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Lv J, Guo L, Gu Y, Xu Y, Xue Q, Yang X, Wang QN, Meng XM, Xu DX, Pan XF, Xu S, Huang Y. National temporal trend for organophosphate pesticide DDT exposure and associations with chronic kidney disease using age-adapted eGFR model. Environ Int 2022; 169:107499. [PMID: 36087379 DOI: 10.1016/j.envint.2022.107499] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/04/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
Whilst certain environmental organochlorine pesticide exposure may still pose significant burden, the associations between dichloro-diphenyl-trichloroethane (DDT) and chronic kidney disease (CKD) remain disputable notwithstanding the potentially inaccurate disease definition between age groups. National DDT exposure burden atlas was depicted from 92,061 participants by measuring their serum concentrations of DDT congeners and major metabolite in the US from 1999 to 2016. Temporal analyses of these toxicant exposure suggested that although serum DDT concentrations exhibited recent decline, the detection rates remain up to 99.8% every year, posing great concern for exposure risk. A total of 3,039 US adults were further included from these participants demonstrating the weighted CKD prevalence of 40.2% using the new age-adapted CKD-EPI40 model compared to 28.0% using the current CKD-EPI method. After adjustment for covariates, logistic regression model results showed individual metabolites and total DDT burden were positively, yet monotonically, associated with risk of CKD incidence (P-trend for all < 0.05), particularly among adults 40 years of age and older. Much heightened renal disease risk was also observed with high DDT exposure (OR, 1.55; 95 % CI, 1.11-2.15) in those who were hypertensive (P for heterogeneity < 0.001) but not with diabetes. The current high DDT exposure risk combined with elevated probability for CKD incidence call for health concerns and management for the environmentally persistent pollutants.
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Affiliation(s)
- Jia Lv
- Department of Toxicology, School of Public Health, Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Lijuan Guo
- Department of Toxicology, School of Public Health, Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Yue Gu
- Department of Nephrology, Henan Provincial Clinical Research Center for Kidney Disease, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China
| | - Ying Xu
- Kidney Disease Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Qingping Xue
- Department of Epidemiology and Biostatistics, Public School, Chengdu Medical College, Chengdu, China
| | - Xue Yang
- Department of Epidemiology and Biostatistics, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Qu-Nan Wang
- Department of Toxicology, School of Public Health, Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Xiao-Ming Meng
- School of Pharmacy, Anhui Medical University, The Key Laboratory of Anti-Inflammatory of Immune Medicines, Ministry of Education, Hefei, China
| | - De-Xiang Xu
- Department of Toxicology, School of Public Health, Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Xiong-Fei Pan
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, West China Second University Hospital, Sichuan University, Wenjiang Institute of Women's and Children's Health, Wenjiang Maternal and Child Health Hospital, Chengdu, China.
| | - Shen Xu
- Department of Urology, Second Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Yichao Huang
- Department of Toxicology, School of Public Health, Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China.
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Luo YH, Long X, Wang B, Zhou C, Tang Y, Krajmalnik-Brown R, Rittmann BE. A Synergistic Platform for Continuous Co-removal of 1,1,1-Trichloroethane, Trichloroethene, and 1,4-Dioxane via Catalytic Dechlorination Followed by Biodegradation. Environ Sci Technol 2021; 55:6363-6372. [PMID: 33881824 DOI: 10.1021/acs.est.1c00542] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Groundwater co-contaminated with 1,4-dioxane, 1,1,1-trichloroethane (TCA), and trichloroethene (TCE) is among the most urgent environmental concerns of the U.S. Department of Defense (DoD), U.S. Environmental Protection Agency (EPA), and industries related to chlorinated solvents. Inspired by the pressing need to remove all three contaminants at many sites, we tested a synergistic platform: catalytic reduction of 1,1,1-TCA and TCE to ethane in a H2-based membrane palladium-film reactor (H2-MPfR), followed by aerobic biodegradation of ethane and 1,4-dioxane in an O2-based membrane biofilm reactor (O2-MBfR). During 130 days of continuous operation, 1,1,1-TCA and TCE were 95-98% reductively dechlorinated to ethane in the H2-MPfR, and ethane served as the endogenous primary electron donor for promoting 98.5% aerobic biodegradation of 1,4-dioxane in the O2-MBfR. In addition, the small concentrations of the chlorinated intermediate from the H2-MPfR, dichloroethane (DCA) and monochloroethane (MCA), were fully biodegraded through aerobic biodegradation in the O2-MBfR. The biofilms in the O2-MBfR were enriched in phylotypes closely related to the genera Pseudonocardia known to biodegrade 1,4-dioxane.
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Affiliation(s)
- Yi-Hao Luo
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287 United States
| | - Xiangxing Long
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287 United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, Tempe, Arizona 85008, United States
| | - Boya Wang
- Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, Florida 32310, United States
| | - Chen Zhou
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287 United States
| | - Youneng Tang
- Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, Florida 32310, United States
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287 United States
| | - Bruce E Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287 United States
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3
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Wang W, Wu Y. Sequential coupling of bio-augmented permeable reactive barriers for remediation of 1,1,1-trichloroethane contaminated groundwater. Environ Sci Pollut Res Int 2019; 26:12042-12054. [PMID: 30827025 DOI: 10.1007/s11356-019-04676-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 02/22/2019] [Indexed: 06/09/2023]
Abstract
Sequential coupling of high-density luffa sponge (HDLS) immobilized microorganism and permeable reactive barriers (IM Bio-PRBs) was superior to intimate coupling of free microorganism and permeable reactive barriers (FM Bio-PRBs) for remediation of 1,1,1-trichloroethane contaminated groundwater. IM Bio-PRBs had much better performance to removal 1,1,1-trichloroethane (1,1,1-TCA) and prevent the transport of 1,1,1-TCA and inorganic ions (NO3-, PO43-, and SO42-). The majority of them were prevented and accumulated in upgradient of IM Bio-PRBs. 1,1,1-TCA and inorganic ions in there contributed to the much faster growth of microorganism in upgradient aquifer. Therefore, the removal of 1,1,1-TCA and consumption of inorganic ions in upgradient of Bio-PRBs played a constructive role in reducing the processing load of following zero-valent iron (ZVI) PRBs and the negative effect of free microorganism cells (biological clogging) and inorganic ions (chemical clogging) on Bio-PRB permeability. In addition, IM Bio-PRBs were more conducive to accelerate the removal of 1,1,1-TCA in long-term remediation and 1,1,1-TCA residual concentration significantly lower than the safety standard of 0.2 mg L-1. The change of terminal by-products of 1,1,1-TCA contaminated groundwater in Bio-PRBs showed that 1,1,1-TCA could be effectively de-chlorinated and mineralized in Bio-PRBs. The reductant H2S (prolong the service life of ZVI-PRBs) was much more produced and utilized in IM Bio-PRBs. Taken together, sequentially coupled IM Bio-PRBs had a better overall performance, and its service life could be prolonged. It was a different design and idea to update conventional PRB remediation technology and theory.
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Affiliation(s)
- Wenbing Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Yanqing Wu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
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Wang W, Wu Y. Effects of biological clogging on 1,1,1-TCA and its intermediates distribution and fate in heterogeneous saturated bio-augmented permeable reactive barriers. Environ Sci Pollut Res Int 2018; 25:28628-28641. [PMID: 30094670 DOI: 10.1007/s11356-018-2908-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/03/2018] [Indexed: 06/08/2023]
Abstract
Biological clogging in porous media was an important concern in the design of bio-augmented permeable reactive barriers (Bio-PRBs) that were used to remediate groundwater with dense non-aqueous phase liquids (DNAPLs). Here, we used laboratory sandbox experiments to develop and calibrate reactive transport models (C1 and C2) simulating 1,1,1-trichloroethane (1,1,1-TCA) change in heterogeneous saturated porous media. The routine (1,1,1-TCA chain kinetic reactions) and subroutine (the relationship between hydraulic conductivity (K) and time (t)) were included in the model computer code. The simulation results suggested that the model C1 had the applicability for simulating contaminant transport and fate in bio-augmented flow field. By using the model C1 which was suitable for constant K condition, the performance of different types of Bio-PRBs was evaluated, and the regularity of contaminants chain kinetic reactions in different heterogeneous saturated porous media was obtained. The results demonstrated that Bio-PRBs in immobilized microorganism (IM) protocol were more superior to Bio-PRBs in free microorganism (FM) protocol. In addition, by using the model C2 (updated model C1) which was suitable for decreasing K condition, the different and optimized regularity of contaminants transport and transformation was obtained. The results showed that microbial growth which further decreased K was beneficial to preventing the transport of contaminants and accelerating the transformation of contaminants. However, the negative effects of biological clogging on hydraulic conductivity and relative hydraulic conductivity ratio in FM Bio-PRBs were significantly stronger than that in IM Bio-PRBs. Deploying IM Bio-PRBs for groundwater remediation would be much more efficient and meet the design criteria. The research work had guiding significance to engineering and provided consultation for designing and optimizing Bio-PRBs system. To make the design and optimization of Bio-PRBs system convenient, it was very essential to choose the suitable mathematical model (C1 or C2).
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Affiliation(s)
- Wenbing Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Yanqing Wu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
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5
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Thompson LA, Ikenaka Y, Yohannes YB, Ichise T, Ito G, Bortey-Sam N, van Vuren JJ, Wepener V, Smit NJ, Darwish WS, Nakayama SMM, Mizukawa H, Ishizuka M. Human Health Risk from Consumption of Marine Fish Contaminated with DDT and Its Metabolites in Maputo Bay, Mozambique. Bull Environ Contam Toxicol 2018; 100:672-676. [PMID: 29546500 DOI: 10.1007/s00128-018-2323-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 03/12/2018] [Indexed: 06/08/2023]
Abstract
Many countries with incidence of malaria, including those surrounding Maputo Bay, use dichloro-diphenyl-trichloroethane (DDT) to reduce mosquitoes. This study is the first to estimate the human health risk associated with consumption of marine fish from Maputo Bay contaminated with DDTs. The median for ∑DDTs was 3.8 ng/g ww (maximum 280.9 ng/g ww). The overall hazard ratio for samples was 1.5 at the 75th percentile concentration and 28.2 at the 95th percentile. These calculations show increased potential cancer risks due to contamination by DDTs, data which will help policy makers perform a risk-benefit analysis of DDT use in malaria control programs in the region.
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Affiliation(s)
- L A Thompson
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Y Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Y B Yohannes
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Department of Chemistry, College of Natural and Computational Science, University of Gondar, Gondar, Ethiopia
| | - T Ichise
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - G Ito
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - N Bortey-Sam
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - J J van Vuren
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - V Wepener
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - N J Smit
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - W S Darwish
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Food Control Department, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - S M M Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - H Mizukawa
- Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - M Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
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6
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Khan NA, Johnson MD, Carroll KC. Spectroscopic methods for aqueous cyclodextrin inclusion complex binding measurement for 1,4-dioxane, chlorinated co-contaminants, and ozone. J Contam Hydrol 2018; 210:31-41. [PMID: 29478672 DOI: 10.1016/j.jconhyd.2018.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/25/2018] [Accepted: 02/08/2018] [Indexed: 06/08/2023]
Abstract
Recalcitrant organic contaminants, such as 1,4-dioxane, typically require advanced oxidation process (AOP) oxidants, such as ozone (O3), for their complete mineralization during water treatment. Unfortunately, the use of AOPs can be limited by these oxidants' relatively high reactivities and short half-lives. These drawbacks can be minimized by partial encapsulation of the oxidants within a cyclodextrin cavity to form inclusion complexes. We determined the inclusion complexes of O3 and three common co-contaminants (trichloroethene, 1,1,1-trichloroethane, and 1,4-dioxane) as guest compounds within hydroxypropyl-β-cyclodextrin. Both direct (ultraviolet or UV) and competitive (fluorescence changes with 6-p-toluidine-2-naphthalenesulfonic acid as the probe) methods were used, which gave comparable results for the inclusion constants of these species. Impacts of changing pH and NaCl concentrations were also assessed. Binding constants increased with pH and with ionic strength, which was attributed to variations in guest compound solubility. The results illustrate the versatility of cyclodextrins for inclusion complexation with various types of compounds, binding measurement methods are applicable to a wide range of applications, and have implications for both extraction of contaminants and delivery of reagents for treatment of contaminants in wastewater or contaminated groundwater.
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Affiliation(s)
- Naima A Khan
- Water Science and Management, Plant & Environmental Science, New Mexico State University, MSC 3167, P.O. Box 30001, Las Cruces, NM 88003-8001, United States
| | - Michael D Johnson
- Department of Chemistry of and Biochemistry, New Mexico State University, Las Cruces, NM 88003-8003, United States
| | - Kenneth C Carroll
- Water Science and Management, Plant & Environmental Science, New Mexico State University, MSC 3167, P.O. Box 30001, Las Cruces, NM 88003-8001, United States.
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7
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Li H, Qiu YF, Wang XL, Yang J, Yu YJ, Chen YQ, Liu YD. Biochar supported Ni/Fe bimetallic nanoparticles to remove 1,1,1-trichloroethane under various reaction conditions. Chemosphere 2017; 169:534-541. [PMID: 27898326 DOI: 10.1016/j.chemosphere.2016.11.117] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 11/17/2016] [Accepted: 11/21/2016] [Indexed: 06/06/2023]
Abstract
In this study, Ni/Fe nanoparticles supported by biochar to stimulate the reduction of 1,1,1-trichloroethane (1,1,1-TCA) in groundwater remediation was investigated. In order to enhance the reactivity of ZVI (zero valent iron) nanoparticles, surface modification of ZVI was performed using nickel and biochar. The removal efficiency of 1,1,1-TCA increased from 42.3% to 99.3% as the biochar-to-Ni/Fe mass ratio increased from 0 to 1.0. However a higher biochar-to-Ni/Fe ratio showed little difference in the 1,1,1-TCA degradation efficiency. In the presence of Ni, atomic hydrogen generated by ZVI corrosion could be absorbed in the metal additive's lattice and then produce a hydride-like species (H) that represented the primary redox-active entity. The effects of various factors were evaluated, including pH, humic acid (HA) and inorganic matters (Cl-, CO32-, HCO3-, NO3- and SO42-). The degradation of 1,1,1-TCA was greatly affected by pH. The presence of Cl-, CO32-, HCO3- and SO42- had negligible effects, but NO3- and HA showed a significant inhibitory effects on 1,1,1-TCA degradation. In conclusion, biochar supported Ni/Fe nanoparticles could be highly effective for 1,1,1-TCA degradation.
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Affiliation(s)
- Hui Li
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, PR China
| | - Yue-Feng Qiu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, PR China
| | - Xiao-Li Wang
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, PR China
| | - Jie Yang
- Research Institute of Wastes and Soil Remediation, Shanghai Academy of Environmental Sciences, Shanghai, 200233, PR China
| | - Yun-Jiang Yu
- Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou, 510535, PR China.
| | - Ya-Qin Chen
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, PR China
| | - Yong-di Liu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, PR China.
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8
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Patterson BM, Lee M, Bastow TP, Wilson JT, Donn MJ, Furness A, Goodwin B, Manefield M. Concentration effects on biotic and abiotic processes in the removal of 1,1,2-trichloroethane and vinyl chloride using carbon-amended ZVI. J Contam Hydrol 2016; 188:1-11. [PMID: 26934432 DOI: 10.1016/j.jconhyd.2016.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/05/2016] [Accepted: 02/14/2016] [Indexed: 06/05/2023]
Abstract
A permeable reactive barrier, consisting of both zero valent iron (ZVI) and a biodegradable organic carbon, was evaluated for the remediation of 1,1,2-trichloroethane (1,1,2-TCA) contaminated groundwater. During an 888 day laboratory column study, degradation rates initially stabilized with a degradation half-life of 4.4±0.4 days. Based on the accumulation of vinyl chloride (VC) and limited production of 1,1-dichloroethene (1,1-DCE) and 1,2-dichloroethane (1,2-DCA), the dominant degradation pathway was likely abiotic dichloroelimination to form VC. Degradation of VC was not observed based on the accumulation of VC and limited ethene production. After a step reduction in the influent concentration of 1,1,2-TCA from 170±20 mg L(-1) to 39±11 mg L(-1), the degradation half-life decreased 5-fold to 0.83±0.17 days. The isotopic enrichment factor of 1,1,2-TCA also changed after the step reduction from -14.6±0.7‰ to -0.72±0.12‰, suggesting a possible change in the degradation mechanism from abiotic reductive degradation to biodegradation. Microbiological data suggested a co-culture of Desulfitobacterium and Dehalococcoides was responsible for the biodegradation of 1,1,2-TCA to ethene.
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Affiliation(s)
- Bradley M Patterson
- CSIRO Land and Water Flagship, Private Bag No. 5, Wembley, WA 6913, Australia; School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA 6009, Australia.
| | - Matthew Lee
- Centre for Marine Bio-Innovation, University of New South Wales, Sydney, NSW 2052, Australia
| | - Trevor P Bastow
- CSIRO Land and Water Flagship, Private Bag No. 5, Wembley, WA 6913, Australia
| | - John T Wilson
- Scissortail Environment Solutions, LLC. Ada, OK 74821, USA
| | - Michael J Donn
- CSIRO Land and Water Flagship, Private Bag No. 5, Wembley, WA 6913, Australia
| | - Andrew Furness
- CSIRO Land and Water Flagship, Private Bag No. 5, Wembley, WA 6913, Australia
| | - Bryan Goodwin
- Goodwin Remediation Consulting, Victoria 3018, Australia
| | - Mike Manefield
- Centre for Marine Bio-Innovation, University of New South Wales, Sydney, NSW 2052, Australia
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9
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Chowdhury AIA, Krol MM, Kocur CM, Boparai HK, Weber KP, Sleep BE, O'Carroll DM. nZVI injection into variably saturated soils: Field and modeling study. J Contam Hydrol 2015; 183:16-28. [PMID: 26496622 DOI: 10.1016/j.jconhyd.2015.10.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 09/18/2015] [Accepted: 10/07/2015] [Indexed: 05/20/2023]
Abstract
Nano-scale zero valent iron (nZVI) has been used at a number of contaminated sites over the last decade. At most of these sites, significant decreases in contaminant concentrations have resulted from the application of nZVI. However, limited work has been completed investigating nZVI field-scale mobility. In this study, a field test was combined with numerical modeling to examine nZVI reactivity along with transport properties in variably saturated soils. The field test consisted of 142L of carboxymethyle cellulose (CMC) stabilized monometallic nZVI synthesized onsite and injected into a variably saturated zone. Periodic groundwater samples were collected from the injection well, as well as, from two monitoring wells to analyze for chlorinated solvents and other geochemistry indicators. This study showed that CMC stabilized monometallic nZVI was able to decrease tricholorethene (TCE) concentrations in groundwater by more than 99% from the historical TCE concentrations. A three dimensional, three phase, finite difference numerical simulator, (CompSim) was used to further investigate nZVI and polymer transport at the variably saturated site. The model was able to accurately predict the field observed head data without parameter fitting. In addition, the numerical simulator estimated the mass of nZVI delivered to the saturated and unsaturated zones and distinguished the nZVI phase (i.e. aqueous or attached). The simulation results showed that the injected slurry migrated radially outward from the injection well, and therefore nZVI transport was governed by injection velocity and viscosity of the injected solution. A suite of sensitivity analyses was performed to investigate the impact of different injection scenarios (e.g. different volume and injection rate) on nZVI migration. Simulation results showed that injection of a higher nZVI volume delivered more iron particles at a given distance; however, the travel distance was not proportional to the increase in volume. Moreover, simulation results showed that using a 1D transport equation to simulate nZVI migration in the subsurface may overestimate the travel distance. This is because the 1D transport equation assumes a constant velocity while pore water velocity radially decreases from the well during injection. This study suggests that on-site synthesized nZVI particles are mobile in the subsurface and that a numerical simulator can be a valuable tool for optimal design of nZVI field applications.
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Affiliation(s)
- Ahmed I A Chowdhury
- Department of Civil and Environmental Engineering, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B9, Canada
| | - Magdalena M Krol
- Department of Civil Engineering, Lassonde School of Engineering, York University, 4700 Keele St., Toronto, ON M3J 1P3, Canada
| | - Christopher M Kocur
- Department of Civil and Environmental Engineering, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B9, Canada
| | - Hardiljeet K Boparai
- Department of Civil and Environmental Engineering, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B9, Canada
| | - Kela P Weber
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON K7K 7B4, Canada
| | - Brent E Sleep
- Department of Civil Engineering, University of Toronto, 35 St. George St., Toronto, ON M5S 1A4, Canada
| | - Denis M O'Carroll
- Department of Civil and Environmental Engineering, The University of Western Ontario, 1151 Richmond Street, London, ON N6A 5B9, Canada.
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Adamson DT, Anderson RH, Mahendra S, Newell CJ. Evidence of 1,4-dioxane attenuation at groundwater sites contaminated with chlorinated solvents and 1,4-dioxane. Environ Sci Technol 2015; 49:6510-6518. [PMID: 25970261 DOI: 10.1021/acs.est.5b00964] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
There is a critical need to develop appropriate management strategies for 1,4-dioxane (dioxane) due to its widespread occurrence and perceived recalcitrance at groundwater sites where chlorinated solvents are present. A comprehensive evaluation of California state (GeoTracker) and Air Force monitoring records was used to provide significant evidence of dioxane attenuation at field sites. Temporal changes in the site-wide maximum concentrations were used to estimate source attenuation rates at the GeoTracker sites (median length of monitoring period = 6.8 years). While attenuation could not be established at all sites, statistically significant positive attenuation rates were confirmed at 22 sites. At sites where dioxane and chlorinated solvents were present, the median value of all statistically significant dioxane source attenuation rates (equivalent half-life = 31 months; n = 34) was lower than 1,1,1-trichloroethane (TCA) but similar to 1,1-dichloroethene (1,1-DCE) and trichloroethene (TCE). Dioxane attenuation rates were positively correlated with rates for 1,1-DCE and TCE but not TCA. At this set of sites, there was little evidence that chlorinated solvent remedial efforts (e.g., chemical oxidation, enhanced bioremediation) impacted dioxane attenuation. Attenuation rates based on well-specific records from the Air Force data set confirmed significant dioxane attenuation (131 out of 441 wells) at a similar frequency and extent (median equivalent half-life = 48 months) as observed at the California sites. Linear discriminant analysis established a positive correlation between dioxane attenuation and increasing concentrations of dissolved oxygen, while the same analysis found a negative correlation with metals and CVOC concentrations. The magnitude and prevalence of dioxane attenuation documented here suggest that natural attenuation may be used to manage some but not necessarily all dioxane-impacted sites.
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Affiliation(s)
- David T Adamson
- †GSI Environmental Inc., Houston, Texas 77098, United States
| | - R Hunter Anderson
- ‡Air Force Civil Engineer Center, Lackland Air Force Base, San Antonio, Texas 78236 United States
| | - Shaily Mahendra
- §Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, United States
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Said TO, Okbah MA, Mohamed LA, Othman IM. Detection of persistent OCPs and PCBs congeners in the near-shore coastal waters of Alexandria, Egypt. Environ Monit Assess 2015; 187:353. [PMID: 25971520 DOI: 10.1007/s10661-015-4537-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 04/13/2015] [Indexed: 06/04/2023]
Abstract
The residues of 19 EPA-organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in water samples collected from the near-shore surface water of Alexandria coast, Egypt, using gas chomatograph-electron capture detector (GC-ECD) and gas chromatograph-mass spectometer (GC-MS). Higher concentrations of hexachlorocyclohexane (HCH)s, TC, and 2,2-bis (p-chlorophenyl)-1,1,1-trichloroethane (DDT)s with 1.36, 0.556, and 36.97 ngl(-1) were recorded, respectively, with a maximum of 165.46 ngl(-1) of PCBs during June 2014, which was clearly affected by higher sewage activities during summer season. Among DDTs metabolites, p,p-DDT was the most dominant with a maximum of 36.31 ngl(-1) recorded at El-Montazah station during June 2014.
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Affiliation(s)
- Tarek O Said
- National Institute of Oceanography and Fisheries, Alexandria, Egypt,
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12
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Valhondo C, Carrera J, Ayora C, Barbieri M, Nödler K, Licha T, Huerta M. Behavior of nine selected emerging trace organic contaminants in an artificial recharge system supplemented with a reactive barrier. Environ Sci Pollut Res Int 2014; 21:11832-11843. [PMID: 24793065 DOI: 10.1007/s11356-014-2834-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 03/24/2014] [Indexed: 06/03/2023]
Abstract
Artificial recharge improves several water quality parameters, but has only minor effects on recalcitrant pollutants. To improve the removal of these pollutants, we added a reactive barrier at the bottom of an infiltration basin. This barrier contained aquifer sand, vegetable compost, and clay and was covered with iron oxide dust. The goal of the compost was to sorb neutral compounds and release dissolved organic carbon. The release of dissolved organic carbon should generate a broad range of redox conditions to promote the transformation of emerging trace organic contaminants (EOCs). Iron oxides and clay increase the range of sorption site types. In the present study, we examined the effectiveness of this barrier by analyzing the fate of nine EOCs. Water quality was monitored before and after constructing the reactive barrier. Installation of the reactive barrier led to nitrate-, iron-, and manganese-reducing conditions in the unsaturated zone below the basin and within the first few meters of the saturated zone. Thus, the behavior of most EOCs changed after installing the reactive barrier. The reactive barrier enhanced the removal of some EOCs, either markedly (sulfamethoxazole, caffeine, benzoylecgonine) or slightly (trimethoprim) and decreased the removal rates of compounds that are easily degradable under aerobic conditions (ibuprofen, paracetamol). The barrier had no remarkable effect on 1H-benzotriazole and tolyltriazole.
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Affiliation(s)
- Cristina Valhondo
- GHS Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain,
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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: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Ma H, Zhang H, Wang L, Wang J, Chen J. Comprehensive screening and priority ranking of volatile organic compounds in Daliao River, China. Environ Monit Assess 2014; 186:2813-2821. [PMID: 24389912 DOI: 10.1007/s10661-013-3582-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 12/12/2013] [Indexed: 06/03/2023]
Abstract
An analytical strategy for comprehensive screening of target and non-target volatile organic compounds (VOCs) in surface water was developed, and it was applied to the analysis of VOCs in water samples from Daliao River. The target VOCs were quantified using purge and trap-gas chromatography-mass spectrometry (P&T-GC/MS). Among 20 water samples, 34 VOCs were detected at least once. For the screening of non-target VOCs, the double distillation apparatus was used for the pre-concentration of VOCs prior to P&T-GC/MS analysis. Subsequently, deconvolution software and NIST mass spectral library were applied for the identification of the non-target compounds. A total of 17 non-target VOCs were identified. The most frequently detected VOCs (detection frequencies >80 %) included toluene, benzene, naphthalene, 1,2-dichloroethane, 1,1,2-trichloroethane, and methyl tert-butyl ether. The distribution of VOCs obviously varied according to the sampling sites. The total concentrations of VOCs in water samples collected from the heavily industrialized cities (Anshan and Liaoyang) and the busy port city (Yingkou) were relatively high. The top ten priority VOCs, including naphthalene, 1,2-dichloroethane, o-xylene, 1,3-dichlorobenzene, tetrachloroethene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, ethylbenzene, m-xylene, and p-xylene, were obtained by the ranking of the detected VOCs according to their occurrence and ecological effects. These compounds should be given more attention in monitoring and drainage control strategies.
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Affiliation(s)
- Huilian Ma
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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Man YB, Chan JKY, Wang HS, Wu SC, Wong MH. DDTs in mothers' milk, placenta and hair, and health risk assessment for infants at two coastal and inland cities in China. Environ Int 2014; 65:73-82. [PMID: 24472823 DOI: 10.1016/j.envint.2014.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 12/24/2013] [Accepted: 01/01/2014] [Indexed: 06/03/2023]
Abstract
This study is a one of the very few investigating the dichloro-diphenyl-trichloroethanes (DDTs) (summation of o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in multiple human matrices in mothers' milk, placenta and hair collected from residents from two coastal cities: Guiyu (GY) and Taizhou (TZ) and one inland city: Lin'an (LA). TZ (milk: 360±319ng/g lipid wt.) showed significantly higher concentrations of DDTs than those from LA (milk: 190±131ng/g lipid wt.), whereas, concentrations of DDTs in GY (milk: 305±109ng/g lipid wt.) were in between TZ and LA. In addition, levels of DDTs in the human tissues from TZ (placenta: 122±109ng/g lipid wt.; hair: 79.9±215ng/g dry wt.) were significantly higher than those from Lin'an (placenta: 49.2±30.2ng/g lipid wt.; hair: 10.8±7.09ng/g dry wt.). The above concentrations of DDTs in milk exceeded the Codex Maximum Residue Limits/Extraneous Maximum Residue Limits for milk (20ng/g lipid wt. whole milk), indicating that the human milk samples were grossly polluted. The present study revealed that human specimens collected from the coastal city (TZ) were more contaminated with inland one (LA), based on the levels of DDTs contained in samples which may be due to the higher dietary exposure to DDTs via consumption of contaminated seafood. The estimated daily intakes of DDTs by GY, TZ and LA infants were 1.69±1.86, 1.48±0.79, and 0.95±0.73μg/kg body wt./day, respectively which did not exceed 10μg/kg body wt./day, the provisional tolerable daily intake proposed by the Food and Agriculture Organization/World Health Organization.
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Affiliation(s)
- Yu Bon Man
- School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang 311300, China; Department of Science and Environmental Studies, The Hong Kong Institute of Education, Tai Po, Hong Kong, China; State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong, China
| | - Janet Kit Yan Chan
- State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong, China; School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam, Hong Kong, China
| | - Hong Sheng Wang
- State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong, China; Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Sheng Chun Wu
- School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang 311300, China; State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong, China
| | - Ming Hung Wong
- School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang 311300, China; Department of Science and Environmental Studies, The Hong Kong Institute of Education, Tai Po, Hong Kong, China; State Key Laboratory in Marine Pollution - Croucher Institute for Environmental Sciences, Hong Kong Baptist University and City University of Hong Kong, Hong Kong, China.
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Wu X, Lu S, Qiu Z, Sui Q, Lin K, Du X, Luo Q. The reductive degradation of 1,1,1-trichloroethane by Fe(0) in a soil slurry system. Environ Sci Pollut Res Int 2014; 21:1401-1410. [PMID: 23904257 DOI: 10.1007/s11356-013-2029-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Accepted: 07/19/2013] [Indexed: 06/02/2023]
Abstract
Most studies on the treatment of chlorinated contaminants by Fe(0) focus on aqueous system tests. However, few is known about the effectiveness of these tests for degrading chlorinated contaminants such as 1,1,1-trichloroethane (TCA) in soil. In this work, the reductive degradation performance of 1,1,1-TCA by Fe(0) was thoroughly investigated in a soil slurry system. The effects of various factors including acid-washed iron, the initial 1,1,1-TCA concentration, Fe(0) dosage, slurry pH, and common constituents in groundwater and soil such as Cl(-), HCO3 (-), SO4 (2-), and NO3 (-) anions and humic acid (HA) were evaluated. The experimental results showed that 1,1,1-TCA could be effectively degraded in 12 h for an initial Fe(0) dosage of 10 g L(-1) and a soil/water mass ratio of 1:5. The soil slurry experiments showed two-stage degradation kinetics: a slow reaction in the first stage and a fast reductive degradation of 1,1,1-TCA in the second stage. The reductive degradation of 1,1,1-TCA was expedited as the mass concentration of Fe(0) increased. In addition, high pHs adversely affected the degradation of 1,1,1-TCA over a pH range of 5.4-8.0 and the reductive degradation efficiency decreased with increasing slurry pH. The initial 1,1,1-TCA concentration and the presence of Cl(-) and SO4(2-) anions had negligible effects. HCO3(-) anions had a accelerative effect on 1,1,1-TCA removal, and both NO3(-) and HA had inhibitory effects. A Cl(-) mass balance showed that the amount of Cl(-) ions released into the soil slurry system during the 1,1,1-TCA degradation increased with increasing reaction time, suggesting that the main degradation mechanism of 1,1,1-TCA by Fe(0) in a soil slurry system was reductive dechlorination with 1,1-DCA as the main intermediate. In conclusion, this study provides a theoretical basis for the practical application of the remediation of contaminated sites containing chlorinated solvent.
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Affiliation(s)
- Xiaoliang Wu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, China
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Li B, Li L, Lin K, Zhang W, Lu S, Luo Q. Removal of 1,1,1-trichloroethane from aqueous solution by a sono-activated persulfate process. Ultrason Sonochem 2013; 20:855-863. [PMID: 23266439 DOI: 10.1016/j.ultsonch.2012.11.014] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/21/2012] [Accepted: 11/25/2012] [Indexed: 06/01/2023]
Abstract
1,1,1-Trichloroethane (TCA), labeled as a priority pollutant by the Environmental Protection Agency (EPA) of China, can be removed from groundwater by sonochemical oxidation. The sonochemical oxidation of TCA in the presence of persulfate (PS) showed a significant synergistic effect. The operational parameters, ultrasonic frequency, PS/TCA molar ratio, radical scavenger, inorganic anions (Cl(-), CO(3)(2-), HCO(3)(-) and NO(3)(-)) and humic acid (HA), were evaluated during the investigation of the sonochemical reaction. The results showed that the degradation of TCA followed pseudo-first-order kinetics, and the rate constant was found to increase with increasing ultrasonic frequency but to decrease with both an increasing PS/TCA molar ratio and an increasing concentration of inorganic anions. With a concentration of 4.46mg/L of HA in solution, an enhanced effect was observed. Further addition of HA retarded the degradation rate of TCA. TCA could be eliminated almost completely by sono-activated persulfate oxidation, with sulfate and hydroxyl radicals serving as the principal oxidants as confirmed by the addition of radical scavengers. Eleven chlorinated degradation intermediates were detected and quantified by purge and trap gas chromatography coupled with mass spectrometry (P&T-GC-MS) in the absence of pH buffer. Three TCA degradation pathways were therefore proposed. In conclusion, the sono-activated persulfate oxidation process appears to be a highly promising technique for the remediation of TCA-contaminated groundwater.
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Affiliation(s)
- Bingzhi Li
- Shanghai Academy of Environmental Sciences, Shanghai 200233, China.
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Mahendra S, Grostern A, Alvarez-Cohen L. The impact of chlorinated solvent co-contaminants on the biodegradation kinetics of 1,4-dioxane. Chemosphere 2013; 91:88-92. [PMID: 23237300 DOI: 10.1016/j.chemosphere.2012.10.104] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 10/30/2012] [Accepted: 10/31/2012] [Indexed: 06/01/2023]
Abstract
1,4-Dioxane (dioxane), a probable human carcinogen, is used as a solvent stabilizer for 1,1,1-trichloroethane (TCA) and other chlorinated solvents. Consequently, TCA and its abiotic breakdown product 1,1-dichloroethene (DCE) are common co-contaminants of dioxane in groundwater. The aerobic degradation of dioxane by microorganisms has been demonstrated in laboratory studies, but the potential effects of environmentally relevant chlorinated solvent co-contaminants on dioxane biodegradation have not yet been investigated. This work evaluated the effects of TCA and DCE on the transformation of dioxane by dioxane-metabolizing strain Pseudonocardia dioxanivorans CB1190, dioxane co-metabolizing strain Pseudonomas mendocina KR1, as well as Escherichia coli expressing the toluene monooxygenase of strain KR1. In all experiments, both TCA and DCE inhibited the degradation of dioxane at the tested concentrations. The inhibition was not competitive and was reversible for strain CB1190, which did not transform the chlorinated solvents. For both strain KR1 and toluene monooxygenase-expressing E. coli, inhibition of dioxane degradation by chlorinated solvents was competitive and irreversible, and the chlorinated solvents were degraded concurrently with dioxane. These data suggest that the strategies for biostimulation or bioaugmentation of dioxane will need to consider the presence of chlorinated solvents during site remediation.
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Affiliation(s)
- Shaily Mahendra
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA.
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Anderson RH, Anderson JK, Bower PA. Co-occurrence of 1,4-dioxane with trichloroethylene in chlorinated solvent groundwater plumes at US Air Force installations: Fact or fiction. Integr Environ Assess Manag 2012; 8:731-737. [PMID: 22492728 DOI: 10.1002/ieam.1306] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/23/2012] [Accepted: 03/16/2012] [Indexed: 05/31/2023]
Abstract
Increasing regulatory attention to 1,4-dioxane has prompted the United States Air Force (USAF) to evaluate potential environmental liabilities, primarily associated with legacy contamination, at an enterprise scale. Although accurately quantifying environmental liability is operationally difficult given limited historic environmental monitoring data, 1,4-dioxane is a known constituent (i.e., stabilizer) of chlorinated solvents, in particular 1,1,1-trichloroethane (TCA). Evidence regarding the co-occurrence of 1,4-dioxane and trichloroethylene (TCE), however, has been heavily debated. In fact, the prevailing opinion is that 1,4-dioxane was not a constituent of past TCE formulations and, therefore, these 2 contaminants would not likely co-occur in the same groundwater plume. Because historic handling, storage, and disposal practices of chlorinated solvents have resulted in widespread groundwater contamination at USAF installations, significant potential exists for unidentified 1,4-dioxane contamination. Therefore, the objective of this investigation is to determine the extent to which 1,4-dioxane co-occurs with TCE compared to TCA, and if these chemicals are co-contaminants, whether or not there is significant correlation using available monitoring data. To accomplish these objectives, the USAF Environmental Restoration Program Information Management System (ERPIMS) was queried for all relevant records for groundwater monitoring wells (GMWs) with 1,4-dioxane, TCA, and TCE, on which both categorical and quantitative analyses were carried out. Overall, ERPIMS contained 5788 GMWs from 49 installations with records for 1,4-dioxane, TCE, and TCA analytes. 1,4-Dioxane was observed in 17.4% of the GMWs with detections for TCE and/or TCA, which accounted for 93.7% of all 1,4-dioxane detections, verifying that 1,4-dioxane is seldom found independent of chlorinated solvent contamination. Surprisingly, 64.4% of all 1,4-dioxane detections were associated with TCE independently. Given the extensive data set, these results conclusively demonstrate for the first time that 1,4-dioxane is a relatively common groundwater co-contaminant with TCE. Trend analysis demonstrated a positive log-linear relationship where median 1,4-dioxane levels increased between approximately 6% and approximately 20% of the increase in TCE levels. In conclusion, this data mining exercise suggests that 1,4-dioxane has a probability of co-occurrence of approximately 17% with either TCE and/or TCA. Given the challenges imposed by remediation of 1,4-dioxane and the pending promulgation of a federal regulatory standard, environmental project managers should use the information presented in this article for prioritization of future characterization efforts to respond to the emerging issue. Importantly, site investigations should consider 1,4-dioxane a potential co-contaminant of TCE in groundwater plumes.
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Affiliation(s)
- Richard H Anderson
- Air Force Center for Engineering and the Environment, Technical Support Division, 2261 Hughes, Site 155, Lackland AFB, Texas 78236, USA.
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Do SH, Batchelor B. Reductive dechlorination of chlorinated hydrocarbons as non-aqueous phase liquid (NAPL): preliminary investigation on effects of cement doses. Sci Total Environ 2012; 430:82-87. [PMID: 22634553 DOI: 10.1016/j.scitotenv.2012.04.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 04/27/2012] [Accepted: 04/28/2012] [Indexed: 06/01/2023]
Abstract
The reactivities of various types of iron mixtures to degrade chlorinated hydrocarbons (PCE, TCE and 1,1,1-TCA) in the form of non-aqueous phase liquids were investigated. The iron mixtures included a mixture of Fe(II) and Portland cement (Fe(II)-C), a mixture of Fe(II), Fe(III) and Ca(OH)(2) (Fe(II/III)-L), and a mixture of Fe(II), Fe(III), Ca(OH)(2), and Portland cement (Fe(II/III)-C). When the same amount of Fe(II) was used, Fe(II)-C was more reactive with chlorinated ethylenes (i.e. PCE and TCE) than Fe(II/III)-L. The reductive pathway for high concentrations of total PCE (i.e. above solubility) with Fe(II)-C was determined to be a combination of two-electron transfer, β-elimination and hydrogenolysis. Increasing the cement dose from 5% to 10% in Fe(II)-C did not affect PCE dechlorination rates, but it did favor the β-elimination pathway. In addition, when Fe(II/III)-C with 5%C was used, PCE dechlorination was similar to that by Fe(II)-C, but this mixture did not effectively degrade TCE. A modified second-order kinetic model was developed and shown to appropriately describe degradation of TCE at high concentrations. Fe(II/III)-L effectively degraded high concentrations of 1,1,1-TCA at rates that were similar to those obtained with Fe(II)-C using 10% C. Moreover, both increasing cement doses and the presence of Fe(III) increased dechlorination rates of 1,1,1-TCA, which was mainly through the hydrogenolysis pathway. The reactivity of Fe(II/III)-L was strongly dependent on the target compound (i.e. less reactivity with TCE, more with 1,1,1-TCA). Therefore, Fe(II/III)-L could be a potential mixture for degrading 1,1,1-TCA, but it should be modified to degrade TCE more effectively.
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Affiliation(s)
- Si-Hyun Do
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Republic of Korea.
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Basu D, Asolekar SR. Evaluation of substrate removal kinetics for UASB reactors treating chlorinated ethanes. Environ Sci Pollut Res Int 2012; 19:2419-2427. [PMID: 22286857 DOI: 10.1007/s11356-012-0754-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 01/10/2012] [Indexed: 05/31/2023]
Abstract
PURPOSE Lack of focus on the treatment of wastewaters bearing potentially hazardous pollutants like 1,1,2 trichloroethane and 1,1,2,2 tetrachloroethane in anaerobic reactors has provided an impetus to undertake this study. The objective of this exercise was to quantify the behavior of upflow anaerobic sludge blanket reactors and predict their performance based on the overall organic substrate removal. METHODS The reactors (wastewater-bearing TCA (R2), and wastewater-bearing TeCA (R3)) were operated at different hydraulic retention times (HRTs), i.e., 36, 30, 24, 18, and 12 h corresponding to food-to-mass ratios varying in the range of 0.2–0.7 mg chemical oxygen demand (COD) mg−1 volatile suspended solids day−1. The process kinetics of substrate utilization was evaluated on the basis of experimental results, by applying three mathematical models namely first order, Grau second order, and Michaelis-Menten type kinetics. RESULTS The results showed that the lowering of HRT below 24 h resulted in reduced COD removal efficiencies and higher effluent pollutant concentrations in the reactors. The Grau second-order model was successfully applied to obtain the substrate utilization kinetics with high value of R 2 (>0.95). The Grau second-order substrate removal constant (K 2) was calculated as 1.12 and 7.53 day−1 for reactors R2 and R3, respectively. CONCLUSION This study demonstrated the suitability of Grau second-order kinetic model over other models, for predicting the performance of reactors R2 and R3, in treating wastewaters containing chlorinated ethanes under different organic and hydraulic loading conditions.
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Affiliation(s)
- Debolina Basu
- Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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Lu C, Bjerg PL, Zhang F, Broholm MM. Sorption of chlorinated solvents and degradation products on natural clayey tills. Chemosphere 2011; 83:1467-1474. [PMID: 21459403 DOI: 10.1016/j.chemosphere.2011.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 02/26/2011] [Accepted: 03/06/2011] [Indexed: 05/30/2023]
Abstract
The sorption of chlorinated solvents and degradation products on seven natural clayey till samples from three contaminated sites was investigated by laboratory batch experiments in order to obtain reliable sorption coefficients (K(d) values). The sorption isotherms for all compounds were nearly linear, but fitted by Freundlich isotherms slightly better over the entire concentration range. For chloroethylenes, tetrachloroethylene (PCE) was most strongly sorbed to the clayey till samples (K(d)=0.84-2.45Lkg(-1)), followed by trichloroethylene (TCE, K(d)=0.62-0.96Lkg(-1)), cis-dichloroethylene (cis-DCE, K(d)=0.17-0.82Lkg(-1)) and vinyl chloride (VC, K(d)=0.12-0.36Lkg(-1)). For chloroethanes, 1,1,1-trichloroethane (1,1,1-TCA) was most strongly sorbed (K(d)=0.2-0.45Lkg(-1)), followed by 1,1-dichloroethane (1,1-DCA, K(d)=0.16-0.24Lkg(-1)) and chloroethane (CA, K(d)=0.12-0.18Lkg(-1)). This is consistent with the order of hydrophobicity of the compounds. The octanol-water coefficient (logK(ow)) correlated slightly better with logK(d) values than logK(oc) values indicating that the K(d) values may be independent of the actual organic carbon content (f(oc)). The estimated logK(oc) or logK(d) for chlorinated solvents and degradation products determined by regression of data in this study were significantly higher than values determined by previously published empirical relationships. The site specific K(d) values as well as the new empirical relationship compared well with calculations on water and soil core concentration for cis-DCE and VC from the Rugårdsvej site. In conclusion, this study with a wide range of chlorinated ethenes and ethanes--in line with previous studies on PCE and TCE--suggest that sorption in clayey tills could be higher than typically expected.
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Affiliation(s)
- Cong Lu
- College of Environment and Resources, Jilin University, 2519 Jie Fang Road, Changchun, China
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Scheutz C, Durant ND, Hansen MH, Bjerg PL. Natural and enhanced anaerobic degradation of 1,1,1-trichloroethane and its degradation products in the subsurface--a critical review. Water Res 2011; 45:2701-2723. [PMID: 21474158 DOI: 10.1016/j.watres.2011.02.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 02/03/2011] [Accepted: 02/23/2011] [Indexed: 05/30/2023]
Abstract
1,1,1-Trichloroethane (TCA) in groundwater is susceptible to a variety of natural degradation mechanisms. Evidence of intrinsic decay of TCA in aquifers is commonly observed; however, TCA remains a persistent pollutant at many sites and some of the daughter products that accumulate from intrinsic decay of TCA have been determined to be more toxic than the parent compound. Research advances from the past decade indicate that in situ enhanced reductive dechlorination (ERD) offers promise as a cost-effective solution toward the cleanup of groundwater contaminated with TCA and its transformation daughter products. Laboratory studies have demonstrated that pure or mixed cultures containing certain Dehalobacter (Dhb) bacteria can catalyze respiratory dechlorination of TCA and 1,1-dichloroethane (1,1-DCA) to monochloroethane (CA) in groundwater systems. 16S rRNA Dhb gene probes have been used as biomarkers in groundwater samples to both assess ERD potential and quantify growth of Dhb in ERD applications at TCA sites. Laboratory findings suggest that iron-bearing minerals and methanogenic bacteria that co-occur in reduced aquifers may synergistically affect dechlorination of TCA. Despite these advances, a number of significant challenges remain, including an inability of any known cultures to completely dechlorinate TCA to ethane. CA is commonly observed as a terminal product of the biological reductive dechlorination of TCA and 1,1-DCA. Also important is the lack of rigorous field studies demonstrating the utility of bioaugmentation with Dhb cultures for remediation of TCA in the field. In this paper we review the state-of-the-science of TCA degradation in aquifers, examining results from both laboratory experiments and twenty-two field case studies, focusing on the capabilities and limits of ERD technology, and identifying aspects of the technology that warrant further development.
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Affiliation(s)
- Charlotte Scheutz
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
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24
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Wang C, Ma X, Walsh MP. Competitive uptake and phytomonitoring of chlorinated contaminant mixtures by Redosier dogwood (Cornus sericea). Int J Phytoremediation 2011; 13:333-344. [PMID: 21598796 DOI: 10.1080/15226514.2010.495146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Plant uptake is an important process in phytoremediation. The robust uptake of volatile organic compounds (VOCs) by plants offers opportunities to establish quantitative relationships between VOCs in plant tissues and in groundwater for the purpose of phytoscreening or phytomonitoring. Most previous research pertaining to phytoremediation neglected the competitive effects of co-contaminants on the uptake of VOCs by plants, yet recent studies appeared to indicate high competitive effects of co-contamination. This study investigated the competitive uptake of three chlorinated compounds in the presence and absence of other co-contaminants by Redosier dogwood in a greenhouse and examined the implications of this competitive phenomenon for phytomonitoring of contaminant mixtures in groundwater. Concentrations of VOCs in stems decreased along the height in both single and bi-solute systems, in agreement with previous observations in the literature. Examination of the VOCs in single and bi-solute systems showed that concentrations of individual compounds are comparable in single and bi-solute systems, yet the ratios of contaminants along the height in bi-solute systems revealed interesting trends. TCE/PCE ratio increased along height while TCE/1,1,2-TCA ratio was roughly constant. The result indicated that sampling point as well as the physicochemical properties of co-contaminants is highly important in phytomonitoring of contaminant mixtures.
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Affiliation(s)
- Chen Wang
- Department of Civil & Environmental Engineering, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
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Ronen D, Lev-Wiener H, Graber ER, Dahan O, Weisbrod N. Simultaneous counter-flow of chlorinated volatile organic compounds across the saturated-unsaturated interface region of an aquifer. Water Res 2010; 44:2107-2112. [PMID: 20044117 DOI: 10.1016/j.watres.2009.12.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 12/08/2009] [Accepted: 12/09/2009] [Indexed: 05/28/2023]
Abstract
Concentrations of chlorinated volatile organic compounds (Cl-VOCs) at the saturated-unsaturated interface region (SUIR; depth of approximately 18m) of a sandy phreatic aquifer were measured in two monitoring wells located 25m apart. The concentrations of the Cl-VOCs obtained above and below the water table along a 413-day period are interpreted to depict variable, simultaneous and independent movement of trichlorothene, tetrachloroethene, 1,1-dichloroethene, cis-1,2-dichloroethene, 1,1,1-trichloroethane, chloroform and 1,1-dichloroethane vapors in opposite directions across the SUIR.
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Affiliation(s)
- Daniel Ronen
- Hydrological Service and Water Quality Division, Israel Water Authority, POB 20365, Tel Aviv 61203, Israel.
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26
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Zoccolillo L, Amendola L, Insogna S. Comparison of atmosphere/aquatic environment concentration ratio of volatile chlorinated hydrocarbons between temperate regions and Antarctica. Chemosphere 2009; 76:1525-1532. [PMID: 19541344 DOI: 10.1016/j.chemosphere.2009.05.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/21/2009] [Accepted: 05/27/2009] [Indexed: 05/27/2023]
Abstract
For the purpose of understanding the transport and deposition mechanisms and the air-water distribution of some volatile chlorinated hydrocarbons (VCHCs), their atmosphere/aquatic environment concentration ratio was evaluated. In addition, for the purpose of differentiating VCHC behaviour in a temperate climate from its behaviour in a polar climate, the atmosphere/aquatic environment concentration ratio evaluated in matrices from temperate zones was compared with the concentration ratio evaluated in Antarctic matrices. In order to perform air samplings also at rigid Antarctic temperatures, the sampling apparatus, consisting of a diaphragm pump and canisters, was suitably modified. Chloroform, 1,1,1-trichloroethane, tetrachloromethane, 1,1,2-trichloroethylene and tetrachloroethylene were measured in air, water and snow using specific techniques composed of a purpose-made cryofocusing-trap-injector (for air samples) and a modified purge-and-trap injector (for aqueous samples) coupled to a gas chromatograph with mass spectrometric detection operating in selected ion monitoring mode. The VCHCs were retrieved in all the investigated matrices, both Italian and Antarctic, with concentrations varying from tens to thousands of ng m(-3) in air and from digits to hundreds of ng kg(-1) in water and snow. The atmosphere/aquatic environment concentration ratios were always found to be lower than 1. In particular, the Italian air/water concentration ratios were smaller than the Antarctic ones, by reason of the higher atmospheric photochemical activity in temperate zones. On the other hand, the Antarctic air/snow concentration ratios proved to be largely in favour of snow with respect to the Italian ratios, thus corroborating the hypothesis of a more efficient VCHC deposition mechanism and accumulation on Antarctic snow.
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Affiliation(s)
- Lelio Zoccolillo
- Department of Chemistry, University of Rome La Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy.
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Mishra VK, Upadhyay AR, Tripathi BD. Bioaccumulation of heavy metals and two organochlorine pesticides (DDT and BHC) in crops irrigated with secondary treated waste water. Environ Monit Assess 2009; 156:99-107. [PMID: 18654831 DOI: 10.1007/s10661-008-0466-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 06/26/2008] [Indexed: 05/26/2023]
Abstract
Four crop plants Oryza sativa (rice), Solanum melongena (brinjal), Spinacea oleracea (spinach) and Raphanus sativus (radish) were grown to study the impact of secondary treated municipal waste water irrigation. These plants were grown in three plots each of 0.5 ha, and irrigated with secondary treated waste water from a sewage treatment plant. Sludge from the same sewage treatment plant was applied as manure. Cultivated plants were analyzed for accumulation of heavy metals and pesticides. Results revealed the accumulation of six heavy metals cadmium (Cd), chromium (Cr), iron (Fe), copper (Cu), nickel (Ni), and zinc (Zn) as well as two pesticides [1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane; DDT] and benzene hexa chloride (BHC). Order of the plants for the extent of bioaccumulation was S. oleracea > R. sativus > S. melongena > O. sativa. The study has shown the secondary treated waste water can be a source of contamination to the soil and plants.
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Affiliation(s)
- Virendra K Mishra
- Pollution Ecology Research Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India.
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Grostern A, Chan WWM, Edwards EA. 1,1,1-trichloroethane and 1,1-dichloroethane reductive dechlorination kinetics and co-contaminant effects in a Dehalobacter-containing mixed culture. Environ Sci Technol 2009; 43:6799-6807. [PMID: 19764252 DOI: 10.1021/es901038x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
1,1,1-Trichloroethane (1,1,1-TCA) is a common groundwater contaminant that can be reductively dechlorinated to 1,1-dichloroethane (1,1-DCA) and monochloroethane, and can support the growth of certain dehalorespiring strains of Dehalobacter We used reductive dehalogenase cell-free extract assays (with reduced methyl viologen) and whole cell suspension dechlorination assays (with hydrogen) and a Dehalobacter-containing enrichment culture to explore the kinetics of l,1,1-TCA and 1,1-DCA reductive dechlorination in the presence of the common co-contaminants trichloroethene (TCE), cis-dichloroethene (cDCE), and vinyl chloride (VC). These chlorinated ethenes were most significant inhibitors of 1,1,1-TCA dechlorination in cell-free extracts, indicating direct effects on the reductive dehalogenase enzyme(s). The inhibition was present but less pronounced in whole cell suspension assays. None of the chlorinated ethenes inhibited 1,1-DCA dechlorination in cell-free extract assays, yet cDCE and particularly VC were inhibitors in whole cell assays, indicating an effect on Dehalobacter, but not on the dehalogenase enzyme(s). Marked differences in kinetic parameters for 1,1,1-TCA and 1,1-DCA, and an uncoupling of these two activities in cultures grown on 1,1-DCA compared to those grown on 1,1,1-TCA was strong evidence for the existence of distinct 1,1,1-TCA and 1,1-DCA reductive dehalogenase enzymes.
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Affiliation(s)
- Ariel Grostern
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, Canada
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Millet DB, Atlas EL, Blake DR, Blake NJ, Diskin GS, Holloway JS, Hudman RC, Meinardi S, Ryerson TB, Sachse GW. Halocarbon emissions from the United States and Mexico and their global warming potential. Environ Sci Technol 2009; 43:1055-1060. [PMID: 19320157 DOI: 10.1021/es802146j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We use recent aircraft measurements of a comprehensive suite of anthropogenic halocarbons, carbon monoxide (CO), and related tracers to place new constraints on North American halocarbon emissions and quantify their global warming potential. Using a chemical transport model (GEOS-Chem) we find that the ensemble of observations are consistent with our prior best estimate of the U.S. anthropogenic CO source, but suggest a 30% underestimate of Mexican emissions. We develop an optimized CO emission inventory on this basis and quantify halocarbon emissions from their measured enhancements relative to CO. Emissions continue for many compounds restricted under the Montreal Protocol, and we show that halocarbons make up an important fraction of the total greenhouse gas source for both countries: our best estimate is 9% (uncertainty range 6-12%) and 32% (21-52%) of equivalent CO2 emissions for the U.S. and Mexico, respectively, on a 20 year time scale. Performance of bottom-up emission inventories is variable, with underestimates for some compounds and overestimates for others. Ongoing methylchloroform emissions are significant in the U.S. (2.8 Gg/y in 2004-2006), in contrast to bottom-up estimates (< 0.05 Gg), with implications for tropospheric OH calculations. Mexican methylchloroform emissions are minor.
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Affiliation(s)
- Dylan B Millet
- University of Minnesota, St. Paul, Minnesota 55108, USA.
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30
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Singh PB, Singh V. Bioaccumulation of hexachlorocyclohexane, dichlorodiphenyltrichloroethane, and estradiol-17beta in catfish and carp during the pre-monsoon season in India. Fish Physiol Biochem 2008; 34:25-36. [PMID: 18649020 DOI: 10.1007/s10695-007-9142-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Accepted: 05/03/2007] [Indexed: 05/26/2023]
Abstract
This investigation was performed to monitor hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane (DDT, and its metabolites, refered to as DDTs), plasma levels of estradiol-17beta (E2), and the gonadosomatic index (GSI) between sampling sites of unpolluted ponds of Gujartal, Jaunpur (control site) and the polluted rivers Gomti (Jaunpur) and Ganga (Varanasi), which affect the reproductive physiology of some edible catfish and carp during the pre-monsoon season. HCHs and DDTs were measured by gas liquid chromatography (GLC) and hormones by radioimmunoassay (RIA). The results indicated that the level of HCHs and DDTs was very high in both the catfish and the carp captured from the polluted rivers compared with the fish captured from the control site. The GSI and E2 values were lower in both groups of fish when compared to the fish from the control site. The results also indicate that catfish showed greater bioaccumulation of HCHs and DDTs than carp, above the permissible limit, as compared to the fish from the control site. In conclusion, fish from the Gomti and Ganga rivers were highly polluted when compared with fish from the control site, as was evident from high levels of tissue bioaccumulation of HCHs and DDTs and decreased levels of plasma E2, inhibiting the reproductive physiology of these species at the receptor level. The levels exceeded the maximum residue limits (MRL) as recommended by Codex, hence it is suggested that the fish should be avoided for food purposes.
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Affiliation(s)
- Pratap B Singh
- Fish Reproductive Toxicology Laboratory, Department of Zoology, Tilak Dhari College, Jaunpur 222 002, India.
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Lougheed T. Environmental stain fading fast. Environ Health Perspect 2007; 115:A20. [PMID: 17366804 DOI: 10.1289/ehp.115-a20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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32
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Johns DO, Dills RL, Morgan MS. Evaluation of dynamic headspace with gas chromatography/mass spectrometry for the determination of 1,1,1-trichloroethane, trichloroethanol, and trichloroacetic acid in biological samples. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 817:255-61. [PMID: 15686993 DOI: 10.1016/j.jchromb.2004.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 12/14/2004] [Indexed: 10/26/2022]
Abstract
A sensitive and reproducible method is described for the analysis of trichloroacetic acid in urine and 1,1,1-trichloroethane in blood using dynamic headspace GC/MS. Samples were analyzed using the soil module of a modified purge and trap autosampler to facilitate the use of disposable purging vessels. Coefficients of variation were below 3.5% for both analytes, and response was linear in the range of 0.01-7.0 microg/ml for trichloroacetic acid and 0.9 ng/ml-2.2 microg/ml for 1,1,1-trichloroethane. Attempts at using dynamic headspace for the analysis of trichloroethanol in urine were unsuccessful.
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Affiliation(s)
- Douglas O Johns
- Department of Environmental and Occupational Health Sciences, University of Washington, Box 357234, Seattle, WA 98195-7234, USA.
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Reimann S, Manning AJ, Simmonds PG, Cunnold DM, Wang RHJ, Li J, McCulloch A, Prinn RG, Huang J, Weiss RF, Fraser PJ, O'Doherty S, Greally BR, Stemmler K, Hill M, Folini D. Low European methyl chloroform emissions inferred from long-term atmospheric measurements. Nature 2005; 433:506-8. [PMID: 15690037 DOI: 10.1038/nature03220] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2004] [Accepted: 11/16/2004] [Indexed: 11/09/2022]
Abstract
Methyl chloroform (CH3CCl3, 1,1,1,-trichloroethane) was used widely as a solvent before it was recognized to be an ozone-depleting substance and its phase-out was introduced under the Montreal Protocol. Subsequently, its atmospheric concentration has declined steadily and recent European methyl chloroform consumption and emissions were estimated to be less than 0.1 gigagrams per year. However, data from a short-term tropospheric measurement campaign (EXPORT) indicated that European methyl chloroform emissions could have been over 20 gigagrams in 2000 (ref. 6), almost doubling previously estimated global emissions. Such enhanced emissions would significantly affect results from the CH3CC13 method of deriving global abundances of hydroxyl radicals (OH) (refs 7-12)-the dominant reactive atmospheric chemical for removing trace gases related to air pollution, ozone depletion and the greenhouse effect. Here we use long-term, high-frequency data from Mace Head, Ireland and Jungfraujoch, Switzerland, to infer European methyl chloroform emissions. We find that European emission estimates declined from about 60 gigagrams per year in the mid-1990s to 0.3-1.4 and 1.9-3.4 gigagrams per year in 2000-03, based on Mace Head and Jungfraujoch data, respectively. Our European methyl chloroform emission estimates are therefore higher than calculated from consumption data, but are considerably lower than those derived from the EXPORT campaign in 2000 (ref. 6).
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Affiliation(s)
- Stefan Reimann
- Empa, Institute of Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
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Igisu H, Narimatsu H. [Trichloroacetic acid and trichloroethanol in urine]. Nihon Rinsho 2004; 62 Suppl 12:479-81. [PMID: 15658368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- Hideki Igisu
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health
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Sato K, Uematsu Y, Isagawa S, Tateba H, Tomizawa M, Oosaki K, Hasebe A, Shibuya S, Nii H, Higashinaka R, Watanabe I, Yamazaki T, Tanamoto KI, Maitani T. [Analysis of residual solvents in natural flavorings by headspace GC using the standard addition method]. Shokuhin Eiseigaku Zasshi 2004; 45:302-6. [PMID: 15794087 DOI: 10.3358/shokueishi.45.302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Headspace GC using the standard addition method has been developed for the simultaneous determination of organic solvents in natural flavorings. The procedure can be outlined as follows: an aliquot of the sample is transferred to a 10 mL vial. To each vial, a DMSO solution containing solvents at different concentrations is added as the standard solution. The vials are kept at 50 degrees C (for automatic injection) or 40 degrees C (for hand-operated injection) for 40 minutes. One mL of the vapor phase in each vial is injected into a gas chromatograph equipped with an Aquatic-2 column (0.25 mm i.d. x 60 m). To evaluate this method, we conducted a performance study in collaboration with 10 laboratories, using ginger oleoresin. We analyzed 6 solvents (methanol, 2-propanol, acetone, dichloromethane, hexane, and 1,1,2-trichloroethene) for which the maximum residue limits are established in Japan's Specifications and Standards for Food Additives. Methanol and acetone existed in the ginger oleoresin, so only the other that four kinds of solvents were added to it. Eight of the laboratories used automatic injection, while the remaining two used hand-operated injection. Statistical analyses were conducted on the data obtained from the 8 laboratories. Repeatability standard deviations (RSDr) ranged from 4.3 to 11.4%, and reproducibility standard deviations (RSDR) ranged from 8.4 to 19.0%.
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Affiliation(s)
- Kyoko Sato
- National Institute of Health Sciences, Tokyo, Japan
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Abstract
This article presents the current knowledge and clinical applications of the use of biomarkers of exposure to the halogenated solvents 1,1,1 trichloroethane (methylchloroform), trichloroethylene, tetrachloroethylene (perchloroethylene), and 1,1 dichloroethylene (vinylidene chloride). Although some studies have shown that protein and DNA adducts may form with chlorinated hydrocarbons, their application has not been validated sufficiently to justify their use as biologic markers of exposure.
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Affiliation(s)
- Javier C Waksman
- University of Colorado Health Sciences Center Denver, CO, CO 80262, USA.
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Fantuzzi G, Righi E, Predieri G, Pinotti MA, Aggazzotti G. [Halogenated volatile organic compounds in bottled mineral water and soft drinks]. Ann Ig 2004; 16:727-34. [PMID: 15697002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
74 mineral natural water samples and 56 samples of different commercial drinks have been analysed by head-space chromatography in order to evidence the presence of volatile halogenated organic compounds (VHO). Trihalomethanes (THM) as drinking water chlorination by-products and trichloroethane, carbon tetrachloride, trichloroethylene and tetrachloroethylene as ubiquitarious substances have been investigated. The presence of VHO has been evidenced in 20,3% of mineral natural water samples and in the 58,9% of the commercial soft drinks: this latest group has usually shown higher levels of the investigated compounds. The results of the present study has been compared with a similar study performed in 1991 in the same area: the VHO values observed in the present study appear to be lower than those obtained in the previous study.
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Affiliation(s)
- G Fantuzzi
- Dipartimento di Scienze Igienistiche, Microbiologiche e Biostatistiche, Università degli Studi di Modena e Reggio Emilia.
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39
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Abstract
This paper describes a generalized methodology that enables the translation of expert knowledge about any complex process involved in a remedial decision into easy-to-use decision tools. The methodology is applied to evaluate reductive dechlorination as a remedial possibility at sites contaminated with trichloroethene (TCE), building on an existing protocol/scoring system put forth by the US Air Force and the US EPA. An alternate scoring system is proposed, which has two major advantages, namely that it: (i) attributes relative weights to findings based on expert beliefs; and (ii) systematically includes negative weights for negative findings. The ability of the proposed scoring system to assess the bioattenuation potential of TCE is demonstrated using data from extensively studied sites.
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Affiliation(s)
- Neil A Stiber
- USEPA Office of Research and Development, Office of Science Policy, Washington, DC 20460, USA
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40
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Chrysikopoulos CV, Vogler ET. Acoustically enhanced multicomponent NAPL ganglia dissolution in water saturated packed columns. Environ Sci Technol 2004; 38:2940-2945. [PMID: 15212271 DOI: 10.1021/es034665n] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The impact of acoustic pressure waves on multicomponent nonaqueous phase liquid (NAPL) ganglia dissolution in water saturated columns packed with glass beads was investigated. Laboratory data from dissolution experiments with two and three component NAPL mixtures suggested that acoustic waves significantly enhance ganglia dissolution due to the imposed oscillatory interstitial water velocity. The dissolution enhancement was shown to be directly proportional to the acoustic wave frequency. Furthermore, it was demonstrated that the greatest dissolution enhancement in the presence of acoustic waves is associated with the component of the NAPL mixture having the smallest equilibrium aqueous solubility. Finally, square shaped acoustic waves were shown to lead to greater NAPL dissolution enhancement compared to sinusoidal and triangular acoustic waves. The results of this study suggested that aquifer remediation using acoustic waves is a promising method particularly for aquifers contaminated with NAPLs containing components with very low equilibrium aqueous solubilities.
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Coulibaly L, Labib ME, Hazen R. A GIS-based multimedia watershed model: development and application. Chemosphere 2004; 55:1067-1080. [PMID: 15051375 DOI: 10.1016/j.chemosphere.2004.01.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2003] [Revised: 11/11/2003] [Accepted: 01/09/2004] [Indexed: 05/24/2023]
Abstract
A multimedia model was developed using publicly available geographical information system (GIS) data, chemical release information and local monitoring networks to assess the fate of trichloroethene (TCE) within the Passaic River Watershed. Seven environmental media, air, water, sediment, surface soil, terrestrial vegetation, root zone soil and vadose zone soil, were modeled in this study along with their sub-compartments. The Passaic River Watershed is described using the NJDEP geographical information system (GIS) resources, the United States Geological Survey (USGS) and the United States Soil Conservation Services (US SCS) soil data. The introduction of spatial resolution to a multimedia, unsteady state model is performed in this work, and represents an important step in expanding the use of equilibrium models to provide far reaching information on the fate of toxic contaminants within a given environmental unit. The spatial representation of cross-boundary fluxes was successfully demonstrated with the use of sub-watershed as an environmental unit and the direct assessment of TCE for each of the 11 sub-watersheds that make up the Passaic River Basin in northern New Jersey. Important data gaps identified during the development of this model include the lack of comprehensive monitoring data on organic contaminants, and non-uniformity among available physical environmental data from different government agencies.
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Affiliation(s)
- Lansana Coulibaly
- Kleinfelder Inc., Navy CLEAN, 1230 Columbia Street, Suite 400, San Diego, CA 92101, USA.
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42
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Weissflog L, Krüger G, Elansky N, Putz E, Pfennigsdorff A, Seyfarth KU, Nüchter M, Lange C, Kotte K. Input of trichloroacetic acid into the vegetation of various climate zones--measurements on several continents. Chemosphere 2003; 52:443-449. [PMID: 12738268 DOI: 10.1016/s0045-6535(03)00209-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Trichloroacetic acid (TCA, CCl(3)COOH) is a phytotoxic chemical. Although TCA salts and derivates were once used as herbicides to combat perennial grasses and weeds, they have since been banned because of their indiscriminate herbicidal effects on woody plant species. However, TCA can also be formed in the atmosphere. For instance, the high-volatile C(2)-chlorohydrocarbons tetrachloroethene (TECE, C(2)Cl(4)) and 1,1,1-trichloroethane (TCE, CCl(3)CH(3)) can react under oxidative conditions in the atmosphere to form TCA and other substances. The ongoing industrialisation of Southeast Asia, South Africa and South America means that use of TECE as solvents in the metal and textile industries of these regions in the southern hemisphere can be expected to rise. The increasing emissions of this substance--together with the rise in the atmospheric oxidation potential caused by urban activities, slash and burn agriculture and forest fires in the southern hemisphere--could lead to a greater input/formation of TCA in the vegetation located in the lee of these emission sources. By means of biomonitoring studies, the input/formation of TCA in vegetation was detected at various locations in South America, North America, Africa, and Europe.
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Affiliation(s)
- Ludwig Weissflog
- Department of Analytical Chemistry, UFZ-Centre for Environmental Research, Permoserstrasse 15, 04301 Leipzig, Germany.
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43
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Shouakar-Stash O, Frape SK, Drimmie RJ. Stable hydrogen, carbon and chlorine isotope measurements of selected chlorinated organic solvents. J Contam Hydrol 2003; 60:211-228. [PMID: 12504360 DOI: 10.1016/s0169-7722(02)00085-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Stable hydrogen isotopes of two chlorinated solvents, trichloroethylene (TCE) and 1,1,1-trichloroethane (TCA), provided by five different manufacturers, were determined and compared to their carbon and chlorine isotopic signatures. The isotope ratio for delta2H of different TCEs ranged between +466.9 per thousand and +681.9 per thousand, for delta13C between -31.57 per thousand and -27.37 per thousand, and for delta37Cl between -3.19 per thousand and +3.90 per thousand. In the case of the TCAs, the isotope ratio for delta2H ranged between -23.1 per thousand and +15.1 per thousand, for delta13C between -27.39 per thousand and -25.84 per thousand, and for delta37Cl between -3.54 per thousand and +1.39 per thousand. As well, a column experiment was carried out to dechlorinate tetrachloroethylene (PCE) to TCE using iron. The dechlorination products have completely different hydrogen isotope ratios than the manufactured TCEs. Compared to the positive values of delta2H in manufactured TCEs (between +466.9 per thousand and +681.9 per thousand), the dechlorinated products had a very depleted delta2H (less than -300 per thousand). This finding has strong implications for distinguishing dechlorination products (PCE to TCE) from manufactured TCE. In addition, the results of this study show the potential of combining 2H/1H analyses with 13C/12C and 37Cl/35Cl for isotopic fingerprinting applications in organic contaminant hydrogeology.
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Affiliation(s)
- Orfan Shouakar-Stash
- Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
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Wang KH, Hsieh YH, Chao PW, Cgang CY. The photocatalytic degradation of trichloroethane by chemical vapor deposition method prepared titanium dioxide catalyst. J Hazard Mater 2002; 95:161-174. [PMID: 12409246 DOI: 10.1016/s0304-3894(02)00135-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The purpose of the investigation was to study the photocatalytic reaction of trichloroethane using a TiO(2) catalyst deposited in an annular reactor by the chemical vapor deposition (CVD) method. The experimental results indicated the highest decomposition rate of the trichloroethane was 2.71 micro mol/(sm(2)) and the conversion ratio reached a maximum of 99.9%. When the humidity was below 154 micro M, the reaction rate slightly increased with increasing humidity. However, the reaction rate decreased as the humidity increased >154 micro M. Oxygen played a role as an electron acceptor in the reaction, and reduced the recombination of the photogenerated electron-hole pairs. Therefore, the reaction rate rose as the oxygen concentration increased. Nevertheless, after the oxygen concentration reached 12%, the reaction rate reached it maximum and was constant in spite of increasing oxygen concentration. As the initial reactant concentration increased, the reaction rate increased, but the conversion ratio dropped. An increase of light intensity resulted in an increase in the number of photons and thus increased the reaction rate. Accordingly the decomposition of trichloroethane could be fitted by the semi-empirical bimolecular Langmuir-Hinshelwood model. Moreover, the reaction rate was proportional to the 0.48-order of the light intensity.
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Affiliation(s)
- Kuo-Hua Wang
- Department of Labor Relations, Institute of Labor, Chinese Culture University, 55 Huw Kang Road, Yang Ming Shan, Taipei, Taiwan.
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45
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Abstract
Individuals who lived near 2 electronic manufacturing plants were exposed to odorous chlorinated solvents by inhalation (directly) and by out gassing from well water. An exposure zone was defined by concentrations of trichloroethylene, 1,1,1-trichloroethane, tetrachloroethylene, and vinyl chloride in groundwater. The author adopted trichloroethylene as a "shorthand" for the exposure designation. Residents complained of impaired recall and concentration, and of dizziness; therefore, the focus of this investigation was brain functions. Neurobehavioral functions, Profile of Mood States, frequencies of 35 symptoms, and questionnaire responses provided by 236 residents from exposure zones were compared with responses provided by 161 unexposed regional referents and by 67 Phoenix residents who lived outside the exposure zone areas. Pulmonary functions were measured with spirometry. Residents of the exposure zones were compared with regional referents, and the former had significantly (p < .05) delayed simple and choice reaction times, impaired balance, delayed blink reflex latency R-1, and abnormal color discrimination. In addition, these individuals had impaired (1) cognitive functions, (2) attention and perceptual motor speed, and (3) recall. Individuals who lived in exposure zones had airway obstructions. Adverse mood state scores and frequencies of 33 of 35 symptoms were elevated. In conclusion, individuals who lived in the exposure zones had neurobehavioral impairments, reduced pulmonary functions, elevated Profile of Mood State scores, and excessive symptom frequencies.
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Affiliation(s)
- Kaye H Kilburn
- University of Southern California, Keck School of Medicine, Environmental Sciences Laboratory, Los Angeles, California, USA
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Kommalapati RR, Valsaraj KT, Constant WD. Soil-water partitioning and desorption hysteresis of volatile organic compounds from a Louisiana Superfund site soil. Environ Monit Assess 2002; 73:275-290. [PMID: 11878636 DOI: 10.1023/a:1013190302163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The adsorption and desorption of three volatile organic compounds (1,2-dichloroethane, 1,1,2- trichloroethane and 1,1,2,2-tetrachloroethane) from a previously uncontaminated clayey soil sample from a Superfund site in North Baton Rouge, Louisiana was studied. In the linear range of the adsorption isotherm, the partition constants were not affected by the presence of the co-solutes. The adsorption isotherms over a wide concentration range on the soil followed the nonlinear Freundlich isotherm. The desorption of the compounds showed significant hysteresis at all concentrations studied. Approximately 20 to 70% of the adsorbed mass of organic compounds resisted the desorption even after five months of successive desorption steps. The desorption of four compounds (1,2-dichloroethane, 1,1,2-trichloroethane, 1,4-dichlorobenzene and hexachlorobutadiene) from a contaminated soil sample from the same site was also studied. The aqueous concentration declined as the successive desorption steps progressed. For hexachlorobutediene the desorption can be visualized as occurring in two stages. The first stage involved a 'loosely bound' or 'reversible' fraction and the second stage involved a 'tightly bound' or 'resistant' fraction.
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Affiliation(s)
- R R Kommalapati
- Department of Civil Engineering, Prairie View A and M University, Texas, USA
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Altissimo L, Andreoli E, Giacometti A, Marcomini A. Time trends of 1,1,1-trichloroethane, trichloroethylene, and perchloroethylene in confined and unconfined aquifers of a groundwater system in northern Italy. Ann Chim 2002; 92:61-71. [PMID: 11993276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The concentrations of 1,1,1-trichloroethane, trichloroethylene, and perchloroethylene were recorded in a groundwater system of Northern Italy over the period 1985-1997. In the unconfined recharging aquifer these chemicals showed a remarkable overall decline which was accompanied by a five-fold reduction in their consumption (from approx. 250 to approx. 50 tons year-1) over the same period. The time trends for the confined aquifers indicated a steady decline for 1,1,1-trichloroethane which was accompanied by a constant concentration of trichloroethylene and an increasing presence of perchloroethylene. It is suggested that the confined aquifers are recording a contamination which took place in the unconfined recharging aquifer before monitoring period (1982) started. At present, in most of the study area 1,1,1-trichloroethane contamination is below the detection limit (0.1 microgram/L). For trichloroethylene and perchloroethylene, the average unconfined aquifer contamination accounts for approx. 1 +/- 1 and approx. 4 +/- 3 micrograms/L, respectively, while in the confined aquifers the average concentrations are approx. 8 +/- 3 and approx. 35 +/- 5 micrograms/L, respectively.
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Affiliation(s)
- Lorenzo Altissimo
- Centro Idrico di Novoledo, via Palladio 124, 36030 Villaverla, Vicenza, Italy
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Woodfine D, MacLeod M, Mackay D. A regionally segmented national scale multimedia contaminant fate model for Canada with GIS data input and display. Environ Pollut 2002; 119:341-355. [PMID: 12166668 DOI: 10.1016/s0269-7491(01)00344-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Regional scale mass balance models are valuable tools for describing the fate of chemicals in areas with defined and fairly homogeneous environmental characteristics and chemical use patterns. These models often show that contaminant inflows from outside the region of interest are significant compared with local emissions. This is most likely for persistent chemicals and those that are efficiently transported in air or water. As a result regional levels of environmental contamination are controlled by external factors and meaningful evaluation requires assessment of contaminant fate in neighboring regions. A linked set of regional models thus has the potential to describe quantitatively the impact of chemical emissions over a wider geographic scale with significant spatial differences in environmental characteristics and chemical use patterns. We describe here a national scale contaiminant fate model for Canada based on the existing 24-region ChemCAN model. The ecological regions, which were previously treated individually, are linked with flows of air and water deduced from GIS analysis to provide a comprehensive description of contaminant fate over the entire country, including long-range transport between regions. The model is applied to describe the national-scale fate of three chemicals in Canada, benzene, trichloroethene, and diethylhexyl phthalate, exploiting GIS analysis for interpretation and presentation of model results. Agreement between predicted multimedia environmental concentrations and measured values is satisfactory for all three chemicals. In total this work represents an initial attempt to address the different processes of both linking a regional model and using GIS as a tool for data analysis and management.
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Affiliation(s)
- David Woodfine
- Canadian Environmental Modelling Centre, Trent University, Peterborough, Ontario, Canada
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Bresnitz EA, Gittleman JL, Shic F, Temple B, Henretig F. A national survey of regional poison control centers' management of occupational exposure calls. J Occup Environ Med 1999; 41:93-9. [PMID: 10029953 DOI: 10.1097/00043764-199902000-00003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Regional poison control centers (PCCs) were surveyed nationally to assess their policies and practices in handling work-related exposures. A 24-item survey was mailed to the executive directors of 44 American Association of Poison Control Centers' certified PCCs nationwide. The survey also requested permission to call the PCC to conduct a blinded role-playing exercise of a case of work-related trichloroethane exposure. Responses on the management questionnaire were compared with the actual responses provided by information specialists in the role-playing exercise. Seventy-five percent of PCCs completed the survey; 43% completed the telephone role-playing exercise. Survey respondents generally overestimated what they thought was routinely done to assess work-related calls, compared with what actually occurred at the time of the work-related call in the role-playing exercise. For example, 32% indicated that their PCC asked about the activities of nearby workers, but none of the PCC staff actually did so. Eighty-nine percent of the PCC executive directors surveyed thought that their staff routinely advised callers to notify their employer about work-related exposure concerns, but this occurred in only 11% of the calls. We concluded that PCCs' responses to work-related calls are inadequate. Given the public health impact of work-related calls, PCCs should develop, implement, and monitor written protocols to better address the public health issues of workplace poisonings.
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Affiliation(s)
- E A Bresnitz
- Department of Community and Preventive Medicine, MCP Hahnemann School of Medicine, MCP Hahnemann University of the Health Sciences, Philadelphia, PA, USA
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50
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Abstract
The analysis of organic pollutants in drinking water is a topic of wide interest, reflecting on public health and life quality. Many different methodologies have been developed and are currently employed in this context, but they often require a time-consuming sample pre-treatment. This step affects the recovery of the highly volatile compounds. Trace analysis of volatile organic pollutants in water can be performed 'on-line' by membrane inlet mass spectrometry (MIMS). In MIMS, the sample is separated from the vacuum of the mass spectrometer by a thin polymeric hollow-fibre membrane. Gases and organic volatile compounds diffuse and concentrate from the sample into the hollow-fibre membrane, and from there into the mass spectrometer. The main advantages of the technique are that no pre-treatment of samples before analysis is needed and that it has fast response times and on-line monitoring capabilities. This paper reports the set-up of the analytical conditions for the analysis of volatile organohalogen compounds (chloroform, bromoform, bromodichloromethane, chlorodibromomethane, tetrachloroethylene, trichloroethylene, 1,1,1-trichloroethane, and carbon tetrachloride). Linearity of response, repeatability, detection limits, and spectra quality are evaluated.
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Affiliation(s)
- P Bocchini
- Dipartimento di Chimica 'G. Ciamician', Università degli Studi di Bologna, via F. Selmi 2, 40126 Bologna, Italy.
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