title: Abiotic reductive dechlorination of chlorinated ethylenes by soil.
abstract: Abiotic reductive dechlorination of chlorinated ethylenes by soil in anaerobic environments was characterized to improve knowledge of the behavior of chlorinated ethylenes in natural systems, including systems modified to promote attenuation of contaminants. Target organics in the soil suspension reached sorption equilibrium in 2 days and the sorption isotherm of target organics was properly described by the linear sorption model. A modified Langmuir-Hinshelwood model was developed to describe the kinetics of reductive dechlorination of target organics by soil. The rate constants for the reductive dechlorination of chlorinated ethylenes at the reactive surfaces of reduced soils were found in the range between 0.055 (+/- 8.9%) and 2.60 (+/- 3.2%) day(-1). The main transformation products in reduced soil suspensions were C2 hydrocarbons. No chlorinated intermediates were observed at concentrations above detection limits. Five cycles of reduction of the soil followed by oxidation of the soil with trichloroethylene (TCE) did not affect the removal of TCE. The removal was affected by the reductants used and increased in the order: Fe(II) < dithionite < Fe(II) + dithionite.
authors.affiliation: Environment and Process Technology Division, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, South Korea.
authors.forename: Woojin
authors.initials: W
authors.lastname: Lee
authors.forename: Bill
authors.initials: B
authors.lastname: Batchelor
mesh_terms: D000693:Anaerobiosis; D004227:Dithionite / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010316:Particle Size; D012987:Soil / Q000032:analysis*
chemical_list: D005030:Ethylenes; D006843:Hydrocarbons, Chlorinated; D012987:Soil; D004227:Dithionite; D007501:Iron