title: Apparent first-order kinetics in the transformation of 1,1,1-trichloroethane in groundwater following a transient release.
abstract: A transient release of 1,1,1-trichloroethane (TCA) to an otherwise uncontaminated aquifer at a manufacturing facility presented a useful opportunity to validate the results of previous laboratory and field studies on TCA transformation in groundwater. Abiotic TCA transformation to 1,1-dichloroethylene (DCE) and acetic acid at the site exhibited first-order kinetics with half-life of 2.9 years 15 degrees C. Degradation effects were seen to overwhelm chemical retardation effects on the DCE/TCA concentration ratio in groundwater. The kinetic data was sufficient to date the release to within one week of when it actually occurred. A kinetic approach may be applicable to dating the releases on other contaminated sites where a single transient release is indicated. The transformation of dissolved TCA in groundwater with a half-life of several years can be expected at many contaminated sites.
authors.affiliation: Geology Department, Middlebury College, Vermont 05753, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Wing
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D002140:California; D004000:Dichloroethylenes / Q000737:chemistry; D005618:Fresh Water / Q000032:analysis*; D006207:Half-Life; D007700:Kinetics; D012997:Solvents / Q000032:analysis / Q000737:chemistry*; D013696:Temperature; D014240:Trichloroethanes / Q000032:analysis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004000:Dichloroethylenes; D012997:Solvents; D014240:Trichloroethanes; D014874:Water Pollutants, Chemical; C024566:1,1,1-trichloroethane; C029297:vinylidene chloride; D019342:Acetic Acid