highly polluting. Based on the

electrocoagulation process, developed by the research team, see Figure 1, for the

treatment of arsenic from waste water, a procedure for the design of a continuous

electrocoagulation reactor was developed: a set of batch experience, using this data a

kinetic model was proposed and the kinetic parameters determined; then a continuous

electrocoagulation reactor was design and built, to test the scale up procedure.

The batch reactor was built as two concentric graphite cylinders, that are operated as an

air lift reactor, using air that is supply to the inner cylinder. The continuous

electrocoagulation reactor has three concentric cylinders units that are set up inside a

larger tank. Previously the use of iron nanoparticles for the arsenic removal and other

heavy metals has been study, as well as the electrocoagulation, but there is no

mechanism, stoichiometry or kinetic model to represent them. The contribution and

innovation of this research is the combination of both technics, his potentials and

advantages and bring them to bigger scales and arsenic concentration, besides the own

design of the reactor and its way of operation (Figure 1)

In this research 11 batch experiments were done, obtaining efficiencies of arsenic

removal over 98% at 45[min] of reaction time. Then 6 continuous experiments were

done, obtaining efficiencies over 90% of arsenic removal at 30[min] of residence time

by adding mechanical stirring.

A kinetic model was propose to fit the batch data and based on this model a continuous

reactor was design, Figure 2 shows the actual reactor. Figure 3 shows the results for the

Arsenic removal for the batch reactor.


190

Figure 1 – Process flow Diagram Arsenic Treatment (Liquid Industrial Wastewater)

Figure 2 – General overview of the reactor

Figure 3 – Results of Arsenic Remotion (Batch Experiment)

The analysis of the experiment data and the model that was developed shows that:

1. The kinetics determination of the electrocoagulation of arsenic using iron nano

particles on a batch reactor should be used as the basic data for the scale up of a

continuous reactor.


191

2. The continuous reactor operation shows that a set of three units of basic

electrocoagulation reactor and a mechanical stirred is a set up that allows for a

good mixing and maintenance of the electrocoagulation units.

3. The removal of the arsenic on the waste water is similar for the batch reactor at

the same current density 38 (A/m2), 95% (batch) and 90%(continuous)


192

Nº REF.: P463

Desalination of sandstone with two different setups under an applied electric field

Ondřej Matyščáka, Jorge Feijoo Condeb

*, Lisbeth M. Ottosen

c

aDepartment of Civil Engineering, Brno University of Technology, 602 00 Brno, Czech

Republic bDept. of Natural resources and environmental. University of Vigo Campus Lagoas,

36310 Vigo-Spain cDepartment of Civil Engineering, Technical University of Denmark, 2800 Kgs. Lyngby,

Denmark

* [email protected]

Soluble salts are considered as one of the main degradation agents which can affect the

architectural heritage [1, 2]. There are currently many different techniques that try to

decrease the salt concentration to the levels meeting safety limits. At the present time,

the technique called electrokinetics is the most highlighted. The efficiency and the

suitability of this technique have been demonstrated in several studies both in the

laboratory [3-5] and in the pilot scale test [6]. The present study aims to compare the

removal efficiency of chlorides from a sandstone when two different electrokinetic

setups are used.

The laboratory experiment was conducted with a big block of sandstone of 0.02 m3

which was contaminated with unknown amount of chlorides. The main goal of this

investigation was to analyse the removal efficiency of chlorides in the areas where the

electrode units were placed. In the first electrokinetic setup, 6 plastic cylinders

(electrode units) of 0.03 m2 filled with the clay poultices were placed oppositely at

different heights of the sandstone block (upper, middle and bottom placement). The

placement of the cylinders covered about 5.6 % of the total rock surface. The second

electrokinetic setup consisted of two casings (electrode units) filled with clay poultices

were placed oppositely as well. The covering with casings was about 9.3 % of the total

rock surface. The results obtained from these two different setups were compared.

It was shown that the bigger surface area covered with the electrode units, the bigger

influence on desalination efficiency it had. Therefore it was found out that the second

electrokinetic setup showed higher removal efficiency for chlorides from the sandstone.

It was also shown that the distance between the electrode units was a limiting factor of

this technique.


193

Figure 1.: average mass of chloride (2 test per setup) extracted by the poultices applied close to

the electrodes at different heights

References

[1] Charola, A.E. Salts in the deterioration of porous materials: an overview. Journal

of America Institute of Conservation 39 (2000) 327-343.

[2] Doehne, E. Salt weathering: a selective review. Segesmund S., Weiss T. and

Vollbrecht A. Natural stone weathering phenomena, conservation strategies and

case studies. Geological Society. London. Special publications, 205, 51-64

(2002).

[3] Ottosen, L.M.; Christensen, I. (2012) Electrokinetic desalination of sandstones for

NaCl removal – Test of different clay poultices at the electrodes. Electrochimica

Acta

[4] Feijoo. J.; Nóvoa. X.R.; Rivas. T.; Mosquera. M.J.; Taboada. J.; Montojo. C.;

Carrera. F. (2012).- “Granite desalination using electromigration. Influence of

type of granite and saline contaminant”. Journal of Cultural Heritage.

[5] Rörig-Dalgaard. I.; Ottosen. L.M.; Hansen. K.K. (2012).- “Diffusion and

electromigration in clay bricks influenced by differences in the pore system

resulting from firing”. Construction and Building Materials 27 390-397

[6] Ottosen. L.M.; Rörig-Dalgaard. I.; Villumsen. A. (2008).- “Electrochemical

removal of salts from masonry- experiences from pilot scale”

Acknowledgements

J. Feijoo research was funded by a FPU-predoctoral grant by the Ministerio de

Educación of Spain.


194

Nº REF.: P472

Evaluation of microbial communities, growth rates and susbtrate consumption under electrical field

M. Zeyoudi and S.W. Hasan*

Institute Center for Water and Environment (iWATER), Chemical and Environmental

Engineering Department, Masdar Institute of Science and Technology, Abu Dhabi,

United Arab Emirates, PO Box 54224

*Corresponding author: e-mail address: [email protected]

The application of electro-technologies in the UAE existing biological treatment

methods requires further understanding of the behavior of the microorganisms

(biodegraders) to improve the quality of the treated effluent. Therefore, the primary

objective of this research study was to evaluate the microbial communities present in

bio-electrochemical reactor under different operating conditions such as current density

and exposure time to electricity to achieve system process stability. This study was

divided into two Phases. In Phase 1, a laboratory scale study was conducted at different

current density ranging between 5 and 20 A/m2

continuously supplied with no addition

of substrate. Phase 2 evaluated the bacteria count, substrate utilization rate (organic

removal), and microbial process biokinetics (bacteria growth rate and doubling time) at

continuous supply of electric field at different current density (Stage 1), and at

intermittent supply of electric field at constant current density of 15 A/m2 (Stage 2). The

results from Phase 1 revealed that the continuous supply of electric field had significant

stimulation effect on microorganisms at low current density of 5 A/m2 (bacteria count

has increased from 80,000 (initially) to 1,686,600 CFU/mL after 12 h) when compared

to the bacteria count at high current density of 20 A/m2

(bacteria count has increased

from 80,000 (initially) to 263,600 CFU/mL after 12 h). Moreover, in Phase 2 – Stage 1,

the bacteria count in the bioreactors has increased from 200,000 CFU/mL (initially) to

540,000, 920,000, 1,460,000 and 320,000 CFU/mL at 15, 10, 5, and 0 (control) A/m2,

respectively. However, the growth rate of living microorganisms at intermittent supply

(Phase 2 – Stage 2) of electricity at 15 A/m2 was also higher (0.1 1/h) when compared

to the control reactor through which no electric field was supplied (0.08 1/h). A similar

observation was reported with respect to substrate removal as the concentration of

sCOD was 35, 25, 25, 24, and 54 mg/L at 5 min ON yet with 10, 15, 20, 30 min OFF,

and Control, respectively. The success of this study would contribute to the

implementation of electro-technologies in the wastewater treatment plants in the UAE.

References

[1] M. Zeyoudi. , Microbial process biokinetics under DC electrical field for bio-

electrochemical wastewater treatment related applications, M.Sc. thesis, Masdar

Institute of Science and Technology, Abu Dhabi - UAE (2014)

[2] V. Wei, M. Elektorowicz, and J.A. Oleszkiewicz, Influence of electric current on

bacterial viability in wastewater treatment. Water res. 45 (2011) 5058-5062


Poster Session: Organic and chlorinated organic compounds remediation


197

Nº REF.: P507

Electrokinetic-Fenton process for remediation of PAHs-contaminated railroad soil

Woo-Sung Junga,*

, Jae-Young Leea, Young-Min Cho

a and Ji-Won Yang

b

aKorea Railroad Research Institute, Uiwang-si, 437-757, Republic of Korea

bKorea Advanced Institute of Science and Technology, Daejeon-city, 305-701, Republic

of Korea


1. Introduction

Because the railroad yard and soil-contaminating facilities are scattered over broad area,

it’s difficult in identifying the soil contamination status as well as monitoring and

controlling the soil contamination source. Soil contamination at railroad site is mostly

around refueling facilities where the soil is contaminated by spilled, leaked or dropped

oil and at station area, heavy oil such as grease or lubricant leaked during the train stops

for extended time causes the contamination which takes more time and cost in restoring

than the area contaminated by diesel. This study, to purify the railroad oil-contaminated

soil, is intended to determine the activity parameter to enhance the applicability and

processing efficiency as well as identify the optimal processing efficiency by applying

such complex technique as Electrokinetic-Fenton process, thereby identifying the

applicability to soil-contaminated railroad yard.

2. Experiment

Electro-kinetic reactor was fabricated with 4cm-diameter and 20cm-long glass

cylindrical tube and tested at constant-current condition of 5~10mA(0.4~0.8 mA/cm2)

and 75 mL electrode device was attached to both ends of reactor and the tube to

discharge the gas generated by electrolysis was placed on top. Graphite plate was used

for electrode and the voltage could be raised up to 200V using DC supply device.

Kaolinite was used as soil specimen which was dried and crushed to the grain sized less

than 150 μm passing through No. 100 sieve. Clay was used as contamination medium

and PAHs (aromatic hydrocarbon) which is the oil component was determined the

model contaminant. Phenanthrene-contaminated soil was made by mixing

phenanthrene-acetone solution with soil and evaporating acetone. Initial soil

contamination concentration was set as 600~700 mg/kg dry soil and during the test,

variation in soil voltage and electric osmotic quantity were measured. After finishing

the test (Table 1) soil specimen was cut into the piece in certain length and dried before

analyzing the concentration of phenanthrene remained in soil.


198

Table 1. Experimental condition of electrokinetic-fenton process tests

No. Current (mA) Concentration (%) Period (week) Electrode change (time)

1

5 3.5

1

None 2 2

3 3

4

10 3.5

1

None 5 2

6 3

7 4

8 10 10 2 None

9 10

3.5 4 1 10

Figure 1. Schematic diagram of electrokinetic-fenton process

3. Result & Discussions

As a result, maximum efficiency was 80.5% as shown in Table 2. However, the size of

soil grain was 150 μm or less, the removal efficiency would possibly be increased to

90% in soil with greater permeability. The longer the process period the higher the

efficiency and the pollutant in cathode, besides anode, could be eliminated by replacing

the electrode.

Table 2. Result of electrokinetic-fenton process tests

Test No Current

(㎃)

Concentration

(%)

Electro

exchange

(time )

Process

period

(week)

Total EOF

(ml)

Removal

rate (%)

1

5 3.5 None

1 495 15.1

2 2 811 29.9

3 3 1262 32.2

4

10 3.5 None

1 1033 21.8

5 2 1582 40.6

6 3 2115 55.9

7 4 2354 61.4

8 10 10 None 2 1348 51.2

9 10 3.5 1 4 2405 80.5

H2 gas venting

Voltagemeter

Power supply

Anode(+) Cathode(-)

O2 gas venting

Soil(clay)

Cathode

tank

Soil (clay)

Anode

tank


199

As indicated in Fig. 2(a) and (b), as the process time was extended in 5 mA and 10 mA,

removal rate was accordingly increased and movement of hydrogen peroxide was

getting faster in line with increased electro—osmosis at higher current. Thus very few

cathode was removed at 5 mA which was however increased even at cathode at 10 mA.

Fig. 2(c) compares a 2-week test result with hydrogen peroxide 3.5% and 10%,

respectively and no significant difference was indicated. (Exp. no. 5, 8). Such result

proved that dissolution speed as constraint and increase in concentration of hydrogen

peroxide had insignificant effect on removal rate. As a result of electrokinetic-Fenton

test, in removing the pollutant, smooth flow of hydrogen peroxide and stability are the

critical factor and supply location & concentration of hydrogen peroxide, induced

current and process period had a significant effect on pollutant removal rate. In addition,

replacing the electrode also significantly increased the pollutant removal rate in cathode.

(a) Experimental No. 1-3 (b) Experimental No. 4-8 (c) Experimental No. 5, 7, 8, 9

Figure 2. Result of electrokinetic-fenton process tests

Acknowledgements

This work was financially supported by R&D program through the basic research of

Korea by the Ministry of Science, ICT & Future Planning (grant number PK14003B).

References

[1] Manachan, S.E., Environment Chemistry, Willard Grant Press, Boston(2009).

[2] Albert T. Yeung, Contaminate Extractability by Electrokinetics, Enviro. Eng.

Science 23 (2006).

[3] EPA., Subsurface Characterization and Monitering Techniques: Vol II(2008)

[4] Michael J. H., The use of electrokintics to enhance the degradation of organic

contaminants in soils(20103)

[5] Jurate Virkutyte, Mica Sillanpaa, Electrokinetic Soil Remediation-critical

Overview, the Science of the Total Enviro. 289(2012)


200

Nº REF.: P515

Characterization and regeneration of Pd/Al2O3 catalyst along a three electrodes column for chlorobenzene remediation.

Ibrahim E, Mousa1, Ali Ciblak

2, Roya Nazari

2 and Akram N. Alshawabkeh

2*

1 Department of Environmental biotechnology, Genetic engineering and biotechnology

institute (GEBRI), University of Sadat city, Minoufia 22857, Egypt. 2 Department of Civil and Environmental Engineering, Northeastern University, 400

Snell Engineering, 360 Huntington Avenue, Boston, Massachusetts 02115, United States

Abstract

Advanced oxidation processes are reported as promising methods for the remediation of

groundwater contaminated with chlorinated compounds. In our previous study, the

effectiveness of Pd/Al2O3 catalyzed electro-fenton method, an advanced oxidation

process, is investigated in a three-electrodes column for the remediation of

chlorobenzene (CB). Three inert electrodes, one MMO anode and two MMO cathodes

are placed sequentially in the column to generate acidic vicinity for fenton’s reaction.

Pd/Al2O3 particles are packed on the first cathode to enhance H2O2 production needed

to facilitate CB oxidation. In this study, long term catalytic efficiency of palladium

particles is evaluated. After 200 hours of electrolysis, Pd/Al2O3 was regenerated through

reduction by 2% hydrazine. Both new, used and regenerated catalysts were

characterized by field emission scanning electron microscopy (FESEM) equipped with

energy dispersion spectroscopy. The profile of metals and surface texture for both used

and regenerated catalyst was determined. The catalytic activity of regenerated, Pd/Al2O3

was evaluated in the three-electrodes column under different conditions and compared

with new one. The results showed that iron depositions increase and aluminum metal

decreases in used comparing to new catalyst. It was found that both new and used had

same ratio of Pd. A tendency of absence of chloride in used and regenerated catalyst

was observed. Regeneration of Pd/Al2O3 increase CB removal by 40%. Results show

that enhancement of Pd catalyst activity through the regeneration of catalysts is noticed.

Fig. Microstructure of Pd/Al2O3 pellets before and after catalysis processes with FESEM images (10K X).


201

Table 1 Variation of element composition for fresh and spent Pd/Al2O3 pellets after catalysis process.

Fresh pellets Spent pellets

Element Point #1 Point #2 Point #3 Point #4 average Point #1 Point #2 Point #3 Point #4 average

C K 5.09 6.4 6.66 6.48 6.16 16.55 25.18 18.08 19.54 19.84

O K 35.51 35.08 32.59 36.84 35.01 32.48 35.77 39.3 33.28 35.21

AlK 56.19 54.07 56.9 57.44 56.15 39.05 31.50 36.7 39.25 36.63

PdL 3.22 4.46 3.41 3.85 3.74 3.87 3.55 3.11 3.45 3.50

S K

0.58 0.42 0.52 0.64 0.54

FeK

7.45 3.34 2.04 3.84 4.17

NaK

0.44 0.38 0.41

0.23 0.24

0.24


202

Nº REF.: P535

Removal of a thiazine, an azo and a triarylmethane dyes from dyes polluted kaolinite by electrokinetic remediation

Effendia,b

, Shunitz Tanaka a,*

a Graduate School of Environmental Science, Hokkaido University, Sapporo Hokkaido,

060-0810, Japan b Department of Chemistry, Faculty of Mathematics and Natural Science, State

University of Padang, Padang, West Sumatera ,25131, Indonesia


Dyes, even in low concentration are visually detected and affect the aquatic life and

food cycle. Methylene Blue (MB) is one of the most commonly used substances for

dyeing cotton, wood, and silk. MB can have various harmful effects such as breathing,

vomiting, several headache, diarrhea, painful micturation and methemoglobinea [1].

Methyl Orange (MO) also use as an pH indicator. The reductive cleavage of the azo

linkage to produce aromatic amines and can even lead to intestinal cancer .High content

in living systems can prove to be harmful.While Phenol Red (PR) inhibits the growth of

renal epithelial cells. Direct/indirect contact, leads to irritation to the eyes, respiratory

system and skin. And also toxic to muscle fibres and has mutagenic effects [2].The

molecular structure of dyes shown in Figure 1.

Figure 1. Molecular Structure of dyes. a) Methylene Blue, b) Methyl Orange and c). Phenol Red

Several methods can be used to remove dye from soil such as biological, physical and

chemical processes. However, the application of electrokinetic remediation is very

promising for soil decontamination polluted by heavy metal [2], and organic

compounds such as Reactive Black 5 (RB5) [3]and Lissamine Green B (LGB) [4] dyes.

Previous rsearch repoted about the removal of dye by several technique [5-8]. This

study proposed the removal of dyes by the electrokinetic remediation by finding the

optimm conditions such as electrolyte , pH,and extractan to obtain the higher percentage

in dye removal.

Materials and Methods

Kaolinite sample preparation

150 g of kaolinite clay mix with 55.5 ml of 0.3 gL-1 dye solution. The mixture stood for

24 h and load to EKR chamber. EKR set up (Fig 2) associate with graphite electrode

and certain electrolyte. A DC Current 30 V and 10 mA use as an electric resources. The

monitoring voltage drop and current density were taken periodically by data logger.

And process will running during 7 to 15 days. After the process was finished, the

a

a b

a

c

a



203

sampes were taken from equipment setup and divided by five sections, named S1- S5

from anode to chatode. Measuring the pH by adding potassium chloride 1M solution to

dry kaolinite in certain ratio by using pH meter. Contaminant was extracted with

benzoic acid in water, benzoic acid in xylene and potassium chloride in ethanol

respectively. Finally, the contaminant concentration was determined by absorbance

measurements using UV-Visible spectrophotometer at the maximum wavelength of

dyes means at 665 nm for MB, 440 nm for MO and 560 nm for PR. The result shown

on the Table 1.

Figure 2. Schematic diagram of modified equipment of EKR Cell

Table 1. Percentage Removal of Dyes by kinds of fluid processing after EKR Process

Dye By H2O (%) By Na2SO4 (%) By NaH2PO4 (%)

Methylene Blue 56 75 84

Methyl Orange 72 78 90

Phenol Red 79 82 92

Conclusion

Distribution of pH and concentration for five sections in kaolinite sample from anode to

cathode after EKR is different for any electrolytes. The characterization and behavior

of EKR system was different among all dyes since the difference the structure and the

charge of the dyes

References

[1] G.Muthuraman, Tjoon Tow Teng, Cheu Peng Leh, I.Norli, Journal of Hazardous

Materials, 163 (2009) 363-369.

[2] R.S. Putra, S. Tanaka, Separation and Purification Technology, 79 (2011) 208-

215.

[3] M.Pazos, M.T.Ricart, M.A.Sanroman, C.Cameselle, Electrochemica Acta 52

(2007) 3393-3398.

[4] M.Pazos, C.Cameselle, M.A.Sanroman, Environmental Engineering Science, 25

(2008) 419-426.

[5] A.A.Amina,S.B.Girgis,A.N.Fathy, Dyes Pigment 76 (2008) 282-289.

[6] D.Kavitha,C.Namasivayam, Biresour.Technol, 98 (2007) 14-21.

[7] S.Lakshmi,R.Renganathan,S.Fujita, J.Photo Chem.Photobiol.A.Chem 88 (1995)

163-167.

[8] M.Pianizza,A.Barbucci,R.Ricotti,G.Cerisola, Sep.Purif.Technol, 54 (2007) 382-

387.


204

Nº REF.: P541

Construction and characterization of dimensional stable anodes with iridium and tantalium by painting, immersion and electrophoretic

deposition for the electrokinetic treatment of polluted soil by hydrocarbon

R. A. Herradaa, A. Medel,

b F. Manríqueza, E. Bustos

a*

a Centro de Investigación y Desarrollo Tecnológico en Electroquímica, S.C. Parque

Tecnológico Querétaro, Sanfandila, Pedro Escobedo, 76703 Querétaro, México. b Universidad de Barcelona, Facultad de Química, Martí i Franquès, 1 08028

Barcelona.

* [email protected]

The electrokinetic treatment (EKT) of polluted soils by organic and inorganic

compounds has been developed five years ago at CIDETEQ with an efficiency close to

80 % in less than 8 hours developing the EKT in situ or ex situ. EKT is developing

applying direct current between at least two electrodes (anode and cathode), which are

placed into the soil to be treated, when passing current between the electrodes there are

different transport processes, as electro-migration, electro-osmosis, electrophoresis and

electrolysis of water. These processes have been reported in the literature, one of them

is showed in Figure 1 [1-2].

Figure 1. Representation of the circular 2D arrangement of anodes (+) around the cathode (-)

extracting the support electrolyte with the hydrocarbon (A) and using a power supply (B).

There are different factors that can be tested to continue improving this technology. A

critical factor that is nowadays under investigation is the material and the coating of the

working electrode, due to their crucial influence on the global efficiency of the EKT.

For EKT different coated electrodes have been used as IrO2, SnO2 and Ta2O5, which

generate chemisorbed hydroxyl radicals (OH) at interface level by the highest oxidation

over potentials and roughness, properties that favor the transformation or degradation of

organic compounds as hydrocarbons (HC).

The main goal of this research is modified titanium electrodes starting from the same

modifier solution (which includes iridium and tantalium) but using three different

deposition techniques: immersion, painting and electrophoretic deposition to construct

these dimensional stable anodes for the EKR of polluted soil by hydrocarbon (HC).

+

+

+

+

+ +

- A

A

B



205

The modified surfaces were characterized by Raman spectroscopy, Cyclic Voltammetry

(CV), Electrochemical Impedance Spectroscopy (EIS), Diffraction X-Ray (DRX),

perfilometry, Scanning Emission Microscopy (SEM) and Energy Dispersive X-Ray

spectroscopy (EDX). The production of OH was made by Electron Paramagnetic

Resonance (EPR) and UV-Vis spectrophotometry. Additionally, the HC removal was

evaluated using UV-Vis, Gas Chromatography couple Flame Ionization Detector (GC-

FID) and Chemical Oxygen Demand (COD).

References

[1] E. Bustos, J. Cárdenas, M. Pérez, B. Ochoa. Patente MX/a/2014/000833.

[2] M. Pérez – Corona, B. Ochoa, J. Cárdenas, G. Hernández, S. Solís, R.

Fernández, M. Teutli, E. Bustos. Recent. Res. Devel. Electrochem. (2013) 9: 59-

80.


206

Nº REF.: P573

Enhancing solutions for electrokinetic remediation of dredged sediments polluted with fuel

F. Rozasa, M. Castellote*

b

a,b Institute of Construction Science Eduardo Torroja, IETcc-CSIC. 28033, Madrid

Spain

*[email protected]

Since most organic contaminants do not have a net negative or positive charge, zeta

potential, is one of the most important parameters concerning their transport because

this potential controls the direction and rate of the EOF; therefore, ionic surfactants

seem to be the most appropriate, to remove them, as they introduce charged species that

can be moved by electromigration. However, non-ionic surfactants are often used

because of their lower critical micelle concentration compared to ionic surfactants,

higher degree of surface-tension reduction, and relatively constant properties in the presence of salt, which result in better performance and lower concentration requirements [1,2]. Maybe for this reason, as well as because of the complex matrix/surfactant/contaminant interactions, the results found in the literature concerning

the use of surfactants in the electrokinetic remediation of organic compounds are sometimes contradictory [3-7].

In this paper electrokinetic remediation experiments of dredged material from a harbour

contaminated with automotive fuel have been carried out. The removal was

investigated testing a total of 22 different experimental conditions analysing the

influence of different enhancing solutions as three commercial non ionic surfactants,

one biosurfactant, one complexing agent and one weak acid. The results obtained have

been explained on the basis of the interactions between the contaminants and the

enhancing electrolytes with the matrix, analysing the influence of the z-potential,

electro-osmotic flow and enhancing chemicals in the removal of fuel. For one specific

system, the electrophoretic zeta potential of the contaminated matrix in a solution has

found to be related to the electroosmotic averaged zeta potential in the experiment, and

not to the efficiency in extraction.

Figure 1. Decontamination percentages in the remediation experiments in function of (C +

EH), where C =contribution of contaminant and the EH= contribution of enhancing solution

y = 5.7163xR² = 0.9532

0

25

50

75

100

0 5 10 15 20

deco

nta

min

ati

on

/ %

(C+EH),/mV

b)

0

5

10

15

20

C ESa)

mailto:*[email protected]


207

The efficiency of the extraction has been correlated to a parameter accounting for two

contributions, fuel and surfactant, calculated on the basis of differences in the

electrophoretic zeta potential in different conditions (Figure 1).

This reveals the necessity of selecting the most appropriate surfactant by making prior

tests of interactions between the contaminants/enhancing electrolytes/matrix, seeming to

be the zeta potentials obtained in these additional tests, the key parameter for assessing

the remediation efficiency.

References

[1] Y. H. Shen, Sorption of non-ionic surfactants to soil: the role of soil mineral

composition. Chemosphere 41 (2000) 711–716.

[2] J. W. Yang, Y. J. Lee, Electrokinetic removal of PAHs, in: K. R. Reddy, C.

Cameselle, Electrochemical Remediation Technologies for Polluted Soils,

Sediments and Groundwater. Wiley, New-Jersey, 2009, pp. 197–217.

[3] S. D. Haigh, A review of the interaction of surfactants with organic contaminants

in soil. Sci. Total Environ. 185 (1996) 161–170.

[4] R. E. Saichek, K. R. Reddy, Electrokinetically enhanced remediation of

hydrophobic organic compounds in soils: A review. Crit. Rev. Environ. Sci.

Technol. 35 (2005) 115–192.

[5] C. Cameselle, K. R. Reddy, Development and 385 enhancement of electro-

osmotic flow for the removal of contaminants from soils. Electrochim. Acta 86

(2012) 10–22.

[6] M. Pazos, O. Iglesias, J. Gómez, E. Rosales, M. A. Sanromán. Remediation of

contaminated marine sediment using electrokinetic-Fenton technology. J. Ind.

Eng. Chem. 19(3) (2013) 932–937.

[7] K. Maturi, K. R. Reddy. Simultaneous removal of organic compounds and heavy

metals from soils by electrokinetic remediation with a modified cyclodextrin.

Chemosphere 63(6) (2006) 1022–1031.


208

Nº REF.: P576

Electrodescontamination of soils contaminated with dyes for industrial use.

Felipe Hernández-Luisa*

, Mario V. Vázquezb, Raquel Rodríguez-Raposo

a,

Domingo Grandosoa, Mariano Pérez

a, Graciliano Ruiz

a, Carmen D. Arbelo

c

a Departamento de Química (U.D. Química Física), Facultad de Ciencias (Sección

Química), Universidad de La Laguna, Tenerife, España b Grupo Interdisciplinario de Estudios Moleculares (GIEM), Instituto de Química,

Universidad de Antioquia, Medellín, Colombia c Departamento de Biología Animal, Edafología y Geología, Facultad de Ciencias

(Sección Biología), Universidad de La Laguna, Tenerife, España

*Corresponding author: [email protected] (Felipe Hernández Luis)

The problem of contaminated water and soils requires the constant development of

appropriate methodologies to eliminate different types of contaminant. In this sense, the

technical Electrokinetic remediation of soils (electroremediation) has been applied

successfully to mobilize a large number of pollutants, both organic and inorganic.

As it is well known, this technical Electrokinetic decontamination consists of, basically,

the application of an electric field between two inert electrodes that are in contact with

moist soil. This electric field gives rise to a series of transport phenomena which favour

the movement of both loaded and unloaded substances in soils, including Ionic

migration, electrophoresis, electro-osmotic flow and diffusion.

This paper presents some preliminary tests on soil decontamination (first synthetic and

then on natural soils with different characteristics contaminated with dissolutions of dye

commonly used in the industry.) This combines the technical Electrokinetic remediation

(electroremediacion) with the physical method of adsorption.

Some of these dyes-compounds are being studied by our interdisciplinary group and

among them we can mention the following:

Remazol Red 23

Fast Green FCF

Tartrazine

Remazol is a reactive dye chromospheres contains a substituent that reacts with the

substrate. Reactive dyes have good fastness properties owing to the bonding that occurs

during dyeing. Reactive dyes are most commonly used in dyeing of cellulose like cotton

or flax, but also wool is dye able with reactive dyes. Reactive dyeing is the most

important method for the coloration of cellulosic fibres, wool and nylon.


http://en.wikipedia.org/wiki/Chromophore

http://en.wikipedia.org/wiki/Substituent

http://en.wikipedia.org/wiki/Chemical_reaction


209

Fast Green FCF is a sea green triarylmethane food dye. This substance has been found

to have carcinogenic effects in experimental animals, as well as mutagenic effects in

both experimental animals and humans. It furthermore risks irritation of eyes, skin,

digestive tract, and respiratory tract in its undiluted form.

Tartrazine is a synthetic lemon-yellow azo dye primarily used as a food coloring. It is

water soluble and is a commonly used colour all over the world, mainly for yellow.

Various types of medications include tartrazine to give a yellow, orange or green hue to

a liquid, capsule, pill, lotion, or gel, primarily for easy identification. Types of

pharmaceutical products that may contain tartrazine include vitamins, antacids, cold

medications (including cough drops and throat lozenges), lotions and prescription drugs.

Coloring-soil adsorption studies are underway simultaneously both by the Spanish

groups like the Colombian (first floor synthetic, as we said before, and then with natural

soils with high or low organic matter, to see the effect of the buffering power of the

soil).

The cells used are similar to those used in previous studies from our group, being the

dimensions of the cylinder containing the pasta soil : water 20 cm long by 2.5 cm in

diameter. The electrodes used were rods of graphite 8 cm2 in area exposed to the

dissolution.

The follow-up is being done by UV-V absorption spectrophotometry and as adsorbents;

once the dyes have been mobilized we tested the re-adsorption, mainly with cork and

sawdust of different tree species, previously subjected to a chemical pre-treatment.

References

[1] M.V. Vázquez, C.D. Arbelo, F. Hernández-Luis, D. Grandoso, M. Lemus,

Portugaliae Electrochimica 27 (2009) 419

[2] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, D. Grandoso, M. Lemus, D.

Benjumea, C.D. Arbelo, Geoderma 148 (2009) 261

[3] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, Land Contamination &

Reclamation 16 (2008) 249

[4] D. A. Vasco, C. Ramírez, D. M. Benjumea, F. Hernández-Luis, M. V. Vázquez,

Innovación 19 (2007) 15

http://en.wikipedia.org/wiki/Sea_green

http://en.wikipedia.org/wiki/Food_coloring

http://en.wikipedia.org/wiki/Mutagen

http://en.wikipedia.org/wiki/Lemon_%28color%29

http://en.wikipedia.org/wiki/Azo_compound

http://en.wikipedia.org/wiki/Dye

http://en.wikipedia.org/wiki/Food_coloring

http://en.wikipedia.org/wiki/Vitamins

http://en.wikipedia.org/wiki/Antacids

http://en.wikipedia.org/wiki/Throat_lozenge

Poster Session: EKR in combination with other techniques


213

Nº REF.: P646

Electrochemical dechlorination of TCE with mixtures of humic acid, metal ions and nitrates in a simulated karst groundwater

Noushin Fallahpoura, XuhuiMao

a,b, LjiljanaRajic

a, SonghuYuan

a,c, Akram N.

Alshawabkeha,*

aCivil and Environmental Engineering Department, Northeastern University, Boston,

MA, 02115, USA. bSchool of Resource and Environmental Science. Wuhan University, Wuhan City,

430072, P. R. China. cState Key Lab of Biogeology and Environmental Geology, China University of

Geosciences, Wuhan, 430074, P. R. China.

*Corresponding author: E-mail: [email protected]

Abstract

A small-scale flow-through limestone column was used to evaluate the effect of

common coexisting organic and inorganic compounds on the dechlorination of

trichloroethylene. An iron electrolysis system installed in the column was tested for the

treatment of contaminant mixtures in groundwater. The system consists of an iron anode

and a copper foam cathode. In the absence of humic acid (organic matters) and

dichromate, selenate, and nitrate (inorganic matters), 90% of initial TCE was

dechlorinated under optimum conditions (90 mA current, 1 mL/min flow rate, and 1

mg/L initial TCE concentration). As humic acid competes for the reactive sites on iron

anode with TCE, its aggregates inhibit the reduction rate of TCE to some extent. Metal

ions (strong oxidants) also compete with TCE for electron transformation. Dissolved

hexavalent chromium concentrations were reduced completely to trivalent chromium

due to the ferrous species from iron anode. TCE reduction rate was decreased by 1.5

times in the presence of dichromate. Selenate effect on TCE remediation rate was not as

strong as that of dichromate as the removal efficacy of TCE decreased by only 10%. In

addition, selenatecomplexation with dissolved iron released by iron anode corrosion

result in aggregates, which may coat the iron surface and decline dechlorination rate.

The present investigation indicates that the electrochemical reduction on a copper foam

cathode is capable to remediate TCE significantly (around 80%) even in the presence of

high concentration of nitrate (40 mg/L). Although the system presented here can clean a

mixture of contaminants, this system can be engineered and optimized to treat TCE in

mixtures with a relatively wide variety of contaminants.



214

Nº REF.: P651

Comparison on electrokinetics and soil flushing for removal of metals after in-situ soil mixing

Cha-Dol Lee1, Su-Won Lee

1, Eun-Ki Jeon

1, Kitae Baek

1, 2, *

1Department of Environmental Engineering, Chonbuk National University, 567 Baekje-

daero, Deokjin-gu, Jeonju, Jeollabuk-do, Republic of Korea 2Department of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-


Corresponding authorTel: +82-63-270-2437, Fax: +82-63-270-2449,E-mail :

[email protected]

Generally, different principles should be applied to remove organic and inorganic

contaminants from soil. In Korea, biodegradation, chemical oxidation, and chemical

flushing are common remediation techniques for petroleum contaminated site, while

chemical extraction is the most common choice for metals-contaminated site. In this

study, the lab-scale batch experiments were carried out to remove contaminants using

combined process of chemical oxidation and extraction for mixed contaminated soil

with diesel and heavy metals.A sequence of oxidation-extraction and simultaneous

application showed similar removal of petroleum, while the sequence of extraction-

oxidation showed lower removal of petroleum. The oxidation process removed organic

pollutants effectively, however, the metals still remained in the soil. The metals could

be removed by soil flushing and electrokineticremediation. As a result, 10-30% of

heavy metals were removedby soil flushing and electrokinetics. EDTA was the most

effective to extract Cu and Pb compared to others from contaminated soils. This result

indicates that extraction and oxidation could be applied to remediate mixed wastes-

contaminated site with metals and petroleum.

Acknowledgement

This work was supported by KEITI through GAIA project (201200055003)


215

Nº REF.: P675

Soils contaminated with drugs in common use: An attemp to use the electroremediation, in combination with the adsorptiom, on industrial

waste, as a prevention tool of contamination.

Felipe Hernández-Luisa*

, Mario V. Vázquezb, Elisa G. Carvajal

b, Sandra Dévora

c,

Susan Abdalác, Raquel Rodríguez-Raposo

a, Domingo Martín-Herrera

c, Carmen D.

Arbelod

a Departamento de Química (U.D. Química Física), Facultad de Ciencias (Sección

Química), Universidad de La Laguna, Tenerife, España b Grupo Interdisciplinario de Estudios Moleculares (GIEM), Instituto de Química,

Universidad de Antioquia, Medellín, Colombia c Unidad de Farmacología y Farmacognosia, Facultad de Ciencias de la Salud

(Sección Farmacia), Universidad de La Laguna, Tenerife, España d

Departamento de Biología Animal, Edafología y Geología, Facultad de Ciencias

(Sección Biología), Universidad de La Laguna, Tenerife, España

*Corresponding author: [email protected] (Felipe Hernández Luis)

New emerging contaminants listed more and more. Among others we can mention

powerful drugs such as anti-inflammatory agents, analgesics, antipyretics, etc. are being

used increasingly, often without medical supervision one. Non-steroidal anti-

inflammatory drugs (NSAIDs) are really an issue of growing concern in relation to their

presence in the environment, particularly in the soil and the water. An important issue

that is being conducted, on the more developed countries, is obviously control and

responsible consumption of these drugs through campaigns of awareness, as well as the

creation of recollection points of excess of such products, many of them expired, for

their subsequent destruction or controlled recycling.

Some of these compounds are being studied by our interdisciplinary group and among

them we can mention the following:

Paracetamol

Ibuprofen

Naproxen

Ketoprofen

Aspirin

Diclofenac



216

In the case of soils, it is primarily interesting to analyze the extent of adsorption of these

compounds doing the corresponding adsorption isotherms for, and then define the

working conditions to mobilize these compounds in the studied matrix. Among others

there are to define the pH of the soil and solvents, chemical changes that can occur

before the changes of pH produced by the advance of the fronts of acidic and alkaline

electro-generated in the electrodics chambers, applied electric field and duration of the

experiment of electroremediacion, etc.

In the first phase of the experiments in which we find ourselves, we have used before a

natural soil, whose complexity is well known, a synthetic soil based on kaolin that is a

clay mineral, part of the group of industrial minerals, with the chemical composition

Al2Si2O5(OH)4. The results are promising, although we found some experimental

problems: with the quantification of the drug should be made by UV spectroscopy, it is

necessary that extraction solutions (mixing kaolin - dissolution of the drug), after being

filtered are perfectly transparent, so that it does not produce transmittance reading

errors. To do this, we must choose a proper particle size and a few suitable ultra-filters

vacuum.

Once we have solved partly these problems, the next step is to repeat the process with

natural soils. We have chosen two quite different characteristics: one with a high

content of organic matter (Ravelo) and another with less organic matter (Junquito) both

from the Tenerife Island (Canary-Spain). This is important since it affects the soil buffer

capacity and everything that brings with it. In parallel, our group of Colombia will try to

rehearse with two similar soils with lots of organic matter and another with low organic

matter collected in areas close to the city of Medellin (Antioquia Department).

The Colombian group, in addition to working with UV spectroscopy has made

preliminary studies with different variants of voltammetry, presenting quantification

fewer problems now which do not affect both the transparency of the dissolutions.

Once studied the adsorption soil-drugs and working conditions for the mobilization of

the latter by the application of an electric field, the next step is to locate industrial waste

cheap and easy-to-handle that hold the drugs and they can be removed for subsequent

treatment safely and efficiently. For now we are rehearsing with various adsorbents as

shells of fruits, cork, sawdust and even don’t have significant results that indicate the

goodness of the method, although, in principle, all allows us to be optimistic.

References

[1] M.V. Vázquez, C.D. Arbelo, F. Hernández-Luis, D. Grandoso, M. Lemus,

Portugaliae Electrochimica 27 (2009) 419

[2] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, D. Grandoso, M. Lemus, D.

Benjumea, C.D. Arbelo, Geoderma 148 (2009) 261

[3] M.V. Vázquez, D.A. Vasco, F. Hernández-Luis, Land Contamination &

Reclamation 16 (2008) 249

[4] D. A. Vasco, C. Ramírez, D. M. Benjumea, F. Hernández-Luis, M. V. Vázquez,

Innovación 19 (2007) 15

http://en.wikipedia.org/wiki/Clay_mineral

http://en.wikipedia.org/wiki/Industrial_minerals

http://en.wikipedia.org/wiki/Aluminium

http://en.wikipedia.org/wiki/Silicon

http://en.wikipedia.org/wiki/Oxygen

http://en.wikipedia.org/wiki/Hydroxide

electrokinetic remediation (erem2014) · techniques for the remediation of soils contaminated with...

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