title: C, Cl and H compound-specific isotope analysis to assess natural versus Fe(0) barrier-induced degradation of chlorinated ethenes at a contaminated site.
abstract: Compound-specific isotopic analysis of multiple elements (C, Cl, H) was tested to better assess the effect of a zero-valent iron-permeable reactive barrier (ZVI-PRB) installation at a site contaminated with tetrachloroethene (PCE) and trichloroethene (TCE). The focus was on (1) using (13)C to evaluate natural chlorinated ethene biodegradation and the ZVI-PRB efficiency; (2) using dual element (13)C-(37)Cl isotopic analysis to distinguish biotic from abiotic degradation of cis-dichloroethene (cis-DCE); and (3) using (13)C-(37)Cl-(2)H isotopic analysis of cis-DCE and TCE to elucidate different contaminant sources. Both biodegradation and degradation by ZVI-PRB were indicated by the metabolites that were detected and the (13)C data, with a quantitative estimate of the ZVI-PRB efficiency of less than 10% for PCE. Dual element (13)C-(37)Cl isotopic plots confirmed that biodegradation was the main process at the site including the ZVI-PRB area. Based on the carbon isotope data, approximately 45% and 71% of PCE and TCE, respectively, were estimated to be removed by biodegradation. (2)H combined with (13)C and (37)Cl seems to have identified two discrete sources contributing to the contaminant plume, indicating the potential of δ(2)H to discriminate whether a compound is of industrial origin, or whether a compound is formed as a daughter product during degradation.
authors.affiliation: Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona, Spain. Electronic address: carmeaudi@ub.edu.
authors.forename: Carme
authors.initials: C
authors.lastname: Audí-Miró
authors.affiliation: Institute of Groundwater Ecology, Helmholtz Zentrum München-National Research Center for Environmental Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Cretnik
authors.affiliation: Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Torrentó
authors.affiliation: Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona, Spain.
authors.forename: Mònica
authors.initials: M
authors.lastname: Rosell
authors.affiliation: Department of Earth & Environmental Sciences, 200 University Ave. W, N2L 3G1 Waterloo, Ontario, Canada.
authors.forename: Orfan
authors.initials: O
authors.lastname: Shouakar-Stash
authors.affiliation: Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Otero
authors.affiliation: Université de Neuchâtel, CHYN - Centre d'Hydrogéologie, Rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland.
authors.forename: Jordi
authors.initials: J
authors.lastname: Palau
authors.affiliation: Institute of Groundwater Ecology, Helmholtz Zentrum München-National Research Center for Environmental Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Elsner
authors.affiliation: Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Soler
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002713:Chlorine / Q000032:analysis*; D004785:Environmental Pollutants / Q000032:analysis*; D005030:Ethylenes / Q000032:analysis*; D006859:Hydrogen / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007554:Isotopes
chemical_list: D004785:Environmental Pollutants; D005030:Ethylenes; D007554:Isotopes; D002713:Chlorine; D002244:Carbon; D006859:Hydrogen; C036216:ethylene; D007501:Iron
keywords: Chlorinated ethenes; Stable isotopes; Zero-valent iron