Permeable reactive barrier Permeable reactive barrier using nanoscale iron particles using nanoscale iron particles in As contaminated subsurface in 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 Low reactivity, bad permeability, high cost of terrestrial excavation in classic PRB terrestrial excavation in classic PRB Techniques development to reduce the extensive Techniques development to reduce the extensive excavation, excavation, to enhance the reactivity, and to keep the to enhance the reactivity, and to keep the good permeability good permeability The optimal emplacement condition of nano part The optimal emplacement condition of nano part icles icles : technique of deposition and injection of nan : technique of deposition and injection of nan o particle o particle Expected effect Remediation of As/heavy metal- contaminated subsurface around the metal mining areas ` Perm eable reactive B arrier Perm eable reactive B arrier ` Perm eable reactive B arrier Perm eable reactive B arrier 산산산 산산 산산 Permeable reactive Permeable reactive barrier barrier using using iron-oxide coated iron-oxide coated sand sand Groundwater flow quartz hematite feldspar Remediation technique Remediation technique for As contaminated soil for As contaminated soil using indigenous bacteria using 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 Contamination of downstream waters, soil, and terrestrial plants terrestrial plants by the release of arsenic and heavy metals by the release of arsenic and heavy metals Investigation of mobilization of As Investigation of mobilization of As by increase of microbial activity depending on by increase of microbial activity depending on supplying C-source supplying C-source Development of remediation technique for As Development of remediation technique for As contamination soil contamination soil As contamination site As tolerance microbe Inoculation C-source Removal of As Removal of As Soil Soil contaminated contaminated with As with As As contamination of the groundwater (approximately 20 countries in world) AGRG Arsenic Geochemistry Research Group Development of Electrokinetic Soil Proc Development of Electrokinetic Soil Proc ess ess to remediate the Heavy metal in soil to remediate the Heavy metal in soil Electro de cell Anode Cathod e Electrod e cell Compacted soil cell DC power supply O 2 H 2 H + OH - H 2 O metal Soils are contaminated with heavy metals Soils are contaminated with heavy metals which migrate and which migrate and threaten human health threaten human health Soils having low permeability are resistant t Soils having low permeability are resistant t o in-situ remediation techniques o in-situ remediation techniques A candidate technology for this type of remedi A candidate technology for this type of remedi al measure is electokinetic soil flushing al measure is electokinetic soil flushing Various enhancement techniques have been Various enhancement techniques have been proposed and used proposed and used Advantages Effective in non-permeable soils such as clayey soils Application to various types of contaminants including orga nic and inorganic contaminants & radionuclides Minimization of secondary impacts Low operational cost Phyto-remediation/extraction Phyto-remediation/extraction of toxic elements from soils of toxic elements from soils Investigation Investigation into the mechanisms of hyperaccumulation of into the mechanisms of hyperaccumulation of As, Au and U As, Au and U Using plants to extract toxic elements from mi Using plants to extract toxic elements from mi ning sites ning sites Removal toxic elements Removal toxic elements from contaminated sites and recovery of from contaminated sites and recovery of economic elements economic elements Phytoremediation Phytoremediation cost effective, large areas, cost effective, large areas, public acceptance, public acceptance, hydraulic pumping pressure, after closu hydraulic pumping pressure, after closu re maintenance, no re maintenance, no excavation, mineralizing organics excavation, mineralizing organics Derived from: www.calacademy.org U,As,A u Phytoextraction Process - A cost-effective remedia A cost-effective remedia tion technique for large a tion technique for large a reas with low-level contam reas with low-level contam ination ination 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 soils elements in the soils