Permeable reactive barrier using nanoscale iron particles in As contaminated subsurface Emplacement of nano-particle - Emplacement into reactive barrier.

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  • Slide 1
  • Permeable reactive barrier using nanoscale iron particles 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 terrestrial excavation in classic PRB Techniques development to reduce the extensive excavation, to enhance the reactivity, and to keep the good permeability The optimal emplacement condition of nano particles : technique of deposition and injection of nano particle Expected effect Remediation of As/heavy metal-contaminated subsurface around the metal mining areas Permeable reactive barrier using iron-oxide coated sand Groundwater flow quartz hematite feldspar Remediation technique for As contaminated soil 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 terrestrial plants by the release of arsenic and heavy metals Investigation of mobilization of As by increase of microbial activity depending on supplying C-source Development of remediation technique for As contamination soil As contamination site As tolerance microbe InoculationC-source Removal of As Soilcontaminated with As As contamination of the groundwater (approximately 20 countries in world) AGRG Arsenic Geochemistry Research Group Development of Electrokinetic Soil Process to remediate the Heavy metal in soil Electrode cell Anode Cathode Electrode cell Compacted soil cell DC power supply O2O2 H2H2 H+H+ OH - H2OH2O metal Soils are contaminated with heavy metals which migrate and Soils are contaminated with heavy metals which migrate and threaten human health threaten human health Soils having low permeability are resistant to in-situ remediation techniques Soils having low permeability are resistant to in-situ remediation techniques A candidate technology for this type of remedial measure is electokinetic soil flushing A candidate technology for this type of remedial measure is electokinetic 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 of toxic elements from soils Investigation Investigation into the mechanisms of hyperaccumulation of As, Au and U into the mechanisms of hyperaccumulation of As, Au and U Using plants to extract toxic elements from mining sites Using plants to extract toxic elements from mining sites Removal toxic elements Removal toxic elements from contaminated sites and recovery of economic elements from contaminated sites and recovery of economic elements Phytoremediation cost effective, large areas, public acceptance, Phytoremediation cost effective, large areas, public acceptance, hydraulic pumping pressure, after closure maintenance, no hydraulic pumping pressure, after closure maintenance, no excavation, mineralizing organics excavation, mineralizing organics Derived from: www.calacademy.org U,As,Au Phytoextraction Process - A cost-effective remediation technique for large areas with low-level contamination Hyperaccumulators can accumulate elements in the above-ground biomass. Using traditional harvest process to remove toxic elements in the soils
  • Slide 2
  • Development of in-situ monitoring technologies as a Development of in-situ monitoring technologies as a quantification/qualification method for the continuous evaluation for PAHs-contaminated soils evaluation for PAHs-contaminated soils In-situ immobilization of metals by bacteria 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 & groundwater Activation or injection of indigenous metal-reducing bacteria with in-situ Advantages of cost-effective and environment-friendly remediation technology and environment-friendly remediation technology Mechanisms of dissimilatory metal reduction - Direct (biologic) mechanism - Indirect (combined biologic-chemical) mechnism using electron shuttle Remediation process monitoring for PAH-contaminated soil using Laser-induced fluorescence(LIF) The highly desirable need for real time, in-situ monitoring techniques for PAH-contaminated soils & remediation process Investigation of the effecting variables on the fluorescence intensity and collection of data concerning calibration method and quantification programm most aromatic : exhibit high fluorescence quantum yields in uv-light, - High selectivity and sensitivity for PAHs Development of monitoring techniques for field application based on the LIF spectroscopy showing the high selectivity and sensitivity for PAHs Development of monitoring techniques for field application based on the LIF spectroscopy showing the high selectivity and sensitivity for PAHs overcome the limitation of traditional analytical method quantification using time-resolved analysis MPRG Metal and PAH Research Group Biosorption process using bacteria in metal contaminated groundwater in metal contaminated groundwater Biosorption characteristics of heavy metals by bacteria Biosorption 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 barrier contaminated groundwater in permeable reactive barrier Commercial application for the in low concentrated wastewater Advantages: highly selective, efficient, easy to operate, cost-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 Soils Using Biosurfactants Synthetic surfactant low bioavailability in biodegradation process due to toxicity process due to toxicity Biosurfactants high biodegradation rate due to enhanced solubility and low toxicity Development of the Biosurfactant-Enhanced Bioremediation Technique Feasibility of biosurfactant-enhanced biodegradation process to remediate the PAHs-contaminated soil Polycyclic Aromatic Hydrocarbons (PAHs) hydrophobic and most are practically insoluble persistence in the environment most exist in strongly adsorbed forms in soils Biosurfactants 1) unique chemical structures (beneficial for remediation) 2) naturally occurring, biodegradable product 3) possible to stimulate in-situ production at the site

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