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Title: Monitoring microbial dechlorination of tetrachloroethene (PCE) in groundwater using compound-specific stable carbon isotope ratios: Microcosm and field studies

Abstract

The determination of compound-specific stable isotope ratios is a promising new tool to assess biodegradation of organic compounds in groundwater. In this study, the occurrence of carbon isotope fractionation during dechlorination of tetrachloroethene (PCE) to ethene was evaluated in a PCE-contaminated aquifer and in a microcosm that was based on aquifer material from the site. In the microcosm, all dechlorination steps were accompanied by carbon isotope fractionation. The largest fractionation occurred during dechlorination of cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC), resulting in a large enrichment of {sup 13}C in the remaining cDCE and VC. Stable carbon isotope ratios ({delta}{sup 13}C) of cDCE and VC increased from {minus}25.7 to {minus}1.5{per_thousand} and {minus}37.0 to {minus}2.5{per_thousand}, respectively. The {delta}{sup 13}C of ethene was initially {minus}60.2{per_thousand} and approached the {delta}{sup 13}C of the added PCE ({minus}27.3{per_thousand}) as dechlorination came to completion. A similar carbon isotope pattern was observed for PCE dechlorination at the field site. Strong enrichment of {sup 13}C in cDCE and VC during microbial dechlorination may serve as a powerful tool to monitor the last two dechlorination steps, which frequently determine the rate of complete dechlorination of chlorinated ethenes at field sites undergoing intrinsic bioremediation.

Authors:
; ;  [1]
  1. Univ. of Waterloo, Ontario (Canada)
Publication Date:
OSTI Identifier:
687390
Resource Type:
Journal Article
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 33; Journal Issue: 16; Other Information: PBD: 15 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; GROUND WATER; REMEDIAL ACTION; CHLORINATED ALIPHATIC HYDROCARBONS; BIODEGRADATION; DECHLORINATION; ISOTOPE RATIO; CARBON 13

Citation Formats

Hunkeler, D., Aravena, R., and Butler, B.J. Monitoring microbial dechlorination of tetrachloroethene (PCE) in groundwater using compound-specific stable carbon isotope ratios: Microcosm and field studies. United States: N. p., 1999. Web. doi:10.1021/es981282u.
Hunkeler, D., Aravena, R., & Butler, B.J. Monitoring microbial dechlorination of tetrachloroethene (PCE) in groundwater using compound-specific stable carbon isotope ratios: Microcosm and field studies. United States. doi:10.1021/es981282u.
Hunkeler, D., Aravena, R., and Butler, B.J. Sun . "Monitoring microbial dechlorination of tetrachloroethene (PCE) in groundwater using compound-specific stable carbon isotope ratios: Microcosm and field studies". United States. doi:10.1021/es981282u.
@article{osti_687390,
title = {Monitoring microbial dechlorination of tetrachloroethene (PCE) in groundwater using compound-specific stable carbon isotope ratios: Microcosm and field studies},
author = {Hunkeler, D. and Aravena, R. and Butler, B.J.},
abstractNote = {The determination of compound-specific stable isotope ratios is a promising new tool to assess biodegradation of organic compounds in groundwater. In this study, the occurrence of carbon isotope fractionation during dechlorination of tetrachloroethene (PCE) to ethene was evaluated in a PCE-contaminated aquifer and in a microcosm that was based on aquifer material from the site. In the microcosm, all dechlorination steps were accompanied by carbon isotope fractionation. The largest fractionation occurred during dechlorination of cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC), resulting in a large enrichment of {sup 13}C in the remaining cDCE and VC. Stable carbon isotope ratios ({delta}{sup 13}C) of cDCE and VC increased from {minus}25.7 to {minus}1.5{per_thousand} and {minus}37.0 to {minus}2.5{per_thousand}, respectively. The {delta}{sup 13}C of ethene was initially {minus}60.2{per_thousand} and approached the {delta}{sup 13}C of the added PCE ({minus}27.3{per_thousand}) as dechlorination came to completion. A similar carbon isotope pattern was observed for PCE dechlorination at the field site. Strong enrichment of {sup 13}C in cDCE and VC during microbial dechlorination may serve as a powerful tool to monitor the last two dechlorination steps, which frequently determine the rate of complete dechlorination of chlorinated ethenes at field sites undergoing intrinsic bioremediation.},
doi = {10.1021/es981282u},
journal = {Environmental Science and Technology},
number = 16,
volume = 33,
place = {United States},
year = {1999},
month = {8}
}