Permeable reactive barrier Permeable reactive barrier using nanoscale iron particlesusing nanoscale iron particlesin As contaminated subsurfacein As contaminated subsurface

Emplacement of nano-particle

- Emplacement into reactive

barrier- Finding the optimal condition

Permeable reactive barrier

- immobilization of As and heavy metals in the mining areas- Keeping the groundwater flow

Nanoscale iron particle

- innovative barrier material- High surface area and reactivity

Low reactivity, bad permeability, high cost of terrestrial Low reactivity, bad permeability, high cost of terrestrial

excavation in classic PRBexcavation in classic PRB

Techniques development to reduce the extensive excavation, Techniques development to reduce the extensive excavation,

to enhance the reactivity, and to keep the good permeabilityto enhance the reactivity, and to keep the good permeability

The optimal emplacement condition of nano particlesThe optimal emplacement condition of nano particles

: technique of deposition and injection of nano particle: technique of deposition and injection of nano particle

Expected effect Remediation of As/heavy metal-contaminated subsurface around the metal mining areas

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Permeable reactive BarrierPermeable reactive Barrier

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Permeable reactive BarrierPermeable reactive Barrier

산화철 피복 모래

Permeable reactive barrierPermeable reactive barrierusing using

iron-oxide coated sandiron-oxide coated sandGroundwater flow

quartz hematite

feldspar

Remediation technique Remediation technique for As contaminated soil for As contaminated soil using indigenous bacteriausing indigenous bacteria

Source of arsenic

- Natural source: volcanic action, rock erosion - Industrial product: semiconductors, herbicides

Biological treatment

-microbe activity depending on C-source

- Removal of As by leaching mechanism

Contamination of downstream waters, soil, and terrestrial plants Contamination of downstream waters, soil, and terrestrial plants

by the release of arsenic and heavy metalsby the release of arsenic and heavy metals

Investigation of mobilization of As Investigation of mobilization of As

by increase of microbial activity depending on supplying C-sourceby increase of microbial activity depending on supplying C-source

Development of remediation technique for As contamination soilDevelopment of remediation technique for As contamination soil

As contamination site

As tolerance microbe

Inoculation C-source

Removal of AsRemoval of As

Soil Soil contaminated contaminated

with Aswith As

As contamination of the groundwater(approximately 20 countries in world)

AGRG Arsenic Geochemistry Research Group

Development of Electrokinetic Soil Process Development of Electrokinetic Soil Process

to remediate the Heavy metal in soilto remediate the Heavy metal in soil

Electrode cell

Anode Cathode

Electrode cell

Compacted soil cell

DC power supply

O2 H2

H+OH-

H2O

metal

Soils are contaminated with heavy metals which migrate and Soils are contaminated with heavy metals which migrate and

threaten human healththreaten human health

Soils having low permeability are resistant to in-situ remediation Soils having low permeability are resistant to in-situ remediation techniques techniques

A candidate technology for this type of remedial measure is electA candidate technology for this type of remedial measure is elect

okinetic soil flushingokinetic soil flushing

Various enhancement techniques have been proposed and used Various enhancement techniques have been proposed and used

Advantages Effective in non-permeable soils such as clayey soils

Application to various types of contaminants including organic and inorganic contaminants & radionuclides

Minimization of secondary impacts

Low operational cost

Phyto-remediation/extraction Phyto-remediation/extraction of toxic elements from soilsof toxic elements from soils

Investigation Investigation into the mechanisms of hyperaccumulation of As, Au and Uinto the mechanisms of hyperaccumulation of As, Au and U

Using plants to extract toxic elements from mining sitesUsing plants to extract toxic elements from mining sites

Removal toxic elements Removal toxic elements from contaminated sites and recovery of economic elementsfrom contaminated sites and recovery of economic elements

PhytoremediationPhytoremediation cost effective, large areas, public acceptance, cost effective, large areas, public acceptance, hydraulic pumping pressure, after closure maintenance, nohydraulic pumping pressure, after closure maintenance, no excavation, mineralizing organicsexcavation, mineralizing organics

Derived from: www.calacademy.org

U,As,Au

Phytoextraction Process

- A cost-effective remediation techniA cost-effective remediation technique for large areas with low-level coque for large areas with low-level contaminationntamination

Hyperaccumulators can Hyperaccumulators can accumulate elements in the accumulate elements in the above-ground biomass.above-ground biomass.

Using traditional harvest Using traditional harvest

process to remove toxic process to remove toxic

elements in the soilselements in the soils

Development of in-situ monitoring technologies as a Development of in-situ monitoring technologies as a

quantification/qualification method for the continuousquantification/qualification method for the continuous evaluation for PAHs-contaminated soilsevaluation for PAHs-contaminated soils

In-situ immobilization of metals by In-situ immobilization of metals by bacteriabacteria

Dissimilatory metal-reducing bacteria (Anaerobe)- Metabolism with heavy metals in soil & groundwater- Transformation of heavy metals to more stable forms※ to more immobile forms of heavy metals for in-situ immobilization

No excavation of contaminated soil & groundwaterNo excavation of contaminated soil & groundwater

Activation or injection of Activation or injection of indigenous metal-reducing bacteria with in-situindigenous metal-reducing bacteria with in-situ

Advantages of cost-effectiveAdvantages of cost-effective and environment-friendly remediation technologyand environment-friendly remediation technology

Mechanisms ofdissimilatory metal reduction - Direct (biologic) mechanism - Indirect (combined biologic-chemical) mechnism using electron shuttle

Remediation process monitoring Remediation process monitoring for PAH-contaminated soil for PAH-contaminated soil

using Laser-induced fluorescence(LIF) using Laser-induced fluorescence(LIF)

The highly desirable need for real time, in-situ monitoring technThe highly desirable need for real time, in-situ monitoring techn

iques for PAH-contaminated soils & remediation processiques for PAH-contaminated soils & remediation process

Investigation of the effecting variables on the fluorescence intenInvestigation of the effecting variables on the fluorescence intensity and collection of data concerning calibration method and qsity and collection of data concerning calibration method and q

uantification programmuantification programm

– most aromatic : exhibit high fluorescence quantum yields in uv-light, - High selectivity and sensitivity for PAHs

Development of monitoring techniques for field application basDevelopment of monitoring techniques for field application based on the LIF spectroscopy showing the high selectivity and sened on the LIF spectroscopy showing the high selectivity and sen

sitivity for PAHssitivity for PAHs

– overcome the limitation of traditional analytical method– quantification using time-resolved analysis

MPRG Metal and PAH Research Group

Biosorption process using bacteriaBiosorption process using bacteria

in metal contaminated groundwaterin metal contaminated groundwater

Biosorption characteristics of heavy metals by bacteriaBiosorption characteristics of heavy metals by bacteria

Immobilization technique using bacteria as effective adsorbent Immobilization technique using bacteria as effective adsorbent

Application to the removal and recovery of heavy metals from Application to the removal and recovery of heavy metals from

contaminated groundwater in permeable reactive barriercontaminated groundwater in permeable reactive barrier

Commercial application for the in low concentrated wastewater Commercial application for the in low concentrated wastewater Advantages: highly selective, efficient, easy to operate, cost-Advantages: highly selective, efficient, easy to operate, cost-

effective effective

Biosorption mechanism on the surface of bacteria

- entrapment by cellular components

- active transport across the cell memebrane

- cation exchange or complexation

- cell surface adsorption Biosorption process in batch system

Bioremediation of Organic-contaminated Bioremediation of Organic-contaminated Soils Using BiosurfactantsSoils Using Biosurfactants

Synthetic surfactant Synthetic surfactant low bioavailability in biodegradation low bioavailability in biodegradation process due to toxicityprocess due to toxicity

Biosurfactants Biosurfactants high biodegradation rate due to enhanced high biodegradation rate due to enhanced solubility and low toxicity solubility and low toxicity

Development of Development of the Biosurfactant-Enhanced the Biosurfactant-Enhanced Bioremediation TechniqueBioremediation Technique

Feasibility of biosurfactant-enhanced biodegradation process to Feasibility of biosurfactant-enhanced biodegradation process to

remediate the PAHs-contaminated soilremediate the PAHs-contaminated soil

•Polycyclic Aromatic Hydrocarbons (PAHs) hydrophobic and most are practically insolub

lepersistence in the environmentmost exist in strongly adsorbed forms in soil

s

•Biosurfactants

1) unique chemical structures (beneficial for remediation) 2) naturally occurring, biodegradable product

3) possible to stimulate in-situ production at the site