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Gil-Villalba S, Palau J, Soder-Walz JM, Vallecillo MA, Corregidor J, Tirado A, Shouakar-Stash O, Guivernau M, Viñas M, Soler A, Rosell M. Use of isotopic (C, Cl) and molecular biology tools to assess biodegradation in a source area of chlorinated ethenes after biostimulation with Emulsified Vegetable Oil (EVO). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175351. [PMID: 39151619 DOI: 10.1016/j.scitotenv.2024.175351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 08/04/2024] [Accepted: 08/05/2024] [Indexed: 08/19/2024]
Abstract
Enhanced In Situ Bioremediation (EISB) using Emulsified Vegetable Oil (EVO) as a long-term electron donor has gained prominence for the treatment of groundwater contaminated with chlorinated ethenes (CEs). This study explores the potential of isotopic and molecular biology tools (MBT) to investigate the CEs (PCE, TCE and cis-DCE) bioremediation using EVO in a contaminated site. A multiple approach using C and Cl-CSIA, quantification of Dehalococcoides (Dhc) and specific reductive dechlorination (RD) gene population, and hydrochemical data in microcosm experiments and field samples was applied. Despite the high partitioning of CEs into the EVO phase, the carbon isotopic values of the remaining CEs fraction in the aqueous phase did not exhibit significant changes caused by phase partitioning in laboratory experiments. Both microcosm experiments and field data revealed a rapid RD of PCE and TCE, resulting in the transient accumulation of cis-DCE, which was slowly degraded to vinyl chloride (VC). These results agreed with the presence of Dhc populations and a shift to stronger reducing conditions in the field: i) RD functional genes (tceA, vcrA and bvcA) exhibited a trend to higher values and ii) a substantial increase in Dhc populations (up to 30% of the total bacterial populations) was observed over time. The dual-element isotope slope ΛC-Cl for RD of cis-DCE obtained from field data (ΛC - Cl = 5 ± 3) was similar to the one determined from the microcosm experiments under controlled anoxic conditions (ΛC - Cl = 4.9 ± 0.8). However, ΛC-Cl values differ from those reported so far for laboratory studies with Dhc strains and mixed cultures containing Dhc, i.e., between 8.3 and 17.8. This observation underscores the potential variety of reductive dehalogenases involved during cis-DCE RD and the importance of determining site-specific Λ and ɛ values in order to improve the identification and quantification of transformation processes in the field.
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Affiliation(s)
- Sergio Gil-Villalba
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí Franquès s/n, 08028 Barcelona, Spain.
| | - Jordi Palau
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí Franquès s/n, 08028 Barcelona, Spain
| | - Jesica M Soder-Walz
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain
| | - Miguel A Vallecillo
- Environmental Resources Management Iberia SAU, Rambla de Catalunya 33, 08007 Barcelona, Spain
| | - Jordi Corregidor
- Environmental Resources Management Iberia SAU, Rambla de Catalunya 33, 08007 Barcelona, Spain
| | - Andrea Tirado
- Environmental Resources Management Iberia SAU, Rambla de Catalunya 33, 08007 Barcelona, Spain
| | | | - Miriam Guivernau
- Sustainability in Biosystems Programme, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, Caldes de Montbui, Barcelona, Spain
| | - Marc Viñas
- Sustainability in Biosystems Programme, Institute of Agrifood Research and Technology (IRTA), Torre Marimon, Caldes de Montbui, Barcelona, Spain
| | - Albert Soler
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí Franquès s/n, 08028 Barcelona, Spain
| | - Monica Rosell
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí Franquès s/n, 08028 Barcelona, Spain
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Zhang X, Yi L, Li R. Identification of dense nonaqueous phase liquid sources in groundwater: a review of isotope technique. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:52688-52706. [PMID: 39190252 DOI: 10.1007/s11356-024-34427-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 07/15/2024] [Indexed: 08/28/2024]
Abstract
Excessive dense nonaqueous phase liquids (DNAPLs) in subsurface aquifers posed a threat to human health and sustainable development of groundwater resources. Accurately identifying the sources of DNAPLs is crucial for groundwater remediation and prevention efforts. In the previous studies, significant advances were made in using isotope techniques for identifying DNAPLs in groundwater. In this paper, we provide a comprehensive overview of the commonly used isotopic tools applied to source identification. This overview will outline the advantages and limitations of the isotope technique and describe the needs for future research. Isotope tracing techniques are based on the unique isotopic characteristics of DNAPLs from different sources, enabling the identification and differentiation of DNAPL sources. The δ13C and δ37Cl values are most commonly used for identifying DNAPLs in groundwater. In field applications, however, the differences in isotopic characteristics from diverse sources can be weakened after undergoing a series of human and natural factors, which can affect the accuracy of source identification. To improve the accuracy of DNAPL source identification, a dual-isotope tracing approach seems the best available solution. Nonetheless, in the face of complex polluted environments, the dual-isotope method seems stretched. Therefore, further researches remain to be carried out to accurately and efficiently assess the sources of DNAPLs in groundwater and their individual contributions. This is a prerequisite for groundwater resource conservation and remediation efforts.
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Affiliation(s)
- Xiang Zhang
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, PR China
| | - Lixin Yi
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, PR China.
| | - Ruotong Li
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, PR China
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Prieto-Espinoza M, Malleret L, Ravier S, Höhener P. A Novel Multi-ion Evaluation Scheme to Determine Stable Chlorine Isotope Ratios ( 37Cl/ 35Cl) of Chlordecone by LC-QTOF. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2711-2721. [PMID: 37883681 DOI: 10.1021/jasms.3c00270] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Organochlorinated pesticides are highly persistent organic pollutants having important adverse effects in the environment. To study their fate, compound-specific isotope analysis (CSIA) may be used to investigate their degradation pathways and mechanisms but is currently limited to 13C isotope ratios. The assessment of 37Cl isotope ratios from mass spectra is complicated by the large number of isotopologues of polychlorinated compounds. For method development, chlordecone (C10Cl10O2H2; hydrate form), an organochlorine insecticide that led to severe contamination of soils and aquatic ecosystems of the French West Indies, was taken as a model analyte. Chlorine isotope analysis of chlordecone hydrate was evaluated using high-resolution liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), enabling smooth ionization to detect the molecular ion. First, a new evaluation scheme is presented to correct for multiple isotope presence in polychlorinated compounds. The scheme is based on probability calculations of the most frequent isotopologues, distributions by binomial probability functions, and corrections for the presence of nonchlorine heavy isotopes. Second, mobile-phase modifiers, ionization energy (sampling cone tension) and scan time were optimized for accurate chlorine isotope ratios. Chlordecone standard samples were measured up to 10-fold and bracketed with a second chlordecone external standard. δ37Cl values were obtained after conversion to the SMOC scale by a two-point calibration. The robustness of the analysis method and evaluation scheme were tested and gave satisfactory results with standard errors (σm) of ±0.34‰ for precision and ±0.89‰ for long-term accuracy of chlorine isotope ratios of chlordecone hydrate. This work opens perspectives for applications of the C-Cl CSIA approach to investigate the fate of highly toxic and low reactive polychlorinated compounds in the environment.
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Affiliation(s)
- Maria Prieto-Espinoza
- Aix Marseille University - CNRS UMR 7376, Laboratory of Environmental Chemistry, Marseille, France
| | - Laure Malleret
- Aix Marseille University - CNRS UMR 7376, Laboratory of Environmental Chemistry, Marseille, France
| | - Sylvain Ravier
- Aix Marseille University - CNRS UMR 7376, Laboratory of Environmental Chemistry, Marseille, France
| | - Patrick Höhener
- Aix Marseille University - CNRS UMR 7376, Laboratory of Environmental Chemistry, Marseille, France
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Buchner D, Martin PR, Scheckenbach J, Kümmel S, Gelman F, Haderlein SB. Expanding the calibration range of compound-specific chlorine isotope analysis by the preparation of a 37 Cl-enriched tetrachloroethylene. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2022; 36:e9378. [PMID: 35975721 DOI: 10.1002/rcm.9378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/18/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
RATIONALE The recent development of reliable GC/qMS methods for δ37 Cl compound-specific stable isotope analysis (CSIA) paves the way for dual carbon-chlorine isotope analysis of chlorinated ethenes and thus allows deeper insights into underlying transformation processes/mechanisms. A two-point calibration is indispensable for the precise and correct conversion of raw data to the international δ37 ClSMOC scale. The currently available calibration standards for tetrachloroethylene (PCE) span only a very narrow range from -2.52‰ (EIL2) to +0.29‰ (EIL1), which is considerably smaller than observed δ37 Cl isotope enrichment in (bio-)transformation studies (up to 12‰). METHODS We describe the preparation and evaluation of a new 37 Cl-enriched PCE standard to avoid bias in δ37 Cl CSIA arising from extrapolation beyond the calibration range. The preparation comprised: (i) partial PCE reduction by zero-valent zinc in a system of PCE, ethanol (initial volume ratio 3/5) and trace amounts of water followed by (ii) liquid-liquid extraction and (iii) a subsequent fractional distillation to purify the 37 Cl-enriched PCE. RESULTS The obtained PCE (PCEenriched ) showed a purity of 98.8% (mole fraction) and a δ37 ClSMOC value of +10.8 ± 0.5‰. The evaluation of an experimental dataset with and without extrapolation showed no significant variation. CONCLUSIONS The new PCE standard (PCEenriched ) expands the calibration range to 13.3‰ (previously 2.8‰) and thus prevents potential bias introduced by extrapolation beyond the calibration range.
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Affiliation(s)
- Daniel Buchner
- Department of Geosciences, University of Tübingen, Tübingen, Germany
| | - Philipp R Martin
- Department of Geosciences, University of Tübingen, Tübingen, Germany
| | | | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
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Compound-specific carbon isotope analysis of volatile organic compounds in complex soil extracts using purge and trap concentration coupled to heart-cutting two-dimensional gas chromatography-isotope ratio mass spectrometry. J Chromatogr A 2021; 1655:462480. [PMID: 34479096 DOI: 10.1016/j.chroma.2021.462480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/22/2021] [Accepted: 08/14/2021] [Indexed: 11/20/2022]
Abstract
Compound-specific carbon isotope analysis (CSIA) is a powerful tool to track the origin and fate of organic subsurface contaminants including petroleum and chlorinated hydrocarbons and is typically applied to water samples. However, soil can form a significant contaminant reservoir. In soil samples, it can be challenging to recover sufficient amounts of volatile organic compounds (VOC) to perform CSIA. Soil samples often contain complex contaminant mixtures and gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) is highly dependent on good chromatographic separation due to the conversion to a single analyte. To extend the applicability of CSIA to complex volatile organic compound mixtures in soil samples, and to recover sufficient amounts of target compounds for carbon CSIA, we compared two soil extraction solvents, tetraglyme (TGDE) and methanol, and developed a heart-cutting two-dimensional GC-GC-C-IRMS method. We used purge & trap concentration of solvent-water mixtures to increase the amount of analyte delivered to the column and thus lower method detection limits. We optimized purge & trap and chromatographic parameters for twelve target compounds, including one suffering from poor purge efficiency. By using a 30 m thick-film non-polar column in the first and a 15 m polar column in the second dimension, we achieved good chromatographic separation for the target compounds in difficult matrices and high accuracy (trueness and precision) for carbon isotopic analysis. Tetraglyme extraction was shown to offer advantages over methanol for purge & trap concentration, leading to lower target compound method detection limits for CSIA of soil samples. The applicability of the developed method was demonstrated for a case study on soil extracts from a former manufacturing facility. Our approach extends the applicability of CSIA to an important matrix that often controls the long-term fate of contaminants in the subsurface.
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Wang G, Jiang N, Liu Y, Wang X, Liu Y, Jiao D, Wang H. Competitive microbial degradation among PBDE congeners in anaerobic wetland sediments: Implication by multiple-line evidences including compound-specific stable isotope analysis. JOURNAL OF HAZARDOUS MATERIALS 2021; 412:125233. [PMID: 33513555 DOI: 10.1016/j.jhazmat.2021.125233] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/29/2020] [Accepted: 01/22/2021] [Indexed: 06/12/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are widespread contaminants in the environment. Microbial reductive debromination is one of the important attenuation processes for PBDEs in the anaerobic sediments. This study first investigated the interaction between BDE-47 and BDE-153 during the microbial degradation in wetland sediments by the multiple-line approaches including biodegradation kinetics, microbial community structures and stable isotope composition. BDE-47 and BDE-153 biodegradation fitted pseudo-zero-order kinetics, with the higher degradation rates in single than combined exposure, indicating the mutual inhibition in co-exposure condition. BDE-47 and BDE-153 shared the common dehalogenators (genus Dehalococcoides and Acinetobacter) with enrichment in combined exposure, indicating the potential competition in dehalogenating bacteria during biodegradation. Microbial degradation could lead to the isotopic fractionation of BDE-47 and BDE-153, with the smaller changes in δ13C in combined than single exposure. The apparent kinetic isotope effect of carbon (AKIEC) was different between BDE-47 and BDE-153 in single exposure, whilst identical in combined exposure, indicating the similar degradation mechanism for BDE-47 and BDE-153 in co-exposure condition. These results revealed that the competition on microbial degradation occurred among PBDEs in co-exposure condition, which was important for the comprehensive risk assessment of simultaneous exposure to multiple PBDE congeners in the environment.
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Affiliation(s)
- Guoguang Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Na Jiang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Yu Liu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China; Environmental Information Institute, Dalian Maritime University, Dalian 116026, China
| | - Xu Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Yuxin Liu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Dian Jiao
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Haixia Wang
- Navigation College, Dalian Maritime University, Dalian 116026, China
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Tang C, Tan J, Tang C, Liu H, Zhang P, Liu D, Peng X. Chlorine isotope analysis of polychlorinated organic pollutants using gas chromatography-high resolution mass spectrometry and evaluation of isotope ratio calculation schemes by experiment and numerical simulation. J Chromatogr A 2021; 1651:462311. [PMID: 34146960 DOI: 10.1016/j.chroma.2021.462311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/28/2021] [Accepted: 05/29/2021] [Indexed: 11/28/2022]
Abstract
Compound-specific isotope analysis of chlorine (CSIA-Cl) is a practicable and high-performance approach for revelation of transformation processes and source identification of chlorinated organic pollutants. This study conducted CSIA-Cl for typical polychlorinated organic pollutants using gas chromatography-high resolution mass spectrometry (GCHRMS) with an alternate injection mode using perchloroethylene (PCE) and trichloroethylene (TCE) as model analytes. PCE and TCE standards from two manufacturers were employed for method development, and chlorine isotope ratio calculation schemes were evaluated by experiment and numerical simulation. The achieved precision (standard deviation of isotope ratios) was up to 0.21‰ for PCE and 0.43‰ for TCE. The limits of detection for CSIA-Cl of were 0.05 μg/mL (0.05 ng on column), and the linearities were 0.05-1 μg/mL. Two isotope ratio calculation schemes, i.e., one using complete molecular isotopologues and another using the first pair of neighboring chlorine isotopologues of each analyte, were evaluated in terms of accuracy and precision. The complete-isotopologue scheme showed evidently higher precision and was more competent to reflect trueness than the isotopologue-pair scheme and the two schemes could present completely different outcomes. The method has been successfully applied to PCE and TCE reagents from different suppliers, a trichloromethane reagent, and a plastic material. The relative isotope ratio variations (Δ37Cl) of PCE and TCE in the reagents and plastic material were from -1.84±0.7‰ to 15.12±0.85‰. The analytes from different sources could mostly be discerned from each other by chlorine isotope ratios. This study will be conducive to transformation process elucidation and source identification of for PCE and TCE, and facilitate CSIA-Cl using GC-MS for more polychlorinated organic pollutants, particularly in selection and optimization of isotope ratio calculation schemes.
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Affiliation(s)
- Caiming Tang
- Laboratory of Advanced Analytical Chemistry and Detection Technology, Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
| | - Jianhua Tan
- Guangzhou Quality Supervision and Testing Institute, Guangzhou 510110, China
| | - Caixing Tang
- The Third Affiliated Hospital of Sun Yat-sen University, Lingnan Hospital, Guangzhou 510630, China
| | - Huachun Liu
- Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
| | - Peilin Zhang
- Guangzhou Quality Supervision and Testing Institute, Guangzhou 510110, China
| | - Deyun Liu
- Guangzhou Quality Supervision and Testing Institute, Guangzhou 510110, China
| | - Xianzhi Peng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
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Ojeda AS, Zheng J, Phillips E, Sherwood Lollar B. Implications of regression bias for multi-element isotope analysis for environmental remediation. Talanta 2021; 226:122113. [PMID: 33676669 DOI: 10.1016/j.talanta.2021.122113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/07/2021] [Accepted: 01/09/2021] [Indexed: 11/24/2022]
Abstract
Measuring changes in the stable isotope ratios of multiple elements (e.g. Δδ13C, Δδ37Cl, and Δδ2H) during the (bio)transformation of environmental contaminants has provided new insights into reaction mechanisms and tools to optimize remediation efforts. Dual-isotope analysis, wherein changes in one isotopic system are plotted against another (to derive an interpretational parameter expressed as Λ), is a key tool in multi-element isotopic assessment. To date, most dual-isotope analyses use ordinary linear regression (OLR) for the calculation, which can be subject to regression attenuation and thus an inherent artifact that depresses slope values, expressed as Λ. Here, a series of Monte Carlo simulations were constructed to represent common data conditions and variations within dual-isotope data to test the degree of bias when deriving Λ using OLR compared to an alternative regression technique, the York method. The degree of bias was quantified compared to the modeled or "true" Λ value. For all simulations, the York method provided the least bias in slope estimates (<1%) over all data conditions tested. In contrast, OLR produced unbiased estimates only under a limited set of conditions, which was validated through a mathematical model proof. Both the mathematical model and simulations show that bias of at least 5% in OLR occurs when the extent of enrichment in the x-variable (XM) is equal to or less than ≈15 times the 1σ precision in the isotope measurement (σX), for both Cl/C and C/H plots. The results give practitioners tools to evaluate whether bias is present in data and to estimate the extent to which this negatively impacts the interpretations and predictions of remediation potential for new and previously published datasets. This study demonstrates that integration of such robust statistical tools is essential for dual-isotope interpretations widely used in contaminant hydrogeology but relevant to other disciplines including environmental chemistry and ecology.
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Affiliation(s)
| | - Jingyi Zheng
- Auburn University, Department of Mathematics and Statistics, Auburn, AL, 36849, USA
| | - Elizabeth Phillips
- University of Toronto, Department of Earth Sciences, Toronto, ON, M5S 3B1, Canada
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Liu Y, Kümmel S, Yao J, Nijenhuis I, Richnow HH. Dual C-Cl isotope analysis for characterizing the anaerobic transformation of α, β, γ, and δ-hexachlorocyclohexane in contaminated aquifers. WATER RESEARCH 2020; 184:116128. [PMID: 32777634 DOI: 10.1016/j.watres.2020.116128] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/26/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
Hexachlorocyclohexanes (HCHs) are widespread and persistent environmental pollutants, which cause heavy contamination in soil, sediment and groundwater. An anaerobic consortium, which was enriched on β-HCH using a soil sample from a contaminated area of a former pesticide factory, was capable to transform α, β, γ, and δ-HCH via tetrachlorocyclohexene isomers stoichiometrically to benzene and chlorobenzene. The carbon and chlorine isotope enrichment factors (εC and εCl) of the dehalogenation of the four isomers ranged from -1.9 ± 0.3 to -6.4 ± 0.7‰ and from -1.6 ± 0.2 to -3.2 ± 0.6‰, respectively, and the correlation of δ37Cl and δ13C (Λ values) of the four isomers ranged from 1.1 ± 0.1 to 2.4 ± 0.2. The evaluation of Λ and the apparent kinetic isotope effects (AKIE) for carbon and chlorine may lead to the hypothesis that the two eliminated chlorine atoms of α- and γ-HCH were in axial positions, the same as for the β-HCH conformer which has six chlorine atoms in axial positions after ring flip. The dichloroelimination of δ-HCH resulted in distinct AKIE and Λ values as one chlorine atom is in axial whereas the other chlorine atoms are in the equatorial positions. Significant chlorine and carbon isotope fractionations of HCH isomers were observed in the samples from a contaminated aquifer (Bitterfeld, Germany). The 37Cl/35Cl and 13C/12C isotope fractionation patterns of HCH isomers from laboratory experiments were used diagnostically in a model to characterize microbial dichloroelimination in the field study. The comparison of isotope fractionation patterns indicates that the transformation of HCH isomers at the field was mainly governed by microbial dichloroelimination transformation.
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Affiliation(s)
- Yaqing Liu
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318, Leipzig, Germany
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318, Leipzig, Germany
| | - Jun Yao
- School of Water Resources and Environment, China University of Geosciences, Beijing, Beijing, 100083, China
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318, Leipzig, Germany.
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318, Leipzig, Germany.
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10
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Zimmermann J, Halloran LJS, Hunkeler D. Tracking chlorinated contaminants in the subsurface using compound-specific chlorine isotope analysis: A review of principles, current challenges and applications. CHEMOSPHERE 2020; 244:125476. [PMID: 31830644 DOI: 10.1016/j.chemosphere.2019.125476] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Many chlorinated hydrocarbons have gained notoriety as persistent organic pollutants in the environment. Engineered and natural remediation efforts require a monitoring tool to track the progress of degradation processes. Compound-specific isotope analysis (CSIA) is a robust method to evaluate the origin and fate of contaminants in the environment and does not rely on concentration measurements. While carbon CSIA has established itself in the routine assessment of contaminated sites, studies incorporating chlorine isotopes have only recently become more common. Although some aspects of chlorine isotope analysis are more challenging than carbon isotope analysis, having additional isotopic data yields valuable information for contaminated site management. This review provides an overview of chlorine isotope fractionation of chlorinated contaminants in the subsurface by different processes and presents analytical techniques and unresolved challenges in chlorine isotope analysis. A summary of successful field applications illustrates the potential of using chlorine isotope data. Finally, approaches in modelling chlorine isotope fractionation due to degradation, diffusion, and sorption processes are discussed.
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Affiliation(s)
- Jeremy Zimmermann
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland.
| | - Landon J S Halloran
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland
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11
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Gafni A, Siebner H, Bernstein A. Potential for co-metabolic oxidation of TCE and evidence for its occurrence in a large-scale aquifer survey. WATER RESEARCH 2020; 171:115431. [PMID: 31893553 DOI: 10.1016/j.watres.2019.115431] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 11/30/2019] [Accepted: 12/20/2019] [Indexed: 06/10/2023]
Abstract
Trichloroethylene (TCE) is a groundwater pollutant that is prevalent worldwide. In contaminated groundwater, TCE can be biodegraded following either reductive dechlorination or aerobic co-metabolic oxidation. However, since the co-metabolic process is not accompanied by indicative and easily detectable transformation products, little is known about its prominence in the environment. To estimate the environmental importance of the oxidative process, a regional groundwater survey was conducted. In this survey, polluted water from 100 wells along the Israeli Coastal Aquifer was sampled. Geochemical data indicated oxic conditions prevailing in most sites. The sampled groundwater was used for microcosm experiments, functional gene analysis, and TCE compound-specific isotope analysis (δ13C and δ37Cl). Enrichments of methane and toluene oxidizers in microcosms indicated the high potential of the indigenous microbial community to co-metabolically oxidize TCE. This was further reinforced by the high abundance of mmoX and PHE functional genes quantified in some of the sites (yet lower abundance of TOD functional gene was found). Finally, compound-specific isotope analysis was used to assess the magnitude of TCE oxidation in practice. Applying the isotopic tool for scattered points on a regional scale demanded the consideration of a wide δ13C range of source TCE, hampering the ability to detect small shifts of a single permil. Thus, despite the high potential for the oxidation process, no evidence was attained for the natural occurrence of the process, and significant isotopic shifts were restricted to actively treated sites only. This limitation should be considered in future regional scale studies, in which no single source is defined.
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Affiliation(s)
- Almog Gafni
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Hagar Siebner
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Anat Bernstein
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel.
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Gafni A, Gelman F, Ronen Z, Bernstein A. Variable carbon and chlorine isotope fractionation in TCE co-metabolic oxidation. CHEMOSPHERE 2020; 242:125130. [PMID: 31669996 DOI: 10.1016/j.chemosphere.2019.125130] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/12/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Identifying co-metabolic TCE oxidation in polluted groundwater is challenging due to lack of indicative by-products. This challenge may theoretically be resolved if the oxidation process can be characterized by a distinct dual isotope enrichment. In this work, we aimed to explore the carbon and chlorine isotope effects associated with TCE oxidation by a variety of oxygenases. These included pure strains and enrichment cultures of methane, toluene and ammonia oxidizers, as well as experiments with crude extracts. Isotope effects determined for TCE oxidation by toluene and ammonia oxidizers were mostly in line with expected values for epoxidation mechanism (ϵ13C -11.0 ± 0.7 to -24.8 ± 0.2‰ and ϵ37Cl +0.9 ± 0.5 to +1.0 ± 0.4‰), whereas, the methanotrophs resulted in distinctively different isotope effects (ϵ13C -2.4 ± 0.4 to -3.4 ± 0.8‰ and ϵ37Cl -1.8 ± 0.2 to -2.9 ± 0.9‰). It is suggested that in TCE oxidation by methanotrophs, substrate binding rather than bond cleavage is rate limiting, leading to this unexpected isotope effect. On the environmental level, our results imply that the oxidative process can be differentiated if catalyzed by toluene and ammonia oxidizers or by methanotrophs. Additionally, the oxidative process can be distinguished from the reductive one. However, using dual isotope analysis in the field may result in an under-estimation of the overall co-metabolic process if methanotrophs are to be excluded due to low isotope effects.
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Affiliation(s)
- Almog Gafni
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Faina Gelman
- Geological Survey of Israel, 32 Yesha'ayahu Leibowitz St, Jerusalem, 9692100, Israel
| | - Zeev Ronen
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Anat Bernstein
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel.
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Murray AM, Ottosen CB, Maillard J, Holliger C, Johansen A, Brabæk L, Kristensen IL, Zimmermann J, Hunkeler D, Broholm MM. Chlorinated ethene plume evolution after source thermal remediation: Determination of degradation rates and mechanisms. JOURNAL OF CONTAMINANT HYDROLOGY 2019; 227:103551. [PMID: 31526529 DOI: 10.1016/j.jconhyd.2019.103551] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 06/10/2023]
Abstract
The extent, mechanism(s), and rate of chlorinated ethene degradation in a large tetrachloroethene (PCE) plume were investigated in an extensive sampling campaign. Multiple lines of evidence for this degradation were explored, including compound-specific isotope analysis (CSIA), dual C-Cl isotope analysis, and quantitative real-time polymerase chain reaction (qPCR) analysis targeting the genera Dehalococcoides and Dehalogenimonas and the genes vcrA, bvcA, and cerA. A decade prior to this sampling campaign, the plume source was thermally remediated by steam injection. This released dissolved organic carbon (DOC) that stimulated microbial activity and created reduced conditions within the plume. Based on an inclusive analysis of minor and major sampling campaigns since the initial site characterization, it was estimated that reduced conditions peaked 4 years after the remediation event. At the time of this study, 11 years after the remediation event, the redox conditions in the aquifer are returning to their original state. However, the DOC released from the remediated source zone matches levels measured 3 years prior and plume conditions are still suitable for biotic reductive dechlorination. Dehalococcoides spp., Dehalogenimonas spp., and vcrA, bvcA, and cerA reductive dehalogenase genes were detected close to the source, and suggest that complete, biotic PCE degradation occurs here. Further downgradient, qPCR analysis and enriched δ13C values for cis-dichloroethene (cDCE) suggest that cDCE is biodegraded in a sulfate-reducing zone in the plume. In the most downgradient portion of the plume, lower levels of specific degraders supported by dual C-Cl analysis indicate that the biodegradation occurs in combination with abiotic degradation. Additionally, 16S rRNA gene amplicon sequencing shows that organizational taxonomic units known to contain organohalide-respiring bacteria are relatively abundant throughout the plume. Hydraulic conductivity testing was also conducted, and local degradation rates for PCE and cDCE were determined at various locations throughout the plume. PCE degradation rates from sampling campaigns after the thermal remediation event range from 0.11 to 0.35 yr-1. PCE and cDCE degradation rates from the second to the third sampling campaigns ranged from 0.08 to 0.10 yr-1 and 0.01 to 0.07 yr-1, respectively. This is consistent with cDCE as the dominant daughter product in the majority of the plume and cDCE degradation as the time-limiting step. The extensive temporal and spatial analysis allowed for tracking the evolution of the plume and the lasting impact of the source remediation and illustrates that the multiple lines of evidence approach is essential to elucidate the primary degradation mechanisms in a plume of such size and complexity.
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Affiliation(s)
- Alexandra Marie Murray
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
| | - Cecilie B Ottosen
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
| | - Julien Maillard
- Laboratory for Environmental Biotechnology, ENAC-IIE, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Christof Holliger
- Laboratory for Environmental Biotechnology, ENAC-IIE, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Anders Johansen
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Lærke Brabæk
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
| | - Inge Lise Kristensen
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
| | - Jeremy Zimmermann
- Centre for Hydrogeology & Geothermics (CHYN), University of Neuchatel, Rue Emile Argand 11, CH 2000 Neuchatel, Switzerland
| | - Daniel Hunkeler
- Centre for Hydrogeology & Geothermics (CHYN), University of Neuchatel, Rue Emile Argand 11, CH 2000 Neuchatel, Switzerland
| | - Mette M Broholm
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
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Thouement HAA, Kuder T, Heimovaara TJ, van Breukelen BM. Do CSIA data from aquifers inform on natural degradation of chlorinated ethenes in aquitards? JOURNAL OF CONTAMINANT HYDROLOGY 2019; 226:103520. [PMID: 31377464 DOI: 10.1016/j.jconhyd.2019.103520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 05/24/2019] [Accepted: 07/02/2019] [Indexed: 06/10/2023]
Abstract
Back-diffusion of chlorinated ethenes (CEs) from low-permeability layers (LPLs) causes contaminant persistence long after the primary spill zones have disappeared. Naturally occurring degradation in LPLs lowers remediation time frames, but its assessment through sediment sampling is prohibitive in conventional remediation projects. Scenario simulations were performed with a reactive transport model (PHT3D in FloPy) accounting for isotope effects associated with degradation, sorption, and diffusion, to evaluate the potential of CSIA data from aquifers in assessing degradation in aquitards. The model simulated a trichloroethylene (TCE) DNAPL and its pollution plume within an aquifer-aquitard-aquifer system. Sequential reductive dechlorination to ethene and sorption were uniform in the aquitard and did not occur in the aquifer. After 10 years of loading the aquitard through diffusion from the plume, subsequent source removal triggered release of TCE by back-diffusion. In the upper aquifer, during the loading phase, δ13C-TCE was slightly enriched (up to 2‰) due to diffusion effects stimulated by degradation in the aquitard. In the upper aquifer, during the release phase, (i) source removal triggered a huge δ13C increase especially for higher CEs, (ii) moreover, downstream decreasing isotope ratios (caused by downgradient later onset of the release phase) with temporal increasing isotope ratios reflect aquitard degradation (as opposed to downstream increasing and temporally constant isotope ratios in reactive aquifers), and (iii) the carbon isotope mass balance (CIMB) enriched up to 4‰ as lower CEs (more depleted, less sorbing) have been transported deeper into the aquitard. Thus, enriched CIMB does not indicate oxidative transformation in this system. The CIMB enrichment enhanced with more sorption and lower aquitard thickness. Thin aquitards are quicker flushed from lower CEs leading to faster CIMB enrichment over time. CIMB enrichment is smaller or nearly absent when daughter products accumulate. Aquifer CSIA patterns indicative of aquitard degradation were similar in case of linear decreasing rate constants but contrasted with previous simulations assuming a thin bioactive zone. The Rayleigh equation systematically underestimates the extent of TCE degradation in aquifer samples especially during the loading phase and for conditions leading to long remediation time frames (low groundwater flow velocity, thicker aquitards, strong sorption in the aquitard). The Rayleigh equation provides a good and useful picture on aquitard degradation during the release phase throughout the sensitivity analysis. This modelling study provides a framework on how aquifer CSIA data can inform on the occurrence of aquitard degradation and its pitfalls.
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Affiliation(s)
- Héloïse A A Thouement
- Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands.
| | - Tomasz Kuder
- School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street, SEC 710, Norman, OK 73019, United States of America
| | - Timo J Heimovaara
- Department of Geoscience and Engineering, Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | - Boris M van Breukelen
- Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
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A concept for studying the transformation reaction of hexachlorocyclohexanes in food webs using multi-element compound-specific isotope analysis. Anal Chim Acta 2019; 1064:56-64. [DOI: 10.1016/j.aca.2019.03.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/04/2019] [Accepted: 03/15/2019] [Indexed: 01/30/2023]
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16
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Ojeda AS, Phillips E, Mancini SA, Lollar BS. Sources of Uncertainty in Biotransformation Mechanistic Interpretations and Remediation Studies using CSIA. Anal Chem 2019; 91:9147-9153. [DOI: 10.1021/acs.analchem.9b01756] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ann Sullivan Ojeda
- Department of Earth Sciences, The University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1, Canada
| | - Elizabeth Phillips
- Department of Earth Sciences, The University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1, Canada
| | - Silvia A. Mancini
- Geosyntec Consultants Inc., 243 Islington Avenue #1201, Etobicoke, Ontario M8X 1Y9, Canada
| | - Barbara Sherwood Lollar
- Department of Earth Sciences, The University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1, Canada
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17
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Rodríguez-Fernández D, Torrentó C, Palau J, Marchesi M, Soler A, Hunkeler D, Domènech C, Rosell M. Unravelling long-term source removal effects and chlorinated methanes natural attenuation processes by C and Cl stable isotopic patterns at a complex field site. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:286-296. [PMID: 30029110 DOI: 10.1016/j.scitotenv.2018.07.130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/10/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
The effects of contaminant sources removal in 2005 (i.e. barrels, tank, pit and wastewater pipe sources) on carbon tetrachloride (CT) and chloroform (CF) concentration in groundwater were assessed at several areas of a fractured multi-contaminant aquifer (Òdena, Spain) over a long-term period (2010-2014). Changes in redox conditions, in these chlorinated methanes (CMs) concentration and in their carbon isotopic compositions (δ13C) were monitored in multilevel wells. δ13C values from these wells were compared to those obtained from sources (barrels, tank and pit before their removal, 2002-2005) and to commercial solvents values in literature. Additionally, CMs natural attenuation processes were identified by C-Cl isotope slopes (Λ). Analyses revealed the downstream migration of the pollutant focus and an efficient removal of DNAPLs in the pit source's influence area. However, the removal of the contaminated soil from former tank and wastewater pipe was incomplete as leaching from unsaturated zone was proved, evidencing these areas are still active sources. Nevertheless, significant CMs degradation was detected close to all sources and Λ values pointed to different reactions. For CT in the tank area, Λ value fitted with hydrogenolysis pathway although other possible reduction processes were also uncovered. Near the wastewater pipe area, CT thiolytic reduction combined with hydrogenolysis was derived. The highest CT degradation extent accounted for these areas was 72 ± 11% and 84 ± 6%, respectively. For CF, the Λ value in the pit source's area was consistent with oxidation and/or with transport of CF affected by alkaline hydrolysis from upstream interception trenches. In contrast, isotope data evidenced CF reduction in the tank and wastewater pipe influence areas, although the observed Λ slightly deviates from the reference values, likely due to the continuous leaching of CF degraded in the non-saturated zone by a mechanism different from reduction.
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Affiliation(s)
- Diana Rodríguez-Fernández
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain.
| | - Clara Torrentó
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain; Centre for Hydrogeology and Geothermics, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Jordi Palau
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain; Centre for Hydrogeology and Geothermics, University of Neuchâtel, 2000 Neuchâtel, Switzerland; Institute of Environmental Assessment and Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Barcelona, Spain
| | - Massimo Marchesi
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain; Politecnico di Milano, Dept. of Civil and Environmental Engineering (DICA), Piazza L. Da Vinci, 32, 20133 Milano, Italy
| | - Albert Soler
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Cristina Domènech
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain
| | - Mònica Rosell
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain
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18
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Filippini M, Nijenhuis I, Kümmel S, Chiarini V, Crosta G, Richnow HH, Gargini A. Multi-element compound specific stable isotope analysis of chlorinated aliphatic contaminants derived from chlorinated pitches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 640-641:153-162. [PMID: 29859433 DOI: 10.1016/j.scitotenv.2018.05.285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
Tetrachloroethene and trichloroethene are typical by-products of the industrial production of chloromethanes. These by-products are known as "chlorinated pitches" and were often dumped in un-contained waste disposal sites causing groundwater contaminations. Previous research showed that a strongly depleted stable carbon isotope signature characterizes chlorinated compounds associated with chlorinated pitches whereas manufactured commercial compounds have more enriched carbon isotope ratios. The findings were restricted to a single case study and one element (i.e. carbon). This paper presents a multi-element Compound-Specific Stable Isotope Analysis (CSIA, including carbon, chlorine and hydrogen) of chlorinated aliphatic contaminants originated from chlorinated pitches at two sites with different hydrogeology and different producers of chloromethanes. The results show strongly depleted carbon signatures at both sites whereas the chlorine and the hydrogen signatures are comparable to those presented in the literature for manufactured commercial compounds. Multi-element CSIA allowed the identification of sources and site-specific processes affecting chloroethene transformation in groundwater as a result of emergency remediation measures. CSIA turned out to be an effective forensic tool to address the liability for the contamination, leading to a conviction for the crimes of unintentional aggravated public water supply poisoning and environmental disaster.
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Affiliation(s)
- Maria Filippini
- Department of Biological, Geological and Environmental Sciences, Alma Mater Studiorum - University of Bologna, Italy
| | - Ivonne Nijenhuis
- Department for Isotope Biogeochemistry, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
| | - Steffen Kümmel
- Department for Isotope Biogeochemistry, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
| | - Veronica Chiarini
- Department of Biological, Geological and Environmental Sciences, Alma Mater Studiorum - University of Bologna, Italy
| | - Giovanni Crosta
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Italy
| | - Hans H Richnow
- Department for Isotope Biogeochemistry, Helmholtz Center for Environmental Research-UFZ, Leipzig, Germany
| | - Alessandro Gargini
- Department of Biological, Geological and Environmental Sciences, Alma Mater Studiorum - University of Bologna, Italy.
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19
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Chlorine and bromine isotope fractionation of halogenated organic pollutants on gas chromatography columns. J Chromatogr A 2017; 1514:103-109. [DOI: 10.1016/j.chroma.2017.07.058] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 11/30/2022]
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20
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Van Breukelen BM, Thouement HAA, Stack PE, Vanderford M, Philp P, Kuder T. Modeling 3D-CSIA data: Carbon, chlorine, and hydrogen isotope fractionation during reductive dechlorination of TCE to ethene. JOURNAL OF CONTAMINANT HYDROLOGY 2017; 204:79-89. [PMID: 28764859 DOI: 10.1016/j.jconhyd.2017.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 07/14/2017] [Accepted: 07/15/2017] [Indexed: 06/07/2023]
Abstract
Reactive transport modeling of multi-element, compound-specific isotope analysis (CSIA) data has great potential to quantify sequential microbial reductive dechlorination (SRD) and alternative pathways such as oxidation, in support of remediation of chlorinated solvents in groundwater. As a key step towards this goal, a model was developed that simulates simultaneous carbon, chlorine, and hydrogen isotope fractionation during SRD of trichloroethene, via cis-1,2-dichloroethene (and trans-DCE as minor pathway), and vinyl chloride to ethene, following Monod kinetics. A simple correction term for individual isotope/isotopologue rates avoided multi-element isotopologue modeling. The model was successfully validated with data from a mixed culture Dehalococcoides microcosm. Simulation of Cl-CSIA required incorporation of secondary kinetic isotope effects (SKIEs). Assuming a limited degree of intramolecular heterogeneity of δ37Cl in TCE decreased the magnitudes of SKIEs required at the non-reacting Cl positions, without compromising the goodness of model fit, whereas a good fit of a model involving intramolecular CCl bond competition required an unlikely degree of intramolecular heterogeneity. Simulation of H-CSIA required SKIEs in H atoms originally present in the reacting compounds, especially for TCE, together with imprints of strongly depleted δ2H during protonation in the products. Scenario modeling illustrates the potential of H-CSIA for source apportionment.
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Affiliation(s)
- Boris M Van Breukelen
- Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The Netherlands.
| | - Héloïse A A Thouement
- Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The Netherlands
| | - Philip E Stack
- Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK
| | - Mindy Vanderford
- HydroGeoLogic, Inc., 4407 Jane St., Bellaire, TX 77401, United States
| | - Paul Philp
- School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street, SEC 710, Norman, OK 73019, United States
| | - Tomasz Kuder
- School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street, SEC 710, Norman, OK 73019, United States
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21
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Torrentó C, Palau J, Rodríguez-Fernández D, Heckel B, Meyer A, Domènech C, Rosell M, Soler A, Elsner M, Hunkeler D. Carbon and Chlorine Isotope Fractionation Patterns Associated with Different Engineered Chloroform Transformation Reactions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6174-6184. [PMID: 28482655 DOI: 10.1021/acs.est.7b00679] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To use compound-specific isotope analysis for confidently assessing organic contaminant attenuation in the environment, isotope fractionation patterns associated with different transformation mechanisms must first be explored in laboratory experiments. To deliver this information for the common groundwater contaminant chloroform (CF), this study investigated for the first time both carbon and chlorine isotope fractionation for three different engineered reactions: oxidative C-H bond cleavage using heat-activated persulfate, transformation under alkaline conditions (pH ∼ 12) and reductive C-Cl bond cleavage by cast zerovalent iron, Fe(0). Carbon and chlorine isotope fractionation values were -8 ± 1‰ and -0.44 ± 0.06‰ for oxidation, -57 ± 5‰ and -4.4 ± 0.4‰ for alkaline hydrolysis (pH 11.84 ± 0.03), and -33 ± 11‰ and -3 ± 1‰ for dechlorination, respectively. Carbon and chlorine apparent kinetic isotope effects (AKIEs) were in general agreement with expected mechanisms (C-H bond cleavage in oxidation by persulfate, C-Cl bond cleavage in Fe(0)-mediated reductive dechlorination and E1CB elimination mechanism during alkaline hydrolysis) where a secondary AKIECl (1.00045 ± 0.00004) was observed for oxidation. The different dual carbon-chlorine (Δδ13C vs Δδ37Cl) isotope patterns for oxidation by thermally activated persulfate and alkaline hydrolysis (17 ± 2 and 13.0 ± 0.8, respectively) vs reductive dechlorination by Fe(0) (8 ± 2) establish a base to identify and quantify these CF degradation mechanisms in the field.
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Affiliation(s)
- Clara Torrentó
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Jordi Palau
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Diana Rodríguez-Fernández
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Benjamin Heckel
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
| | - Armin Meyer
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
| | - Cristina Domènech
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Mònica Rosell
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Albert Soler
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich , Marchioninistrasse 17, D-81377 Munich, Germany
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
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22
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Heckel B, Rodríguez-Fernández D, Torrentó C, Meyer A, Palau J, Domènech C, Rosell M, Soler A, Hunkeler D, Elsner M. Compound-Specific Chlorine Isotope Analysis of Tetrachloromethane and Trichloromethane by Gas Chromatography-Isotope Ratio Mass Spectrometry vs Gas Chromatography-Quadrupole Mass Spectrometry: Method Development and Evaluation of Precision and Trueness. Anal Chem 2017; 89:3411-3420. [DOI: 10.1021/acs.analchem.6b04129] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Benjamin Heckel
- Institute
of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Diana Rodríguez-Fernández
- Grup
de Mineralogia Aplicada i Geoquímica de Fluids, Departament
de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències
de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès,
s/n 08028, Barcelona, Spain
| | - Clara Torrentó
- Centre
d’Hydrogéologie et de Géothermie (CHYN), Université de Neuchâtel (UNINE), Rue Emile-Argand 11, Neuchâtel 2000, Switzerland
| | - Armin Meyer
- Institute
of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Jordi Palau
- Grup
de Mineralogia Aplicada i Geoquímica de Fluids, Departament
de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències
de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès,
s/n 08028, Barcelona, Spain
- Centre
d’Hydrogéologie et de Géothermie (CHYN), Université de Neuchâtel (UNINE), Rue Emile-Argand 11, Neuchâtel 2000, Switzerland
| | - Cristina Domènech
- Grup
de Mineralogia Aplicada i Geoquímica de Fluids, Departament
de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències
de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès,
s/n 08028, Barcelona, Spain
| | - Mònica Rosell
- Grup
de Mineralogia Aplicada i Geoquímica de Fluids, Departament
de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències
de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès,
s/n 08028, Barcelona, Spain
| | - Albert Soler
- Grup
de Mineralogia Aplicada i Geoquímica de Fluids, Departament
de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències
de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès,
s/n 08028, Barcelona, Spain
| | - Daniel Hunkeler
- Centre
d’Hydrogéologie et de Géothermie (CHYN), Université de Neuchâtel (UNINE), Rue Emile-Argand 11, Neuchâtel 2000, Switzerland
| | - Martin Elsner
- Institute
of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
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23
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Wu L, Kümmel S, Richnow HH. Validation of GC-IRMS techniques for δ 13C and δ 2H CSIA of organophosphorus compounds and their potential for studying the mode of hydrolysis in the environment. Anal Bioanal Chem 2017; 409:2581-2590. [PMID: 28168550 DOI: 10.1007/s00216-017-0203-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/03/2017] [Accepted: 01/10/2017] [Indexed: 11/28/2022]
Abstract
Compound-specific stable isotope analysis (CSIA) is among the most promising tools for studying the fate of organic pollutants in the environment. However, the feasibility of multidimensional CSIA was limited by the availability of a robust method for precise isotope analysis of heteroatom-bearing organic compounds. We developed a method for δ 13C and δ 2H analysis of eight organophosphorus compounds (OPs) with different chemical properties. In particular, we aimed to compare high-temperature conversion (HTC) and chromium-based HTC (Cr/HTC) units to explore the limitations of hydrogen isotope analysis of heteroatom-bearing compounds. Analysis of the amount dependency of the isotope values (linearity analysis) of OPs indicated that the formation of HCl was a significant isotope fractionation process leading to inaccurate δ 2H analysis in HTC. In the case of nonchlorinated OPs, by-product formation of HCN, H2S, or PH3 in HTC was observed but did not affect the dynamic range of reproducible isotope values above the limit of detection. No hydrogen-containing by-products were found in the Cr/HTC process by use of ion trap mass spectrometry analysis. The accuracy of gas chromatography - isotope ratio mass spectrometry was validated in comparison with elemental analyzer - isotope ratio mass spectrometry. Dual-isotope fractionation yielded Λ values of 0 ± 0 at pH 7, 7 ± 1 at pH 9, and 30 ± 6 at pH 12, indicating the potential of 2D CSIA to characterize the hydrolysis mechanisms of OPs. This is the first report on the combination of δ 2H and δ 13C isotope analysis of OPs, and this is the first study providing a systematic evaluation of HTC and Cr/HTC for hydrogen isotope analysis using OPs as target compounds. Graphical Abstract Comparison of δ2H measurement of non-chlorinated and chlorinated OPs via GC-Cr/HTC-IRMS and GC-HTC-IRMS system.
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Affiliation(s)
- Langping Wu
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Permoserstrasse 15, 04318, Leipzig, Germany.
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24
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Ebert KA, Laskov C, Elsner M, Haderlein SB. Calibration bias of experimentally determined chlorine isotope enrichment factors: the need for a two-point calibration in compound-specific chlorine isotope analysis. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:68-74. [PMID: 27689937 DOI: 10.1002/rcm.7752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE The recent development of compound-specific online chlorine isotope analysis (37 Cl-CSIA) methods has fostered dual chlorine-carbon isotope studies to gain better insights into sources and environmental transformation reactions of chlorinated ethenes. One-point and two-point calibration schemes are currently used to convert raw data to the international δ37 ClSMOC scale, but a critical evaluation of best practices to arrive at reliable δ37 ClSMOC signatures and enrichment factors was missing and is presented here. METHODS Aqueous solutions of neat perchloroethylene and trichloroethylene (TCE) and aqueous samples from a TCE biodegradation experiment with pure cultures of Desulfitobacterium hafniense Y51 were analysed for their chlorine isotope ratios using GC/qMS and GC/IRMS. The δ37 ClSMOC values were obtained using one-point and two-point calibration schemes. Chlorine isotope enrichment factors, εCl , were calculated using both approaches and the corresponding bias of δ37 ClSMOC values introduced by the different types of calibration was determined. RESULTS Different calibration methods resulted in significant differences (up to 30%) in both δ37 Cl signatures and εCl values. CONCLUSIONS Our results demonstrate that a two-point calibration together with comprehensive information on reference materials is indispensable and should become standard practice for reliable 37 Cl-CSIA of organic compounds. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Karin A Ebert
- Center for Applied Geoscience, University of Tübingen, Hölderlinstr. 12, 72074, Tübingen, Germany
| | - Christine Laskov
- Center for Applied Geoscience, University of Tübingen, Hölderlinstr. 12, 72074, Tübingen, Germany
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Stefan B Haderlein
- Center for Applied Geoscience, University of Tübingen, Hölderlinstr. 12, 72074, Tübingen, Germany
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25
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Clark JA, Stotler RL, Frape SK, Illman WA. Compound-Specific Isotope Analyses to Assess TCE Biodegradation in a Fractured Dolomitic Aquifer. GROUND WATER 2017; 55:88-99. [PMID: 27377471 DOI: 10.1111/gwat.12440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
The potential for trichloroethene (TCE) biodegradation in a fractured dolomite aquifer at a former chemical disposal site in Smithville, Ontario, Canada, is assessed using chemical analysis and TCE and cis-DCE compound-specific isotope analysis of carbon and chlorine collected over a 16-month period. Groundwater redox conditions change from suboxic to much more reducing environments within and around the plume, indicating that oxidation of organic contaminants and degradation products is occurring at the study site. TCE and cis-DCE were observed in 13 of 14 wells sampled. VC, ethene, and/or ethane were also observed in ten wells, indicating that partial/full dechlorination has occurred. Chlorine isotopic values (δ37 Cl) range between 1.39 to 4.69‰ SMOC for TCE, and 3.57 to 13.86‰ SMOC for cis-DCE. Carbon isotopic values range between -28.9 and -20.7‰ VPDB for TCE, and -26.5 and -11.8‰ VPDB for cis-DCE. In most wells, isotopic values remained steady over the 15-month study. Isotopic enrichment from TCE to cis-DCE varied between 0 and 13‰ for carbon and 1 and 4‰ for chlorine. Calculated chlorine-carbon isotopic enrichment ratios (ϵCl /ϵC ) were 0.18 for TCE and 0.69 for cis-DCE. Combined, isotopic and chemical data indicate very little dechlorination is occurring near the source zone, but suggest bacterially mediated degradation is occurring closer to the edges of the plume.
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Affiliation(s)
- Justin A Clark
- Department of Earth & Environmental Sciences, University of Waterloo, 200 University Ave W, Waterloo, Ontario N2L 3G1, Canada
| | | | - Shaun K Frape
- Department of Earth & Environmental Sciences, University of Waterloo, 200 University Ave W, Waterloo, Ontario N2L 3G1, Canada
| | - Walter A Illman
- Department of Earth & Environmental Sciences, University of Waterloo, 200 University Ave W, Waterloo, Ontario N2L 3G1, Canada
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26
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Höhener P. Simulating stable carbon and chlorine isotope ratios in dissolved chlorinated groundwater pollutants with BIOCHLOR-ISO. JOURNAL OF CONTAMINANT HYDROLOGY 2016; 195:52-61. [PMID: 27894785 DOI: 10.1016/j.jconhyd.2016.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 11/07/2016] [Accepted: 11/15/2016] [Indexed: 06/06/2023]
Abstract
BIOCHLOR is a well-known simple tool for evaluating the transport of dissolved chlorinated solvents in groundwater, ideal for rapid screening and teaching. This work extends the BIOCHLOR model for the calculation of stable isotope ratios of carbon and chlorine isotopes in chloroethenes. An exact solution for the three-dimensional reactive transport of a chain of degrading compounds including sorption is provided in a spreadsheet and applied for modeling the transport of individual isotopes 12C, 13C, 35Cl, 37Cl from a constant source. The model can consider secondary isotope effects that can occur in the breaking of CCl bonds. The model is correctly reproducing results for δ13C and δ37Cl modeled by a previously published 1-D numerical model without secondary isotope effects, and is also reproducing results from a microcosm experiment with secondary chlorine isotope effects. Two applications of the model using field data from literature are further given and discussed. The new BIOCHLOR-ISO model is distributed as a spreadsheet (MS EXCEL) along with this publication.
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Affiliation(s)
- Patrick Höhener
- Aix Marseille Univ, CNRS UMR 7376, Laboratoire Chimie Environnement, 3 place Victor Hugo, F-13331 Marseille, France.
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27
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Zakon Y, Halicz L, Lev O, Gelman F. Compound-specific bromine isotope ratio analysis using gas chromatography/quadrupole mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1951-1956. [PMID: 27501429 DOI: 10.1002/rcm.7672] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 06/20/2016] [Accepted: 06/20/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE Brominated organic compounds (BOCs) are common persistent toxic pollutants. Compound-specific stable bromine isotope ratio analysis is one of the potential approaches for investigating BOC transformations in the environment. In the present study, we demonstrate that precise bromine isotope analysis of BOCs can be successfully performed by gas chromatography/quadrupole mass spectrometry (GC/qMS) systems that are widely available in analytical laboratories. METHODS Optimization and validation of the GC/qMS method were performed by analysis of bromoform, 3-bromophenol and 4-bromotoluene. In addition, comparison of the results obtained by GC/qMS and GC/multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) for 1,2-dibromoethane and 3-bromophenol samples with different bromine isotope composition was carried out to evaluate the analytical performance of the developed method. RESULTS Precisions in the range 0.2-0.3‰ were attained for sample amounts in the range of tens to thousands pmol. Good correlation between the results obtained by GC/qMS and GC/MC-ICPMS for laboratory standard materials (1,2-dibromoethane and 3-bromophenol) (regression coefficient R(2) > 0.98) was achieved. CONCLUSIONS The GC/qMS method for bromine isotope analysis shows a good performance and can be applied routinely for studying transformations of BOCs. Due to the observed dependence of the measured isotope ratios on the amount of the analyte and the calculation scheme applied, normalization of the results versus appropriate standards is required for source attribution applications. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Yevgeni Zakon
- Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem, 95501, Israel
- Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Ludwik Halicz
- Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem, 95501, Israel
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 02-089, Warsaw, Poland
| | - Ovadia Lev
- Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Faina Gelman
- Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem, 95501, Israel
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28
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Palau J, Jamin P, Badin A, Vanhecke N, Haerens B, Brouyère S, Hunkeler D. Use of dual carbon-chlorine isotope analysis to assess the degradation pathways of 1,1,1-trichloroethane in groundwater. WATER RESEARCH 2016; 92:235-243. [PMID: 26874254 DOI: 10.1016/j.watres.2016.01.057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 01/27/2016] [Accepted: 01/30/2016] [Indexed: 06/05/2023]
Abstract
Compound-specific isotope analysis (CSIA) is a powerful tool to track contaminant fate in groundwater. However, the application of CSIA to chlorinated ethanes has received little attention so far. These compounds are toxic and prevalent groundwater contaminants of environmental concern. The high susceptibility of chlorinated ethanes like 1,1,1-trichloroethane (1,1,1-TCA) to be transformed via different competing pathways (biotic and abiotic) complicates the assessment of their fate in the subsurface. In this study, the use of a dual C-Cl isotope approach to identify the active degradation pathways of 1,1,1-TCA is evaluated for the first time in an aerobic aquifer impacted by 1,1,1-TCA and trichloroethylene (TCE) with concentrations of up to 20 mg/L and 3.4 mg/L, respectively. The reaction-specific dual carbon-chlorine (C-Cl) isotope trends determined in a recent laboratory study illustrated the potential of a dual isotope approach to identify contaminant degradation pathways of 1,1,1-TCA. Compared to the dual isotope slopes (Δδ(13)C/Δδ(37)Cl) previously determined in the laboratory for dehydrohalogenation/hydrolysis (DH/HY, 0.33 ± 0.04) and oxidation by persulfate (∞), the slope determined from field samples (0.6 ± 0.2, r(2) = 0.75) is closer to the one observed for DH/HY, pointing to DH/HY as the predominant degradation pathway of 1,1,1-TCA in the aquifer. The observed deviation could be explained by a minor contribution of additional degradation processes. This result, along with the little degradation of TCE determined from isotope measurements, confirmed that 1,1,1-TCA is the main source of the 1,1-dichlorethylene (1,1-DCE) detected in the aquifer with concentrations of up to 10 mg/L. This study demonstrates that a dual C-Cl isotope approach can strongly improve the qualitative and quantitative assessment of 1,1,1-TCA degradation processes in the field.
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Affiliation(s)
- Jordi Palau
- University of Neuchâtel, Centre for Hydrogeology and Geothermics (CHYN), Building UniMail, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland; Institute of Environmental Assessment and Water Research (IDAEA), CSIC, Jordi Girona 18-26, Barcelona 08034, Spain.
| | - Pierre Jamin
- University of Liège, Fac. Applied Sciences, Dpt ArGEnCo, Geo³-Hydrogeology and Environmental Geology, Building B52, 4000 Sart-Tilman, Belgium
| | - Alice Badin
- University of Neuchâtel, Centre for Hydrogeology and Geothermics (CHYN), Building UniMail, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | | | - Bruno Haerens
- AECOM, Maria-Theresiastraat 34A, 3000 Leuven, Belgium
| | - Serge Brouyère
- University of Liège, Fac. Applied Sciences, Dpt ArGEnCo, Geo³-Hydrogeology and Environmental Geology, Building B52, 4000 Sart-Tilman, Belgium
| | - Daniel Hunkeler
- University of Neuchâtel, Centre for Hydrogeology and Geothermics (CHYN), Building UniMail, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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29
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Wittlingerová Z, Macháčková J, Petruželková A, Zimová M. Occurrence of perchloroethylene in surface water and fish in a river ecosystem affected by groundwater contamination. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:5676-5692. [PMID: 26578381 DOI: 10.1007/s11356-015-5806-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/11/2015] [Indexed: 06/05/2023]
Abstract
Long-term monitoring of the content of perchloroethylene (PCE) in a river ecosystem affected by groundwater contamination was performed at a site in the Czech Republic. The quality of surface water was monitored quarterly between 1994 and 2013, and fish were collected from the affected ecosystem to analyse the content of PCE in their tissue in 1998, 2011 and 2012. Concentrations of PCE (9-140 μg/kg) in the tissue of fish collected from the contaminated part of the river were elevated compared to the part of the river unaffected by the contamination (ND to 5 μg/kg PCE). The quality of surface water has improved as a result of groundwater remediation during the evaluated period. Before the remedial action, PCE concentrations ranged from 30 to 95 μg/L (1994-1997). Following commencement of remedial activities in September 1997, a decrease in the content of PCE in the surface water to 7.3 μg/L (1998) and further to 1 μg/L (2011) and 1.1 μg/L (2012) led to a progressive decrease in the average concentration of PCE in the fish muscle tissue from 79 μg/kg (1998) to 24 (2011) and 30 μg/kg (2012), respectively. It was determined that the bioconcentration of PCE does not have a linear dependence because the decrease in contamination in the fish muscle tissue is not directly proportional to the decrease in contamination in the river water. The observed average bioconcentration factors were 24 and 28 for the lower concentrations of PCE and 11 for the higher concentrations of PCE in the river. In terms of age, length and weight of the collected fish, weight had the greatest significance for bioconcentration, followed by the length, with age being evaluated as a less significant factor.
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Affiliation(s)
- Zdena Wittlingerová
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol, 165 21, Czech Republic
| | - Jiřina Macháčková
- Technical University of Liberec, Institute of Nanomaterials, Advanced Technologies and Innovation, Studentská 1402/2, Liberec 1, 461 17, Czech Republic.
| | - Anna Petruželková
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol, 165 21, Czech Republic
| | - Magdalena Zimová
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, Suchdol, 165 21, Czech Republic
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30
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Miska ME, Shouakar-Stash O, Holmstrand H. Stable chlorine isotope analysis of chlorinated acetic acids using gas chromatography/quadrupole mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:2341-2348. [PMID: 26563705 DOI: 10.1002/rcm.7407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/23/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE The environmental occurrence of chlorinated acetic acids (CAAs) has been extensively studied, but the sources and transport are still not yet fully understood. A promising approach for source apportionment and process studies is the isotopic characterization of target compounds. We present the first on-line stable chlorine isotope analysis of CAAs by use of gas chromatography/quadrupole mass spectrometry (GC/qMS). METHODS Following approved procedures for concentration analysis, CAAs extracted into MTBE were methylated to GC-amenable methyl esters (mCAAs). These mCAAs were then analyzed by GC/qMS for their stable chlorine isotope composition using a sample/standard-bracketing approach (CAA standards in the range δ(37) Cl -6.3 to -0.2 ‰, Standard Mean Ocean Chloride). RESULTS Cross-calibration of the herein presented method with off-line reference methods (thermal ionization and continuous-flow GC isotope ratio mass spectrometry; TI-MS and CF-GC/IRMS, respectively) shows good agreement between the methods (regression slope for GC/qMS vs reference method data sets: 0.92 ± 0.29). Sample amounts as small as 10 pmol Cl can herewith be analyzed with a precision of 0.1 to 0.4 ‰. CONCLUSIONS This method should be useful for environmental studies of CAAs at ambient concentrations in precipitations (<0.06 to 100 nmol L(-1) ), surface waters (<0.2 to 5 nmol L(-1) ) and soil (<0.6 to 2000 nmol kg(-1) dry soil) where conventional off-line methods cannot be applied.
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Affiliation(s)
- Milena E Miska
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden
| | - Orfan Shouakar-Stash
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada
- Isotope Tracer Technologies Inc, Waterloo, Ontario, Canada
| | - Henry Holmstrand
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden
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31
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Buchner D, Behrens S, Laskov C, Haderlein SB. Resiliency of Stable Isotope Fractionation (δ(13)C and δ(37)Cl) of Trichloroethene to Bacterial Growth Physiology and Expression of Key Enzymes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:13230-13237. [PMID: 26505909 DOI: 10.1021/acs.est.5b02918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Quantification of in situ (bio)degradation using compound-specific isotope analysis requires a known and constant isotope enrichment factor (ε). Because reported isotope enrichment factors for microbial dehalogenation of chlorinated ethenes vary considerably we studied the potential effects of metabolic adaptation to TCE respiration on isotope fractionation (δ(13)C and δ(37)Cl) using a model organism (Desulfitobacterium hafniesne Y51), which only has one reductive dehalogenase (PceA). Cells grown on TCE for the first time showed exponential growth until 10(9) cells/mL. During exponential growth, the cell-normalized amount of PceA enzyme increased steadily in the presence of TCE (up to 21 pceA transcripts per cell) but not with alternative substrates (<1 pceA transcript per cell). Cultures initially transferred or subcultivated on TCE showed very similar isotope fractionation, both for carbon (εcarbon: -8.6‰ ± 0.3‰ or -8.8‰ ± 0.2‰) and chlorine (εchlorine: -2.7‰ ± 0.3‰) with little variation (0.7‰) for the different experimental conditions. Thus, TCE isotope fractionation by D. hafniense strain Y51 was affected by neither growth phase, pceA transcription, or translation, nor by PceA content per cell, suggesting that transport limitations did not affect isotope fractionation. Previously reported variable ε values for other organohalide-respiring bacteria might thus be attributed to different expression levels of their multiple reductive dehalogenases.
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Affiliation(s)
- Daniel Buchner
- Department of Geosciences, Center for Applied Geosciences, University of Tübingen , 72074 Tübingen, Germany
| | - Sebastian Behrens
- Department of Geosciences, Center for Applied Geosciences, University of Tübingen , 72074 Tübingen, Germany
| | - Christine Laskov
- Department of Geosciences, Center for Applied Geosciences, University of Tübingen , 72074 Tübingen, Germany
| | - Stefan B Haderlein
- Department of Geosciences, Center for Applied Geosciences, University of Tübingen , 72074 Tübingen, Germany
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32
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Julien M, Nun P, Höhener P, Parinet J, Robins RJ, Remaud GS. Enhanced forensic discrimination of pollutants by position-specific isotope analysis using isotope ratio monitoring by (13)C nuclear magnetic resonance spectrometry. Talanta 2015; 147:383-9. [PMID: 26592622 DOI: 10.1016/j.talanta.2015.10.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/30/2015] [Accepted: 10/04/2015] [Indexed: 12/31/2022]
Abstract
In forensic environmental investigations the main issue concerns the inference of the original source of the pollutant for determining the liable party. Isotope measurements in geochemistry, combined with complimentary techniques for contaminant identification, have contributed significantly to source determination at polluted sites. In this work we have determined the intramolecular (13)C profiles of several molecules well-known as pollutants. By giving additional analytical parameters, position-specific isotope analysis performed by isotope ratio monitoring by (13)C nuclear magnetic resonance (irm-(13)C NMR) spectrometry gives new information to help in answering the major question: what is the origin of the detected contaminant? We have shown that isotope profiling of the core of a molecule reveals both the raw materials and the process used in its manufacture. It also can reveal processes occurring between the contamination site 'source' and the sampling site. Thus, irm-(13)C NMR is shown to be a very good complement to compound-specific isotope analysis currently performed by mass spectrometry for assessing polluted sites involving substantial spills of pollutant.
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Affiliation(s)
- Maxime Julien
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Pierrick Nun
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Patrick Höhener
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement FRE 3416, Place Victor Hugo 3, 13331 Marseille, France
| | - Julien Parinet
- University of Aix-Marseille-CNRS, Laboratoire Chimie Environnement FRE 3416, Place Victor Hugo 3, 13331 Marseille, France
| | - Richard J Robins
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Gérald S Remaud
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230, 2 rue de la Houssinière BP 92208, F-44322 Nantes, France.
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Xu Y, He Y, Zhang Q, Xu J, Crowley D. Coupling between Pentachlorophenol Dechlorination and Soil Redox As Revealed by Stable Carbon Isotope, Microbial Community Structure, and Biogeochemical Data. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5425-5433. [PMID: 25853431 DOI: 10.1021/es505040c] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Carbon isotopic analysis and molecular-based methods were used in conjunction with geochemical data sets to assess the dechlorination of pentachlorophenol (PCP) when coupled to biogeochemical processes in a mangrove soil having no prior history of anthropogenic contamination. The PCP underwent 96% dechlorination in soil amended with acetate, compared to 21% dehalogenation in control soil. Carbon isotope analysis of residual PCP demonstrated an obvious enrichment of 13C (εC, -3.01±0.1%). Molecular and statistical analyses demonstrated that PCP dechlorination and Fe(III) reduction were synergistically combined electron-accepting processes. Microbial community analysis further suggested that enhanced dechlorination of PCP during Fe(III) reduction was mediated by members of the multifunctional family of Geobacteraceae. In contrast, PCP significantly suppressed the growth of SO4(2-) reducers, which, in turn, facilitated the production of CH4 by diversion of electrons from SO4(2-) reduction to methanogenesis. The integrated data regarding stoichiometric alterations in this study gives direct evidence showing PCP, Fe(III), and SO4(2-) reduction, and CH4 production are coupled microbial processes during changes in soil redox.
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Affiliation(s)
- Yan Xu
- †Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou 310058, China
| | - Yan He
- †Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou 310058, China
| | - Qian Zhang
- †Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou 310058, China
| | - Jianming Xu
- †Institute of Soil and Water Resources and Environmental Science, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou 310058, China
| | - David Crowley
- ‡Department of Environmental Sciences, University of California, Riverside, Riverside, California 92521, United States
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Kozell A, Yecheskel Y, Balaban N, Dror I, Halicz L, Ronen Z, Gelman F. Application of dual carbon-bromine isotope analysis for investigating abiotic transformations of tribromoneopentyl alcohol (TBNPA). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:4433-4440. [PMID: 25723316 DOI: 10.1021/es504887d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Many of polybrominated organic compounds, used as flame retardant additives, belong to the group of persistent organic pollutants. Compound-specific isotope analysis is one of the potential analytical tools for investigating their fate in the environment. However, the isotope effects associated with transformations of brominated organic compounds are still poorly explored. In the present study, we investigated carbon and bromine isotope fractionation during degradation of tribromoneopentyl alcohol (TBNPA), one of the widely used flame retardant additives, in three different chemical processes: transformation in aqueous alkaline solution (pH 8); reductive dehalogenation by zero-valent iron nanoparticles (nZVI) in anoxic conditions; oxidative degradation by H2O2 in the presence of CuO nanoparticles (nCuO). Two-dimensional carbon-bromine isotope plots (δ(13)C/Δ(81)Br) for each reaction gave different process-dependent isotope slopes (Λ(C/Br)): 25.2 ± 2.5 for alkaline hydrolysis (pH 8); 3.8 ± 0.5 for debromination in the presence of nZVI in anoxic conditions; ∞ in the case of catalytic oxidation by H2O2 with nCuO. The obtained isotope effects for both elements were generally in agreement with the values expected for the suggested reaction mechanisms. The results of the present study support further applications of dual carbon-bromine isotope analysis as a tool for identification of reaction pathway during transformations of brominated organic compounds in the environment.
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Affiliation(s)
- Anna Kozell
- †Geological Survey of Israel, 30 Malhei Israel Street, Jerusalem 95501, Israel
- ‡Department of Chemistry, The Hebrew University, Jerusalem 91904, Israel
| | - Yinon Yecheskel
- §Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Noa Balaban
- ∥Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Sede Boqer 84990, Israel
| | - Ishai Dror
- §Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ludwik Halicz
- †Geological Survey of Israel, 30 Malhei Israel Street, Jerusalem 95501, Israel
- ⊥Biological and Chemical Research Centre, University of Warsaw, 02-089, Poland
| | - Zeev Ronen
- ∥Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Sede Boqer 84990, Israel
| | - Faina Gelman
- †Geological Survey of Israel, 30 Malhei Israel Street, Jerusalem 95501, Israel
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Palau J, Cretnik S, Shouakar-Stash O, Höche M, Elsner M, Hunkeler D. C and Cl isotope fractionation of 1,2-dichloroethane displays unique δ¹³C/δ³⁷Cl patterns for pathway identification and reveals surprising C-Cl bond involvement in microbial oxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:9430-9437. [PMID: 25010210 DOI: 10.1021/es5031917] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This study investigates dual element isotope fractionation during aerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via oxidative cleavage of a C-H bond (Pseudomonas sp. strain DCA1) versus C-Cl bond cleavage by S(N)2 reaction (Xanthobacter autotrophicus GJ10 and Ancylobacter aquaticus AD20). Compound-specific chlorine isotope analysis of 1,2-DCA was performed for the first time, and isotope fractionation (ε(bulk)(Cl)) was determined by measurements of the same samples in three different laboratories using two gas chromatography-isotope ratio mass spectrometry systems and one gas chromatography-quadrupole mass spectrometry system. Strongly pathway-dependent slopes (Δδ13C/Δδ37Cl), 0.78 ± 0.03 (oxidation) and 7.7 ± 0.2 (S(N)2), delineate the potential of the dual isotope approach to identify 1,2-DCA degradation pathways in the field. In contrast to different ε(bulk)(C) values [-3.5 ± 0.1‰ (oxidation) and -31.9 ± 0.7 and -32.0 ± 0.9‰ (S(N)2)], the obtained ε(bulk)(Cl) values were surprisingly similar for the two pathways: -3.8 ± 0.2‰ (oxidation) and -4.2 ± 0.1 and -4.4 ± 0.2‰ (S(N)2). Apparent kinetic isotope effects (AKIEs) of 1.0070 ± 0.0002 (13C-AKIE, oxidation), 1.068 ± 0.001 (13C-AKIE, S(N)2), and 1.0087 ± 0.0002 (37Cl-AKIE, S(N)2) fell within expected ranges. In contrast, an unexpectedly large secondary 37Cl-AKIE of 1.0038 ± 0.0002 reveals a hitherto unrecognized involvement of C-Cl bonds in microbial C-H bond oxidation. Our two-dimensional isotope fractionation patterns allow for the first time reliable 1,2-DCA degradation pathway identification in the field, which unlocks the full potential of isotope applications for this important groundwater contaminant.
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Affiliation(s)
- Jordi Palau
- Centre for Hydrogeology and Geothermics, University of Neuchâtel , 2000 Neuchâtel, Switzerland
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Badin A, Buttet G, Maillard J, Holliger C, Hunkeler D. Multiple dual C-Cl isotope patterns associated with reductive dechlorination of tetrachloroethene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:9179-9186. [PMID: 25000152 DOI: 10.1021/es500822d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Dual isotope slopes are increasingly used to identify transformation pathways of contaminants. We investigated if reductive dechlorination of tetrachloroethene (PCE) by consortia containing bacteria with different reductive dehalogenases (rdhA) genes can lead to variable dual C-Cl isotope slopes and if different slopes also occur in the field. Two bacterial enrichments harboring Sulfurospirillum spp. but different rdhA genes yielded two distinct δ(13)C to δ(37)Cl slopes of 2.7 ± 0.3 and 0.7 ± 0.2 despite a high similarity in gene sequences. This suggests that PCE reductive dechlorination could be catalyzed according to at least two distinct reaction mechanisms or that rate-limiting steps might vary. At two field sites, two distinct dual isotope slopes of 0.7 ± 0.3 and 3.5 ± 1.6 were obtained, each of which fits one of the laboratory slopes within the range of uncertainty. This study hence provides additional insight into multiple reaction mechanisms underlying PCE reductive dechlorination. It also demonstrates that caution is necessary if a dual isotope approach is used to differentiate between transformation pathways of chlorinated ethenes.
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Affiliation(s)
- Alice Badin
- Centre for Hydrogeology and Geothermics (CHYN), University of Neuchâtel , Rue Emile Argand 11, CH-2000 Neuchâtel, Switzerland
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Liu Y, Gan Y, Zhou A, Liu C, Li X, Yu T. Carbon and chlorine isotope fractionation during Fenton-like degradation of trichloroethene. CHEMOSPHERE 2014; 107:94-100. [PMID: 24875875 DOI: 10.1016/j.chemosphere.2014.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/28/2014] [Accepted: 03/04/2014] [Indexed: 06/03/2023]
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.
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Affiliation(s)
- Yunde Liu
- 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.
| | - Yiqun Gan
- 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.
| | - Aiguo Zhou
- 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.
| | - Cunfu Liu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
| | - Xiaoqian Li
- 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.
| | - Tingting Yu
- 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.
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Lutz SR, Van Breukelen BM. Combined source apportionment and degradation quantification of organic pollutants with CSIA: 1. Model derivation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:6220-6228. [PMID: 24852716 DOI: 10.1021/es405400w] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Compound-specific stable isotope analysis (CSIA) serves as a tool for source apportionment (SA) and for the quantification of the extent of degradation (QED) of organic pollutants. However, simultaneous occurrence of mixing of sources and degradation is generally believed to hamper both SA and QED. On the basis of the linear stable isotope mixing model and the Rayleigh equation, we developed the stable isotope sources and sinks model, which allows for simultaneous SA and QED of a pollutant that is emitted by two sources and degrades via one transformation process. It was shown that the model necessitates at least dual-element CSIA for unequivocal SA in the presence of degradation-induced isotope fractionation, as illustrated for perchlorate in groundwater. The model also enables QED, provided degradation follows instantaneous mixing of two sources. If mixing occurs after two sources have degraded separately, the model can still provide a conservative estimate of the overall extent of degradation. The model can be extended to a larger number of sources and sinks as outlined. It may aid in forensics and natural attenuation assessment of soil, groundwater, surface water, or atmospheric pollution.
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Affiliation(s)
- S R Lutz
- Critical Zone Hydrology Group, Department of Earth Sciences, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam , De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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Jammer S, Voloshenko A, Gelman F, Lev O. Chiral and isotope analyses for assessing the degradation of organic contaminants in the environment: Rayleigh dependence. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3310-3318. [PMID: 24471759 DOI: 10.1021/es4039209] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The Rayleigh equation is frequently used to describe isotope fractionation as a function of conversion. In this article we propose to draw a parallel between isotope and enantiomeric enrichments and derive a set of conditions that allow the use of the Rayleigh approach to describe the enantiomeric enrichment-conversion dependencies. We demonstrate an implementation of the Rayleigh equation for the enantioselective enzymatic hydrolysis of Mecoprop-methyl, Dichlorprop-methyl, and dimethyl-methylsuccinate by lipases from Pseudomonas fluorescens, Pseudomonas cepacia, and Candida rugosa. The data obtained for all the studied reactions gave good fits to the Rayleigh equation, with a linear regression R(2) > 0.96. In addition to that, our analysis of four microcosm studies on the hydrolysis of the individual enantiomers of Dichloroprop methyl, Lactofen, Fenoxaprop-ethyl, and Metalaxyl reported in the literature by other research groups revealed a suitability of the Rayleigh dependence. Two dimensional plots describing the isotope fractionation versus enantiomeric enrichment are demonstrated for all studied cases. Processes not accompanied by enantiomeric enrichment (acid and base hydrolysis) and by isotope enrichment (transesterification) are demonstrated, their 2-D plots are either horizontal or vertical which can illuminate concealed degradation pathways.
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Affiliation(s)
- S Jammer
- The Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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40
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Palau J, Marchesi M, Chambon JCC, Aravena R, Canals À, Binning PJ, Bjerg PL, Otero N, Soler A. Multi-isotope (carbon and chlorine) analysis for fingerprinting and site characterization at a fractured bedrock aquifer contaminated by chlorinated ethenes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 475:61-70. [PMID: 24419287 DOI: 10.1016/j.scitotenv.2013.12.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Revised: 12/13/2013] [Accepted: 12/14/2013] [Indexed: 06/03/2023]
Abstract
The use of compound specific multi-isotope approach (C and Cl) in the characterization of a chlorinated ethenes contaminated fractured aquifer allows the identification of several sources and contaminant plumes, as well as the occurrence of biodegradation and mixing processes. The study site is located in Spain with contamination resulting in groundwater concentrations of up to 50mg/L of trichloroethene (TCE), the most abundant chlorinated ethene, and 7 mg/L of tetrachloroethene (PCE). The potential sources of contamination including abandoned barrels, an underground tank, and a disposal lagoon, showed a wide range in δ(13)C values from -15.6 to -40.5‰ for TCE and from -18.5 to -32.4‰ for PCE, allowing the use of isotope fingerprinting for tracing of the origin and migration of these contaminants in the aquifer. In contrast, there is no difference between the δ(37)Cl values for TCE in the contaminant sources, ranging from +0.53 to +0.66‰. Variations of δ(37)Cl and δ(13)C in the different contaminant plumes were used to investigate the role of biodegradation in groundwater. Moreover, the isotopic data were incorporated into a reactive transport model for determination of whether the isotope pattern observed downstream from the tank's source could be explained by the simultaneous effect of mixing and biodegradation. The results demonstrate that a multi-isotope approach is a valuable tool for characterization of complex sites such as fractured bedrock aquifer contaminated by multiple sources, providing important information which can be used by consultants and site managers to prioritize and design more successful remediation strategies.
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Affiliation(s)
- Jordi Palau
- Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona, Spain.
| | - Massimo Marchesi
- Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona, Spain; Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Julie C C Chambon
- Department of Environmental Engineering, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Ramon Aravena
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Àngels Canals
- Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona, Spain
| | - Philip J Binning
- Department of Environmental Engineering, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Poul L Bjerg
- Department of Environmental Engineering, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Neus Otero
- Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona, Spain
| | - Albert Soler
- Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028 Barcelona, Spain
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Kuder T, van Breukelen BM, Vanderford M, Philp P. 3D-CSIA: carbon, chlorine, and hydrogen isotope fractionation in transformation of TCE to ethene by a Dehalococcoides culture. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:9668-9677. [PMID: 23895211 DOI: 10.1021/es400463p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Carbon (C), chlorine (Cl), and hydrogen (H) isotope effects were determined during dechlorination of TCE to ethene by a mixed Dehalococcoides (Dhc) culture. The C isotope effects for the dechlorination steps were consistent with data published in the past for reductive dechlorination (RD) by Dhc. The Cl effects (combined with an inverse H effect in TCE) suggested that dechlorination proceeded through nucleophilic reactions with cobalamin rather than by an electron transfer mechanism. Depletions of (37)Cl in daughter compounds, resulting from fractionation at positions away from the dechlorination center (secondary isotope effects), further support the nucleophilic dechlorination mechanism. Determination of C and Cl isotope ratios of the reactants and products in the reductive dechlorination chain offers a potential tool for differentiation of Dhc activity from alternative transformation mechanisms (e.g., aerobic degradation and reductive dechlorination proceeding via outer sphere mechanisms), in studies of in situ attenuation of chlorinated ethenes. Hydrogenation of the reaction products (DCE, VC, and ethene) showed a major preference for the (1)H isotope. Detection of depleted dechlorination products could provide a line of evidence in discrimination between alternative sources of TCE (e.g., evolution from DNAPL sources or from conversion of PCE).
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Affiliation(s)
- Tomasz Kuder
- School of Geology and Geophysics, University of Oklahoma , 100 E. Boyd Street, SEC 710, Norman, Oklahoma 73019, United States
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Centler F, Heße F, Thullner M. Estimating pathway-specific contributions to biodegradation in aquifers based on dual isotope analysis: theoretical analysis and reactive transport simulations. JOURNAL OF CONTAMINANT HYDROLOGY 2013; 152:97-116. [PMID: 23896520 DOI: 10.1016/j.jconhyd.2013.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 06/24/2013] [Accepted: 06/28/2013] [Indexed: 06/02/2023]
Abstract
At field sites with varying redox conditions, different redox-specific microbial degradation pathways contribute to total contaminant degradation. The identification of pathway-specific contributions to total contaminant removal is of high practical relevance, yet difficult to achieve with current methods. Current stable-isotope-fractionation-based techniques focus on the identification of dominant biodegradation pathways under constant environmental conditions. We present an approach based on dual stable isotope data to estimate the individual contributions of two redox-specific pathways. We apply this approach to carbon and hydrogen isotope data obtained from reactive transport simulations of an organic contaminant plume in a two-dimensional aquifer cross section to test the applicability of the method. To take aspects typically encountered at field sites into account, additional simulations addressed the effects of transverse mixing, diffusion-induced stable-isotope fractionation, heterogeneities in the flow field, and mixing in sampling wells on isotope-based estimates for aerobic and anaerobic pathway contributions to total contaminant biodegradation. Results confirm the general applicability of the presented estimation method which is most accurate along the plume core and less accurate towards the fringe where flow paths receive contaminant mass and associated isotope signatures from the core by transverse dispersion. The presented method complements the stable-isotope-fractionation-based analysis toolbox. At field sites with varying redox conditions, it provides a means to identify the relative importance of individual, redox-specific degradation pathways.
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Affiliation(s)
- Florian Centler
- UFZ-Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstraße 15, D-04318 Leipzig, Germany.
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Cretnik S, Thoreson KA, Bernstein A, Ebert K, Buchner D, Laskov C, Haderlein S, Shouakar-Stash O, Kliegman S, McNeill K, Elsner M. Reductive dechlorination of TCE by chemical model systems in comparison to dehalogenating bacteria: insights from dual element isotope analysis (13C/12C, 37Cl/35Cl). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6855-6863. [PMID: 23627862 DOI: 10.1021/es400107n] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Chloroethenes like trichloroethene (TCE) are prevalent environmental contaminants, which may be degraded through reductive dechlorination. Chemical models such as cobalamine (vitamin B12) and its simplified analogue cobaloxime have served to mimic microbial reductive dechlorination. To test whether in vitro and in vivo mechanisms agree, we combined carbon and chlorine isotope measurements of TCE. Degradation-associated enrichment factors ε(carbon) and ε(chlorine) (i.e., molecular-average isotope effects) were -12.2‰ ± 0.5‰ and -3.6‰ ± 0.1‰ with Geobacter lovleyi strain SZ; -9.1‰ ± 0.6‰ and -2.7‰ ± 0.6‰ with Desulfitobacterium hafniense Y51; -16.1‰ ± 0.9‰ and -4.0‰ ± 0.2‰ with the enzymatic cofactor cobalamin; -21.3‰ ± 0.5‰ and -3.5‰ ± 0.1‰ with cobaloxime. Dual element isotope slopes m = Δδ(13)C/ Δδ(37)Cl ≈ ε(carbon)/ε(chlorine) of TCE showed strong agreement between biotransformations (3.4 to 3.8) and cobalamin (3.9), but differed markedly for cobaloxime (6.1). These results (i) suggest a similar biodegradation mechanism despite different microbial strains, (ii) indicate that transformation with isolated cobalamin resembles in vivo transformation and (iii) suggest a different mechanism with cobaloxime. This model reactant should therefore be used with caution. Our results demonstrate the power of two-dimensional isotope analyses to characterize and distinguish between reaction mechanisms in whole cell experiments and in vitro model systems.
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Affiliation(s)
- Stefan Cretnik
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
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Aeppli C, Bastviken D, Andersson P, Gustafsson O. Chlorine isotope effects and composition of naturally produced organochlorines from chloroperoxidases, flavin-dependent halogenases, and in forest soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6864-6871. [PMID: 23320408 DOI: 10.1021/es3037669] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The use of stable chlorine isotopic signatures (δ(37)Cl) of organochlorine compounds has been suggested as a tool to determine both their origins and transformations in the environment. Here we investigated the δ(37)Cl fractionation of two important pathways for enzymatic natural halogenation: chlorination by chloroperoxidase (CPO) and flavin-dependent halogenases (FDH). Phenolic products of CPO were highly (37)Cl depleted (δ(37)Cl = -12.6 ± 0.9‰); significantly more depleted than all known industrially produced organochlorine compounds (δ(37)Cl = -7 to +6‰). In contrast, four FDH products did not exhibit any observable isotopic shifts (δ(37)Cl = -0.3 ± 0.6‰). We attributed the different isotopic effect to the distinctly different chlorination mechanisms employed by the two enzymes. Furthermore, the δ(37)Cl in bulk organochlorines extracted from boreal forest soils were only slightly depleted in (37)Cl relative to inorganic Cl. In contrast to previous suggestions that CPO plays a key role in production of soil organochlorines, this observation points to the additional involvement of either other chlorination pathways, or that dechlorination of naturally produced organochlorines can neutralize δ(37)Cl shifts caused by CPO chlorination. Overall, this study demonstrates that chlorine isotopic signatures are highly useful to understand sources and cycling of organochlorines in nature. Furthermore, this study presents δ(37)Cl values of FDH products as well of bulk organochlorines extracted from pristine forest soil for the first time.
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Affiliation(s)
- Christoph Aeppli
- Department of Applied Environmental Science (ITM), Stockholm University, Sweden.
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Wiegert C, Mandalakis M, Knowles T, Polymenakou PN, Aeppli C, Macháčková J, Holmstrand H, Evershed RP, Pancost RD, Gustafsson O. Carbon and chlorine isotope fractionation during microbial degradation of tetra- and trichloroethene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6449-6456. [PMID: 23668287 DOI: 10.1021/es305236y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Two-dimensional compound-specific isotope analysis (2D-CSIA), combining stable carbon and chlorine isotopes, holds potential for monitoring of natural attenuation of chlorinated ethenes (CEs) in contaminated soil and groundwater. However, interpretation of 2D-CSIA data sets is challenged by a shortage of experimental Cl isotope enrichment factors. Here, isotope enrichments factors for C and Cl (i.e., εC and εCl) were determined for biodegradation of tetrachloroethene (PCE) and trichloroethene (TCE) using microbial enrichment cultures from a heavily CE-contaminated aquifer. The obtained values were εC = -5.6 ± 0.7‰ (95% CI) and εCl = -2.0 ± 0.5‰ for PCE degradation and εC = -8.8 ± 0.2‰ and εCl = -3.5 ± 0.5‰ for TCE degradation. Combining the values for both εC and εCl yielded mechanism-diagnostic εCl/εC ratios of 0.35 ± 0.11 and 0.37 ± 0.11 for the degradation of PCE and TCE, respectively. Application of the obtained εC and εCl values to a previously investigated field site gave similar estimates for the fraction of degraded contaminant as in the previous study, but with a reduced uncertainty in assessment of the natural attenuation. Furthermore, 16S rRNA gene clone library analyses were performed on three samples from the PCE degradation experiments. A species closely related to Desulfitobacterium aromaticivorans UKTL dominated the reductive dechlorination process. This study contributes to the development of 2D-CSIA as a tool for evaluating remediation strategies of CEs at contaminated sites.
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Affiliation(s)
- Charline Wiegert
- Department of Applied Environmental Science, ITM, Stockholm University, 106 91 Stockholm, Sweden.
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