title: Reductive dechlorination of tetrachloroethylene in soils by Fe(II)-based degradative solidification/stabilization.
abstract: Fe(II)-based degradative solidification/stabilization (DS/S) is a modification of conventional solidification/stabilization (S/S) that uses Fe(II) as a reducing agent for chlorinated organics while immobilizing inorganic contaminants. Feasibility of the Fe(II)-based DS/S technology in treating soils contaminated with tetrachloroethylene (PCE) was tested in this study. The results of the PCE degradation experiments conducted in the presence of a humic acid suggest that natural organic matter would not significantly interfere with the degradative reaction by the Fe(II)-containing reactive species in DS/S systems. Solid-phase degradation experiments showed that the DS/S technology could effectively treat PCE in soils without substantial production of chlorinated intermediates. A pseudo-first-order rate law reasonably described degradation kinetics. The half-lives of PCE ranged from 13 to 335 days, which are within time spans allowable for typical in-situ DS/S application. Trichloroethylene (TCE) was the only chlorinated product observed in the solid-phase experiments, and its presence was generally transitory with the amount being less than 7% of the initial amount of PCE on a molar basis. A surface reaction appears to control observed PCE degradation kinetics rather than mass transfer to the reactive surface.
authors.affiliation: Department of Civil Engineering, Texas A&M University, College Station 77843, USA.
authors.forename: I
authors.initials: I
authors.lastname: Hwang
authors.forename: B
authors.initials: B
authors.lastname: Batchelor
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis*; D004787:Environmental Pollution / Q000517:prevention & control; D005240:Feasibility Studies; D005296:Ferrous Compounds / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D012989:Soil Pollutants / Q000032:analysis*; D013750:Tetrachloroethylene / Q000032:analysis* / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D005296:Ferrous Compounds; D012989:Soil Pollutants; D013750:Tetrachloroethylene