Electrically induced reduction of trichloroethene in clay.
Chlorinated compounds such as trichloroethene (TCE) are recalcitrant contaminants commonly detected in soil and groundwater. Contemporary remedies such as electron donor amendment tend to be less or ineffective in treating chlorinated compounds in matrix of lower permeability, such as clay. In this study, electrically induced reduction (EIR) was tested by inserting electrodes in saturated clay containing 122.49-125.43 mg TCE kg(-1). Weak electric potentials (E) of 6, 9, and 12 V m(-1) were applied, and up to 97% of TCE were depleted during the study period. Corresponding increases in chloride concentrations was observed during TCE depletion, indicating a reductive dechlorination pathway. No migration of TCE was observed between the two electrodes, neither were intermediate compounds such as dichloroethene (DCE) or vinyl chloride (VC). Results were also tested against a mathematical equation we previously established for field applications. Electrically induced reduction may offer a novel method for in situ degradation of chlorinated contaminants, especially in low-permeable media such as clay.
Jin
Song
S
School of Resources and Environment, Hefei University of Technology, Hefei, PR China. sjin@uwyo.edu
Fallgren
Paul H
PH
D000465:Algorithms; D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D004563:Electrochemistry; D054879:Halogenation; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012987:Soil / Q000032:analysis; D014241:Trichloroethylene / Q000737:chemistry*; D014752:Vinyl Chloride / Q000737:chemistry
D000538:Aluminum Silicates; D012987:Soil; D014241:Trichloroethylene; D000077215:Clay; D014752:Vinyl Chloride