Carbon and chlorine isotope fractionation during Fenton-like degradation of trichloroethene

Yunde Liu; Yiqun Gan; Aiguo Zhou; Cunfu Liu; Xiaoqian Li; Tingting Yu

doi:10.1016/j.chemosphere.2014.03.011

Carbon and chlorine isotope fractionation during Fenton-like degradation of trichloroethene

Chemosphere. 2014 Jul:107:94-100. doi: 10.1016/j.chemosphere.2014.03.011. Epub 2014 Apr 12.

Authors

Yunde Liu¹, Yiqun Gan², Aiguo Zhou³, Cunfu Liu⁴, Xiaoqian Li⁵, Tingting Yu⁶

Affiliations

¹ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China. Electronic address: [email protected].
² State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China. Electronic address: [email protected].
³ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China. Electronic address: [email protected].
⁴ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China. Electronic address: [email protected].
⁵ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China. Electronic address: [email protected].
⁶ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China. Electronic address: [email protected].

PMID: 24875875
DOI: 10.1016/j.chemosphere.2014.03.011

Abstract

Dual isotope approach has been proposed as a viable tool for characterizing and assessing in situ contaminant transformation, however, little data is currently available on its applicability to chlorinated ethenes. This study determined carbon and chlorine isotope fractionation during Fenton-like degradation of trichloroethene (TCE). Carbon and chlorine isotope enrichment factors were εC=-2.9 ± 0.3‰ and εCl=-0.9 ± 0.1‰, respectively. An observed small secondary chlorine isotope effect (AKIECl=1.001) was consistent with an initial transformation by adding hydroxyl radicals (OH) to CC bonds without cleavage of CCl bonds. The relative change in carbon and chlorine isotope ratios (Δ=Δδ(13)C/Δδ(37)Cl) was calculated to be 3.1 ± 0.2, approximately equal to the ratio of chlorine and carbon isotope enrichment factors (εC/εCl=3.2). The similarity of the Δ (or εC/εCl) values between Fenton-like degradation and microbial reductive dechlorination of TCE was observed, indicating that application of solely dual isotope approach may be limited in distinguishing the two transformation pathways.

Keywords: Carbon isotope fractionation; Chlorine isotope fractionation; Fenton-like reaction; Trichloroethene.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carbon Isotopes / chemistry
Carbon Isotopes / isolation & purification
Chemical Fractionation / methods*
Chlorine / chemistry*
Chlorine / isolation & purification*
Environmental Pollutants / chemistry*
Environmental Pollutants / isolation & purification*
Hydrogen Peroxide / chemistry*
Iron / chemistry*
Kinetics
Trichloroethylene / chemistry*
Trichloroethylene / isolation & purification

Substances

Carbon Isotopes
Environmental Pollutants
Fenton's reagent
Trichloroethylene
Chlorine
Hydrogen Peroxide
Iron