Reductive dechlorination of the vinyl chloride surrogate chlorofluoroethene in TCE-contaminated groundwater.
At many trichloroethene (TCE)-contaminated field sites, microbial transformation of TCE results in the accumulation of vinyl chloride (VC), a known carcinogen and neurotoxin. Quantitative tools are needed to determine the in situ rates of VC transformation to ethene in contaminated groundwater. For this study, E-/Z-chlorofluoroethene (E-/Z-CFE) was evaluated as a surrogate for VC in laboratory microcosm and field push-pull tests. Single-well push-pull tests were conducted at a TCE-contaminated field site by injecting E-/Z-CFE and monitoring for the formation of fluoroethene (FE) over a period of up to 80 days. The rates for VC transformation to ethene and E-CFE transformation to FE were within a factor of 2.7 for laboratory microcosm systems and all preferentiallytransformed E-CFE over Z-CFE. In the field, the in situ rates of FE production from injected E-CFE ranged from 0.0018 to 1.15 microM/day, while the in situ rates of E-CFE disappearance ranged from 0.17 to 0.99 microM/day. No significant Z-CFE transformation was observed in field tests, which indicated preferential utilization of E-CFE over Z-CFE under in situ field conditions. The results of this study indicate E-CFE as a potential surrogate for estimating the in situ rates of VC transformation.
Ennis
Elliot
E
Department of Chemistry, Department of Environmental and Molecular Toxicology, and Department of Civil, Construction, and Environmental Engineering, Oregon State University, Corvallis, Oregon 97331, USA.
Reed
Ralph
R
Dolan
Mark
M
Semprini
Lewis
L
Istok
Jonathan
J
Field
Jennifer
J
D002713:Chlorine / Q000737:chemistry / Q000378:metabolism*; D004784:Environmental Monitoring; D010084:Oxidation-Reduction; D013997:Time Factors; D014241:Trichloroethylene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D014752:Vinyl Chloride / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity; D014881:Water Supply / Q000032:analysis*
D014874:Water Pollutants, Chemical; C439617:trichlorofluoroethene; D014241:Trichloroethylene; D002713:Chlorine; D014752:Vinyl Chloride