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Wang G, Guo P, Liu Y, Li C, Wang X, Wang H. Mechanistic characterization of anaerobic microbial degradation of BTBPE in coastal wetland soils: Implication by compound-specific stable isotope analysis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 335:117622. [PMID: 36867899 DOI: 10.1016/j.jenvman.2023.117622] [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: 12/24/2022] [Revised: 02/06/2023] [Accepted: 02/26/2023] [Indexed: 06/18/2023]
Abstract
As a novel brominate flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) has been extensively used in various consumer products, and frequently detected in various environmental matrices. However, the microbial degradation of BTBPE remains unclear in the environment. This study comprehensively investigated the anaerobic microbial degradation of BTBPE and therein stable carbon isotope effect in the wetland soils. BTBPE degradation followed the pseudo-first-order kinetic, with degradation rate of 0.0085 ± 0.0008 day-1. Based on identification of degradation products, stepwise reductive debromination was the main transformation pathway of BTBPE, and tended to keep the stable of 2,4,6-tribromophenoxy group during the microbial degradation. The pronounced carbon isotope fractionation was observed for BTBPE microbial degradation, and carbon isotope enrichment factor (εC) was determined to be -4.81 ± 0.37‰, indicating cleavage of C-Br bond as the rate-limiting step. Compared to previously reported isotope effects, carbon apparent kinetic isotope effect (AKIEC = 1.072 ± 0.004) suggested that the nucleophilic substitution (SN2 reaction) was the potential reaction mechanism for reductive debromination of BTBPE in the anaerobic microbial degradation. These findings demonstrated that BTBPE could be degraded by the anaerobic microbes in wetland soils, and the compound-specific stable isotope analysis was a robust method to discover the underlying reaction mechanisms.
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Affiliation(s)
- Guoguang Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China.
| | - Pengxu Guo
- 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
| | - Chuanyuan Li
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Xu Wang
- 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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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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Trueba-Santiso A, Palau J, Soder-Walz JM, Vicent T, Marco-Urrea E. Assessment of aerobic biodegradation of lower-chlorinated benzenes in contaminated groundwater using field-derived microcosms and compound-specific carbon isotope fractionation. J Environ Sci (China) 2022; 118:204-213. [PMID: 35305769 DOI: 10.1016/j.jes.2021.12.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Biodegradation of lower chlorinated benzenes (tri-, di- and monochlorobenzene) was assessed at a coastal aquifer contaminated with multiple chlorinated aromatic hydrocarbons. Field-derived microcosms, established with groundwater from the source zone and amended with a mixture of lower chlorinated benzenes, evidenced biodegradation of monochlorobenzene (MCB) and 1,4-dichlorobenzene (1,4-DCB) in aerobic microcosms, whereas the addition of lactate in anaerobic microcosms did not enhance anaerobic reductive dechlorination. Aerobic microcosms established with groundwater from the plume consumed several doses of MCB and concomitantly degraded the three isomers of dichlorobenzene with no observable inhibitory effect. In the light of these results, we assessed the applicability of compound stable isotope analysis to monitor a potential aerobic remediation treatment of MCB and 1,4-DCB in this site. The carbon isotopic fractionation factors (ε) obtained from field-derived microcosms were -0.7‰ ± 0.1 ‰ and -1.0‰ ± 0.2 ‰ for MCB and 1,4-DCB, respectively. For 1,4-DCB, the carbon isotope fractionation during aerobic biodegradation was reported for the first time. The weak carbon isotope fractionation values for the aerobic pathway would only allow tracing of in situ degradation in aquifer parts with high extent of biodegradation. However, based on the carbon isotope effects measured in this and previous studies, relatively high carbon isotope shifts (i.e., ∆δ13C > 4.0 ‰) of MCB or 1,4-DCB in contaminated groundwater would suggest that their biodegradation is controlled by anaerobic reductive dechlorination.
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Affiliation(s)
- Alba Trueba-Santiso
- Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Jordi Palau
- MAiMA group, SGR Applied Mineralogy, Geochemistry and Geomicrobiology, Department of Mineralogy, Petrology and Applied Geology, Faculty of Earth Sciences, Universitat de Barcelona (UB), Martí Franquès s/n, 08028 Barcelona, Spain
| | - Jesica M Soder-Walz
- Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Teresa Vicent
- Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Ernest Marco-Urrea
- Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain.
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4
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Wang G, Liu Y, Wang X, Dong X, Jiang N, Wang H. Application of dual carbon-bromine stable isotope analysis to characterize anaerobic micro-degradation mechanisms of PBDEs in wetland bottom-water. WATER RESEARCH 2022; 208:117854. [PMID: 34800854 DOI: 10.1016/j.watres.2021.117854] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs), one kind of persistent organic pollutants, were widely detected in coastal wetlands. Microbial reductive debromination is one of the most important attenuation processes for PBDEs in anaerobic environment, whereas the underlying reaction mechanisms remain elusive. Dual-element stable isotope analysis was recently recognized to distinguish different reaction mechanism for degradation of organic pollutants. In this study, the dual carbon-bromine isotope effects associated with the anaerobic microbial degradation were first investigated to characterize the reaction mechanisms for BDE-47 and BDE-153. Presence of lower brominated congeners indicated stepwise debromination as the main degradation pathway, with the preferential removal of bromine in para position > meta/ortho position. The pronounced isotope fractionation was observed for both carbon and bromine, with similar carbon (εC) and bromine isotope enrichment factor (εBr) between BDE-47 (εC = -5.98‰, εBr = -2.44‰) and BDE-153 (εC = -5.57‰, εBr = -2.06‰) during the microbial degradation. Compared to εC and εBr, the correlation of carbon and isotope effects (ΛC/Br = Δδ81Br/Δδ13C) was almost the same between BDE-47 (0.436) and BDE-153 (0.435), indicating the similar reaction mechanism. The calculated carbon and bromine apparent kinetic isotope effects (AKIEC and AKIEBr) were 1.0773 and 1.0098 for BDE-47 and 1.0716 and 1.0125 for BDE-153, within range reported for degradation of halogenated compounds following nucleophilic substitution. Combination analysis of degradation products, ΛC/Br and AKIE, all the results pointed to that the anaerobic reductive debromination of BDE-47 and BDE-153 followed the nucleophilic aromatic substitution, with the addition of cofactor to the benzene ring concomitant with dissociation of carbon-bromine bond via the inner-sphere electron transfer, and the cleavage of C-Br bond was the rate-determining step. This study contributed to the development of dual carbon-bromine isotope analysis as a robust approach to probe the fate of PBDEs in contaminated sites.
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Affiliation(s)
- Guoguang Wang
- 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
| | - Xu Dong
- 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
| | - Haixia Wang
- Navigation College, Dalian Maritime University, Dalian 116026, China
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Liu X, Li W, Kümmel S, Merbach I, Sood U, Gupta V, Lal R, Richnow HH. Soil from a Hexachlorocyclohexane Contaminated Field Site Inoculates Wheat in a Pot Experiment to Facilitate the Microbial Transformation of β-Hexachlorocyclohexane Examined by Compound-Specific Isotope Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:13812-13821. [PMID: 34609852 DOI: 10.1021/acs.est.1c03322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
β-Hexachlorocyclohexane (β-HCH) is a remnant from former HCH pesticide production. Its removal from the environment gained attention in the last few years since it is the most stable HCH isomer. However, knowledge about the transformation of β-HCH in soil-plant systems is still limited. Therefore, experiments with a contaminated field soil were conducted to investigate the transformation of β-HCH in soil-plant systems by compound specific isotope analysis (CSIA). The results showed that the δ13C and δ37Cl values of β-HCH in the soil of the planted control remained stable, revealing no transformation due to a low bioavailability. Remarkably, an increase of the δ13C and δ37Cl values in soil and plant tissues of the spiked treatments were observed, indicating the transformation of β-HCH in both the soil and the plant. This was surprising as previously it was shown that wheat is unable to transform β-HCH when growing in hydroponic culture or garden soil. Thus, results of this work indicate for the first time that a microbial community of the soil inoculated the wheat and then facilitated the transformation of β-HCH in the wheat, which may have implications for the development of phytoremediation concepts. A high abundance of HCH degraders belonging to Sphingomonas sp., Mycobacterium sp., and others was detected in the β-HCH-treated bulk and rhizosphere soil, potentially supporting the biotransformation.
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Affiliation(s)
- Xiao Liu
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Wang Li
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
- Institute for Applied Geosciences, Technical University Darmstadt, Schnittspahnstraße 9, 64287 Darmstadt, Germany
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Ines Merbach
- Department of Community Ecology, Helmholtz Centre for Environmental Research GmbH - UFZ, Theodor-Lieser-Str. 4, 06102 Halle, Germany
| | - Utkarsh Sood
- The Energy and Resources Institute, Lodhi Road, New Delhi 110003, India
| | - Vipin Gupta
- PhiXGen Private Limited, Gurugram, Haryana 122001, India
| | - Rup Lal
- The Energy and Resources Institute, Lodhi Road, New Delhi 110003, India
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
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Halloran LJS, Vakili F, Wanner P, Shouakar-Stash O, Hunkeler D. Sorption- and diffusion-induced isotopic fractionation in chloroethenes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 788:147826. [PMID: 34134359 DOI: 10.1016/j.scitotenv.2021.147826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 06/12/2023]
Abstract
Isotopic fractionation of groundwater contaminants can occur due to degradation, diffusion and sorption. Of these, only degradation has been extensively explored, yet diffusive isotopic fractionation (DIF) and sorptive isotopic fractionation (SIF) can have significant effects on the isotopic enrichment of groundwater contaminants. Understanding how to mathematically describe and model these processes is vital to the correct interpretation of compound-specific isotope analysis (CSIA) data in the field. Here, models for these physical fractionation processes are developed and described, including the definition of a sorption enrichment factor. These models are then implemented numerically using inverse and finite-element methods to investigate two scenarios, diffusion-sorption and diffusion-sorption-advection, that have been measured in the laboratory. Concentration, δ37Cl, and δ2H data from cis-dichloroethene (cDCE) and trichloroethene (TCE) are used as inputs to the models. Unknown transport parameters including diffusive fractionation exponents are determined from an inverse modelling approach. DIF is shown to have a stronger influence on chlorine isotopologues than on hydrogen isotopologues. For both cDCE and TCE, the sorption enrichment factor of chlorine is found to be negative while that of hydrogen is positive. The presented approach and results provide novel tools and insight into DIF and SIF and underline that these processes should be taken into account when using CSIA to assess contaminant fate.
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Affiliation(s)
- Landon J S Halloran
- Centre d'hydrogéologie et de géothermie (CHYN), Université de Neuchâtel, Neuchâtel, Switzerland.
| | - Fatemeh Vakili
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Philipp Wanner
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Orfan Shouakar-Stash
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada; Isotope Tracer Technologies Inc., Waterloo, Ontario, Canada
| | - Daniel Hunkeler
- Centre d'hydrogéologie et de géothermie (CHYN), Université de Neuchâtel, Neuchâtel, Switzerland
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Feng JR, Ni HG. A modified method to calculate dual-isotope slopes for the natural attenuation of organic pollutants in the environment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:30399-30408. [PMID: 33963995 DOI: 10.1007/s11356-021-14313-7] [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: 01/11/2021] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
Two-dimensional compound-specific isotope analysis has become a powerful tool for distinguishing reaction mechanisms. Lambda (Λ), an essential and important parameter for processing two-dimensional isotope fractionation data, exhibits values specific to a reaction mechanism. In the present article, we modified the existing algorithms for calculation of lambdas based on a review of current methods. Specifically, by regressing [(1000+δE0,2)*(n1*x2)*ΔδEbulk,1] versus [(1000+δE0,1)*(n2*x1)*ΔδEbulk,2] by the York method, a novel method was developed to calculate Λs. The improved method eliminates both the influence of the nonreacting position and the initial isotope signatures. Furthermore, this method retains the advantages of a two-dimensional isotope plot, which eliminates contributions from commitment to catalysis, does not require determination of the fraction of remaining substrate, and can be constructed even from field data. Additionally, the one-sample t test is applied to generate a 95% confidence interval of the dataset of Λris for various reaction mechanisms. The ranges of 5.67-24.8, 8.54-9.80, 0.51-8.35, 25.2-36.8, and 7.09-21.9 are applicable for the oxidation of C-H bonds (ZC=1, ZH=3; ZC and ZH are the number of indistinguishable carbon and hydrogen atoms in intramolecular competition, respectively), oxidation of C-H bonds (ZC=1, ZH=4), aerobic biodegradation of benzene (ZC=6, ZH=6), methanogenic or sulfate-reducing biodegradation of benzene (ZC=6, ZH=6), and nitrate-reducing biodegradation of benzene (ZC=6, ZH=6). The accumulation and correction of these values will make the data measured in the field easier to interpret.
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Affiliation(s)
- Jin-Ru Feng
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, 518055, People's Republic of China
| | - Hong-Gang Ni
- School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, 518055, People's Republic of China.
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Walaszek M, Cary L, Billon G, Blessing M, Bouvet-Swialkowski A, George M, Criquet J, Mossmann JR. Dynamics of chlorinated aliphatic hydrocarbons in the Chalk aquifer of northern France. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143742. [PMID: 33221002 DOI: 10.1016/j.scitotenv.2020.143742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 06/11/2023]
Abstract
The Chalk aquifer used for drinking-water production in the southwest of the Lille European Metropolis is threatened by the presence of chlorinated aliphatic hydrocarbons (CHCs), their concentrations in groundwater regularly exceeding the regulatory limits for drinking water in France. This hinders its use for drinking-water production. Understanding the dynamics and spatial distribution of CHC in the aquifer is a key factor for resource sustainability. For that purpose, an intensive monitoring was undertaken in several well fields and at different depths over eight years. To assess a possible migration and/or degradation of the compounds, the water column in several wells was sampled at various depths with passive samplers. Furthermore, CHC degradation mechanisms were investigated with compound-specific carbon-isotope analysis. The CHC concentrations and their distributions in the area depend on past and current industrial activity, causing plumes emphasized by pumping in the wells, such plumes being multi-source with no identified origin in most wells. In the south area of Les Ansereuilles, reductive dechlorination of tetrachloroethylene from a former industrial laundry highly impacted the surrounding area with its main degradation product cis-1,2-dichloroethylene. The same area is also affected by tetrachlroroethylene from several industrial laundries, textile factories and dyeing industries with also an anaerobic degradation. In the northern part of Les Ansereuilles, tetrachloroethylene, trichloroethane, trichloroethylene and 1,1-dichloroethylene were found as primary products, whereas cis-1,2-dichloroethylene appears to be an anaerobic degradation product of TCE. The other well fields (Houplin-Ancoisne, Seclin and Emmerin) are less impacted by CHC pollution, and it was shown that no CHC degradation occurred in the wells. However, the stratification of CHCs in the well-water columns, their constant concentration values over time caused by the large amount of available CHCs, and the minor degradation occurring in wells are of concern for water operators in the future.
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Affiliation(s)
- Milena Walaszek
- Univ. Lille CNRS, UMR 8516 - LASIRE, Equipe Physico-Chimie de l'Environnement, Lille F-59000, France; BRGM (French Geological Survey), 59810 Lesquin, France
| | - Lise Cary
- BRGM (French Geological Survey), 59810 Lesquin, France.
| | - Gabriel Billon
- Univ. Lille CNRS, UMR 8516 - LASIRE, Equipe Physico-Chimie de l'Environnement, Lille F-59000, France
| | | | | | - Melinda George
- Univ. Lille CNRS, UMR 8516 - LASIRE, Equipe Physico-Chimie de l'Environnement, Lille F-59000, France
| | - Justine Criquet
- Univ. Lille CNRS, UMR 8516 - LASIRE, Equipe Physico-Chimie de l'Environnement, Lille F-59000, France
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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: 5] [Impact Index Per Article: 1.3] [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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Wang X, Xin J, Yuan M, Zhao F. Electron competition and electron selectivity in abiotic, biotic, and coupled systems for dechlorinating chlorinated aliphatic hydrocarbons in groundwater: A review. WATER RESEARCH 2020; 183:116060. [PMID: 32750534 DOI: 10.1016/j.watres.2020.116060] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 06/01/2020] [Accepted: 06/13/2020] [Indexed: 06/11/2023]
Abstract
Chlorinated aliphatic hydrocarbons (CAHs) have been frequently detected in aquifers in recent years. Owing to the bioaccumulation and toxicity of CAHs, it is essential to explore high-efficiency technologies for their complete dechlorination in groundwater. At present, the most widely used abiotic and biotic remediation technologies are based on zero-valent iron (ZVI) and functional anaerobic bacteria (FAB), respectively. However, the main obstacles to the full potential of both technologies in the field include their lowered efficiencies and increased economic costs due to the co-existence of a variety of natural electron acceptors in the environment, such as dissolved oxygen (DO), nitrate (NO3-), sulfate (SO42-), ferric iron (Fe (III)), bicarbonate (HCO3-), and even water, which compete for electrons with the target contaminants. Therefore, a clear understanding of the mechanisms governing electron competition and electron selectivity is significant for the accurate evaluation of the effectiveness of both technologies under natural hydrochemical conditions. We collected data from both abiotic and biotic CAH-remediation systems, summarized the dechlorination and undesired reactions in groundwater, discussed the characterization methods and general principles of electron competition, and described strategies to improve electron selectivity in both systems. Furthermore, we reviewed the emerging ZVI-FAB coupled system, which integrates abiotic and biotic processes to enhance dechlorination performance and electron utilization efficiency. Lastly, we propose future research needs to quantitatively understand the electron competition in abiotic, biotic, and coupled systems in more detail and to promote improved electron selectivity in groundwater remediation.
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Affiliation(s)
- Xiaohui Wang
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Jia Xin
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
| | - Mengjiao Yuan
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Fang Zhao
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
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11
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Halloran LJS, Hunkeler D. Controls on the persistence of aqueous-phase groundwater contaminants in the presence of reactive back-diffusion. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 722:137749. [PMID: 32213436 DOI: 10.1016/j.scitotenv.2020.137749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 06/10/2023]
Abstract
The persistence of groundwater contaminants is influenced by several interacting processes. Physical, physico-chemical, and (bio-)chemical processes all influence the transport of contaminants in the subsurface. However, for a given hydrogeological system, it is generally unclear to which degree each of these phenomena acts as a control on plume behaviour. Here, we present a comprehensive investigation of these processes and their influences on plume behaviour and persistence in layered sedimentary systems. We investigate different scenarios that represent fundamental configurations of common contaminant situations. A confined aquifer over- and underlain by aquitard layers is investigated in a source-removal scenario and a constant-source equilibrium scenario. Additionally, an aquitard overlain and underlain by high permeability units is investigated in a source-removal scenario. In these investigations, we vary layer thickness, as well as parameters governing advection, (back-)diffusion, sorption, and degradation. Extensive analysis of these results enables quantification of the influence of these parameters on maximum down-gradient concentration, plume persistence duration, and plume spatial extent. Finally, parameter space dimensionality reduction is used to establish trends and regimes in which certain processes dominate as controls. A lower limit to plume extent as a function of a novel constructed parameter is also determined. These results provide valuable quantitative information for the assessment of the fate of groundwater contaminants and are applicable to a wide range of aqueous-phase solutes.
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Affiliation(s)
- Landon J S Halloran
- Centre d'Hydrogéologie et de Géothermie (CHYN), Université de Neuchâtel, Switzerland.
| | - Daniel Hunkeler
- Centre d'Hydrogéologie et de Géothermie (CHYN), Université de Neuchâtel, Switzerland
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12
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Liu Y, Liu J, Renpenning J, Nijenhuis I, Richnow HH. Dual C-Cl Isotope Analysis for Characterizing the Reductive Dechlorination of α- and γ-Hexachlorocyclohexane by Two Dehalococcoides mccartyi Strains and an Enrichment Culture. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:7250-7260. [PMID: 32441516 DOI: 10.1021/acs.est.9b06407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Hexachlorocyclohexanes (HCHs) are persistent organic contaminants that threaten human health. Microbial reductive dehalogenation is one of the most important attenuation processes in contaminated environments. This study investigated carbon and chlorine isotope fractionation of α- and γ-HCH during the reductive dehalogenation by three anaerobic cultures. The presence of tetrachlorocyclohexene (TeCCH) indicated that reductive dichloroelimination was the first step of bond cleavage. Isotope enrichment factors (εC and εCl) were derived from the transformation of γ-HCH (εC, from -4.0 ± 0.5 to -4.4 ± 0.6 ‰; εCl, from -2.9 ± 0.4 to -3.3 ± 0.4 ‰) and α-HCH (εC, from -2.4 ± 0.2 to -3.0 ± 0.4 ‰; εCl, from -1.4 ± 0.3 to -1.8 ± 0.2 ‰). During α-HCH transformation, no enantioselectivity was observed, and similar εc values were obtained for both enantiomers. The correlation of 13C and 37Cl fractionation (Λ = Δδ13C/Δδ37Cl ≈ εC/εCl) of γ-HCH (from 1.1 ± 0.3 to 1.2 ± 0.1) indicates similar bond cleavage during the reductive dichloroelimination by the three cultures, similar to α-HCH (1.7 ± 0.2 to 2.0 ± 0.3). The different isotope fractionation patterns during reductive dichloroelimination and dehydrochlorination indicates that dual-element stable isotope analysis can potentially be used to evaluate HCH transformation pathways at contaminated field sites.
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Affiliation(s)
- Yaqing Liu
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, Leipzig 04318, Germany
| | - Jia Liu
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, Leipzig 04318, Germany
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Haidian District, Beijing 100083, PR China
| | - Julian Renpenning
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, Leipzig 04318, Germany
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, Leipzig 04318, Germany
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, Leipzig 04318, Germany
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13
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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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14
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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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15
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Ojeda AS, Phillips E, Sherwood Lollar B. Multi-element (C, H, Cl, Br) stable isotope fractionation as a tool to investigate transformation processes for halogenated hydrocarbons. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:567-582. [PMID: 31993605 DOI: 10.1039/c9em00498j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Compound-specific isotope analysis (CSIA) is a powerful tool to evaluate transformation processes of halogenated compounds. Many halogenated hydrocarbons allow for multiple stable isotopic systems (C, H, Cl, Br) to be measured for a single compound. This has led to a large body of literature describing abiotic and biotic transformation pathways and reaction mechanisms for contaminants such as chlorinated alkenes and alkanes as well as brominated hydrocarbons. Here, the current literature is reviewed and a new compilation of Λ values for multi-isotopic systems for halogenated hydrocarbons is presented. Case studies of each compound class are discussed and thereby the current strengths of multi-element isotope analysis, continuing challenges, and gaps in our current knowledge are identified for practitioners of multi-element CSIA to address in the near future.
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Affiliation(s)
- Ann Sullivan Ojeda
- Department of Geosciences, Auburn University, Auburn, Alabama 36849, USA.
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16
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Büsing J, Buchner D, Behrens S, Haderlein SB. Deciphering the Variability of Stable Isotope (C, Cl) Fractionation of Tetrachloroethene Biotransformation by Desulfitobacterium strains Carrying Different Reductive Dehalogenases Enzymes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1593-1602. [PMID: 31880148 DOI: 10.1021/acs.est.9b05606] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Kinetic isotope effects have been used successfully to prove and characterize organic contaminant transformation on various scales including field and laboratory studies. For tetrachloroethene (PCE) biotransformation, however, causes for the substantial variability of reported isotope enrichment factors (ε) are still not deciphered (εC = -0.4 to -19.0‰). Factors such as different reaction mechanisms and masking of isotope fractionation by either limited intracellular mass transfer or rate-limitations within the enzymatic multistep reaction are under discussion. This study evaluated the contribution of these factors to the magnitude of carbon and chlorine isotope fractionation of Desulfitobacterium strains harboring three different PCE-transforming enzymes (PCE-RdhA). Despite variable single element isotope fractionation (εC = -5.0 to -19.7‰; εCl = -1.9 to -6.3‰), similar slopes of dual element isotope plots (ΛC/Cl values of 2.4 ± 0.1 to 3.6 ± 0.1) suggest a common reaction mechanism for different PCE-RdhAs. Cell envelope properties of the Desulfitobacterium strains allowed to exclude masking effects due to PCE mass transfer limitation. Our results thus revealed that different rate-limiting steps (e.g., substrate channel diffusion) in the enzymatic multistep reactions of individual PCE-RdhAs rather than different reaction mechanisms determine the extent of PCE isotope fractionation in the Desulfitobacterium genus.
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Affiliation(s)
- Johannes Büsing
- Center for Applied Geoscience , University of Tübingen , 72074 Tübingen , Germany
| | - Daniel Buchner
- Center for Applied Geoscience , University of Tübingen , 72074 Tübingen , Germany
| | - Sebastian Behrens
- Department of Civil, Environmental, and Geo-Engineering , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Stefan B Haderlein
- Center for Applied Geoscience , University of Tübingen , 72074 Tübingen , Germany
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17
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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: 1] [Impact Index Per Article: 0.2] [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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18
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Wanner P, Aravena R, Fernandes J, BenIsrael M, Haack EA, Tsao DT, Dunfield KE, Parker BL. Assessing toluene biodegradation under temporally varying redox conditions in a fractured bedrock aquifer using stable isotope methods. WATER RESEARCH 2019; 165:114986. [PMID: 31446293 DOI: 10.1016/j.watres.2019.114986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/09/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
In complex hydrogeological settings little is known about the extent of temporally varying redox conditions and their effect on aromatic hydrocarbon biodegradation. This study aims to assess the impact of changing redox conditions over time on aromatic hydrocarbon biodegradation in a fractured bedrock aquifer using stable isotope methods. To that end, four snapshots of highly spatio-temporally resolved contaminant and redox sensitive species concentrations, as well as stable isotope ratio profiles, were determined over a two-years time period in summer 2016, spring 2017, fall 2017 and summer 2018 in a toluene contaminated fractured bedrock aquifer. The concentration profiles of redox sensitive species and stable isotope ratio profiles for dissolved inorganic carbon (DIC) and sulfate (δ13CDIC, δ34SSO4, δ18OSO4) revealed that the aquifer alternates between oxidising (spring 2017/summer 2018) and reducing conditions (summer 2016/fall 2017). This alternation was attributed to a stronger aquifer recharge with oxygen-rich meltwater in spring 2017/summer 2018 compared to summer 2016/fall 2017. The temporally varying redox conditions coincided with various extents of toluene biodegradation revealed by the different magnitude of heavy carbon (13C) and hydrogen (2H) isotope enrichment in toluene. This indicated that the extent of toluene biodegradation and its contribution to plume attenuation was controlled by the temporally changing redox conditions. The highest toluene biodegradation was observed in summer 2016, followed by spring 2017 and fall 2017, whereby these temporal changes in biodegradation occurred throughout the whole plume. Thus, under temporally varying recharge conditions both the core and the fringe of a contaminant plume can be replenished with terminal electron acceptors causing biodegradation in the whole plume and not only at its distal end as previously suggested by the plume fringe concept. Overall, this study highlights the importance of highly temporally resolved groundwater monitoring to capture temporally varying biodegradation rates and to accurately predict biodegradation-induced contaminant attenuation in fractured bedrock aquifers.
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Affiliation(s)
- Philipp Wanner
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada.
| | - Ramon Aravena
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada; Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Jeremy Fernandes
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Michael BenIsrael
- School of Environmental Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Elizabeth A Haack
- EcoMetrix Inc., 6800 Campobello Road, Mississauga, Ontario, L5N 2L8, Canada
| | - David T Tsao
- BP Corporation North America Inc, Naperville, USA
| | - Kari E Dunfield
- School of Environmental Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Beth L Parker
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
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19
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Lihl C, Renpenning J, Kümmel S, Gelman F, Schürner HKV, Daubmeier M, Heckel B, Melsbach A, Bernstein A, Shouakar-Stash O, Gehre M, Elsner M. Toward Improved Accuracy in Chlorine Isotope Analysis: Synthesis Routes for In-House Standards and Characterization via Complementary Mass Spectrometry Methods. Anal Chem 2019; 91:12290-12297. [DOI: 10.1021/acs.analchem.9b02463] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christina Lihl
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Julian Renpenning
- 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
| | - Faina Gelman
- Geological Survey of Israel, 32 Yeshayahu Leibowitz Street, 9692100 Jerusalem, Israel
| | - Heide K. V. Schürner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Martina Daubmeier
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Benjamin Heckel
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistraße 17, 81377 München, Germany
| | - Aileen Melsbach
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Anat Bernstein
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, 84990 Sede Boqer, Israel
| | - Orfan Shouakar-Stash
- Department of Earth Sciences, University of Waterloo, 200 University Avenue, Waterloo, Ontario, Canada N2L 3G1
| | - Matthias Gehre
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research − UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistraße 17, 81377 München, Germany
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20
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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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21
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Lihl C, Douglas LM, Franke S, Pérez-de-Mora A, Meyer AH, Daubmeier M, Edwards EA, Nijenhuis I, Sherwood Lollar B, Elsner M. Mechanistic Dichotomy in Bacterial Trichloroethene Dechlorination Revealed by Carbon and Chlorine Isotope Effects. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4245-4254. [PMID: 30857389 DOI: 10.1021/acs.est.8b06643] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Tetrachloroethene (PCE) and trichloroethene (TCE) are significant groundwater contaminants. Microbial reductive dehalogenation at contaminated sites can produce nontoxic ethene but often stops at toxic cis-1,2-dichloroethene ( cis-DCE) or vinyl chloride (VC). The magnitude of carbon relative to chlorine isotope effects (as expressed by ΛC/Cl, the slope of δ13C versus δ37Cl regressions) was recently recognized to reveal different reduction mechanisms with vitamin B12 as a model reactant for reductive dehalogenase activity. Large ΛC/Cl values for cis-DCE reflected cob(I)alamin addition followed by protonation, whereas smaller ΛC/Cl values for PCE evidenced cob(I)alamin addition followed by Cl- elimination. This study addressed dehalogenation in actual microorganisms and observed identical large ΛC/Cl values for cis-DCE (ΛC/Cl = 10.0 to 17.8) that contrasted with identical smaller ΛC/Cl for TCE and PCE (ΛC/Cl = 2.3 to 3.8). For TCE, the trend of small ΛC/Cl could even be reversed when mixed cultures were precultivated on VC or DCEs and subsequently confronted with TCE (ΛC/Cl = 9.0 to 18.2). This observation provides explicit evidence that substrate adaptation must have selected for reductive dehalogenases with different mechanistic motifs. The patterns of ΛC/Cl are consistent with practically all studies published to date, while the difference in reaction mechanisms offers a potential answer to the long-standing question of why bioremediation frequently stalls at cis-DCE.
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Affiliation(s)
- Christina Lihl
- Institute of Groundwater Ecology , Helmholtz Zentrum München , Ingolstädter Landstrasse 1 , 85764 Neuherberg , Germany
| | - Lisa M Douglas
- Department of Earth Sciences , University of Toronto , Toronto , Ontario M5S 3B5 , Canada
| | - Steffi Franke
- Department for Isotope Biogeochemistry , Helmholtz-Centre for Environmental Research, UFZ , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Alfredo Pérez-de-Mora
- Institute of Groundwater Ecology , Helmholtz Zentrum München , Ingolstädter Landstrasse 1 , 85764 Neuherberg , Germany
| | - Armin H Meyer
- Institute of Groundwater Ecology , Helmholtz Zentrum München , Ingolstädter Landstrasse 1 , 85764 Neuherberg , Germany
| | - Martina Daubmeier
- Institute of Groundwater Ecology , Helmholtz Zentrum München , Ingolstädter Landstrasse 1 , 85764 Neuherberg , Germany
| | - Elizabeth A Edwards
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , Toronto , Ontario M5S 3E5 , Canada
| | - Ivonne Nijenhuis
- Department for Isotope Biogeochemistry , Helmholtz-Centre for Environmental Research, UFZ , Permoserstrasse 15 , 04318 Leipzig , Germany
| | | | - Martin Elsner
- Institute of Groundwater Ecology , Helmholtz Zentrum München , Ingolstädter Landstrasse 1 , 85764 Neuherberg , Germany
- Chair of Analytical Chemistry and Water Chemistry , Technical University of Munich , Marchioninistrasse 17 , 81377 Munich , Germany
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22
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Heckel B, Phillips E, Edwards E, Sherwood Lollar B, Elsner M, Manefield MJ, Lee M. Reductive Dehalogenation of Trichloromethane by Two Different Dehalobacter restrictus Strains Reveal Opposing Dual Element Isotope Effects. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2332-2343. [PMID: 30726673 DOI: 10.1021/acs.est.8b03717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Trichloromethane (TCM) is a frequently detected and persistent groundwater contaminant. Recent studies have reported that two closely related Dehalobacter strains (UNSWDHB and CF) transform TCM to dichloromethane, with inconsistent carbon isotope effects (ε13CUNSWDHB = -4.3 ± 0.45‰; ε13CCF = -27.5 ± 0.9‰). This study uses dual element compound specific isotope analysis (C; Cl) to explore the underlying differences. TCM transformation experiments using strain CF revealed pronounced normal carbon and chlorine isotope effects (ε13CCF = -27.9 ± 1.7‰; ε37ClCF = -4.2 ± 0.2‰). In contrast, small carbon and unprecedented inverse chlorine isotope effects were observed for strain UNSWDHB (ε13CUNSWDHB = -3.1 ± 0.5‰; ε37ClUNSWDHB = 2.5 ± 0.3‰) leading to opposing dual element isotope slopes (λCF = 6.64 ± 0.14 vs λUNSWDHB = -1.20 ± 0.18). Isotope effects of strain CF were identical to experiments with TCM and Vitamin B12 (ε13CVitamin B12 = -26.0 ± 0.9‰, ε37ClVitamin B12 = -4.0 ± 0.2‰, λVitamin B12 = 6.46 ± 0.20). Comparison to previously reported isotope effects suggests outer-sphere-single-electron transfer or SN2 as possible underlying mechanisms. Cell suspension and cell free extract experiments with strain UNSWDHB were both unable to unmask the intrinsic KIE of the reductive dehalogenase (TmrA) suggesting that enzyme binding and/or mass-transfer into the periplasm were rate-limiting. Nondirected intermolecular interactions of TCM with cellular material were ruled out as reason for the inverse isotope effect by gas/water and gas/hexadecane partitioning experiments indicating specific, yet uncharacterized interactions must be operating prior to catalysis.
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Affiliation(s)
- Benjamin Heckel
- Institute of Groundwater Ecology , Helmholtz Zentrum München , Ingolstädter Landstr. 1 , 85764 Neuherberg , Germany
- Chair of Analytical Chemistry and Water Chemistry , Technical University of Munich , Marchioninistrasse 17 , D-81377 Munich , Germany
| | - Elizabeth Phillips
- Department of Earth Sciences 22 Russell St , University of Toronto , Toronto Ontario M5S 3B1 , Canada
| | - Elizabeth Edwards
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , Toronto , Ontario M5S 3E5 , Canada
| | - Barbara Sherwood Lollar
- Department of Earth Sciences 22 Russell St , University of Toronto , Toronto Ontario M5S 3B1 , Canada
| | - Martin Elsner
- Institute of Groundwater Ecology , Helmholtz Zentrum München , Ingolstädter Landstr. 1 , 85764 Neuherberg , Germany
- Chair of Analytical Chemistry and Water Chemistry , Technical University of Munich , Marchioninistrasse 17 , D-81377 Munich , Germany
| | - Michael J Manefield
- School of Civil and Environmental Engineering, Water Research Centre (WRC) , University of New South Wales , Sydney , New South Wales 2052 , Australia
| | - Matthew Lee
- School of Civil and Environmental Engineering, Water Research Centre (WRC) , University of New South Wales , Sydney , New South Wales 2052 , Australia
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23
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Wanner P, Hunkeler D. Isotope fractionation due to aqueous phase diffusion - What do diffusion models and experiments tell? - A review. CHEMOSPHERE 2019; 219:1032-1043. [PMID: 30682760 DOI: 10.1016/j.chemosphere.2018.12.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/30/2018] [Accepted: 12/05/2018] [Indexed: 05/26/2023]
Abstract
For the interpretation of stable isotope ratio trends in saturated geochemical systems, the magnitude of aqueous phase diffusion-induced isotope fractionation needs to be known. This study reviews how five diffusion models (Fick, Maxwell-Stefan, Einstein, Langevin, Mode-Coupling Theory Analysis (MCTA) of diffusion) predict isotope fractionation due to aqueous phase diffusion and compares them with experimental results. The reviewed diffusion models were not consistent regarding the prediction of the mass (m) dependency of the aqueous phase diffusion coefficient (D). The predictions range from a square root power law (D ∝ m-0.5) to an opposite mass dependency of D (D ∝ mβ). Experimental studies exhibited consistently a weak power law mass dependency of the diffusion coefficient (D ∝ m-β with β < 0.5) for the vast majority of dissolved species and a larger diffusion-induced isotope effect for low weight noble gases (D ∝ m-0.5). The weak power law mass dependency of D for the species other than low weight noble gases is consistent with the MCTA of diffusion. The MCTA suggests that the weak power law mass dependency of D originates from interplays between strongly mass dependent short-term and mass independent long-term solute-solvent interactions. The larger isotope fractionation for low weight noble gases could be attributed to quantum isotope effects significantly magnifying the aqueous phase diffusion-induced isotope fractionation. Our review shows, that except for low weight noble gases a weak power law mass dependency of D is likely the most adequate assumption for aqueous phase diffusion-induced isotope fractionation in geochemical systems.
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Affiliation(s)
- Philipp Wanner
- College of Engineering and Physical Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada.
| | - Daniel Hunkeler
- Centre for Hydrogeology & Geothermics (CHYN), University of Neuchâtel, Rue Emil Argand 11, CH-2000, Neuchâtel, Switzerland
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24
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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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25
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Badin A, Braun F, Halloran LJS, Maillard J, Hunkeler D. Modelling of C/Cl isotopic behaviour during chloroethene biotic reductive dechlorination: Capabilities and limitations of simplified and comprehensive models. PLoS One 2018; 13:e0202416. [PMID: 30133496 PMCID: PMC6104987 DOI: 10.1371/journal.pone.0202416] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 08/02/2018] [Indexed: 11/30/2022] Open
Abstract
Predicting the fate of chloroethenes in groundwater is essential when evaluating remediation strategies. Such predictions are expected to be more accurate when incorporating isotopic parameters. Although secondary chlorine isotope effects have been observed during reductive dechlorination of chloroethenes, development of modelling frameworks and simulation has thus far been limited. We have developed a novel mathematical framework to simulate the C/Cl isotopic fractionation during reductive dechlorination of chloroethenes. This framework differs from the existing state of the art by incorporating secondary isotopic effects and considering both C and Cl isotopes simultaneously. A comprehensive general model (GM), which is expected to be the closest representation of reality thus far investigated, was implemented. A less computationally intensive simplified model (SM), with the potential for use in modelling of complex reactive transport scenarios, was subsequently validated based on its comparison to GM. The approach of GM considers all isotopocules (i.e. molecules differing in number and position of heavy and light isotopes) of each chloroethene as individual species, of which each is degraded at a different rate. Both models GM and SM simulated plausible C/Cl isotopic compositions of tetrachloroethene (PCE), trichloroethene (TCE) and cis-1,2-dichloroethene (cDCE) during sequential dechlorination when using experimentally relevant kinetic and isotopic parameters. The only major difference occurred in the case where different secondary isotopic effects occur at the different non-reacting positions when PCE is dechlorinated down to cDCE. This observed discrepancy stems from the unequal Cl isotope distribution in TCE that arises due to the occurrence of differential secondary Cl isotopic effects during transformation of PCE to TCE. Additionally, these models are shown to accurately reproduce experimental data obtained during reductive dechlorination by bacterial enrichments harbouring Sulfurospirillum spp. where secondary isotope effects are known to have occurred. These findings underscore a promising future for the development of reactive transport models that incorporate isotopic parameters.
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Affiliation(s)
- Alice Badin
- University of Neuchâtel, Centre for Hydrogeology & Geothermics (CHYN), Neuchâtel, Switzerland
| | - Fabian Braun
- Swiss Center for Electronics and Microtechnology (CSEM), Systems Division, Neuchâtel, Switzerland
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Signal Processing Laboratory (LTS5), Lausanne, Switzerland
| | - Landon J. S. Halloran
- University of Neuchâtel, Centre for Hydrogeology & Geothermics (CHYN), Neuchâtel, Switzerland
- * E-mail: (LJSH); (DH)
| | - Julien Maillard
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Environmental Biotechnology, Lausanne, Switzerland
| | - Daniel Hunkeler
- University of Neuchâtel, Centre for Hydrogeology & Geothermics (CHYN), Neuchâtel, Switzerland
- * E-mail: (LJSH); (DH)
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26
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Wanner P, Parker BL, Chapman SW, Lima G, Gilmore A, Mack EE, Aravena R. Identification of Degradation Pathways of Chlorohydrocarbons in Saturated Low-Permeability Sediments Using Compound-Specific Isotope Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:7296-7306. [PMID: 29865795 DOI: 10.1021/acs.est.8b01173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This study aims to investigate whether compound-specific carbon isotope analysis (CSIA) can be used to differentiate the degradation pathways of chlorohydrocarbons in saturated low-permeability sediments. For that purpose, a site was selected, where a complex mixture of chlorohydrocarbons contaminated an aquifer-aquitard system. Almost 50 years after contaminant releases, high-resolution concentration, CSIA, and microbial profiles were determined. The CSIA profiles showed that in the aquitard cis-dichloroethene (cDCE), first considered as a degradation product of trichloroethene (TCE), is produced by the dichloroelimination of 1,1,2,2-tetrachloroethane (TeCA). In contrast, TeCA degrades to TCE via dehydrohalogenation in the aquifer, indicating that the aquifer-aquitard interface separates two different degradation pathways for TeCA. Moreover, the CSIA profiles showed that chloroform (CF) is degraded to dichloromethane (DCM) via hydrogenolysis in the aquitard and, to a minor degree, produced by the degradation of carbon tetrachloride (CT). Several microorganisms capable of degrading chlorohydrocarbons were detected in the aquitard, suggesting that aquitard degradation is microbially mediated. Furthermore, numerical simulations reproduced the aquitard concentration and CSIA profiles well, which allowed the determination of degradation rates for each transformation pathway. This improves the prediction of contaminant fate in the aquitard and potential magnitude of impacts on the adjacent aquifer due to back-diffusion.
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Affiliation(s)
- Philipp Wanner
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences , University of Guelph , 50 Stone Road East , Guelph , Ontario , Canada N1G 2W1
| | - Beth L Parker
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences , University of Guelph , 50 Stone Road East , Guelph , Ontario , Canada N1G 2W1
| | - Steven W Chapman
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences , University of Guelph , 50 Stone Road East , Guelph , Ontario , Canada N1G 2W1
| | - Glaucia Lima
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences , University of Guelph , 50 Stone Road East , Guelph , Ontario , Canada N1G 2W1
- Department of Civil Engineering , University of Toronto , 35 Saint George Street , Toronto , Ontario , Canada , M5S 1A4
| | - Adam Gilmore
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences , University of Guelph , 50 Stone Road East , Guelph , Ontario , Canada N1G 2W1
- Regional Municipality of Halton , 1151 Bronte Road , Oakville , Ontario , Canada L6M 3L1
| | - E Erin Mack
- DuPont , 974 Centre Road , Wilmington , Delaware 19805 , United States
| | - Ramon Aravena
- G360 Institute for Groundwater Research, College of Engineering and Physical Sciences , University of Guelph , 50 Stone Road East , Guelph , Ontario , Canada N1G 2W1
- Department of Earth and Environmental Sciences , University of Waterloo , 200 University Avenue West , Waterloo , Ontario , Canada N2L 3GI
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27
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Rodríguez-Fernández D, Torrentó C, Guivernau M, Viñas M, Hunkeler D, Soler A, Domènech C, Rosell M. Vitamin B 12 effects on chlorinated methanes-degrading microcosms: Dual isotope and metabolically active microbial populations assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:1615-1625. [PMID: 29054650 DOI: 10.1016/j.scitotenv.2017.10.067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 09/21/2017] [Accepted: 10/08/2017] [Indexed: 06/07/2023]
Abstract
Field-derived anoxic microcosms were used to characterize chloroform (CF) and carbon tetrachloride (CT) natural attenuation to compare it with biostimulation scenarios in which vitamin B12 was added (B12/pollutant ratio of 0.01 and 0.1) by means of by-products, carbon and chlorine compound-specific stable-isotope analysis, and the active microbial community through 16S rRNA MiSeq high-throughput sequencing. Autoclaved slurry controls discarded abiotic degradation processes. B12 catalyzed CF and CT biodegradation without the accumulation of dichloromethane, carbon disulphide, or CF. The carbon isotopic fractionation value of CF (ƐCCF) with B12 was -14±4‰, and the value for chlorine (ƐClCF) was -2.4±0.4‰. The carbon isotopic fractionation values of CT (ƐCCT) were -16±6 with B12, and -13±2‰ without B12; and the chlorine isotopic fractionation values of CT (ƐClCT) were -6±3 and -4±2‰, respectively. Acidovorax, Ancylobacter, and Pseudomonas were the most metabolically active genera, whereas Dehalobacter and Desulfitobacterium were below 0.1% of relative abundance. The dual C-Cl element isotope slope (Λ=Δδ13C/Δδ37Cl) for CF biodegradation (only detected with B12, 7±1) was similar to that reported for CF reduction by Fe(0) (8±2). Several reductive pathways might be competing in the tested CT scenarios, as evidenced by the lack of CF accumulation when B12 was added, which might be linked to a major activity of Pseudomonas stutzeri; by different chlorine apparent kinetic isotope effect values and Λ which was statistically different with and without B12 (5±1 vs 6.1±0.5), respectively. Thus, positive B12 effects such as CT and CF degradation catalyst were quantified for the first time in isotopic terms, and confirmed with the major activity of species potentially capable of their degradation. Moreover, the indirect benefits of B12 on the degradation of chlorinated ethenes were proved, creating a basis for remediation strategies in multi-contaminant polluted sites.
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Affiliation(s)
- 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 Franquès s/n, 08028 Barcelona, Spain.
| | - Clara Torrentó
- Centre d'hydrogéologie et de géothermie, Université de Neuchâtel, Rue Emile-Argand 11, Neuchâtel 2000, Switzerland
| | - Miriam Guivernau
- GIRO Joint Research Unit IRTA-UPC, IRTA, Torre Marimon, Caldes de Montbui E-08140, Spain
| | - Marc Viñas
- GIRO Joint Research Unit IRTA-UPC, IRTA, Torre Marimon, Caldes de Montbui E-08140, Spain
| | - Daniel Hunkeler
- Centre d'hydrogéologie et de géothermie, Université de Neuchâtel, Rue Emile-Argand 11, Neuchâtel 2000, Switzerland
| | - 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 Franquès s/n, 08028 Barcelona, Spain
| | - 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 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 Franquès s/n, 08028 Barcelona, Spain
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28
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Heckel B, McNeill K, Elsner M. Chlorinated Ethene Reactivity with Vitamin B12 Is Governed by Cobalamin Chloroethylcarbanions as Crossroads of Competing Pathways. ACS Catal 2018. [DOI: 10.1021/acscatal.7b02945] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Benjamin Heckel
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, D-81377 Munich, Germany
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich, CH-8092 Zurich, Switzerland
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, D-81377 Munich, Germany
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Woods A, Kuntze K, Gelman F, Halicz L, Nijenhuis I. Variable dual carbon-bromine stable isotope fractionation during enzyme-catalyzed reductive dehalogenation of brominated ethenes. CHEMOSPHERE 2018; 190:211-217. [PMID: 28987410 DOI: 10.1016/j.chemosphere.2017.09.128] [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: 06/16/2017] [Revised: 09/13/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
The potential of compound-specific stable isotope analysis (CSIA) to characterize biotransformation of brominated organic compounds (BOCs) was assessed and compared to chlorinated analogues. Sulfurospirillum multivorans and Desulfitobacterium hafniense PCE-S catalyzed the dehalogenation of tribromoethene (TBE) to either vinyl bromide (VB) or ethene, respectively. Significantly lower isotope fractionation was observed for TBE dehalogenation by S. multivorans (εC = -1.3 ± 0.2‰) compared to D. hafniense (εC = -7.7 ± 1.5‰). However, higher fractionation was observed for dibromoethene (DBE) dehalogenation by S. multivorans (εC = -16.8 ± 1.8‰ and -21.2 ± 1.6‰ for trans- and cis-1,2- (DBE) respectively), compared to D. hafniense PCE-S (εC = -9.5 ± 1.2‰ and -14.5 ± 0.7‰ for trans-1,2-DBE and cis-1,2-DBE, respectively). Significant, but similar, bromine fractionation was observed for for S. multivorans (εBr = -0.53 ± 0.15‰, -1.03 ± 0.26‰, and -1.18 ± 0.13‰ for trans-1,2-DBE, cis-1,2-DBE and TBE, respectively) and D. hafniense PCE-S (εBr = -0.97 ± 0.28‰, -1.16 ± 0.36‰, and -1.34 ± 0.32‰ for cis-1,2-DBE, TBE and trans-1,2-DBE, respectively). Variable CBr dual-element slopes were estimated at Λ (εC/εBr) = 1.03 ± 0.2, 17.9 ± 5.8, and 29.9 ± 11.0 for S. multivorans debrominating TBE, cis-1,2-DBE and trans-1,2-DBE, respectively, and at 7.14 ± 1.6, 8.27 ± 3.7, and 8.92 ± 2.4 for D. hafniense PCE-S debrominating trans-1,2-DBE, TBE and cis-1,2-DBE, respectively. A high variability in isotope fractionation, which was substrate property related, was observed for S. multivorans but not D. hafniense, similar as observed for chlorinated ethenes, and may be due to rate-limiting steps preceding the bond-cleavage or differences in the reaction mechanism. Overall, significant isotope fractionation was observed and, therefore, CSIA can be applied to monitor the fate of brominated ethenes in the environment. Isotope effects differences, however, are not systematically comparable to chlorinated ethenes.
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Affiliation(s)
- Angela Woods
- Department for Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany
| | - Kevin Kuntze
- Department for Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany
| | - Faina Gelman
- Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501, Israel
| | - Ludwik Halicz
- Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501, Israel; Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Ivonne Nijenhuis
- Department for Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany.
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30
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Leitner S, Berger H, Gorfer M, Reichenauer TG, Watzinger A. Isotopic effects of PCE induced by organohalide-respiring bacteria. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:24803-24815. [PMID: 28913587 DOI: 10.1007/s11356-017-0075-2] [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: 03/31/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Reductive dechlorination performed by organohalide-respiring bacteria (OHRB) enables the complete detoxification of certain emerging groundwater pollutants such as perchloroethene (PCE). Environmental samples from a contaminated site incubated in a lab-scale microcosm (MC) study enable documentation of such reductive dechlorination processes. As compound-specific isotope analysis is used to monitor PCE degradation processes, nucleic acid analysis-like 16S-rDNA analysis-can be used to determine the key OHRB that are present. This study applied both methods to laboratory MCs prepared from environmental samples to investigate OHRB-specific isotope enrichment at PCE dechlorination. This method linkage can enhance the understanding of isotope enrichment patterns of distinct OHRB, which further contribute to more accurate evaluation, characterisation and prospection of natural attenuation processes. Results identified three known OHRB genera (Dehalogenimonas, Desulfuromonas, Geobacter) in diverse abundance within MCs. One species of Dehalogenimonas was potentially involved in complete reductive dechlorination of PCE to ethene. Furthermore, the isotopic effects of PCE degradation were clustered and two isotope enrichment factors (ε) (- 11.6‰, - 1.7‰) were obtained. Notably, ε values were independent of degradation rates and kinetics, but did reflect the genera of the dechlorinating OHRB.
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Affiliation(s)
- Simon Leitner
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Harald Berger
- AIT Austrian Institute of Technology GmbH, Health & Environment Department, Bioresources, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Markus Gorfer
- AIT Austrian Institute of Technology GmbH, Health & Environment Department, Bioresources, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Thomas G Reichenauer
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Andrea Watzinger
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria.
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Doğan-Subaşı E, Elsner M, Qiu S, Cretnik S, Atashgahi S, Shouakar-Stash O, Boon N, Dejonghe W, Bastiaens L. Contrasting dual (C, Cl) isotope fractionation offers potential to distinguish reductive chloroethene transformation from breakdown by permanganate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 596-597:169-177. [PMID: 28431360 DOI: 10.1016/j.scitotenv.2017.03.292] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/31/2017] [Accepted: 03/31/2017] [Indexed: 06/07/2023]
Abstract
cis-1,2-Dichloroethene (cis-DCE) and trichloroethene (TCE) are persistent, toxic and mobile pollutants in groundwater systems. They are both conducive to reductive dehalogenation and to oxidation by permanganate. In this study, the potential of dual element (C, Cl) compound specific isotope analyses (CSIA) for distinguishing between chemical oxidation and anaerobic reductive dechlorination of cis-DCE and TCE was investigated. Well-controlled cis-DCE degradation batch tests gave similar carbon isotope enrichment factors εC (‰), but starkly contrasting dual element isotope slopes Δδ13C/Δδ37Cl for permanganate oxidation (εC=-26‰±6‰, Δδ13C/Δδ37Cl≈-125±47) compared to reductive dechlorination (εC=-18‰±4‰, Δδ13C/Δδ37Cl≈4.5±3.4). The difference can be tracked down to distinctly different chlorine isotope fractionation: an inverse isotope effect during chemical oxidation (εCl=+0.2‰±0.1‰) compared to a large normal isotope effect in reductive dechlorination (εCl=-3.3‰±0.9‰) (p≪0.05). A similar trend was observed for TCE. The dual isotope approach was evaluated in the field before and up to 443days after a pilot scale permanganate injection in the subsurface. Our study indicates, for the first time, the potential of the dual element isotope approach for distinguishing cis-DCE (and TCE) concentration drops caused by dilution, oxidation by permanganate and reductive dechlorination both at laboratory and field scale.
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Affiliation(s)
- Eylem Doğan-Subaşı
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium; Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München-National Research Center for Environmental Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany
| | - Shiran Qiu
- Institute of Groundwater Ecology, Helmholtz Zentrum München-National Research Center for Environmental Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany
| | - Stefan Cretnik
- Institute of Groundwater Ecology, Helmholtz Zentrum München-National Research Center for Environmental Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany
| | - Siavash Atashgahi
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
| | - Orfan Shouakar-Stash
- Department of Earth Sciences, University of Waterloo, 200 University Avenue W., Waterloo, Ont. N2L 3G1, Canada
| | - Nico Boon
- Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium
| | - Winnie Dejonghe
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
| | - Leen Bastiaens
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium.
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Palau J, Shouakar-Stash O, Hatijah Mortan S, Yu R, Rosell M, Marco-Urrea E, Freedman DL, Aravena R, Soler A, Hunkeler D. Hydrogen Isotope Fractionation during the Biodegradation of 1,2-Dichloroethane: Potential for Pathway Identification Using a Multi-element (C, Cl, and H) Isotope Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10526-10535. [PMID: 28810730 DOI: 10.1021/acs.est.7b02906] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Even though multi-element isotope fractionation patterns provide crucial information with which to identify contaminant degradation pathways in the field, those involving hydrogen are still lacking for many halogenated groundwater contaminants and degradation pathways. This study investigates for the first time hydrogen isotope fractionation during both aerobic and anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) using five microbial cultures. Transformation-associated isotope fractionation values (εbulkH) were -115 ± 18‰ (aerobic C-H bond oxidation), -34 ± 4‰ and -38 ± 4‰ (aerobic C-Cl bond cleavage via hydrolytic dehalogenation), and -57 ± 3‰ and -77 ± 9‰ (anaerobic C-Cl bond cleavage via reductive dihaloelimination). The dual-element C-H isotope approach (ΛC-H = Δδ2H/Δδ13C ≈ εbulkH/εbulkC, where Δδ2H and Δδ13C are changes in isotope ratios during degradation) resulted in clearly different ΛC-H values: 28 ± 4 (oxidation), 0.7 ± 0.1 and 0.9 ± 0.1 (hydrolytic dehalogenation), and 1.76 ± 0.05 and 3.5 ± 0.1 (dihaloelimination). This result highlights the potential of this approach to identify 1,2-DCA degradation pathways in the field. In addition, distinct trends were also observed in a multi- (i.e., Δδ2H versus Δδ37Cl versus Δδ13C) isotope plot, which opens further possibilities for pathway identification in future field studies. This is crucial information to understand the mechanisms controlling natural attenuation of 1,2-DCA and to design appropriate strategies to enhance biodegradation.
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Affiliation(s)
- Jordi Palau
- Centre for Hydrogeology and Geothermics, University of 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, Universitat de Barcelona , Martí i Franquès s/n, 08028 Barcelona, Spain
- Institute of Environmental Assessment and Water Research (IDAEA), CSIC, and Hydrogeology Group (UPC-CSIC) , Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Orfan Shouakar-Stash
- Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
- Isotope Tracer Technologies Inc. , Waterloo, Ontario N2 V 1Z5, Canada
| | - Siti Hatijah Mortan
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona , Carrer de les Sitges s/n, 08193 Bellaterra, Spain
| | - Rong Yu
- Department of Environmental Engineering and Earth Sciences, Clemson University , Clemson, South Carolina 29634, United States
| | - Monica 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 , Martí i Franquès s/n, 08028 Barcelona, Spain
| | - Ernest Marco-Urrea
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona , Carrer de les Sitges s/n, 08193 Bellaterra, Spain
| | - David L Freedman
- Department of Environmental Engineering and Earth Sciences, Clemson University , Clemson, South Carolina 29634, United States
| | - Ramon Aravena
- Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - 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 , Martí i Franquès s/n, 08028 Barcelona, Spain
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, University of Neuchâtel , 2000 Neuchâtel, Switzerland
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Heckel B, Cretnik S, Kliegman S, Shouakar-Stash O, McNeill K, Elsner M. Reductive Outer-Sphere Single Electron Transfer Is an Exception Rather than the Rule in Natural and Engineered Chlorinated Ethene Dehalogenation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9663-9673. [PMID: 28727446 DOI: 10.1021/acs.est.7b01447] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chlorinated ethenes (CEs) such as perchloroethylene, trichloroethylene and dichloroethylene are notorious groundwater contaminants. Although reductive dehalogenation is key to their environmental and engineered degradation, underlying reaction mechanisms remain elusive. Outer-sphere reductive single electron transfer (OS-SET) has been proposed for such different processes as Vitamin B12-dependent biodegradation and zerovalent metal-mediated dehalogenation. Compound-specific isotope effect (13C/12C, 37Cl/35Cl) analysis offers a new opportunity to test these hypotheses. Defined OS-SET model reactants (CO2 radical anions, S2--doped graphene oxide in water) caused strong carbon (εC = -7.9‰ to -11.9‰), but negligible chlorine isotope effects (εCl = -0.12‰ to 0.04‰) in CEs. Greater chlorine isotope effects were observed in CHCl3 (εC = -7.7‰, εCl = -2.6‰), and in CEs when the exergonicity of C-Cl bond cleavage was reduced in an organic solvent (reaction with arene radical anions in glyme). Together, this points to dissociative OS-SET (SET to a σ* orbital concerted with C-Cl breakage) in alkanes compared to stepwise OS-SET (SET to a π* orbital followed by C-Cl cleavage) in ethenes. The nonexistent chlorine isotope effects of chlorinated ethenes in all aqueous OS-SET experiments contrast strongly with pronounced Cl isotope fractionation in all natural and engineered reductive dehalogenations reported to date suggesting that OS-SET is an exception rather than the rule in environmental transformations of chlorinated ethenes.
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Affiliation(s)
- Benjamin Heckel
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Stefan Cretnik
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Sarah Kliegman
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges , Claremont, California 91711, United States
| | - Orfan Shouakar-Stash
- Department of Earth Sciences, University of Waterloo , Waterloo, Ontario, Canada N2L 3G1
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zurich , CH-8092 Zurich, Switzerland
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich , Marchioninistrasse 17, D-81377 Munich, Germany
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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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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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Ponsin V, Buscheck TE, Hunkeler D. Heart-cutting two-dimensional gas chromatography–isotope ratio mass spectrometry analysis of monoaromatic hydrocarbons in complex groundwater and gas-phase samples. J Chromatogr A 2017; 1492:117-128. [DOI: 10.1016/j.chroma.2017.02.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/06/2017] [Accepted: 02/24/2017] [Indexed: 11/29/2022]
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37
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Palau J, Yu R, Hatijah Mortan S, Shouakar-Stash O, Rosell M, Freedman DL, Sbarbati C, Fiorenza S, Aravena R, Marco-Urrea E, Elsner M, Soler A, Hunkeler D. Distinct Dual C-Cl Isotope Fractionation Patterns during Anaerobic Biodegradation of 1,2-Dichloroethane: Potential To Characterize Microbial Degradation in the Field. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2685-2694. [PMID: 28192987 DOI: 10.1021/acs.est.6b04998] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (εbulkC and εbulkCl) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ13C/Δδ37Cl ≈ εbulkC/εbulkCl), 6.8 ± 0.2 and 1.89 ± 0.02, respectively. Determined isotope effects and detected products suggest that the difference on the obtained Λ values for biodihaloelimination could be associated with a different mode of concerted bond cleavage rather than two different reaction pathways (i.e., stepwise vs concerted). Λ values of 1,2-DCA were, for the first time, determined in two field sites under reducing conditions (2.1 ± 0.1 and 2.2 ± 2.9). They were similar to the one obtained for the Dehalogenimonas-containing microcosms (1.89 ± 0.02) and very different from those reported for aerobic degradation pathways in a previous laboratory study (7.6 ± 0.1 and 0.78 ± 0.03). Thus, this study illustrates the potential of a dual isotope analysis to differentiate between aerobic and anaerobic biodegradation pathways of 1,2-DCA in the field and suggests that this approach might also be used to characterize dihaloelimination of 1,2-DCA by different bacteria, which needs to be confirmed in future studies.
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Affiliation(s)
- J Palau
- Centre for Hydrogeology and Geothermics, University of Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Geologia, Universitat de Barcelona , Martí i Franquès s/n, 08028 Barcelona, Spain
- Institute of Environmental Assessment and Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Barcelona, Spain
| | - R Yu
- Department of Environmental Engineering and Earth Sciences, Clemson University , Clemson, South Carolina United States
| | - S Hatijah Mortan
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona , Carrer de les Sitges s/n, 08193 Bellaterra, Spain
| | - O Shouakar-Stash
- Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
- Isotope Tracer Technologies Inc., Waterloo, Ontario Canada N2 V 1Z5
| | - M Rosell
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Geologia, Universitat de Barcelona , Martí i Franquès s/n, 08028 Barcelona, Spain
| | - D L Freedman
- Department of Environmental Engineering and Earth Sciences, Clemson University , Clemson, South Carolina United States
| | - C Sbarbati
- Department of Earth Sciences, "Sapienza" University , P.le A. Moro 5, 00185 Rome, Italy
| | - S Fiorenza
- Remediation Engineering and Technology, BP America, Houston, Texas 77079, United States
| | - R Aravena
- Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - E Marco-Urrea
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona , Carrer de les Sitges s/n, 08193 Bellaterra, Spain
| | - M Elsner
- Helmholtz Zentrum München, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - A Soler
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Geologia, Universitat de Barcelona , Martí i Franquès s/n, 08028 Barcelona, Spain
| | - D Hunkeler
- Centre for Hydrogeology and Geothermics, University of Neuchâtel , 2000 Neuchâtel, Switzerland
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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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39
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Nijenhuis I, Richnow HH. Stable isotope fractionation concepts for characterizing biotransformation of organohalides. Curr Opin Biotechnol 2016; 41:108-113. [DOI: 10.1016/j.copbio.2016.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/23/2016] [Accepted: 06/06/2016] [Indexed: 12/11/2022]
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40
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Badin A, Broholm MM, Jacobsen CS, Palau J, Dennis P, Hunkeler D. Identification of abiotic and biotic reductive dechlorination in a chlorinated ethene plume after thermal source remediation by means of isotopic and molecular biology tools. JOURNAL OF CONTAMINANT HYDROLOGY 2016; 192:1-19. [PMID: 27318432 DOI: 10.1016/j.jconhyd.2016.05.003] [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: 12/23/2015] [Revised: 05/06/2016] [Accepted: 05/17/2016] [Indexed: 06/06/2023]
Abstract
Thermal tetrachloroethene (PCE) remediation by steam injection in a sandy aquifer led to the release of dissolved organic carbon (DOC) from aquifer sediments resulting in more reduced redox conditions, accelerated PCE biodegradation, and changes in microbial populations. These changes were documented by comparing data collected prior to the remediation event and eight years later. Based on the premise that dual C-Cl isotope slopes reflect ongoing degradation pathways, the slopes associated with PCE and TCE suggest the predominance of biotic reductive dechlorination near the source area. PCE was the predominant chlorinated ethene near the source area prior to thermal treatment. After thermal treatment, cDCE became predominant. The biotic contribution to these changes was supported by the presence of Dehalococcoides sp. DNA (Dhc) and Dhc targeted rRNA close to the source area. In contrast, dual C-Cl isotope analysis together with the almost absent VC (13)C depletion in comparison to cDCE (13)C depletion suggested that cDCE was subject to abiotic degradation due to the presence of pyrite, possible surface-bound iron (II) or reduced iron sulphides in the downgradient part of the plume. This interpretation is supported by the relative lack of Dhc in the downgradient part of the plume. The results of this study show that thermal remediation can enhance the biodegradation of chlorinated ethenes, and that this effect can be traced to the mobilisation of DOC due to steam injection. This, in turn, results in more reduced redox conditions which favor active reductive dechlorination and/or may lead to a series of redox reactions which may consecutively trigger biotically induced abiotic degradation. Finally, this study illustrates the valuable complementary application of compound-specific isotopic analysis combined with molecular biology tools to evaluate which biogeochemical processes are taking place in an aquifer contaminated with chlorinated ethenes.
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Affiliation(s)
- Alice Badin
- University of Neuchâtel, Centre for Hydrogeology & Geothermics (CHYN), Rue Emile Argand 11, CH 2000 Neuchâtel, Switzerland
| | - Mette M Broholm
- Technical University of Denmark (DTU), Department of Environmental Engineering, Miljøvej, DTU B113, DK 2800 Kgs. Lyngby, Denmark
| | - Carsten S Jacobsen
- Geological Survey of Denmark and Greenland (GEUS), Department of Geochemistry, Ø. Voldgade 10, 1350 København K, Denmark
| | - Jordi Palau
- University of Neuchâtel, Centre for Hydrogeology & Geothermics (CHYN), Rue Emile Argand 11, CH 2000 Neuchâtel, Switzerland
| | - Philip Dennis
- SiREM, 130 Research Lane, Guelph, Ontario, N1G5G3, Canada
| | - Daniel Hunkeler
- University of Neuchâtel, Centre for Hydrogeology & Geothermics (CHYN), Rue Emile Argand 11, CH 2000 Neuchâtel, Switzerland
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41
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Dolinová I, Czinnerová M, Dvořák L, Stejskal V, Ševců A, Černík M. Dynamics of organohalide-respiring bacteria and their genes following in-situ chemical oxidation of chlorinated ethenes and biostimulation. CHEMOSPHERE 2016; 157:276-285. [PMID: 27236848 DOI: 10.1016/j.chemosphere.2016.05.030] [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: 08/03/2015] [Revised: 04/11/2016] [Accepted: 05/11/2016] [Indexed: 06/05/2023]
Abstract
Application of Fenton's reagent and enhanced reductive dechlorination are currently the most common remediation strategies resulting in removal of chlorinated ethenes. In this study, the influence of such techniques on organohalide-respiring bacteria was assessed at a site contaminated by chlorinated ethenes using a wide spectrum of molecular genetic markers, including 16S rRNA gene of the organohalide-respiring bacteria Dehaloccocoides spp., Desulfitobacterium and Dehalobacter; reductive dehalogenase genes (vcrA, bvcA) responsible for dechlorination of vinyl chloride and sulphate-reducing and denitrifying bacteria. In-situ application of hydrogen peroxide to induce a Fenton-like reaction caused an instantaneous decline in all markers below detection limit. Two weeks after application, the bvcA gene and Desulfitobacterium relative abundance increased to levels significantly higher than those prior to application. No significant decrease in the concentration of a range of chlorinated ethenes was observed due to the low hydrogen peroxide dose used. A clear increase in marker levels was also observed following in-situ application of sodium lactate, which resulted in a seven-fold increase in Desulfitobacterium and a three-fold increase in Dehaloccocoides spp. after 70 days. An increase in the vcrA gene corresponded with increase in Dehaloccocoides spp. Analysis of selected markers clearly revealed a positive response of organohalide-respiring bacteria to biostimulation and unexpectedly fast recovery after the Fenton-like reaction.
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Affiliation(s)
- Iva Dolinová
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
| | - Marie Czinnerová
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
| | - Lukáš Dvořák
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
| | - Vojtěch Stejskal
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
| | - Alena Ševců
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
| | - Miroslav Černík
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
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42
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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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43
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Nijenhuis I, Kuntze K. Anaerobic microbial dehalogenation of organohalides — state of the art and remediation strategies. Curr Opin Biotechnol 2016; 38:33-8. [DOI: 10.1016/j.copbio.2015.11.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/03/2015] [Indexed: 11/26/2022]
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44
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Bioremediation of Hydrocarbons and Chlorinated Solvents in Groundwater: Characterisation, Design and Performance Assessment. SPRINGER PROTOCOLS HANDBOOKS 2016. [DOI: 10.1007/8623_2016_207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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45
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Ratti M, Canonica S, McNeill K, Bolotin J, Hofstetter TB. Isotope Fractionation Associated with the Indirect Photolysis of Substituted Anilines in Aqueous Solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:12766-12773. [PMID: 26418612 DOI: 10.1021/acs.est.5b03119] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Organic micropollutants containing aniline substructures are susceptible to different light-induced transformation processes in aquatic environments and water treatment operations. Here, we investigated the magnitude and variability of C and N isotope fractionation during the indirect phototransformation of four para-substituted anilines in aerated aqueous solutions. The model photosensitizers, namely 9,10-anthraquinone-1,5-disulfonate and methylene blue, were used as surrogates for dissolved organic matter chromophores generating excited triplet states in sunlit surface waters. The transformation of aniline, 4-CH3-, 4-OCH3-, and 4-Cl-aniline by excited triplet states of the photosensitizers was associated with inverse and normal N isotope fractionation, whereas C isotope fractionation was negligible. The apparent 15N kinetic isotope effects (AKIE) were almost identical for both photosensitizers, increased from 0.9958±0.0013 for 4-OCH3-aniline to 1.0035±0.0006 for 4-Cl-aniline, and correlated well with the electron donating properties of the substituent. N isotope fractionation is pH-dependent in that H+ exchange reactions dominate below and N atom oxidation processes above the pKa value of the substituted aniline's conjugate acid. Correlations of C and N isotope fractionation for indirect phototransformation were different from those determined previously for the direct photolysis of chloroanilines and offer new opportunities to distinguish between abiotic degradation pathways.
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Affiliation(s)
- Marco Ratti
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
| | - Silvio Canonica
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
| | - Jakov Bolotin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
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46
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Renpenning J, Keller S, Cretnik S, Shouakar-Stash O, Elsner M, Schubert T, Nijenhuis I. Combined C and Cl isotope effects indicate differences between corrinoids and enzyme (Sulfurospirillum multivorans PceA) in reductive dehalogenation of tetrachloroethene, but not trichloroethene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:11837-11845. [PMID: 25216120 DOI: 10.1021/es503306g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The role of the corrinoid cofactor in reductive dehalogenation catalysis by tetrachloroethene reductive dehalogenase (PceA) of Sulfurospirillum multivorans was investigated using isotope analysis of carbon and chlorine. Crude extracts containing PceA--harboring either a native norpseudo-B12 or the alternative nor-B12 cofactor--were applied for dehalogenation of tetrachloroethene (PCE) or trichloroethene (TCE), and compared to abiotic dehalogenation with the respective purified corrinoids (norpseudovitamin B12 and norvitamin B12), as well as several commercially available cobalamins and cobinamide. Dehalogenation of TCE resulted in a similar extent of C and Cl isotope fractionation, and in similar dual-element isotope slopes (εC/εCl) of 5.0-5.3 for PceA enzyme and 3.7-4.5 for the corrinoids. Both observations support an identical reaction mechanism. For PCE, in contrast, observed C and Cl isotope fractionation was smaller in enzymatic dehalogenation, and dual-element isotope slopes (2.2-2.8) were distinctly different compared to dehalogenation mediated by corrinoids (4.6-7.0). Remarkably, εC/εCl of PCE depended in addition on the corrinoid type: εC/εCl values of 4.6 and 5.0 for vitamin B12 and norvitamin B12 were significantly different compared to values of 6.9 and 7.0 for norpseudovitamin B12 and dicyanocobinamide. Our results therefore suggest mechanistic and/or kinetic differences in catalytic PCE dehalogenation by enzymes and different corrinoids, whereas such differences were not observed for TCE.
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Affiliation(s)
- Julian Renpenning
- Department for Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ , Permoserstrasse 15, D-04318 Leipzig, Germany
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