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Suchana S, Edwards E, Mack EE, Lomheim L, Melo N, Gavazza S, Passeport E. Compatibility of polar organic chemical integrative sampler (POCIS) with compound specific isotope analysis (CSIA) of substituted chlorobenzenes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167628. [PMID: 37804973 DOI: 10.1016/j.scitotenv.2023.167628] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Compound specific isotope analysis (CSIA) is a powerful technique to demonstrate in situ degradation of traditional groundwater contaminants when concentrations are typically in the mg/L range. Currently, an efficient preconcentration method is lacking to expand CSIA to low aqueous concentration environmental samples. Specially for the H- and N-CSIA of heteroatom-bearing non-traditional compounds, the CSIA analytical detection limits are significantly higher than that of the C-CSIA. This work demonstrates the compatibility of polar organic chemical integrative sampler (POCIS) with C-, H-, and N-CSIA using four nitro- and amino-substituted chlorobenzenes that are common industrial feedstocks for numerous applications and are commonly detected in the environment at mg/L to μg/L range. Using lab experiments, we showed isotopic equilibrium in POCIS was achieved after 30 days with either a negligible (<0.5 ‰) or a constant shift for C (<1 ‰) and N (<2 ‰). Similar negligible (<5 ‰) or constant shift (<20 ‰) was evident for H isotope except for 3,4-dichloroaniline. The method quantification limits for the combined sorbent and membrane of one POCIS were comparable to that of the solid phase extraction (SPE) using 10 L water. Next, we demonstrated the field applicability of POCIS for C- and N-CSIA after a 60-day deployment in a pilot constructed wetland by showing <1 ‰ difference between the δ13C and δ15N obtained from POCIS and SPE. Finally, we evaluated whether the biofilm development on POCIS membrane could affect the isotope signature of the sampled compounds during field deployment. Although a diverse microbial community was identified on the membrane after a 60-day deployment, we did not observe significant isotope fractionation. This was likely due to either slower diffusion in the biofilm or microbial degradation of the sampled compounds. This work demonstrates the potential of using POCIS-CSIA as a simple, fast, and sensitive method for low-concentration contaminants, such as pesticides, pharmaceuticals, and flame-retardants.
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Affiliation(s)
- Shamsunnahar Suchana
- Department of Civil & Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada
| | - Elizabeth Edwards
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - E Erin Mack
- Corteva Environmental Remediation, Corteva Agriscience, Wilmington, DE 19805, USA
| | - Line Lomheim
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Natanna Melo
- Laboratório de Saneamento Ambiental, Departamento de Engenharia Civil e Ambiental, Universidade Federal de Pernambuco, Recife, PE 50740-530, Brazil
| | - Sávia Gavazza
- Laboratório de Saneamento Ambiental, Departamento de Engenharia Civil e Ambiental, Universidade Federal de Pernambuco, Recife, PE 50740-530, Brazil
| | - Elodie Passeport
- Department of Civil & Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada; Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada.
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2
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Suchana S, Passeport E. Implications of polar organic chemical integrative sampler for high membrane sorption and suitability of polyethersulfone as a single-phase sampler. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:157898. [PMID: 35952872 DOI: 10.1016/j.scitotenv.2022.157898] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Polar organic chemical integrative sampler (POCIS) contains sorbent, which is typically enclosed between two polyethersulfones (PES) membranes. A significant PES uptake is reported for many contaminants, yet, aqueous concentration is mainly correlated with the sorbent uptake using first-order kinetics. Under high PES sorption, the first-order kinetics often provide erroneous sampling rate for the sorbent phase due to increased membrane resistance. This work evaluated the uptake of four high PES sorbing chemicals, i.e., three Cl- and CH3-substituted nitrobenzenes and one chlorinated aniline using POCIS and the potential of a single-phase PES sampler using laboratory experiments. POCIS calibration results demonstrated that both sorbent and membrane had similar affinity for the target compounds. A rapid PES sorption occurred in the earlier days (<7 days) followed by a gradual increase in the PES phase concentration (equilibrium not achieved after 60 days). Especially, the membrane was the primary sink for 3,4-dichloroaniline and 3,4-dichloronitrobenzene for up to 14 and 31 days, respectively. On the other hand, the single-phase PES sampler showed similar mass uptake as POCIS and reached equilibrium within 19 days under static condition, indicating its potential suitability in the equilibrium regime. PES-water partition coefficient of the target compounds was between 1.2 and 6.5 L/g. Finally, we present a poly-parameter linear-free energy relationship (pp-LFER) using published data to predict the PES-water partition coefficients. The pp-LFER models showed moderate predictability as indicated by R2adj values between 0.7 and 0.9 for both internal and external data set consisting of a wide range of hydrophobic and hydrophilic compounds (-0.1 ≤ logKOW ≤ 7.4). The proposed pp-LFER model can be used to screen high PES-sorbing chemicals to increase the reliability and accuracy of aqueous concentration prediction from POCIS sampling and to select the most appropriate sampling approach for new compounds.
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Affiliation(s)
- Shamsunnahar Suchana
- Department of Civil & Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada
| | - Elodie Passeport
- Department of Civil & Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada; Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada.
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3
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Wu L, Suchana S, Flick R, Kümmel S, Richnow H, Passeport E. Carbon, hydrogen and nitrogen stable isotope fractionation allow characterizing the reaction mechanisms of 1H-benzotriazole aqueous phototransformation. WATER RESEARCH 2021; 203:117519. [PMID: 34391022 DOI: 10.1016/j.watres.2021.117519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/13/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
1H-benzotriazole is part of a larger family of benzotriazoles, which are widely used as lubricants, polymer stabilizers, corrosion inhibitors, and anti-icing fluid components. It is frequently detected in urban runoff, wastewater, and receiving aquatic environments. 1H-benzotriazole is typically resistant to biodegradation and hydrolysis, but can be transformed via direct photolysis and photoinduced mechanisms. In this study, the phototransformation mechanisms of 1H-benzotriazole were characterized using multi-element compound-specific isotope analysis (CSIA). The kinetics, transformation products, and isotope fractionation results altogether revealed that 1H-benzotriazole direct photolysis and indirect photolysis induced by OH radicals involved two alternative pathways. In indirect photolysis, aromatic hydroxylation dominated and was associated with small carbon (εC = -0.65 ± 0.03‰), moderate hydrogen (εH = -21.6‰), and negligible nitrogen isotope enrichment factors and led to hydroxylated forms of benzotriazole. In direct photolysis of 1H-benzotriazole, significant nitrogen (εN = -8.4 ± 0.4 to -4.2 ± 0.3‰) and carbon (εC = -4.3 ± 0.2 to -1.64 ± 0.04‰) isotope enrichment factors indicated an initial N-N bond cleavage followed by nitrogen elimination with a C-N bond cleavage. The results of this study highlight the potential for multi-element CSIA application to track 1H-benzotriazole degradation in aquatic environments.
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Affiliation(s)
- Langping Wu
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George St., Toronto, ON M5S 1A4, Canada
| | - Shamsunnahar Suchana
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George St., Toronto, ON M5S 1A4, Canada
| | - Robert Flick
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, Leipzig 04318, Germany
| | - Hans Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, Leipzig 04318, Germany
| | - Elodie Passeport
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George St., Toronto, ON M5S 1A4, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada.
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4
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Wang G, Liu Y, Tao W, Zhao X, Wang H, Lou Y, Li N, Liu Y. Assessing microbial degradation degree and bioavailability of BDE-153 in natural wetland soils: Implication by compound-specific stable isotope analysis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 260:114014. [PMID: 32000026 DOI: 10.1016/j.envpol.2020.114014] [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: 10/01/2019] [Revised: 12/28/2019] [Accepted: 01/16/2020] [Indexed: 06/10/2023]
Abstract
Microbial degradation is an important pathway for the attenuation of polybrominated diphenyl ethers (PBDEs) in natural soils. In this study, the compound-specific stable isotope analysis (CSIA) was applied to characterize microbial degradation of BDE-153, one of the prevailing and toxic PBDE congeners, in natural wetland soils. During the 45-day incubation, the residual percentages of BDE-153 decreased to 67.9% and 73.6% in non-sterilized soils spiked with 1.0 and 5.0 μg/g, respectively, which were both much lower than those in sterilized soils (96.0% and 97.2%). This result indicated that microbial degradation could accelerate BDE-153 elimination in wetland soils. Meanwhile, the significant carbon isotope fractionation was observed in non-sterilized soils, with δ13C of BDE-153 shifting from -29.4‰ to -26.7‰ for 1.0 μg/g and to -27.2‰ for 5.0 μg/g, respectively, whilst not in sterilized soils. This phenomenon indicated microbial degradation could induce stable carbon isotope fractionation of BDE-153. The carbon isotope enrichment factor (εc) for BDE-153 microbial degradation was first determined as -7.58‰, which could be used to assess the microbial degradation and bioavailability of BDE-153 in wetland soils. Based on δ13C and εc, the new methods were developed to dynamically and quantitatively estimate degradation degree and bioavailability of BDE-153 during degradation process, respectively, which could exclude interference of physical processes. This work revealed that CSIA was a promising method to investigate in situ microbial degradation of PBDEs in field studies.
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Affiliation(s)
- Guoguang Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China; Environmental Information Institute, Dalian Maritime University, Dalian, 116026, China
| | - Yu Liu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China; Environmental Information Institute, Dalian Maritime University, Dalian, 116026, China.
| | - Wei Tao
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Xinda Zhao
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Haixia Wang
- Navigation College, Dalian Maritime University, Dalian, 116026, China
| | - Yadi Lou
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Na Li
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Yuxin Liu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
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Wanner P, Hunkeler D. Isotope fractionation due to aqueous phase diffusion - What do diffusion models and experiments tell? - A review. CHEMOSPHERE 2019; 219:1032-1043. [PMID: 30682760 DOI: 10.1016/j.chemosphere.2018.12.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/30/2018] [Accepted: 12/05/2018] [Indexed: 05/26/2023]
Abstract
For the interpretation of stable isotope ratio trends in saturated geochemical systems, the magnitude of aqueous phase diffusion-induced isotope fractionation needs to be known. This study reviews how five diffusion models (Fick, Maxwell-Stefan, Einstein, Langevin, Mode-Coupling Theory Analysis (MCTA) of diffusion) predict isotope fractionation due to aqueous phase diffusion and compares them with experimental results. The reviewed diffusion models were not consistent regarding the prediction of the mass (m) dependency of the aqueous phase diffusion coefficient (D). The predictions range from a square root power law (D ∝ m-0.5) to an opposite mass dependency of D (D ∝ mβ). Experimental studies exhibited consistently a weak power law mass dependency of the diffusion coefficient (D ∝ m-β with β < 0.5) for the vast majority of dissolved species and a larger diffusion-induced isotope effect for low weight noble gases (D ∝ m-0.5). The weak power law mass dependency of D for the species other than low weight noble gases is consistent with the MCTA of diffusion. The MCTA suggests that the weak power law mass dependency of D originates from interplays between strongly mass dependent short-term and mass independent long-term solute-solvent interactions. The larger isotope fractionation for low weight noble gases could be attributed to quantum isotope effects significantly magnifying the aqueous phase diffusion-induced isotope fractionation. Our review shows, that except for low weight noble gases a weak power law mass dependency of D is likely the most adequate assumption for aqueous phase diffusion-induced isotope fractionation in geochemical systems.
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Affiliation(s)
- Philipp Wanner
- College of Engineering and Physical Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada.
| | - Daniel Hunkeler
- Centre for Hydrogeology & Geothermics (CHYN), University of Neuchâtel, Rue Emil Argand 11, CH-2000, Neuchâtel, Switzerland
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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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Chen G, Shouakar-Stash O, Phillips E, Justicia-Leon SD, Gilevska T, Sherwood Lollar B, Mack EE, Seger ES, Löffler FE. Dual Carbon-Chlorine Isotope Analysis Indicates Distinct Anaerobic Dichloromethane Degradation Pathways in Two Members of Peptococcaceae. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8607-8616. [PMID: 29975517 DOI: 10.1021/acs.est.8b01583] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Dichloromethane (DCM) is a probable human carcinogen and frequent groundwater contaminant and contributes to stratospheric ozone layer depletion. DCM is degraded by aerobes harboring glutathione-dependent DCM dehalogenases; however, DCM contamination occurs in oxygen-deprived environments, and much less is known about anaerobic DCM metabolism. Some members of the Peptococcaceae family convert DCM to environmentally benign products including acetate, formate, hydrogen (H2), and inorganic chloride under strictly anoxic conditions. The current study applied stable carbon and chlorine isotope fractionation measurements to the axenic culture Dehalobacterium formicoaceticum and to the consortium RM comprising DCM degrader Candidatus Dichloromethanomonas elyunquensis. Degradation-associated carbon and chlorine isotope enrichment factors (εC and εCl) of -42.4 ± 0.7‰ and -5.3 ± 0.1‰, respectively, were measured in D. formicoaceticum cultures. A similar εCl of -5.2 ± 0.1‰, but a substantially lower εC of -18.3 ± 0.2‰, were determined for Ca. Dichloromethanomonas elyunquensis. The εC and εCl values resulted in distinctly different dual element C-Cl isotope correlations (ΛC/Cl = Δδ13C/Δδ37Cl) of 7.89 ± 0.12 and 3.40 ± 0.03 for D. formicoaceticum and Ca. Dichloromethanomonas elyunquensis, respectively. The distinct ΛC/Cl values obtained for the two cultures imply mechanistically distinct C-Cl bond cleavage reactions, suggesting that members of Peptococcaceae employ different pathways to metabolize DCM. These findings emphasize the utility of dual carbon-chlorine isotope analysis to pinpoint DCM degradation mechanisms and to provide an additional line of evidence that detoxification is occurring at DCM-contaminated sites.
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Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology, Department of Civil and Environmental Engineering, and Department of Microbiology , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Orfan Shouakar-Stash
- Isotope Tracer Technologies Inc. (IT2) , Waterloo , Ontario N2 V 1Z5 , Canada
- Department of Earth and Environmental Sciences , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
- School of Engineering , University of Guelph , Guelph , Ontario N1G 2W1 , Canada
| | - Elizabeth Phillips
- Department of Earth Sciences , University of Toronto , Toronto , Ontario M5S 3B1 , Canada
| | - Shandra D Justicia-Leon
- School of Biology , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Tetyana Gilevska
- Department of Earth Sciences , University of Toronto , Toronto , Ontario M5S 3B1 , Canada
| | | | - E Erin Mack
- DuPont Corporate Remediation Group , E. I. DuPont de Nemours and Company , Wilmington , Delaware 19805 , United States
| | - Edward S Seger
- The Chemours Company , Wilmington , Delaware 19899 , United States
| | - Frank E Löffler
- Center for Environmental Biotechnology, Department of Civil and Environmental Engineering, and Department of Microbiology , University of Tennessee , Knoxville , Tennessee 37996 , United States
- Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division , University of Tennessee and Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Department of Biosystems Engineering and Soil Science , University of Tennessee , Knoxville , Tennessee 37996 , United States
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Bakkour R, Bolotin J, Sellergren B, Hofstetter TB. Molecularly Imprinted Polymers for Compound-Specific Isotope Analysis of Polar Organic Micropollutants in Aquatic Environments. Anal Chem 2018; 90:7292-7301. [DOI: 10.1021/acs.analchem.8b00493] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Rani Bakkour
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Jakov Bolotin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Börje Sellergren
- Department of Biomedical Sciences, Malmö University, 20506 Malmö, Sweden
| | - Thomas B. Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland
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9
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Passeport E, Zhang N, Wu L, Herrmann H, Sherwood Lollar B, Richnow HH. Aqueous photodegradation of substituted chlorobenzenes: Kinetics, carbon isotope fractionation, and reaction mechanisms. WATER RESEARCH 2018; 135:95-103. [PMID: 29459118 DOI: 10.1016/j.watres.2018.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/03/2018] [Accepted: 02/05/2018] [Indexed: 06/08/2023]
Abstract
Substituted chlorobenzenes are the basic substructure of many surface water contaminants. In this study, the isotope fractionation and reaction mechanisms involved during the aqueous direct and indirect photodegradation of CH3-, Cl-, and NO2- substituted chlorobenzenes were investigated in laboratory experiments. Only 4-nitrochlorobenzene showed slow but isotopically fractionating direct photolysis. During indirect photodegradation using UV/H2O2-generated OH radicals, the pseudo first-order reaction rate constants increased in the order of the NO2- < Cl- < CH3- substituted chlorobenzenes. The most pronounced carbon enrichment factors were observed for nitrochlorobenzenes (up to -4.8 ± 0.5‰), whereas the lowest were for chlorotoluenes (≤-1.0 ± 0.1‰). As the substituents became more electron-withdrawing, the activation energy barrier increased, leading to slower reaction rates, and the transition state changed to a more symmetrical or less reactant-like structure, resulting in larger apparent kinetic isotope effects. The results suggest that the rate-determining step in the reaction with OH radicals was the addition of the electrophile to the benzene ring. Even though further research is needed to quantify isotope fractionation during other transformation processes, these results showed evidence that compound specific isotope analysis can be used as a diagnostic tool for the fate of substituted chlorobenzenes in water.
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Affiliation(s)
- Elodie Passeport
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, ON M5S 3B1, Canada.
| | - Ning Zhang
- Department of Isotope Biogeochemistry, Helmholtz Center for Environmental Research UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Langping Wu
- Department of Isotope Biogeochemistry, Helmholtz Center for Environmental Research UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Hartmut Herrmann
- TROPOS Leibniz Institute for Tropospheric Research, Atmospheric Chemistry Department (ACD), Permoserstrasse 15, 04318 Leipzig, Germany
| | - Barbara Sherwood Lollar
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, ON M5S 3B1, Canada
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Center for Environmental Research UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
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Passeport E, Landis R, Lacrampe-Couloume G, Lutz EJ, Mack EE, West K, Morgan S, Sherwood Lollar B. Sediment Monitored Natural Recovery Evidenced by Compound Specific Isotope Analysis and High-Resolution Pore Water Sampling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:12197-12204. [PMID: 27771950 DOI: 10.1021/acs.est.6b02961] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Monitoring natural recovery of contaminated sediments requires the use of techniques that can provide definitive evidence of in situ contaminant degradation. In this study, a passive diffusion sampler, called "peeper", was combined with Compound Specific Isotope Analysis to determine benzene and monochlorobenzene (MCB) stable carbon isotope values at a fine vertical resolution (3 cm) across the sediment water interface at a contaminated site. Results indicated significant decrease in concentrations of MCB from the bottom to the top layers of the sediment over 25 cm, and a 3.5 ‰ enrichment in δ13C values of MCB over that distance. Benzene was always at lower concentrations than MCB, with consistently more depleted δ13C values than MCB. The redox conditions were dominated by iron reduction along most of the sediment profile. These results provide multiple lines of evidence for in situ reductive dechlorination of MCB to benzene. Stable isotope analysis of contaminants in pore water is a valuable method to demonstrate in situ natural recovery of contaminated sediments. This novel high-resolution approach is critical to deciphering the combined effects of parent contaminant (e.g., MCB) degradation and both production and simultaneous degradation of daughter products, especially benzene.
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Affiliation(s)
- Elodie Passeport
- Department of Earth Sciences, University of Toronto , Toronto, Ontario, M5S 3B1, Canada
| | - Richard Landis
- DuPont Engineering and Technology, Wilmington, Delaware 19803, United States
| | | | - Edward J Lutz
- The Chemours Company, Corporate Remediation Group, Wilmington, Delaware 19899, United States
| | - E Erin Mack
- DuPont Corporate Remediation Group, Wilmington, Delaware 19803, United States
| | - Kathryn West
- AECOM, Deepwater, New Jersey 02907, United States
| | - Scott Morgan
- AECOM, Deepwater, New Jersey 02907, United States
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Vogt C, Dorer C, Musat F, Richnow HH. Multi-element isotope fractionation concepts to characterize the biodegradation of hydrocarbons — from enzymes to the environment. Curr Opin Biotechnol 2016; 41:90-98. [DOI: 10.1016/j.copbio.2016.04.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/22/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
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12
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Chartrand M, Passeport E, Rose C, Lacrampe-Couloume G, Bidleman TF, Jantunen LM, Sherwood Lollar B. Compound specific isotope analysis of hexachlorocyclohexane isomers: a method for source fingerprinting and field investigation of in situ biodegradation. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:505-14. [PMID: 26160416 DOI: 10.1002/rcm.7146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/07/2015] [Accepted: 01/08/2015] [Indexed: 05/06/2023]
Abstract
RATIONALE The manufacturing and uses of hexachlorocyclohexane (HCH) have resulted in a serious environmental challenge and legacy. This study highlights the ability of compound specific isotope analysis (CSIA) to distinguish among various HCH sources and to support the evaluation of the potential for in situ biodegradation in contaminated groundwater. METHODS Tests were conducted to verify the absence of significant isotope fractionation during HCH sample pre-concentration including dichloromethane extraction, solvent exchange into iso-octane, and H2SO4 clean-up, and analysis by gas chromatography/combustion-isotope ratio mass spectrometry (GC/C-IRMS). The method was then applied to four Technical Grade (TG) HCH mixtures procured from different sources and to groundwater samples from a contaminated site. RESULTS The pre-concentration method enabled determination of carbon isotope ratios (δ(13)C values) of HCH isomers with no significant isotopic fractionation. The TG-HCH mixtures had significantly different δ(13)C values. Moreover, for any given TG-HCH, all isomers had δ(13)C values within 1.1‰ of each other - a distinctly uniform fingerprint. At the HCH-contaminated field site, compared with source wells, downgradient wells showed significant (up to 5.1‰) enrichment in (13)C and the δ(13)C values of the HCH isomers were significantly different from each other. CONCLUSIONS A method was successfully developed for the CSIA of HCH isomers that showed potential for HCH source differentiation and identification of HCH in situ biodegradation. At the HCH-contaminated site, the observed preferential isotopic enrichment of certain isomers relative to others for a given source allows differentiation between biodegraded and non-biodegraded HCH.
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Affiliation(s)
- Michelle Chartrand
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, ON, M5S 3B1, Canada
| | - Elodie Passeport
- Department of Civil Engineering, University of Toronto, 35 Russell Street, Toronto, ON, M5S 1A4, Canada
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Carla Rose
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, ON, M5S 3B1, Canada
| | - Georges Lacrampe-Couloume
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, ON, M5S 3B1, Canada
| | - Terry F Bidleman
- Dept. of Chemistry, Umeå University, Linnaeus väg 6, SE-901 87, Umeå, Sweden
| | - Liisa M Jantunen
- Air Quality Processes Research Section, Environment Canada, 6248 Eighth Line, Egbert, ON, L0L1N0, Canada
| | - Barbara Sherwood Lollar
- Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, ON, M5S 3B1, Canada
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