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Blázquez-Pallí N, Torrentó C, Marco-Urrea E, Garriga D, González M, Bosch M. Pilot tests for the optimization of the bioremediation strategy of a multi-layered aquifer at a multi-focus site impacted with chlorinated ethenes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 935:173093. [PMID: 38768723 DOI: 10.1016/j.scitotenv.2024.173093] [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: 01/31/2024] [Revised: 05/03/2024] [Accepted: 05/07/2024] [Indexed: 05/22/2024]
Abstract
A multi-layered aquifer in an industrial area in the north of the Iberian Peninsula is severely contaminated with the chlorinated ethenes (CEs) tetrachloroethylene, trichloroethylene, cis-1,2-dichloroethylene, and vinyl chloride. Both shallow and deep aquifers are polluted, with two differentiated north and south CEs plumes. Hydrogeochemical and isotopic data (δ13C of CEs) evidenced natural attenuation of CEs. To select the optimal remediation strategy to clean-up the contamination plumes, laboratory treatability studies were performed, which confirmed the intrinsic biodegradation potential of the north and south shallow aquifers to fully dechlorinate CEs to ethene after injection of lactate, but also the combination of lactate and sulfidized mZVI as an alternative treatment for the north deep aquifer. In the lactate-amended microcosms, full dechlorination of CEs was accompanied by an increase in 16S rRNA gene copies of Dehalococcoides and Dehalogenimonas, and the tceA, vcrA and bvcA reductive dehalogenases. Three in situ pilot tests were implemented, which consisted in injections of lactate in the north and south shallow aquifers, and injections of lactate and sulfidized mZVI in the north deep aquifer. The hydrogeochemical, isotopic and molecular analyses used to monitor the pilot tests evidenced that results obtained mimicked the laboratory observations, albeit at different dechlorination rates. It is likely that the efficiency of the injections was affected by the amendment distribution. In addition, monitoring of the pilot tests in the shallow aquifers showed the release of CEs due to back diffusion from secondary sources, which limited the use of isotopic data for assessing treatment efficiency. In the pilot test that combined the injection of lactate and sulfidized mZVI, both biotic and abiotic pathways contributed to the production of ethene. This study demonstrates the usefulness of integrating different chemical, isotopic and biomolecular approaches for a more robust selection and implementation of optimal remediation strategies in CEs polluted sites.
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Affiliation(s)
- Natàlia Blázquez-Pallí
- LITOCLEAN, S.L., Environmental site assessment and remediation, c/ Numància 36, 08029 Barcelona, Spain.
| | - Clara Torrentó
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí Franquès s/n, 08028 Barcelona, Spain; Serra Húnter Fellowship, Generalitat de Catalunya, Spain
| | - Ernest Marco-Urrea
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), c/ de les Sitges s/n, 08193 Cerdanyola del Vallès, Spain
| | - David Garriga
- LITOCLEAN, S.L., Environmental site assessment and remediation, c/ Numància 36, 08029 Barcelona, Spain
| | - Marta González
- LITOCLEAN, S.L., Environmental site assessment and remediation, c/ Numància 36, 08029 Barcelona, Spain
| | - Marçal Bosch
- LITOCLEAN, S.L., Environmental site assessment and remediation, c/ Numància 36, 08029 Barcelona, Spain
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2
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Nickels JL, Genereux DP, Knappe DRU. Improved Darcian streambed measurements to quantify flux and mass discharge of volatile organic compounds from a contaminated aquifer to an urban stream. JOURNAL OF CONTAMINANT HYDROLOGY 2023; 253:104124. [PMID: 36603303 DOI: 10.1016/j.jconhyd.2022.104124] [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: 06/29/2022] [Revised: 11/21/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
Quantifying VOC transport from contaminated groundwater to streams is challenging and important for understanding off-site migration of VOCs, cross-media contamination (groundwater to surface water and eventually air), and potential impacts on downstream ecosystems and human populations. A streambed point sampling approach was used to quantify fluxes of water and 14 VOCs from groundwater to an urban stream in North Carolina, USA, during summer (June 2015) and winter (January 2016). The approach is unique in coupling measurements of vertical hydraulic conductivity, vertical hydraulic head gradient, and groundwater VOC concentration at each individual sampling point, reducing or eliminating some potential concerns with other Darcian methods for quantifying VOC inputs to streams. Most results were consistent with discharge of two main VOC plumes on opposite sides of the stream. Plume 1 from the west side was dominated by cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC) at mean concentrations of 19 and 11 μg L-1, respectively. Plume 2 from the east side was dominated by benzene (mean concentration 56 μg L-1). Plume 2 was not previously known, and the improved sampling approach allowed VOC discharge from both plumes to be quantified simultaneously. For 13 of the 14 detected VOCs, the mean VOC flux from groundwater to the stream (fVOC) was higher in January 2016 than in June 2015, mainly because groundwater flux was higher in January. The only exception was cDCE, the most abundant VOC in Plume 1, which had mean fVOC values of 9.8 and 9.5 mg m-2 d-1 in June 2015 and January 2016, respectively. Benzene was the most abundant VOC in Plume 2 and had mean fVOC values of 11 and 37 mg m-2 d-1 in June 2015 and January 2016, respectively. High groundwater flux drove almost all the occurrences of high VOC flux. For a given VOC, the flow-weighted mean concentration (with each VOC concentration weighted by the upward groundwater flux at the VOC sampling point) was generally larger than the unweighted mean concentration. Thus, flow-weighting of concentrations gave a more accurate indication of the average VOC concentration in net groundwater discharge to the stream. An estimate of total VOC mass discharge from groundwater to the study reach of the stream, 3.6 kg of VOC per year, was based on the fVOC results and streambed area in the reach. The bulk of this discharge was due to benzene, cDCE, and VC, with individual mass discharges of 2.1, 0.83, and 0.40 kg yr-1, respectively. Estimates of maximum potential VOC degradation in the streambed suggest that the 3.6 kg yr-1 estimate of mass discharge was not sensitive to potential degradation of VOCs in the streambed sediments above the groundwater sampling depth.
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Affiliation(s)
- J L Nickels
- Department of Marine, Earth, and Atmospheric Sciences, NC State University, Raleigh, NC, United States of America
| | - D P Genereux
- Department of Marine, Earth, and Atmospheric Sciences, NC State University, Raleigh, NC, United States of America.
| | - D R U Knappe
- Department of Civil, Construction, and Environmental Engineering, NC State University, Raleigh, NC, United States of America
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3
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Dutta N, Usman M, Ashraf MA, Luo G, Zhang S. A critical review of recent advances in the bio-remediation of chlorinated substances by microbial dechlorinators. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100359] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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4
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Xing Z, Su X, Zhang X, Zhang L, Zhao T. Direct aerobic oxidation (DAO) of chlorinated aliphatic hydrocarbons: A review of key DAO bacteria, biometabolic pathways and in-situ bioremediation potential. ENVIRONMENT INTERNATIONAL 2022; 162:107165. [PMID: 35278801 DOI: 10.1016/j.envint.2022.107165] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/23/2022] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
Contamination of aquifers and vadose zones with chlorinated aliphatic hydrocarbons (CAH) is a world-wide issue. Unlike other reactions, direct aerobic oxidation (DAO) of CAHs does not require growth substrates and avoids the generation of toxic by-products. Here, we critically review the current understanding of chlorinated aliphatic hydrocarbons-DAO and its application in bioreactors and at the field scale. According to reports on chlorinated aliphatic hydrocarbons-DAO bacteria, isolates mainly consisted of Methylobacterium and Proteobacterium. Chlorinated aliphatic hydrocarbons-DAO bacteria are characterized by tolerance to a high concentration of CAHs and highly efficient removal of CAHs. Trans-1,2-dichloroethylene (t-DCE) is easily transformed biomass for bacteria, followed by 1,2-dichloroethane (1,2-DCA), dichloromethane (DCM), vinyl chloride (VC) and cis-1,2-dichloroethylene (c-DCE). Significant differences in the maximum specific growth rates were observed with different CAHs and biometabolic pathways for DCM, 1,2-DCA, VC and c-DCE degradation have been successfully parsed. Detection of the functional genes etnC and etnE is useful for the determination of active VC DAO bacteria. Additionally, DAO bacteria have been successfully applied to CAHs in new types of bioreactors with satisfactory results. To the best of the authors' knowledge, only one study on DAO-CAHs was conducted in-situ and resulted in 99% CAH removal. Lastly, we put forward future development prospect of chlorinated aliphatic hydrocarbons-DAO.
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Affiliation(s)
- Zhilin Xing
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Xia Su
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Xiaoping Zhang
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Lijie Zhang
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Tiantao Zhao
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China.
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5
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Hart S, Bertolo RA, Agostini MS, Feig R, Lojkasek-Lima P, Gouvea JCR, Barreto FS, Aravena R. Hydrogeochemical and isotopic evaluation of VOC commingled plumes in a weathered fractured bedrock aquifer treated with thermal and bioremediation. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 245:103940. [PMID: 34999305 DOI: 10.1016/j.jconhyd.2021.103940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 12/15/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Chlorinated ethanes and ethenes isotopic analyses in groundwater and hydrogeochemical results from a former industrial area in Sao Paulo (Brazil) were used to confirm the existence and allow further characterization of source areas and their commingled plumes, both before and after thermal and bioremediation treatments. Prior to full scale remediation, a recently identified off-site source area with unknown history and limited access for further intrusive works presented lower δ13C values (-6.5‰ to -1.8‰ for 1,2-DCA) than the downgradient on-site source area (+8.6‰ to +20.0‰). Intermediate δ13C values for 1,2-DCA were identified further downgradient from the sources, within commingled plumes patterns. The isotope and concentration results show the typical degradation patterns associated with biotic reductive dechlorination for chlorinated ethenes and dihaloelimination for 1,2-DCA. Results following remediation treatments show further levels of isotopic enrichment, for chlorinated ethenes and chlorinated ethanes in the tropically weathered and deeper fractured bedrock (gneisses) groundwater. Hydrogeochemical results, isotopic mass balance and Carbon-Chlorine isotope slopes data are coherent with remediation treatment and a complex commingled plume setting. The results of this study confirmed the Temporal Conceptual Model proposed by Hart et al. (2021) and identified the need for further studies to evaluate isotopic dynamics under thermal remediation, including thermal-induced hydrolysis processes.
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Affiliation(s)
- SashaT Hart
- CEPAS Groundwater Research Center, University of Sao Paulo, Rua do Lago, 562, 05508-080 Sao Paulo, SP, Brazil.
| | - Reginaldo A Bertolo
- CEPAS Groundwater Research Center, University of Sao Paulo, Rua do Lago, 562, 05508-080 Sao Paulo, SP, Brazil
| | - Maria S Agostini
- BASF S.A., Av. Brasil, 791, Building E 250, 12521-140 Guaratingueta, SP, Brazil
| | - Roland Feig
- BASF SE, Carl-Bosch-Strasse 38, 67056 Ludwigshafen am Rhein, Germany
| | - Paulo Lojkasek-Lima
- CEPAS Groundwater Research Center, University of Sao Paulo, Rua do Lago, 562, 05508-080 Sao Paulo, SP, Brazil
| | - José C R Gouvea
- CEPAS Groundwater Research Center, University of Sao Paulo, Rua do Lago, 562, 05508-080 Sao Paulo, SP, Brazil
| | - Fernanda S Barreto
- CEPAS Groundwater Research Center, University of Sao Paulo, Rua do Lago, 562, 05508-080 Sao Paulo, SP, Brazil
| | - Ramon Aravena
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, N2L 3G1 Waterloo, Ontario, Canada
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Gilevska T, Sullivan Ojeda A, Kümmel S, Gehre M, Seger E, West K, Morgan SA, Mack EE, Sherwood Lollar B. Multi-element isotopic evidence for monochlorobenzene and benzene degradation under anaerobic conditions in contaminated sediments. WATER RESEARCH 2021; 207:117809. [PMID: 34741903 DOI: 10.1016/j.watres.2021.117809] [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: 03/24/2021] [Revised: 08/10/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Industrial chemicals are frequently detected in sediments due to a legacy of chemical spills. Globally, site remedies for groundwater and sediment decontamination include natural attenuation by in situ abiotic and biotic processes. Compound-specific isotope analysis (CSIA) is a diagnostic tool to identify, quantify, and characterize degradation processes in situ, and in some cases can differentiate between abiotic degradation and biodegradation. This study reports high-resolution carbon, chlorine, and hydrogen stable isotope profiles for monochlorobenzene (MCB), and carbon and hydrogen stable isotope profiles for benzene, coupled with measurements of pore water concentrations in contaminated sediments. Multi-element isotopic analysis of δ13C and δ37Cl for MCB were used to generate dual-isotope plots, which for 2 locations at the study site resulted in ΛC/Cl(130) values of 1.42 ± 0.19 and ΛC/Cl(131) values of 1.70 ± 0.15, consistent with theoretical calculations for carbon-chlorine bond cleavage (ΛT = 1.80 ± 0.31) via microbial reductive dechlorination. For benzene, significant δ2H (122‰) and δ13C (6‰) depletion trends, followed by enrichment trends in δ13C (1.6‰) in the upper part of the sediment, were observed at the same location, indicating not only production of benzene due to biodegradation of MCB, but subsequent biotransformation of benzene itself to nontoxic end-products. Degradation rate constants calculated independently using chlorine isotopic data and carbon isotopic data, respectively, agreed within uncertainty thus providing multiple lines of evidence for in situ contaminant degradation via reductive dechlorination and providing the foundation for a novel approach to determine site-specific in situ rate estimates essential for the prediction of remediation outcomes and timelines.
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Affiliation(s)
- Tetyana Gilevska
- Department of Earth Sciences, University of Toronto, Toronto, ON M5S 3B1, Canada; CNRS/EOST, ITES UMR 7063, Earth and Environment Institute of Strasbourg (ITES), University of Strasbourg, Strasbourg, 67084, France
| | - Ann Sullivan Ojeda
- Department of Earth Sciences, University of Toronto, Toronto, ON M5S 3B1, Canada; Department of Geosciences, Auburn University, Auburn, AL 36849, United States
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Leipzig, 04318, Germany
| | - Matthias Gehre
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Leipzig, 04318, Germany
| | - Edward Seger
- The Chemours Company, Wilmington, DE 19810, United States
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7
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Li F, Deng D, Zeng L, Abrams S, Li M. Sequential anaerobic and aerobic bioaugmentation for commingled groundwater contamination of trichloroethene and 1,4-dioxane. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145118. [PMID: 33610989 DOI: 10.1016/j.scitotenv.2021.145118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/04/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Chlorinated solvents, notably trichloroethene (TCE), and the cyclic ether stabilizer, 1,4-dioxane (dioxane), have been frequently detected commingling in contaminated aquifers. Here we developed a sequential anaerobic and aerobic treatment strategy effective to mitigate the co-contamination of TCE and dioxane, particularly when dioxane is present at ppb levels relevant to many impacted sites. After the primary anaerobic treatment by a halorespiring consortium SDC-9, TCE was effectively removed, though lingering less-chlorinated metabolites, vinyl chloride (VC) and cis-dichloroethene (cDCE). Subsequent aerobic bioaugmentation with Azoarcus sp. DD4, a cometabolic dioxane degrader, demonstrated the ability of DD4 to degrade dioxane at an initial concentration of 20 μg/L to below 0.4 μg/L and its dominance (~7%) in microcosms fed with propane. Even better, DD4 can also transform VC and cDCE in tandem, though cDCE and VC at relatively high concentrations (e.g., 1 mg/L) posed inhibition to propane assimilation and cell growth of DD4. Mutagenesis of DD4 revealed group-2 toluene monooxygenase and group-5 propane monooxygenase are responsible for cDCE and VC co-oxidation, respectively. Overall, we demonstrated the feasibility of a treatment train combining reductive dehalogenation and aerobic co-oxidation processes in tandem to not only effectively clean up prevalent co-contamination of TCE and dioxane at trace levels but also mitigate persistent products (e.g., cDCE and VC) when complete reductive dehalogenation of less-chlorinated ethenes occurs slowly in the field.
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Affiliation(s)
- Fei Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Daiyong Deng
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Lingke Zeng
- Langan Engineering, Parsippany, NJ 07054, USA
| | | | - Mengyan Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
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8
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Herrero J, Puigserver D, Nijenhuis I, Kuntze K, Parker BL, Carmona JM. The role of ecotones in the dehalogenation of chloroethenes in alluvial fan aquifers. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:26871-26884. [PMID: 33495954 DOI: 10.1007/s11356-021-12538-0] [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] [Received: 08/27/2020] [Accepted: 01/13/2021] [Indexed: 05/20/2023]
Abstract
The presence of ecotones in transition zones between geological strata (e.g. layers of gravel and sand interbedded with layers of silt in distal alluvial fan deposits) in aquifers plays a significant role in regulating the flux of matter and energy between compartments. Ecotones are characterised by steep physicochemical and biological gradients and considerable biological diversity. However, the link between organic pollutants and degradation potential in ecotones has scarcely been studied. The aim of this study is to relate the presence of ecotones with the dehalogenation of chloroethenes. A field site was selected where chloroethene contamination occurs in a granular aquifer with geological heterogeneities. The site is monitored by multilevel and conventional wells. Groundwater samples were analysed by chemical, isotopic, and molecular techniques. The main results were as follows: (1) two ecotones were characterised in the source area, one in the upper part of the aquifer and the second in the transition zone to the bottom aquitard, where the aged pool is located; (2) the ecotone located in the transition zone to the bottom aquitard has greater microbial diversity, due to higher geological heterogeneities; (3) both ecotones show the reductive dehalogenation of perchloroethylene and trichloroethylene; and (4) these ecotones are the main zones of the reductive dehalogenation of the pollutants, given the more reductive conditions at the centre of the plume. These findings suggest that ecotones are responsible for natural attenuation, where oxic conditions prevailed at the aquifer and bioremediation strategies could be applied more effectively in these zones to promote complete reductive dehalogenation.
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Affiliation(s)
- Jofre Herrero
- Department of Minerology, Petrology and Applied Geology, Faculty of Earth Sciences, The Water Research Institute (IdRA), University of Barcelona, C/ Martí Franquès sn, Barcelona, Spain.
| | - Diana Puigserver
- Serra Húnter Tenure-elegible Lecturer, Department of Minerology, Petrology and Applied Geology, Faculty of Earth Sciences, The Water Research Institute (IdRA), University of Barcelona, C/ Martí Franquès sn, Barcelona, Spain
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry (ISOBIO), UFZ Centre for Environmental Research Leipzig-Halle, Permoserstr. 15, 04318, Leipzig, Germany
| | - Kevin Kuntze
- Department of Isotope Biogeochemistry (ISOBIO), UFZ Centre for Environmental Research Leipzig-Halle, Permoserstr. 15, 04318, Leipzig, Germany
- Isodetect, Deutscher Platz 5b, 04103, Leipzig, Germany
| | - Beth L Parker
- School of Engineering, University of Guelph 50, Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - José M Carmona
- Department of Minerology, Petrology and Applied Geology, Faculty of Earth Sciences, The Water Research Institute (IdRA), University of Barcelona, C/ Martí Franquès sn, Barcelona, Spain
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Ottosen CB, Rønde V, McKnight US, Annable MD, Broholm MM, Devlin JF, Bjerg PL. Natural attenuation of a chlorinated ethene plume discharging to a stream: Integrated assessment of hydrogeological, chemical and microbial interactions. WATER RESEARCH 2020; 186:116332. [PMID: 32871289 DOI: 10.1016/j.watres.2020.116332] [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: 04/17/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Attenuation processes of chlorinated ethenes in complex near-stream systems result in site-specific outcomes of great importance for risk assessment of contaminated sites. Additional interdisciplinary and comprehensive field research is required to enhance process understanding in these systems. In this study, several methods were combined in a multi-scale interdisciplinary in-situ approach to assess and quantify the near-stream attenuation of a chlorinated ethene plume, mainly consisting of cis-dichloroethene (cis-DCE) and vinyl chloride (VC), discharging to a lowland stream (Grindsted stream, Denmark) over a monitoring period of seven years. The approach included: hydrogeological characterisation, reach scale contaminant mass balance analysis, quantification of contaminant mass discharge, streambed fluxes of chlorinated ethenes quantified using Sediment Bed Passive Flux Meters (SBPFMs), assessment of redox conditions, temporal assessment of contaminant concentrations, microbial analysis, and compound-specific isotope analysis (CSIA). This study site exhibits a special attenuation behaviour not commonly encountered in field studies: the conversion from an initially limited degradation case (2012-16), despite seemingly optimal conditions, to one presenting notable levels of degradation (2019). Hence, this study site provides a new piece to the puzzle, as sites with different attenuation behaviours are required in order to acquire the full picture of the role groundwater-surface water interfaces have in risk mitigation. In spite of the increased degradation in the near-stream plume core, the contaminant attenuation was still incomplete in the discharging plume. A conceptualization of flow, transport and processes clarified that hydrogeology was the main control on the natural attenuation, as short residence times of 0.5-37 days restricted the time in which dechlorination could occur. This study reveals the importance of: taking an integrated approach to understand the influence of all attenuation processes in groundwater - surface water interactions; considering the scale and domain of interest when determining the main processes; and monitoring sufficiently both spatially and temporally to cover the transient conditions.
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Affiliation(s)
- Cecilie B Ottosen
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
| | - Vinni Rønde
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ursula S McKnight
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Michael D Annable
- Department of Environmental Engineering Sciences, University of Florida, FL, United States
| | - Mette M Broholm
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - John F Devlin
- Department of Geology, University of Kansas, Lawrence, KS, United States
| | - Poul L Bjerg
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
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10
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Xiao Z, Jiang W, Chen D, Xu Y. Bioremediation of typical chlorinated hydrocarbons by microbial reductive dechlorination and its key players: A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 202:110925. [PMID: 32800212 DOI: 10.1016/j.ecoenv.2020.110925] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/11/2020] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
Chlorinated hydrocarbon contamination in soils and groundwater has a severe negative impact on the human health. Microbial reductive dechlorination is a major degradation pathway of chlorinated hydrocarbon in anaerobic subsurface environments, has been extensively studied. Recent progress on the diversity of the reductive dechlorinators and the key enzymes of chlororespiration has been well reviewed. Here, we present a thorough overview of the studies related to bioremediation of chloroethenes and polychlorinated biphenyls based on enhanced in situ reductive dechlorination. The major part of this review is to provide an up-to-date summary of functional microorganisms which are either detected during in situ biostimulation or applied in bioaugmentation strategies. The applied biostimulants and corresponding reductive dechlorination products are also summarized and the future research needs are finally discussed.
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Affiliation(s)
- Zhixing Xiao
- College of Urban Construction, Nanjing Tech University, Nanjing, 211816, PR China
| | - Wei Jiang
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, 210096, PR China
| | - Dan Chen
- College of Urban Construction, Nanjing Tech University, Nanjing, 211816, PR China
| | - Yan Xu
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, 210096, PR China.
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11
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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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12
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Gafni A, Siebner H, Bernstein A. Potential for co-metabolic oxidation of TCE and evidence for its occurrence in a large-scale aquifer survey. WATER RESEARCH 2020; 171:115431. [PMID: 31893553 DOI: 10.1016/j.watres.2019.115431] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 11/30/2019] [Accepted: 12/20/2019] [Indexed: 06/10/2023]
Abstract
Trichloroethylene (TCE) is a groundwater pollutant that is prevalent worldwide. In contaminated groundwater, TCE can be biodegraded following either reductive dechlorination or aerobic co-metabolic oxidation. However, since the co-metabolic process is not accompanied by indicative and easily detectable transformation products, little is known about its prominence in the environment. To estimate the environmental importance of the oxidative process, a regional groundwater survey was conducted. In this survey, polluted water from 100 wells along the Israeli Coastal Aquifer was sampled. Geochemical data indicated oxic conditions prevailing in most sites. The sampled groundwater was used for microcosm experiments, functional gene analysis, and TCE compound-specific isotope analysis (δ13C and δ37Cl). Enrichments of methane and toluene oxidizers in microcosms indicated the high potential of the indigenous microbial community to co-metabolically oxidize TCE. This was further reinforced by the high abundance of mmoX and PHE functional genes quantified in some of the sites (yet lower abundance of TOD functional gene was found). Finally, compound-specific isotope analysis was used to assess the magnitude of TCE oxidation in practice. Applying the isotopic tool for scattered points on a regional scale demanded the consideration of a wide δ13C range of source TCE, hampering the ability to detect small shifts of a single permil. Thus, despite the high potential for the oxidation process, no evidence was attained for the natural occurrence of the process, and significant isotopic shifts were restricted to actively treated sites only. This limitation should be considered in future regional scale studies, in which no single source is defined.
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Affiliation(s)
- Almog Gafni
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Hagar Siebner
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Anat Bernstein
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel.
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13
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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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14
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Thouement HAA, Kuder T, Heimovaara TJ, van Breukelen BM. Do CSIA data from aquifers inform on natural degradation of chlorinated ethenes in aquitards? JOURNAL OF CONTAMINANT HYDROLOGY 2019; 226:103520. [PMID: 31377464 DOI: 10.1016/j.jconhyd.2019.103520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 05/24/2019] [Accepted: 07/02/2019] [Indexed: 06/10/2023]
Abstract
Back-diffusion of chlorinated ethenes (CEs) from low-permeability layers (LPLs) causes contaminant persistence long after the primary spill zones have disappeared. Naturally occurring degradation in LPLs lowers remediation time frames, but its assessment through sediment sampling is prohibitive in conventional remediation projects. Scenario simulations were performed with a reactive transport model (PHT3D in FloPy) accounting for isotope effects associated with degradation, sorption, and diffusion, to evaluate the potential of CSIA data from aquifers in assessing degradation in aquitards. The model simulated a trichloroethylene (TCE) DNAPL and its pollution plume within an aquifer-aquitard-aquifer system. Sequential reductive dechlorination to ethene and sorption were uniform in the aquitard and did not occur in the aquifer. After 10 years of loading the aquitard through diffusion from the plume, subsequent source removal triggered release of TCE by back-diffusion. In the upper aquifer, during the loading phase, δ13C-TCE was slightly enriched (up to 2‰) due to diffusion effects stimulated by degradation in the aquitard. In the upper aquifer, during the release phase, (i) source removal triggered a huge δ13C increase especially for higher CEs, (ii) moreover, downstream decreasing isotope ratios (caused by downgradient later onset of the release phase) with temporal increasing isotope ratios reflect aquitard degradation (as opposed to downstream increasing and temporally constant isotope ratios in reactive aquifers), and (iii) the carbon isotope mass balance (CIMB) enriched up to 4‰ as lower CEs (more depleted, less sorbing) have been transported deeper into the aquitard. Thus, enriched CIMB does not indicate oxidative transformation in this system. The CIMB enrichment enhanced with more sorption and lower aquitard thickness. Thin aquitards are quicker flushed from lower CEs leading to faster CIMB enrichment over time. CIMB enrichment is smaller or nearly absent when daughter products accumulate. Aquifer CSIA patterns indicative of aquitard degradation were similar in case of linear decreasing rate constants but contrasted with previous simulations assuming a thin bioactive zone. The Rayleigh equation systematically underestimates the extent of TCE degradation in aquifer samples especially during the loading phase and for conditions leading to long remediation time frames (low groundwater flow velocity, thicker aquitards, strong sorption in the aquitard). The Rayleigh equation provides a good and useful picture on aquitard degradation during the release phase throughout the sensitivity analysis. This modelling study provides a framework on how aquifer CSIA data can inform on the occurrence of aquitard degradation and its pitfalls.
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Affiliation(s)
- Héloïse A A Thouement
- Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands.
| | - Tomasz Kuder
- School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street, SEC 710, Norman, OK 73019, United States of America
| | - Timo J Heimovaara
- Department of Geoscience and Engineering, Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
| | - Boris M van Breukelen
- Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, the Netherlands
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15
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Murray AM, Maillard J, Jin B, Broholm MM, Holliger C, Rolle M. A modeling approach integrating microbial activity, mass transfer, and geochemical processes to interpret biological assays: An example for PCE degradation in a multi-phase batch setup. WATER RESEARCH 2019; 160:484-496. [PMID: 31177078 DOI: 10.1016/j.watres.2019.05.087] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/22/2019] [Accepted: 05/25/2019] [Indexed: 06/09/2023]
Abstract
The rate at which organic contaminants can be degraded in aquatic environments is not only dependent upon specific degrading bacteria, but also upon the composition of the microbial community, mass transfer of the contaminant, and abiotic processes that occur in the environment. In this study, we present three-phase batch experiments of tetrachloroethene (PCE) degradation by a consortium of organohalide-respiring bacteria, cultivated alone or in communities with iron- and/or sulfate-reducers. We developed a modeling approach to quantitatively evaluate the experimental results, comprised of chemical and biomolecular time series data. The model utilizes the IPhreeqc module to couple multi-phase mass transfer between gaseous, organic and aqueous phases with microbial and aquatic geochemical processes described using the geochemical code PHREEQC. The proposed approach is able to capture the contaminant degradation, the microbial population dynamics, the effects of multi-phase kinetic mass transfer and sample removal, and the geochemical reactions occurring in the aqueous phase. The model demonstrates the importance of aqueous speciation and abiotic reactions on the bioavailability of the substrates. The model-based interpretation allowed us to quantify the reaction kinetics of the different bacterial guilds. The model further revealed that the inclusion of sulfate-reducing bacteria lowers the rate of PCE degradation and that this effect is moderated in the presence of iron-reducing bacteria.
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Affiliation(s)
- Alexandra Marie Murray
- 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
| | - Biao Jin
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Science, China
| | - Mette M Broholm
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | - Christof Holliger
- Laboratory for Environmental Biotechnology, ENAC-IIE, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Massimo Rolle
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
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16
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Hermon L, Hellal J, Denonfoux J, Vuilleumier S, Imfeld G, Urien C, Ferreira S, Joulian C. Functional Genes and Bacterial Communities During Organohalide Respiration of Chloroethenes in Microcosms of Multi-Contaminated Groundwater. Front Microbiol 2019; 10:89. [PMID: 30809199 PMCID: PMC6379275 DOI: 10.3389/fmicb.2019.00089] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/16/2019] [Indexed: 02/01/2023] Open
Abstract
Microcosm experiments with CE-contaminated groundwater from a former industrial site were set-up to evaluate the relationships between biological CE dissipation, dehalogenase genes abundance and bacterial genera diversity. Impact of high concentrations of PCE on organohalide respiration was also evaluated. Complete or partial dechlorination of PCE, TCE, cis-DCE and VC was observed independently of the addition of a reducing agent (Na2S) or an electron donor (acetate). The addition of either 10 or 100 μM PCE had no effect on organohalide respiration. qPCR analysis of reductive dehalogenases genes (pceA, tceA, vcrA, and bvcA) indicated that the version of pceA gene found in the genus Dehalococcoides [hereafter named pceA(Dhc)] and vcrA gene increased in abundance by one order of magnitude during the first 10 days of incubation. The version of the pceA gene found, among others, in the genus Dehalobacter, Sulfurospirillum, Desulfuromonas, and Geobacter [hereafter named pceA(Dhb)] and bvcA gene showed very low abundance. The tceA gene was not detected throughout the experiment. The proportion of pceA(Dhc) or vcrA genes relative to the universal 16S ribosomal RNA (16S rRNA) gene increased by up to 6-fold upon completion of cis-DCE dissipation. Sequencing of 16S rRNA amplicons indicated that the abundance of Operational Taxonomic Units (OTUs) affiliated to dehalogenating genera Dehalococcoides, Sulfurospirillum, and Geobacter represented more than 20% sequence abundance in the microcosms. Among organohalide respiration associated genera, only abundance of Dehalococcoides spp. increased up to fourfold upon complete dissipation of PCE and cis-DCE, suggesting a major implication of Dehalococcoides in CEs organohalide respiration. The relative abundance of pceA and vcrA genes correlated with the occurrence of Dehalococcoides and with dissipation extent of PCE, cis-DCE and CV. A new type of dehalogenating Dehalococcoides sp. phylotype affiliated to the Pinellas group, and suggested to contain both pceA(Dhc) and vcrA genes, may be involved in organohalide respiration of CEs in groundwater of the study site. Overall, the results demonstrate in situ dechlorination potential of CE in the plume, and suggest that taxonomic and functional biomarkers in laboratory microcosms of contaminated groundwater following pollutant exposure can help predict bioremediation potential at contaminated industrial sites.
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Affiliation(s)
- Louis Hermon
- Geomicrobiology and Environmental Monitoring Unit, Bureau de Recherches Géologiques et Minières (BRGM), Orléans, France.,CNRS, GMGM UMR 7156, Genomics and Microbiology, Université de Strasbourg, Strasbourg, France
| | - Jennifer Hellal
- Geomicrobiology and Environmental Monitoring Unit, Bureau de Recherches Géologiques et Minières (BRGM), Orléans, France
| | - Jérémie Denonfoux
- Service Recherche, Développement et Innovation-Communautés Microbiennes, GenoScreen, SAS, Lille, France
| | - Stéphane Vuilleumier
- CNRS, GMGM UMR 7156, Genomics and Microbiology, Université de Strasbourg, Strasbourg, France
| | - Gwenaël Imfeld
- CNRS/EOST, LHyGeS UMR 7517, Laboratory of Hydrology and Geochemistry of Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Charlotte Urien
- Service Recherche, Développement et Innovation-Communautés Microbiennes, GenoScreen, SAS, Lille, France
| | - Stéphanie Ferreira
- Service Recherche, Développement et Innovation-Communautés Microbiennes, GenoScreen, SAS, Lille, France
| | - Catherine Joulian
- Geomicrobiology and Environmental Monitoring Unit, Bureau de Recherches Géologiques et Minières (BRGM), Orléans, France
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17
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Gilevska T, Passeport E, Shayan M, Seger E, Lutz EJ, West KA, Morgan SA, Mack EE, Sherwood Lollar B. Determination of in situ biodegradation rates via a novel high resolution isotopic approach in contaminated sediments. WATER RESEARCH 2019; 149:632-639. [PMID: 30583106 DOI: 10.1016/j.watres.2018.11.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/06/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
A key challenge in conceptual models for contaminated sites is identification of the multiplicity of processes controlling contaminant concentrations and distribution as well as quantification of the rates at which such processes occur. Conventional protocol for calculating biodegradation rates can lead to overestimation by attributing concentration decreases to degradation alone. This study reports a novel approach of assessing in situ biodegradation rates of monochlorobenzene (MCB) and benzene in contaminated sediments. Passive diffusion samplers allowing cm-scale vertical resolution across the sediment-water interface were coupled with measurements of concentrations and stable carbon isotope signatures to identify zones of active biodegradation of both compounds. Large isotopic enrichment trends in 13C were observed for MCB (1.9-5.7‰), with correlated isotopic depletion in 13C for benzene (1.0-7.0‰), consistent with expected isotope signatures for substrate and daughter product produced by in situ biodegradation. Importantly in the uppermost sediments, benzene too showed a pronounced 13C enrichment trend of up to 2.2‰, providing definitive evidence for simultaneous degradation as well as production of benzene. The hydrogeological concept of representative elementary volume was applied to CSIA data for the first time and identified a critical zone of 10-15 cm with highest biodegradation potential in the sediments. Using both stable isotope-derived rate calculations and numerical modeling, we show that MCB degraded at a slower rate (0.1-1.4 yr-1 and 0.2-3.2 yr-1, respectively) than benzene (3.3-84.0 yr-1) within the most biologically active zone of the sediment, contributing to detoxification.
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Affiliation(s)
- Tetyana Gilevska
- Department of Earth Sciences, University of Toronto, Toronto, Ontario, M5S 3B1, Canada
| | - Elodie Passeport
- Department of Civil and Mineral Engineering, University of Toronto, Toronto, Ontario, M5S 1A4, Canada; Department of Chemical Engineering and Applied Chemistry, Toronto, Ontario, M5S 3E5, Canada
| | - Mahsa Shayan
- Department of Earth Sciences, University of Toronto, Toronto, Ontario, M5S 3B1, Canada
| | - Edward Seger
- The Chemours Company, Wilmington, DE, 19810, USA
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18
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Weatherill JJ, Atashgahi S, Schneidewind U, Krause S, Ullah S, Cassidy N, Rivett MO. Natural attenuation of chlorinated ethenes in hyporheic zones: A review of key biogeochemical processes and in-situ transformation potential. WATER RESEARCH 2018; 128:362-382. [PMID: 29126033 DOI: 10.1016/j.watres.2017.10.059] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 10/12/2017] [Accepted: 10/28/2017] [Indexed: 06/07/2023]
Abstract
Chlorinated ethenes (CEs) are legacy contaminants whose chemical footprint is expected to persist in aquifers around the world for many decades to come. These organohalides have been reported in river systems with concerning prevalence and are thought to be significant chemical stressors in urban water ecosystems. The aquifer-river interface (known as the hyporheic zone) is a critical pathway for CE discharge to surface water bodies in groundwater baseflow. This pore water system may represent a natural bioreactor where anoxic and oxic biotransformation process act in synergy to reduce or even eliminate contaminant fluxes to surface water. Here, we critically review current process understanding of anaerobic CE respiration in the competitive framework of hyporheic zone biogeochemical cycling fuelled by in-situ fermentation of natural organic matter. We conceptualise anoxic-oxic interface development for metabolic and co-metabolic mineralisation by a range of aerobic bacteria with a focus on vinyl chloride degradation pathways. The superimposition of microbial metabolic processes occurring in sediment biofilms and bulk solute transport delivering reactants produces a scale dependence in contaminant transformation rates. Process interpretation is often confounded by the natural geological heterogeneity typical of most riverbed environments. We discuss insights from recent field experience of CE plumes discharging to surface water and present a range of practical monitoring technologies which address this inherent complexity at different spatial scales. Future research must address key dynamics which link supply of limiting reactants, residence times and microbial ecophysiology to better understand the natural attenuation capacity of hyporheic systems.
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Affiliation(s)
| | - Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Uwe Schneidewind
- Department of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany
| | - Stefan Krause
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | - Sami Ullah
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | | | - Michael O Rivett
- Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, UK; GroundH(2)O Plus Ltd., Quinton, Birmingham, UK
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19
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Rønde V, McKnight US, Sonne AT, Balbarini N, Devlin JF, Bjerg PL. Contaminant mass discharge to streams: Comparing direct groundwater velocity measurements and multi-level groundwater sampling with an in-stream approach. JOURNAL OF CONTAMINANT HYDROLOGY 2017; 206:43-54. [PMID: 28969865 DOI: 10.1016/j.jconhyd.2017.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/15/2017] [Accepted: 09/22/2017] [Indexed: 06/07/2023]
Affiliation(s)
- V Rønde
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
| | - U S McKnight
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - A Th Sonne
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - N Balbarini
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - J F Devlin
- Department of Geology, University of Kansas, Lawrence, KS, United States
| | - P L Bjerg
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
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20
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Kim W, Lee Y, Kim SD. Developing and applying a site-specific multimedia fate model to address ecological risk of oxytetracycline discharged with aquaculture effluent in coastal waters off Jangheung, Korea. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 145:221-226. [PMID: 28738205 DOI: 10.1016/j.ecoenv.2017.07.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/14/2017] [Accepted: 07/17/2017] [Indexed: 06/07/2023]
Abstract
The overuse of oxytetracycline (OTC) in aquaculture has become a problem because of its chronic toxic effects on marine ecosystems. The present study assessed the ecological risk of OTC in the coastal waters near the Jangheung Flatfish Farm using a site-specific multimedia fate model to analyze exposure. Before the model was applied, its performance was validated by comparing it with field data. The coastal waters in the testbed were sampled and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) followed by solid-phase extraction (SPE). The concentrations of OTC measured varied from 7.05 to 95.39ng/L. The results of validating the models showed that the site-specific multimedia fate model performed better (root mean square error (RMSE): 24.217, index of agreement (IOA): 0.739) than conventional fugacity approaches. This result demonstrated the utility of this model in supporting effective future management of aquaculture effluent. The results of probabilistic risk assessment indicated that OTC from aquaculture effluent did not cause adverse effects, even in a maximum-use scenario.
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Affiliation(s)
- Woojung Kim
- Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu Gwangju 500-712, South Korea
| | - Yunho Lee
- Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu Gwangju 500-712, South Korea
| | - Sang Don Kim
- Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu Gwangju 500-712, South Korea; Center for Chemicals Risk Assessment, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu Gwangju 500-712, South Korea.
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21
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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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22
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Şimşir B, Yan J, Im J, Graves D, Löffler FE. Natural Attenuation in Streambed Sediment Receiving Chlorinated Solvents from Underlying Fracture Networks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:4821-4830. [PMID: 28328216 PMCID: PMC6944067 DOI: 10.1021/acs.est.6b05554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Contaminant discharge from fractured bedrock formations remains a remediation challenge. We applied an integrated approach to assess the natural attenuation potential of sediment that forms the transition zone between upwelling groundwater from a chlorinated solvent-contaminated fractured bedrock aquifer and the receiving surface water. In situ measurements demonstrated that reductive dechlorination in the sediment attenuated chlorinated compounds before reaching the water column. Microcosms established with creek sediment or in situ incubated Bio-Sep beads degraded C1-C3 chlorinated solvents to less-chlorinated or innocuous products. Quantitative PCR and 16S rRNA gene amplicon sequencing revealed the abundance and spatial distribution of known dechlorinator biomarker genes within the creek sediment and demonstrated that multiple dechlorinator populations degrading chlorinated C1-C3 alkanes and alkenes co-inhabit the sediment. Phylogenetic classification of bacterial and archaeal sequences indicated a relatively uniform distribution over spatial (300 m horizontally) scale, but Dehalococcoides and Dehalobacter were more abundant in deeper sediment, where 5.7 ± 0.4 × 105 and 5.4 ± 0.9 × 106 16S rRNA gene copies per g of sediment, respectively, were measured. The microbiological and hydrogeological characterization demonstrated that microbial processes at the fractured bedrock-sediment interface were crucial for preventing contaminants reaching the water column, emphasizing the relevance of this critical zone environment for contaminant attenuation.
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Affiliation(s)
- Burcu Şimşir
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jun Yan
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
| | - Jeongdae Im
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01002, United States
| | - Duane Graves
- Geosyntec Consultants, Knoxville, Tennessee 37922, United States
| | - Frank E. Löffler
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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Dolinová I, Štrojsová M, Černík M, Němeček J, Macháčková J, Ševců A. Microbial degradation of chloroethenes: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:13262-13283. [PMID: 28378313 DOI: 10.1007/s11356-017-8867-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 03/17/2017] [Indexed: 05/28/2023]
Abstract
Contamination by chloroethenes has a severe negative effect on both the environment and human health. This has prompted intensive remediation activity in recent years, along with research into the efficacy of natural microbial communities for degrading toxic chloroethenes into less harmful compounds. Microbial degradation of chloroethenes can take place either through anaerobic organohalide respiration, where chloroethenes serve as electron acceptors; anaerobic and aerobic metabolic degradation, where chloroethenes are used as electron donors; or anaerobic and aerobic co-metabolic degradation, with chloroethene degradation occurring as a by-product during microbial metabolism of other growth substrates, without energy or carbon benefit. Recent research has focused on optimising these natural processes to serve as effective bioremediation technologies, with particular emphasis on (a) the diversity and role of bacterial groups involved in dechlorination microbial processes, and (b) detection of bacterial enzymes and genes connected with dehalogenation activity. In this review, we summarise the different mechanisms of chloroethene bacterial degradation suitable for bioremediation and provide a list of dechlorinating bacteria. We also provide an up-to-date summary of primers available for detecting functional genes in anaerobic and aerobic bacteria degrading chloroethenes metabolically or co-metabolically.
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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
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Martina Štrojsová
- 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
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Jan Němeček
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Jiřina Macháčková
- 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.
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
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24
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Atashgahi S, Lu Y, Ramiro-Garcia J, Peng P, Maphosa F, Sipkema D, Dejonghe W, Smidt H, Springael D. Geochemical Parameters and Reductive Dechlorination Determine Aerobic Cometabolic vs Aerobic Metabolic Vinyl Chloride Biodegradation at Oxic/Anoxic Interface of Hyporheic Zones. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:1626-1634. [PMID: 28004913 DOI: 10.1021/acs.est.6b05041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Hyporheic zones mediate vinyl chloride (VC) biodegradation in groundwater discharging into surface waters. At the oxic/anoxic interface (OAI) of hyporheic zones subjected to redox oscillations, VC is degraded via coexisting aerobic ethenotrophic and anaerobic reductive dechlorination pathways. However, the identity of aerobic VC degradation pathways (cometabolic vs metabolic) and their interactions with reductive dechlorination in relation to riverbed sediment geochemistry remain ill-defined. We addressed this using microcosms containing OAI sediments incubated under fluctuating oxic/anoxic atmosphere. Under oxic atmosphere, aerobic metabolic VC oxidation was absent in sediments with high total organic carbon (TOC) and VC was reductively dechlorinated to ethene. Ethene was oxidized by ethenotrophs that can degrade VC cometabolically. Contrastingly, VC was metabolically oxidized by ethenotrophs in low-TOC sediments with low reductive dechlorination potential. Accordingly, enrichment and isolation of metabolic VC-oxidizing ethenotrophs was successful only from the low-TOC sediment. Sequence analysis of etnE genes from the microcosms as well phylogenetic typing of the isolates showed that ethenotrophs in the sediments were facultative anaerobic Proteobacteria capable of coping with OAI-associated redox fluctuations. Our results suggest that local sediment heterogeneity supports/selects divergent VC degradation processes at the OAI and that high reductive dechlorination potential suppresses development of aerobic metabolic VC oxidation potential.
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Affiliation(s)
- Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
- KU Leuven , Division of Soil and Water Management, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
| | - Yue Lu
- Laboratory of Microbiology, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Javier Ramiro-Garcia
- Laboratory of Microbiology, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Peng Peng
- Laboratory of Microbiology, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Farai Maphosa
- Laboratory of Microbiology, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Detmer Sipkema
- Laboratory of Microbiology, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Winnie Dejonghe
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
| | - Hauke Smidt
- Laboratory of Microbiology, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Dirk Springael
- KU Leuven , Division of Soil and Water Management, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
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Impact of a wastewater treatment plant on microbial community composition and function in a hyporheic zone of a eutrophic river. Sci Rep 2015; 5:17284. [PMID: 26607034 PMCID: PMC4660315 DOI: 10.1038/srep17284] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/28/2015] [Indexed: 01/18/2023] Open
Abstract
The impact of the installation of a technologically advanced wastewater treatment plant (WWTP) on the benthic microbial community of a vinyl chloride (VC) impacted eutrophic river was examined two years before, and three and four years after installation of the WWTP. Reduced dissolved organic carbon and increased dissolved oxygen concentrations in surface water and reduced total organic carbon and total nitrogen content in the sediment were recorded in the post-WWTP samples. Pyrosequencing of bacterial 16S rRNA gene fragments in sediment cores showed reduced relative abundance of heterotrophs and fermenters such as Chloroflexi and Firmicutes in more oxic and nutrient poor post-WWTP sediments. Similarly, quantitative PCR analysis showed 1–3 orders of magnitude reduction in phylogenetic and functional genes of sulphate reducers, denitrifiers, ammonium oxidizers, methanogens and VC-respiring Dehalococcoides mccartyi. In contrast, members of Proteobacteria adapted to nutrient-poor conditions were enriched in post-WWTP samples. This transition in the trophic state of the hyporheic sediments reduced but did not abolish the VC respiration potential in the post-WWTP sediments as an important hyporheic sediment function. Our results highlight effective nutrient load reduction and parallel microbial ecological state restoration of a human-stressed urban river as a result of installation of a WWTP.
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Lee SS, Kaown D, Lee KK. Evaluation of the fate and transport of chlorinated ethenes in a complex groundwater system discharging to a stream in Wonju, Korea. JOURNAL OF CONTAMINANT HYDROLOGY 2015; 182:231-243. [PMID: 26433603 DOI: 10.1016/j.jconhyd.2015.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 08/27/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Abstract
Chlorinated ethenes such as trichloroethylene (TCE) are common and persistent groundwater contaminants. If contaminated groundwater discharges to a stream, then stream water pollution near the contamination site also becomes a problem. In this respect, the fate and transport of chlorinated ethenes around a stream in an industrial complex were evaluated using the concentration of each component, and hydrogeochemical, microbial, and compound-specific carbon isotope data. Temporal and spatial monitoring reveal that a TCE plume originating from main and local source zones continues to be discharged to a stream. Groundwater geochemical data indicate that aerobic conditions prevail in the upgradient area of the studied aquifer, whereas conditions become anaerobic in the downgradient. The TCE molar fraction is high at the main and local source zones, ranging from 87.4 to 99.2% of the total volatile organic compounds (VOCs). An increasing trend in the molar fraction of cis-1, 2-Dichloroethene (cis-DCE) and vinyl chloride (VC) was observed in the downgradient zone of the study area. The enriched δ(13)C values of TCE and depleted values of cis-DCE in the stream zone, compared to those of the source zone, also suggest biodegradation of VOCs. Microbial community structures in monitoring wells adjacent to the stream zone in the downgradient area were analyzed using 16S rRNA gene-based pyrosequencing to identify the microorganisms responsible for biodegradation. This was attributed to the high relative abundance of dechlorinating bacteria in monitoring wells under anaerobic conditions farthest from the stream in the downgradient area. The multilateral approaches adopted in this study, combining hydrogeochemical and biomolecular methods with compound-specific analyses, indicate that contaminants around the stream were naturally attenuated by active anaerobic biotransformation processes.
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Affiliation(s)
- Seong-Sun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea
| | - Dugin Kaown
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea
| | - Kang-Kun Lee
- School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea.
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Gilevska T, Ivdra N, Bonifacie M, Richnow HH. Improvement of analytical method for chlorine dual-inlet isotope ratio mass spectrometry of organochlorines. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1343-1350. [PMID: 26405796 DOI: 10.1002/rcm.7220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE The development of compound-specific chlorine isotope analysis (Cl-CSIA) is hindered by the lack of international organochlorine reference materials with isotopic compositions expressed in the δ(37) Cl notation. Thus, a reliable off-line analytical method is needed, allowing direct comparison of the δ(37) Cl values of molecularly different organic compounds with that of ocean-water chloride, to refer measurement results to a Standard Mean Ocean Chloride (SMOC) scale. METHODS The analytical method included sealed-tube combustion of organochlorines, precipitation and subsequent conversion of formed inorganic chlorides into methyl chloride (CH3 Cl) for the determination of δ(37) Cl values by Dual-Inlet Isotope Ratio Mass Spectrometry (DI-IRMS). A sample preparation step most sensitive to the sample size - dissolution of the inorganic copper chlorides formed by combustion of organochlorines - was identified. RESULTS Recovery of 94 ± 5% of chlorine was reached by applying determined optimal conditions for the dissolution, implying good external precision of δ(37) Cl values (-0.18 ± 0.03‰, 1σ, n = 3). Validation of the optimized method by the analysis of the produced and initial CH3 Cl samples with known δ(37) Cl values vs SMOC resulted in a difference of 0.11 ± 0.04‰ (1σ, n = 3), confirming the external precision and accuracy of the entire method. CONCLUSIONS The efficiency of the sample preparation method for CH3 Cl-DI-IRMS analysis is independent both of the chemical structure of the chlorinated compound and of the amount of chlorine in the sample. This method has the potential to be applied to a broad range of chlorinated organic compounds, e.g. reference material for the calibration of methods for Cl-CSIA against SMOC.
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Affiliation(s)
- Tetyana Gilevska
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, D-04318, Leipzig, Germany
| | - Natalija Ivdra
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, D-04318, Leipzig, Germany
- Isodetect GmbH - Company for Isotope Monitoring, Deutscher Platz 5b, D-04103, Leipzig, Germany
| | - Magali Bonifacie
- Equipe Géochimie des Isotopes Stables, Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, UMR 7154 CNRS, F-75005, Paris, France
- Observatoire Volcanologique et Sismologique de Guadeloupe, Institut de Physique du Globe de Paris, UMS3454 CNRS, Le Houëlmont, 97113, Gourbeyre Guadeloupe, France
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, D-04318, Leipzig, Germany
- Isodetect GmbH - Company for Isotope Monitoring, Deutscher Platz 5b, D-04103, Leipzig, Germany
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28
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Freitas JG, Rivett MO, Roche RS, Durrant Neé Cleverly M, Walker C, Tellam JH. Heterogeneous hyporheic zone dechlorination of a TCE groundwater plume discharging to an urban river reach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 505:236-252. [PMID: 25461025 DOI: 10.1016/j.scitotenv.2014.09.083] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 09/25/2014] [Accepted: 09/25/2014] [Indexed: 06/04/2023]
Abstract
The typically elevated natural attenuation capacity of riverbed-hyporheic zones is expected to decrease chlorinated hydrocarbon (CHC) groundwater plume discharges to river receptors through dechlorination reactions. The aim of this study was to assess physico-chemical processes controlling field-scale variation in riverbed-hyporheic zone dechlorination of a TCE groundwater plume discharge to an urban river reach. The 50-m long pool-riffle-glide reach of the River Tame in Birmingham (UK) studied is a heterogeneous high energy river environment. The shallow riverbed was instrumented with a detailed network of multilevel samplers. Freeze coring revealed a geologically heterogeneous and poorly sorted riverbed. A chlorine number reduction approach provided a quantitative indicator of CHC dechlorination. Three sub-reaches of contrasting behaviour were identified. Greatest dechlorination occurred in the riffle sub-reach that was characterised by hyporheic zone flows, moderate sulphate concentrations and pH, anaerobic conditions, low iron, but elevated manganese concentrations with evidence of sulphate reduction. Transient hyporheic zone flows allowing input to varying riverbed depths of organic matter are anticipated to be a key control. The glide sub-reach displayed negligible dechlorination attributed to the predominant groundwater baseflow discharge condition, absence of hyporheic zone, transition to more oxic conditions and elevated sulphate concentrations expected to locally inhibit dechlorination. The tail-of-pool-riffle sub-reach exhibited patchy dechlorination that was attributed to sub-reach complexities including significant flow bypass of a low permeability, high organic matter, silty unit of high dechlorination potential. A process-based conceptual model of reach-scale dechlorination variability was developed. Key findings of practitioner relevance were: riverbed-hyporheic zone CHC dechlorination may provide only a partial, somewhat patchy barrier to CHC groundwater plume discharges to a surface water receptor; and, monitoring requirements to assess the variability in CHC attenuation within a reach are expected to be onerous. Further research on transient hyporheic zone dechlorination is recommended.
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Affiliation(s)
- Juliana G Freitas
- Federal University of São Paulo (UNIFESP), Rua Prof. Artur Riedel, 275, Jd. Eldorado, Diadema, SP 09972-270, Brazil
| | - Michael O Rivett
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Rachel S Roche
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | | | - Caroline Walker
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - John H Tellam
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
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29
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Rivett MO, Dearden RA, Wealthall GP. Architecture, persistence and dissolution of a 20 to 45 year old trichloroethene DNAPL source zone. JOURNAL OF CONTAMINANT HYDROLOGY 2014; 170:95-115. [PMID: 25444120 DOI: 10.1016/j.jconhyd.2014.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 09/11/2014] [Accepted: 09/14/2014] [Indexed: 06/04/2023]
Abstract
A detailed field-scale investigation of processes controlling the architecture, persistence and dissolution of a 20 to 45year old trichloroethene (TCE) dense non-aqueous phase liquid (DNAPL) source zone located within a heterogeneous sand/gravel aquifer at a UK industrial site is presented. The source zone was partially enclosed by a 3-sided cell that allowed detailed longitudinal/fence transect monitoring along/across a controlled streamtube of flow induced by an extraction well positioned at the cell closed end. Integrated analysis of high-resolution DNAPL saturation (Sn) (from cores), dissolved-phase plume concentration (from multilevel samplers), tracer test and permeability datasets was undertaken. DNAPL architecture was determined from soil concentration data using partitioning calculations. DNAPL threshold soil concentrations and low Sn values calculated were sensitive to sorption assumptions. An outcome of this was the uncertainty in demarcation of secondary source zone diffused and sorbed mass that is distinct from trace amounts of low Sn DNAPL mass. The majority of source mass occurred within discrete lenses or pools of DNAPL associated with low permeability geological units. High residual saturation (Sn>10-20%) and pools (Sn>20%) together accounted for almost 40% of the DNAPL mass, but only 3% of the sampled source volume. High-saturation DNAPL lenses/pools were supported by lower permeability layers, but with DNAPL still primarily present within slightly more permeable overlying units. These lenses/pools exhibited approximately linearly declining Sn profiles with increasing elevation ascribed to preferential dissolution of the uppermost DNAPL. Bi-component partitioning calculations on soil samples confirmed that the dechlorination product cDCE (cis-dichloroethene) was accumulating in the TCE DNAPL. Estimated cDCE mole fractions in the DNAPL increased towards the DNAPL interface with the uppermost mole fraction of 0.04 comparable to literature laboratory data. DNAPL dissolution yielded heterogeneous dissolved-phase plumes of TCE and its dechlorination products that exhibited orders of magnitude local concentration variation. TCE solubility concentrations were relatively localised, but coincident with high saturation DNAPL lens source areas. Biotic dechlorination in the source zone area, however, caused cDCE to be the dominant dissolved-phase plume. The conservative tracer test usefully confirmed the continuity of a permeable gravel unit at depth through the source zone. Although this unit offered significant opportunity for DNAPL bypassing and decreased timeframes for dechlorination, it still transmitted a significant proportion of the contaminant flux. This was attributed to dissolution of DNAPL-mudstone aquitard associated sources at the base of the continuous gravel as well as contaminated groundwater from surrounding less permeable sand and gravel horizons draining into this permeable conduit. The cell extraction well provided an integrated metric of source zone dissolution yielding a mean concentration of around 45% TCE solubility (taking into account dechlorination) that was equivalent to a DNAPL mass removal rate of 0.4tonnes per annum over a 16m(2) cell cross sectional area of flow. This is a significant flux considering the source age and observed occurrence of much of the source mass within discrete lenses/pools. We advocate the need for further detailed field-scale studies on old DNAPL source zones that better resolve persistent pool/lens features and are of prolonged duration to assess the ageing of source zones. Such studies would further underpin the application of more surgical remediation technologies.
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Affiliation(s)
- Michael O Rivett
- Water Sciences, School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Rachel A Dearden
- Water Sciences, School of Geography, Earth & Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK; British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK
| | - Gary P Wealthall
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK; Geosyntec Consultants, Inc., 2-130 Research Lane, Guelph, Ontario N1G 5G3, Canada
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Ni Z, Smit M, Grotenhuis T, van Gaans P, Rijnaarts H. Effectiveness of stimulating PCE reductive dechlorination: a step-wise approach. JOURNAL OF CONTAMINANT HYDROLOGY 2014; 164:209-218. [PMID: 24995946 DOI: 10.1016/j.jconhyd.2014.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/05/2014] [Accepted: 06/13/2014] [Indexed: 06/03/2023]
Abstract
Reductive dechlorination of tetrachloroethene (PCE) and its daughter products in aquifers is often hampered by Fe(III) reducing conditions. Rigorous treatment to adjust the redox potential and stimulate dechlorination may be costly and potentially have negative effects on other aquifer functions. A step-wise experimental strategy was applied to investigate the effectiveness of various adjustment scenarios. Batch experiments with ascorbic acid (AA) and sodium lactate (SL) showed that 75μmol electron equivalents per gram dry mass of aquifer material was required to reach a sufficiently low redox potential for the onset of PCE dechlorination. Similar effects of either AA or SL on the measured redox potential suggest electron donors are not specific. However, the relative rates of Fe(III) and sulphate reduction appeared to be specific to the electron donor applied. While redox potential stabilised around -450mV after titration and sulphate was reduced to zero in both treatments, in the AA treatment a faster production of Fe(2+) was observed with a final concentration of 0.46mM compared to only 0.07mM in the SL treatment. In subsequent batch experiments with aquifer material that was pre-treated with AA or SL, PCE reductive dechlorination occurred within 30days. Further stimulation tests with extra electron donor or inoculum revealed that adding electron donor can accelerate the initiation of PCE biodegradation. However, bioaugmentation with dechlorinating bacteria is required to achieve complete reductive dechlorination to ethene. The findings from step-wise approaches are relevant for improving the cost-effectiveness of the design and operation of in-situ bioremediation at initially unfavourable environmental conditions.
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Affiliation(s)
- Zhuobiao Ni
- Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen, Netherlands.
| | - Martijn Smit
- Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen, Netherlands
| | - Tim Grotenhuis
- Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen, Netherlands
| | - Pauline van Gaans
- Soil and Groundwater System, Deltares, P.O. Box 85467, 3508 AL Utrecht, Netherlands
| | - Huub Rijnaarts
- Sub-Department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA Wageningen, Netherlands
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Broholm MM, Hunkeler D, Tuxen N, Jeannottat S, Scheutz C. Stable carbon isotope analysis to distinguish biotic and abiotic degradation of 1,1,1-trichloroethane in groundwater sediments. CHEMOSPHERE 2014; 108:265-273. [PMID: 24559936 DOI: 10.1016/j.chemosphere.2014.01.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 12/06/2013] [Accepted: 01/05/2014] [Indexed: 06/03/2023]
Abstract
The fate and treatability of 1,1,1-TCA by natural and enhanced reductive dechlorination was studied in laboratory microcosms. The study shows that compound-specific isotope analysis (CSIA) identified an alternative 1,1,1-TCA degradation pathway that cannot be explained by assuming biotic reductive dechlorination. In all biotic microcosms 1,1,1-TCA was degraded with no apparent increase in the biotic degradation product 1,1-DCA. 1,1,1-TCA degradation was documented by a clear enrichment in (13)C in all biotic microcosms, but not in the abiotic control, which suggests biotic or biotically mediated degradation. Biotic degradation by reductive dechlorination of 1,1-DCA to CA only occurred in bioaugmented microcosms and in donor stimulated microcosms with low initial 1,1,1-TCA or after significant decrease in 1,1,1-TCA concentration (after∼day 200). Hence, the primary degradation pathway for 1,1,1-TCA does not appear to be reductive dechlorination via 1,1-DCA. In the biotic microcosms, the degradation of 1,1,1-TCA occurred under iron and sulfate reducing conditions. Biotic reduction of iron and sulfate likely resulted in formation of FeS, which can abiotically degrade 1,1,1-TCA. Hence, abiotic degradation of 1,1,1-TCA mediated by biotic FeS formation constitute an explanation for the observed 1,1,1-TCA degradation. This is supported by a high 1,1,1-TCA (13)C enrichment factor consistent with abiotic degradation in biotic microcosms. 1,1-DCA carbon isotope field data suggest that this abiotic degradation of 1,1,1-TCA is a relevant process also at the field site.
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Affiliation(s)
- Mette M Broholm
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
| | - Daniel Hunkeler
- Centre for Hydrogeology, University of Neuchâtel, Neuchâtel, Switzerland.
| | | | - Simon Jeannottat
- Centre for Hydrogeology, University of Neuchâtel, Neuchâtel, Switzerland.
| | - Charlotte Scheutz
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
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32
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Weatherill J, Krause S, Voyce K, Drijfhout F, Levy A, Cassidy N. Nested monitoring approaches to delineate groundwater trichloroethene discharge to a UK lowland stream at multiple spatial scales. JOURNAL OF CONTAMINANT HYDROLOGY 2014; 158:38-54. [PMID: 24424265 DOI: 10.1016/j.jconhyd.2013.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 11/28/2013] [Accepted: 12/06/2013] [Indexed: 06/03/2023]
Abstract
Integrated approaches for the identification of pollutant linkages between aquifers and streams are of crucial importance for evaluating the environmental risks posed by industrial contaminants like trichloroethene (TCE). This study presents a systematic, multi-scale approach to characterising groundwater TCE discharge to a 'gaining' UK lowland stream receiving baseflow from a major Permo-Triassic sandstone aquifer. Beginning with a limited number of initial monitoring points, we aim to provide a 'first pass' mechanistic understanding of the plume's fate at the aquifer/stream interface using a novel combination of streambed diffusion samplers, riparian monitoring wells and drive-point mini-piezometers in a spatially nested sampling configuration. Our results indicate the potential discharge zone of the plume to extend along a stream reach of 120 m in length, delineated by a network of 60 in-situ diffusion samplers. Within this section, a 40 m long sub-reach of higher concentration (>10 μg L(-1)) was identified; centred on a meander bend in the floodplain. 25 multi-level mini-piezometers installed to target this down-scaled reach revealed even higher TCE concentrations (20-40 μg L(-1)), significantly above alluvial groundwater samples (<6 μg L(-1)) from 15 riparian monitoring wells. Significant lateral and vertical spatial heterogeneity in TCE concentrations within the top 1m of the streambed was observed with the decimetre-scale vertical resolution provided by multi-level mini-piezometers. It appears that the distribution of fine-grained material in the Holocene deposits of the riparian floodplain and below the channel is exerting significant local-scale geological controls on the location and magnitude of the TCE discharge. Large-scale in-situ biodegradation of the plume was not evident during the monitoring campaigns. However, detections of cis-1,2-dichloroethene and vinyl chloride in discrete sections of the sediment profile indicate that shallow (e.g., <20 cm) TCE transformation may be significant at a local scale in the streambed deposits. Our findings highlight the need for efficient multi-scale monitoring strategies in geologically heterogeneous lowland stream/aquifer systems in order to more adequately quantify the risk to surface water ecological receptors posed by point-source groundwater contaminants like TCE.
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Affiliation(s)
- John Weatherill
- School of Physical and Geographical Sciences, Keele University, United Kingdom.
| | - Stefan Krause
- School of Geography, Earth and Environmental Sciences, University of Birmingham, United Kingdom
| | - Kevin Voyce
- Environment Agency, Midlands Region, United Kingdom
| | - Falko Drijfhout
- School of Physical and Geographical Sciences, Keele University, United Kingdom
| | - Amir Levy
- School of Physical and Geographical Sciences, Keele University, United Kingdom
| | - Nigel Cassidy
- School of Physical and Geographical Sciences, Keele University, United Kingdom
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33
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Wiegert C, Mandalakis M, Knowles T, Polymenakou PN, Aeppli C, Macháčková J, Holmstrand H, Evershed RP, Pancost RD, Gustafsson O. Carbon and chlorine isotope fractionation during microbial degradation of tetra- and trichloroethene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6449-6456. [PMID: 23668287 DOI: 10.1021/es305236y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Two-dimensional compound-specific isotope analysis (2D-CSIA), combining stable carbon and chlorine isotopes, holds potential for monitoring of natural attenuation of chlorinated ethenes (CEs) in contaminated soil and groundwater. However, interpretation of 2D-CSIA data sets is challenged by a shortage of experimental Cl isotope enrichment factors. Here, isotope enrichments factors for C and Cl (i.e., εC and εCl) were determined for biodegradation of tetrachloroethene (PCE) and trichloroethene (TCE) using microbial enrichment cultures from a heavily CE-contaminated aquifer. The obtained values were εC = -5.6 ± 0.7‰ (95% CI) and εCl = -2.0 ± 0.5‰ for PCE degradation and εC = -8.8 ± 0.2‰ and εCl = -3.5 ± 0.5‰ for TCE degradation. Combining the values for both εC and εCl yielded mechanism-diagnostic εCl/εC ratios of 0.35 ± 0.11 and 0.37 ± 0.11 for the degradation of PCE and TCE, respectively. Application of the obtained εC and εCl values to a previously investigated field site gave similar estimates for the fraction of degraded contaminant as in the previous study, but with a reduced uncertainty in assessment of the natural attenuation. Furthermore, 16S rRNA gene clone library analyses were performed on three samples from the PCE degradation experiments. A species closely related to Desulfitobacterium aromaticivorans UKTL dominated the reductive dechlorination process. This study contributes to the development of 2D-CSIA as a tool for evaluating remediation strategies of CEs at contaminated sites.
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Affiliation(s)
- Charline Wiegert
- Department of Applied Environmental Science, ITM, Stockholm University, 106 91 Stockholm, Sweden.
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34
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Batıoğlu-Pazarbaşı M, Milosevic N, Malaguerra F, Binning PJ, Albrechtsen HJ, Bjerg PL, Aamand J. Discharge of landfill leachate to streambed sediments impacts the mineralization potential of phenoxy acid herbicides depending on the initial abundance of tfdA gene classes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2013; 176:275-83. [PMID: 23454590 DOI: 10.1016/j.envpol.2013.01.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 01/29/2013] [Accepted: 01/31/2013] [Indexed: 05/23/2023]
Abstract
To understand the role of abundance of tfdA gene classes belonging to β- and γ-proteobacteria on phenoxy acid herbicide degradation, streambed sediments were sampled around three seepage meters (SMs) installed in a landfill-impacted groundwater-surface water interface. Highest herbicide mass discharge to SM3, and lower herbicide mass discharges to SM1 and SM2 were determined due to groundwater discharge rates and herbicide concentrations. SM1-sediment with the lowest abundance of tfdA gene classes had the slowest mineralization, whereas SM2- and SM3-sediments with more abundant tfdA genes had faster mineralization. The observed difference in mineralization rates between discharge zones was simulated by a Monod-based kinetic model, which confirmed the role of abundance of tfdA gene classes. This study suggests presence of specific degraders adapted to slow growth rate and high yield strategy due to long-term herbicide exposure; and thus groundwater-surface water interface could act as a natural biological filter and protect stream water quality.
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Affiliation(s)
- Meriç Batıoğlu-Pazarbaşı
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark.
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35
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Hamonts K, Kuhn T, Vos J, Maesen M, Kalka H, Smidt H, Springael D, Meckenstock RU, Dejonghe W. Temporal variations in natural attenuation of chlorinated aliphatic hydrocarbons in eutrophic river sediments impacted by a contaminated groundwater plume. WATER RESEARCH 2012; 46:1873-1888. [PMID: 22280951 DOI: 10.1016/j.watres.2012.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 12/22/2011] [Accepted: 01/02/2012] [Indexed: 05/31/2023]
Abstract
Chlorinated aliphatic hydrocarbons (CAHs) often discharge into rivers as contaminated groundwater baseflow. Biotransformation, sorption and dilution of CAHs in the impacted river sediments have been reported to reduce discharge, but the effect of temporal variations in environmental conditions on the occurrence and extent of those processes in river sediments is largely unknown. We monitored the reduction of CAH discharge into the Zenne River during a 21-month period. Despite a relatively stable influx of CAHs from the groundwater, the total reduction in CAH discharge from 120 to 20 cm depth in the river sediments, on average 74 ± 21%, showed moderate to large temporal variations, depending on the riverbed location. High organic carbon and anaerobic conditions in the river sediments allowed microbial reductive dechlorination of both chlorinated ethenes and chlorinated ethanes. δ(13)C values of the CAHs showed that this biotransformation was remarkably stable over time, despite fluctuating pore water temperatures. Daughter products of the CAHs, however, were not detected in stoichiometric amounts and suggested the co-occurrence of a physical process reducing the concentrations of CAHs in the riverbed. This process was the main process causing temporal variations in natural attenuation of the CAHs and was most likely dilution by surface water-mixing. However, higher spatial resolution monitoring of flow transients in the riverbed is required to prove dilution contributions due to dynamic surface water-groundwater flow exchanges. δ(13)C values and a site-specific isotope enrichment factor for reductive dechlorination of the main groundwater pollutant vinyl chloride (VC) allowed assessment of changes over time in the extent of both biotransformation and dilution of VC for different scenarios in which those processes either occurred consecutively or simultaneously between 120 and 20 cm depth in the riverbed. The extent of reductive dechlorination of VC ranged from 27 to 89% and differed spatially but was remarkably stable over time, whereas the extent of VC reduction by dilution ranged from 6 to 94%, showed large temporal variations, and was often the main process contributing to the reduction of VC discharge into the river.
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Affiliation(s)
- Kelly Hamonts
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
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36
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Schmidt TC, Jochmann MA. Origin and fate of organic compounds in water: characterization by compound-specific stable isotope analysis. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2012; 5:133-155. [PMID: 22482787 DOI: 10.1146/annurev-anchem-062011-143143] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Within the past 15 years, compound-specific stable isotope analysis has continued to increase in popularity in the area of contaminant hydrology of organic molecules. In particular, in cases where concentration data alone are insufficient to elucidate environmental processes unequivocally, the isotope signature can provide additional unique information. Specifically, it can help answer questions about contaminant source apportionment, quantification of biotic and abiotic processes, and identification of transformation reactions on a mechanistic level. We review advances in laboratory and field investigations and exemplary applications in contaminant hydrology via stable isotope analysis. We also highlight future directions in the field.
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Affiliation(s)
- Torsten C Schmidt
- Instrumental Analytical Chemistry, University of Duisburg-Essen, 45141 Essen, Germany.
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37
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Courbet C, Rivière A, Jeannottat S, Rinaldi S, Hunkeler D, Bendjoudi H, de Marsily G. Complementing approaches to demonstrate chlorinated solvent biodegradation in a complex pollution plume: Mass balance, PCR and compound-specific stable isotope analysis. JOURNAL OF CONTAMINANT HYDROLOGY 2011; 126:315-329. [PMID: 22115095 DOI: 10.1016/j.jconhyd.2011.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 07/25/2011] [Accepted: 08/30/2011] [Indexed: 05/31/2023]
Abstract
This work describes the use of different complementing methods (mass balance, polymerase chain reaction assays and compound-specific stable isotope analysis) to demonstrate the existence and effectiveness of biodegradation of chlorinated solvents in an alluvial aquifer. The solvent-contaminated site is an old chemical factory located in an alluvial plain in France. As most of the chlorinated contaminants currently found in the groundwater at this site were produced by local industries at various times in the past, it is not enough to analyze chlorinated solvent concentrations along a flow path to convincingly demonstrate biodegradation. Moreover, only a few data were initially available to characterize the geochemical conditions at this site, which were apparently complex at the source zone due to (i) the presence of a steady oxygen supply to the groundwater by irrigation canal losses and river infiltration and (ii) an alkaline pH higher than 10 due to former underground lime disposal. A demonstration of the existence of biodegradation processes was however required by the regulatory authority within a timeframe that did not allow a full geochemical characterization of such a complex site. Thus a combination of different fast methods was used to obtain a proof of the biodegradation occurrence. First, a mass balance analysis was performed which revealed the existence of a strong natural attenuation process (biodegradation, volatilization or dilution), despite the huge uncertainty on these calculations. Second, a good agreement was found between carbon isotopic measurements and PCR assays (based on 16S RNA gene sequences and functional genes), which clearly indicated reductive dechlorination of different hydrocarbons (Tetrachloroethene--PCE-, Trichloroethene--TCE-, 1,2-cisDichloroethene--cis-1,2-DCE-, 1,2-transDichloroethene-trans--1,2-DCE-, 1,1-Dichloroethene--1,1-DCE-, and Vinyl Chloride--VC) to ethene. According to these carbon isotope measurements, although TCE biodegradation seems to occur only in the upgradient part of the studied zone, DCE and VC dechlorination (originating from the initial TCE dechlorination) occurs along the entire flowpath. TCE reductase was not detected among the Dehalococcoides bacteria identified by quantitative PCR (qPCR), while DCE and VC reductases were present in the majority of the population. Reverse transcriptase PCR assays (rt-PCR) also indicated that bacteria and their DCE and VC reductases were active. Mass balance calculations showed moreover that 1,1-DCE was the predominant DCE isomer produced by TCE dechlorination in the upgradient part of the site. Consequently, coupling rt-PCR assays with isotope measurements removes the uncertainties inherent in a simple mass balance approach, so that when the three methods are used jointly, they allow the identification and quantification of natural biodegradation, even under apparently complex geochemical and hydraulic conditions.
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Affiliation(s)
- Christelle Courbet
- Univ. Pierre et Marie Curie, Paris 06, UMR Sisyphe, 4 place Jussieu 75252 Paris, France
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38
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Himmelheber DW, Pennell KD, Hughes JB. Evaluation of a laboratory-scale bioreactive in situ sediment cap for the treatment of organic contaminants. WATER RESEARCH 2011; 45:5365-5374. [PMID: 21872291 PMCID: PMC3183260 DOI: 10.1016/j.watres.2011.06.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 04/07/2011] [Accepted: 06/17/2011] [Indexed: 05/31/2023]
Abstract
The development of bioreactive sediment caps, in which microorganisms capable of contaminant transformation are placed within an in situ cap, provides a potential remedial design that can sustainably treat sediment and groundwater contaminants. The goal of this study was to evaluate the ability and limitations of a mixed, anaerobic dechlorinating consortium to treat chlorinated ethenes within a sand-based cap. Results of batch experiments demonstrate that a tetrachloroethene (PCE)-to-ethene mixed consortium was able to completely dechlorinate dissolved-phase PCE to ethene when supplied only with sediment porewater obtained from a sediment column. To simulate a bioreactive cap, laboratory-scale sand columns inoculated with the mixed culture were placed in series with an upflow sediment column and directly supplied sediment effluent and dissolved-phase chlorinated ethenes. The mixed consortium was not able to sustain dechlorination activity at a retention time of 0.5 days without delivery of amendments to the sediment effluent, evidenced by the loss of cis-1,2-dichloroethene (cis-DCE) dechlorination to vinyl chloride. When soluble electron donor was supplied to the sediment effluent, complete dechlorination of cis-DCE to ethene was observed at retention times of 0.5 days, suggesting that sediment effluent lacked sufficient electron donor to maintain active dechlorination within the sediment cap. Introduction of elevated contaminant concentrations also limited biotransformation performance of the dechlorinating consortium within the cap. These findings indicate that in situ bioreactive capping can be a feasible remedial approach, provided that residence times are adequate and that appropriate levels of electron donor and contaminant exist within the cap.
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Affiliation(s)
- David W Himmelheber
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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39
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Tiehm A, Schmidt KR. Sequential anaerobic/aerobic biodegradation of chloroethenes—aspects of field application. Curr Opin Biotechnol 2011; 22:415-21. [DOI: 10.1016/j.copbio.2011.02.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 02/02/2011] [Accepted: 02/03/2011] [Indexed: 10/18/2022]
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40
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Hunkeler D, Abe Y, Broholm MM, Jeannottat S, Westergaard C, Jacobsen CS, Aravena R, Bjerg PL. Assessing chlorinated ethene degradation in a large scale contaminant plume by dual carbon-chlorine isotope analysis and quantitative PCR. JOURNAL OF CONTAMINANT HYDROLOGY 2011; 119:69-79. [PMID: 21030108 DOI: 10.1016/j.jconhyd.2010.09.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Revised: 09/20/2010] [Accepted: 09/21/2010] [Indexed: 05/30/2023]
Abstract
The fate of chlorinated ethenes in a large contaminant plume originating from a tetrachloroethene (PCE) source in a sandy aquifer in Denmark was investigated using novel methods including compound-specific carbon and chlorine isotope analysis and quantitative real-time polymerase chain reaction (qPCR) methods targeting Dehaloccocoides sp. and vcrA genes. Redox conditions were characterized as well based on concentrations of dissolved redox sensitive compounds and sulfur isotopes in SO(4)(2-). In the first 400 m downgradient of the source, the plume was confined to the upper 20 m of the aquifer. Further downgradient it widened in vertical direction due to diverging groundwater flow reaching a depth of up to 50 m. As the plume dipped downward and moved away from the source, O(2) and NO(3)(-) decreased to below detection levels, while dissolved Fe(2+) and SO(4)(2-) increased above detectable concentrations, likely due to pyrite oxidation as confirmed by the depleted sulfur isotope signature of SO(4)(2-). In the same zone, PCE and trichloroethene (TCE) disappeared and cis-1,2-dichloroethene (cDCE) became the dominant chlorinated ethene. PCE and TCE were likely transformed by reductive dechlorination rather than abiotic reduction by pyrite as indicated by the formation of cDCE and stable carbon isotope data. TCE and cDCE showed carbon isotope trends typical for reductive dechlorination with an initial depletion of (13)C in the daughter products followed by an enrichment of (13)C as degradation proceeded. At 1000 m downgradient of the source, cDCE was the dominant chlorinated ethene and had reached the source δ(13)C value confirming that cDCE was not affected by abiotic or biotic degradation. Further downgradient (up to 1900 m), cDCE became enriched in (13)C by up to 8 ‰ demonstrating its further transformation while vinylchloride (VC) concentrations remained low (<1 μg/L) and ethene was not observed. The correlated shift of carbon and chlorine isotope ratios of cDCE by 8 and 3.9 ‰, respectively, the detection of Dehaloccocides sp genes, and strongly reducing conditions in this zone provide strong evidence for reductive dechlorination of cDCE. The significant enrichment of (13)C in VC indicates that VC was transformed further, although the mechanism could not be determined. The transformation of cDCE was the rate limiting step as no accumulation of VC occurred. In summary, the study demonstrates that carbon-chlorine isotope analysis and qPCR combined with traditional approaches can be used to gain detailed insight into the processes that control the fate of chlorinated ethenes in large scale plumes.
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Affiliation(s)
- Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, Neuchâtel, Switzerland.
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41
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Roy JW, Bickerton G. Proactive screening approach for detecting groundwater contaminants along urban streams at the reach-scale. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:6088-6094. [PMID: 20617839 DOI: 10.1021/es101492x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Here we outline and demonstrate a screening approach for the detection of groundwater contaminants along urban streams within unconsolidated beds. It involves the rapid acquisition of groundwater samples along urban stream reaches at a spacing of about 10 m and from depths of about 25-75 cm below the streambed, with analyses for a suite of potential contaminants. This screening approach may serve two functions: a) providing information for assessing and mitigating the toxicity and eutrophication risks to aquatic ecosystems posed by groundwater contaminants and b) detecting and identifying groundwater contamination in urban settings more rapidly and inexpensively compared to land-based well installations. The screening approach was tested at three urban streams, each affected by a known chlorinated-solvent plume. All three known groundwater plumes were detected and roughly delineated. Multiple, previously unknown, areas or types of groundwater contamination were also identified at each stream. The newly identified contaminants and plumes included petroleum hydrocarbons (BTEX, naphthalene, MTBE), 1,4-dioxane, nitrate and phosphate, road salt, and various metals (including arsenic, cadmium, chromium, copper, lead) at elevated concentrations compared to background values and relevant Canadian water quality guidelines. These findings suggest that this screening approach may be a useful tool for both ecologists performing ecological assessments and stream restorations and for hydrogeologists undertaking groundwater protection activities. Given the numerous contaminants detected, it may be appropriate to apply this technique proactively to better determine the pervasiveness of urban groundwater contaminants, especially along urban streams.
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Affiliation(s)
- James W Roy
- National Water Research Institute, Environment Canada, Burlington, Ontario, Canada.
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Mattes TE, Alexander AK, Coleman NV. Aerobic biodegradation of the chloroethenes: pathways, enzymes, ecology, and evolution. FEMS Microbiol Rev 2010; 34:445-75. [DOI: 10.1111/j.1574-6976.2010.00210.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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43
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Chuang AS, Jin YO, Schmidt LS, Li Y, Fogel S, Smoler D, Mattes TE. Proteomic analysis of ethene-enriched groundwater microcosms from a vinyl chloride-contaminated site. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:1594-1601. [PMID: 20121086 DOI: 10.1021/es903033r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Contamination of groundwater with vinyl chloride (VC), a known human carcinogen, is a common environmental problem at plastics manufacturing, dry cleaning, and military sites. At many sites, there is the potential to cleanup VC groundwater plumes with aerobic VC-oxidizing microorganisms (e.g., methanotrophs, etheneotrophs, and VC-assimilating bacteria). Environmental biotechnologies that reveal the presence and activity of VC-oxidizing bacteria in contaminated groundwater samples would provide valuable lines of evidence that bioremediation of VC is occurring at a site. We applied targeted shotgun mass spectrometry-based proteomic methods to ethene-enriched groundwater microcosms from a VC-contaminated site. Polypeptides from the enzymes alkene monooxygenase (EtnC) and epoxyalkane:CoM transferase (EtnE), both of which are expressed by aerobic etheneotrophs and VC-assimilating bacteria, were identified in 7 of the 14 samples analyzed. Bioinformatic analysis revealed that 2 EtnC and 5 EtnE peptides were unique to deduced EtnC and EtnE sequences from two different cultivated strains. In addition, several partial EtnE genes sequenced from microcosms matched with observed EtnE peptides. Our results have revealed broader etheneotroph functional gene diversity and demonstrate the feasibility, speed, and accuracy of applying a targeted metaproteomics approach to identifying protein biomarkers from etheneotrophs in complex environmental samples.
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Affiliation(s)
- Adina S Chuang
- Department of Civil and Environmental Engineering, University of Iowa, Iowa City, IA, USA
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