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Chen Y, Yuan CJ, Xu BJ, Cao JY, Lee MY, Liu M, Wu Q, Du Y. Suppressing Organic Bromine but Promoting Bromate: Is the Ultraviolet/Ozone Process a Double-Edged Sword for the Toxicity of Wastewater to Mammalian Cells? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11649-11660. [PMID: 38872439 DOI: 10.1021/acs.est.4c00329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Brominated byproducts and toxicity generation are critical issues for ozone application to wastewater containing bromide. This study demonstrated that ultraviolet/ozone (UV/O3, 100 mJ/cm2, 1 mg-O3/mg-DOC) reduced the cytotoxicity of wastewater from 14.2 mg of pentol/L produced by ozonation to 4.3 mg of pentol/L (1 mg/L bromide, pH 7.0). The genotoxicity was also reduced from 1.65 to 0.17 μg-4-NQO/L by UV/O3. Compared with that of O3 alone, adsorbable organic bromine was reduced from 25.8 to 5.3 μg/L by UV/O3, but bromate increased from 32.9 to 71.4 μg/L. The UV/O3 process enhanced the removal of pre-existing precursors (highly unsaturated and phenolic compounds and poly aromatic hydrocarbons), while new precursors were generated, yet the combined effect of UV/O3 on precursors did not result in a significant change in toxicity. Instead, UV radiation inhibited HOBr concentration through both rapid O3 decomposition to reduce HOBr production and decomposition of the formed HOBr, thus suppressing the AOBr formation. However, the hydroxyl radical-dominated pathway in UV/O3 led to a significant increase of bromate. Considering both organic bromine and bromate, the UV/O3 process effectively controlled both cytotoxicity and genotoxicity of wastewater to mammalian cells, even though an emphasis should be also placed on managing elevated bromate. Futhermore, other end points are needed to evaluate the toxicity outcomes of the UV/O3 process.
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Affiliation(s)
- Ying Chen
- College of Architecture and Environment, Sichuan University, Chengdu 610000, China
| | - Chang-Jie Yuan
- College of Architecture and Environment, Sichuan University, Chengdu 610000, China
| | - Bao-Jun Xu
- College of Architecture and Environment, Sichuan University, Chengdu 610000, China
| | - Jie-Yu Cao
- College of Architecture and Environment, Sichuan University, Chengdu 610000, China
| | - Min-Yong Lee
- Division of Chemical Research, National Institute of Environmental Research, Seogu, Incheon 22689, Republic of Korea
| | - Min Liu
- College of Architecture and Environment, Sichuan University, Chengdu 610000, China
| | - Qianyuan Wu
- Key Laboratory of Microorganism Application and Risk Control of Shenzhen, Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Ye Du
- College of Architecture and Environment, Sichuan University, Chengdu 610000, China
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2
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Brinkmann MT, Rong K, Xie Y, Yan T. Formation potential of disinfection byproducts during chlorination of petroleum hydrocarbon-contaminated drinking water. CHEMOSPHERE 2024; 357:142057. [PMID: 38636920 DOI: 10.1016/j.chemosphere.2024.142057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/19/2024] [Accepted: 04/15/2024] [Indexed: 04/20/2024]
Abstract
Recent leaks of underground fuel storage tanks in the Pearl Harbor region have led to direct release of un-weathered petroleum hydrocarbons (PHCs) into drinking water sources, which then directly underwent chlorination disinfection treatment. Since the control of disinfection byproducts (DBPs) traditionally focuses natural organic matters (NOM) from source water and little is known about the interactions between free chlorine and un-weathered PHCs, laboratory chlorination experiments in batch reactors were conducted to determine the formation potential of DBPs during chlorination of PHC-contaminated drinking water. Quantitative analysis of regulated DBPs showed that significant quantities of THM4 (average 3,498 μg/L) and HAA5 (average 355.4 μg/L) compounds were formed as the result of chlorination of un-weathered PHCs. Amongst the regulated DBPs, THM4, which were comprised primarily of chloroform and bromodichloromethane, were more abundant than HAA5. Numerous unregulated DBPs and a large diversity of unidentified potentially halogenated organic compounds were also produced, with the most abundant being 1,1-dichloroacetone, 1,2-dibromo-3-chloropropane, chloropicrin, dichloroacetonitrile, and trichloracetonitrile. Together, the results demonstrated the DBP formation potential when PHC-contaminated water undergoes chlorination treatment. Further studies are needed to confirm the regulated DBP production and health risks under field relevant conditions.
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Affiliation(s)
- Mandy-Tanita Brinkmann
- Department of Civil, Environmental, and Construction Engineering, University of Hawaii at, Manoa, USA
| | - Kexin Rong
- Water Resources Research Center, University of Hawaii at, Manoa, USA
| | - Yuefeng Xie
- Department of Civil, Construction, and Environmental Engineering, The Pennsylvania State University, Middletown, PA, 17057, USA
| | - Tao Yan
- Department of Civil, Environmental, and Construction Engineering, University of Hawaii at, Manoa, USA; Water Resources Research Center, University of Hawaii at, Manoa, USA.
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3
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Xie Y, Zhang K, Shen Z, Feng M, Wang C. Simulated sunlight/periodate-triggered formation of toxic halogenated bisphenols in highly saline water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:26320-26329. [PMID: 38523216 DOI: 10.1007/s11356-024-32962-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 03/13/2024] [Indexed: 03/26/2024]
Abstract
Periodate (PI)-based oxidation using the activators, such as metal ions and light irradiation, has emerged as a feasible treatment strategy for the effective remediation of contaminated water and wastewater. Given the pervasive nature of PI residues and solar exposure during application, the role of solar light in remediating the challenging highly saline water matrices needs to be elucidated. In this study, bisphenol A (BPA) was selected as the targeted micropollutant, which can be efficiently eliminated by the simulated sunlight (SSL)/PI system in the presence of high-level Cl- (up to 846.0 mM) at pH 7.0. The presence of different background constituents of water, such as halides, nitrate, and dissolved organic matter, had no effect, or even accelerated BPA abatement. Particularly, the ubiquitous Br- or I- appreciably enhanced the BPA transformation efficiency, which may be ascribed to the generation of high-selective reactive HOBr or HOI. The in silico predictions suggested that the transformation products generated by halide-mediated SSL/PI systems via halogen substitutions showed greater persistence, bioaccumulation, and aquatic toxicity than BPA itself. These findings highlighted a widespread phenomenon during PI-based oxidative treatment of highly saline water, which needs special attention under solar light illumination.
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Affiliation(s)
- Yuwei Xie
- College of the Environment & Ecology, Xiamen University, Xiamen, 361100, People's Republic of China
| | - Kaiting Zhang
- College of the Environment & Ecology, Xiamen University, Xiamen, 361100, People's Republic of China
| | - Zhen Shen
- College of the Environment & Ecology, Xiamen University, Xiamen, 361100, People's Republic of China
| | - Mingbao Feng
- College of the Environment & Ecology, Xiamen University, Xiamen, 361100, People's Republic of China
| | - Chong Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, People's Republic of China.
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4
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von Gunten U. Oxidation processes and me. WATER RESEARCH 2024; 253:121148. [PMID: 38387263 DOI: 10.1016/j.watres.2024.121148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/12/2024] [Accepted: 01/14/2024] [Indexed: 02/24/2024]
Abstract
This publication summarizes my journey in the field of chemical oxidation processes for water treatment over the last 30+ years. Initially, the efficiency of the application of chemical oxidants for micropollutant abatement was assessed by the abatement of the target compounds only. This is controlled by reaction kinetics and therefore, second-order rate constant for these reactions are the pre-requisite to assess the efficiency and feasibility of such processes. Due to the tremendous efforts in this area, we currently have a good experimental data base for second-order rate constants for many chemical oxidants, including radicals. Based on this, predictions can be made for compounds without experimental data with Quantitative Structure Activity Relationships with Hammet/Taft constants or energies of highest occupied molecular orbitals from quantum chemical computations. Chemical oxidation in water treatment has to be economically feasible and therefore, the extent of transformation of micropollutants is often limited and mineralization of target compounds cannot be achieved under realistic conditions. The formation of transformation products from the reactions of the target compounds with chemical oxidants is inherent to oxidation processes and the following questions have evolved over the years: Are the formed transformation products biologically less active than the target compounds? Is there a new toxicity associated with transformation products? Are transformation products more biodegradable than the corresponding target compounds? In addition to the positive effects on water quality related to abatement of micropollutants, chemical oxidants react mainly with water matrix components such as the dissolved organic matter (DOM), bromide and iodide. As a matter of fact, the fraction of oxidants consumed by the DOM is typically > 99%, which makes such processes inherently inefficient. The consequences are loss of oxidation capacity and the formation of organic and inorganic disinfection byproducts also involving bromide and iodide, which can be oxidized to reactive bromine and iodine with their ensuing reactions with DOM. Overall, it has turned out in the last three decades, that chemical oxidation processes are complex to understand and to manage. However, the tremendous research efforts have led to a good understanding of the underlying processes and allow a widespread and optimized application of such processes in water treatment practice such as drinking water, municipal and industrial wastewater and water reuse systems.
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Affiliation(s)
- Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf, Switzerland; ENAC, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale, CH-1000, Lausanne, Switzerland.
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5
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Yin Q, Ji Y, Guo Y, Manoli K, Chen W, Zhang L, Yu X, Feng M. Environmental fate and risk evolution of calcium channel blockers from chlorine-based disinfection to sunlit surface waters. WATER RESEARCH 2024; 249:120968. [PMID: 38070349 DOI: 10.1016/j.watres.2023.120968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 01/03/2024]
Abstract
Organic micropollutants present in disinfected wastewater and discharged to sunlit surface waters may be transformed by multiple processes, such as chlorination due to the presence of chlorine residuals, solar irradiation as well as solar-irradiated chlorine residues. This study reports, for the first time, the multi-scenario degradation kinetics, transformation products, and risk evolution of calcium channel blockers (CCBs), a class of emerging pharmaceutical contaminants with worldwide prevalence in natural waters and wastewater. It was found that the chlorination of the studied CCBs (amlodipine (AML) and verapamil (VER)) was dominated by the reaction of HOCl with their neutral species, with second-order rate constants of 6.15×104 M-1 s-1 (AML) and 7.93×103 M-1 s-1 (VER) at pH 5.0-11.0. Bromination is much faster than chlorination, with the measured kapp,HOBr values of 2.94×105 M-1 s-1 and 6.58×103 M-1 s-1 for AML and VER, respectively, at pH 7.0. Furthermore, both CCBs would undergo photolytic attenuations with hydroxyl and carbonate radicals as the dominant reactive species in water. Notably, free chlorine mainly contributed to their abatement during the solar/chlorine treatment. Additionally, the halogen addition on the aromatic ring was observed during chlorination and bromination of the two CCBs. Cyclization was observed under solar irradiation only, while the aromatic ring was opened in the solar/chlorine system. Some products generated by the three transformation processes exhibited non-negligible risks of high biodegradation recalcitrance and toxicity, potentially threatening the aquatic environment and public health. Overall, this study elucidated the environmental fate of typical CCBs under different transformation processes to better understand the resulting ecological risks in these environmental scenarios.
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Affiliation(s)
- Qian Yin
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Yuefei Ji
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yating Guo
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | | | - Wenzheng Chen
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Lei Zhang
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen 361102, China; Core Facility of Biomedical, Xiamen University, Xiamen 361102, China
| | - Xin Yu
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China
| | - Mingbao Feng
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China.
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Gao X, Wang X, Jiang Y, Kong D, Pan X, Ma J, Liu Y. Chloro- and bromo-benzoquinone formation and transformation mechanisms in a drinking water-distribution system. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132692. [PMID: 37801978 DOI: 10.1016/j.jhazmat.2023.132692] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 09/30/2023] [Accepted: 09/30/2023] [Indexed: 10/08/2023]
Abstract
Halogenated benzoquinones (HBQs) are frequently detected in tap water. HBQ levels are correlated with water age. As the water-transmission distance (water age) increases, the levels of bromo-benzoquinones (Br-BQs) decreased and those of chloro-benzoquinones (Cl-BQs) remained relatively stable in drinking water-distribution system in the presence of residual chlorine. 2,3,5,6-Tetrachloro-1,4-benzoquinone (TCBQ) and 2,6-dibromo-1,4-benzoquinone (DBBQ) were the most abundant Cl-BQ and Br-BQ, with maximum concentrations of 60.2 and 181.4 ng/L, respectively. TCBQ and DBBQ were chosen as representatives of HBQs to investigate their reactions with chlorine, including kinetics, pathways, and changes in toxicity. The hydrolysis and chlorination rates of HBQs were significantly pH-dependent, and the kinetic rates of DBBQ were faster than TCBQ in the pH range of 5-10. Chlorination converted highly toxic TCBQ and DBBQ to less-toxic chlorinated/brominated aliphatic disinfection by-products (DBPs), thereby reducing the overall toxicity of water bodies. This study provides comprehensive insights into the distinct life cycles of TCBQ and DBBQ in drinking water, covering formation, transformation, and toxicity. These findings provide a nuanced understanding of the risks posed by HBQs at various locations within the drinking water distribution system, offering valuable guidance for improving the control of DBPs in drinking water.
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Affiliation(s)
- Xiaoting Gao
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Xianshi Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Youwei Jiang
- College of Hydraulic and Civil Engineering, Xinjiang Agricultural University, Urumqi 830052, Xinjiang, China
| | - Dezhen Kong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xiangrui Pan
- Qihe County Agriculture and Rural Bureau, Dezhou 251100, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yanan Liu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai institute of pollution control and ecological security, Shanghai 200092, China.
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7
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Keltsch NG, Pütz E, Dietrich C, Wick A, Tremel W, Ternes TA. Bromination of Quorum Sensing Molecules: Vanadium Bromoperoxidase and Cerium Dioxide Nanocrystals via Free Active Bromine Transform Bacterial Communication. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18491-18498. [PMID: 37222552 DOI: 10.1021/acs.est.3c00459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The halogenation of quorum sensing molecules (QSMs) is known to be catalyzed by enzymes such as haloperoxidase (HPO) as well as cerium dioxide nanocrystals (NC), which mimic enzymes. Those enzymes and mimics can influence biological processes such as biofilm formation, where bacteria use QSMs for the "chemical" communication between each other and the coordination of surface colonization. However, not much is known about the degradation behavior of a broad spectrum of QSMs, especially for HPO and its mimics. Therefore, in this study, the degradation of three QSMs with different molecule moieties was elucidated. For this purpose, different batch experiments were carried out with HPOs, NCs and free active bromine (FAB). For N-β-ketocaproyl-homoserine lactone (3-Oxo-C6-AHL), N-cis-tetradec-9Z-enoyl-homoserine lactone (C14:1-AHL) and 2-heptyl-4-quinolone (HHQ) a fast degradation and moiety-specific transformations were observed. The HPO vanadium bromoperoxidase as well as cerium dioxide NCs catalyzed the formation of the same brominated transformation products (TPs). Since the same TPs are formed in batch experiments with FAB it is very likely that FAB is playing a major role in the catalytical reaction mechanism leading to the transformation of QSMs. In this study in total 17 TPs could be identified in different levels of confidence and the catalytic degradation processes for two QS groups (unsaturated AHLs and alkyl quinolones) with cerium dioxide NCs and vanadium bromoperoxidase were expanded.
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Affiliation(s)
- N G Keltsch
- Bundesanstalt für Gewässerkunde, Am Mainzer Tor 1, 56068 Koblenz, Germany
- Universität Koblenz-Landau, Universitätsstraße 1, 56070 Koblenz, Germany
| | - E Pütz
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany
| | - C Dietrich
- Bundesanstalt für Gewässerkunde, Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - A Wick
- Bundesanstalt für Gewässerkunde, Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - W Tremel
- Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany
| | - T A Ternes
- Bundesanstalt für Gewässerkunde, Am Mainzer Tor 1, 56068 Koblenz, Germany
- Universität Koblenz-Landau, Universitätsstraße 1, 56070 Koblenz, Germany
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8
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Zhou Y, Jiao JJ, Huang H, Liu YD, Zhong R, Yang X. Insights into C-C Bond Cleavage Mechanisms in Dichloroacetonitrile Formation during Chlorination of Long-Chain Primary Amines, Amino Acids, and Dipeptides. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18834-18845. [PMID: 37183372 DOI: 10.1021/acs.est.2c07779] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Dichloroacetonitrile (DCAN) as one of the potentially prioritized regulated DBPs has drawn great attention; however, understanding its formation, especially the C-C bond cleavage mechanisms, is limited. In this study, DCAN formation mechanisms from long-chain primary amines, amino acids, and dipeptides during chlorination were investigated by a combined computational and experimental approach. The results indicate that nitriles initially generate for all of the above precursors, then they undergo β-C-hydroxylation or/and α-C-chlorination processes, and finally, DCAN is produced through the Cα-Cβ bond cleavage. For the first time, the underlying mechanism of the C-C bond cleavage was unraveled to be electron transfer from the O- anion into its attached C atom in the chlorinated nitriles, leading to the strongly polarized Cα-Cβ bond heterocleavage and DCAN- formation. Moreover, DCAN molar yields of precursors studied in the present work were found to be determined by their groups at the γ-site of the amino group, where the carbonyl group including -CO2-, -COR, and -CONHR, the aromatic group, and the -OH group can all dramatically facilitate DCAN formation by skipping over or promoting the time-consuming β-C-hydroxylation process and featuring relatively lower activation free energies in the C-C bond cleavage. Importantly, 4-amino-2-hydroxybutyric acid was revealed to possess the highest DCAN yield among all the known aliphatic long-chain precursors to date during chlorination. Additionally, enonitriles, (chloro-)isocyanates, and nitriles can be generated during DCAN formation and should be of concern due to their high toxicities.
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Affiliation(s)
- Yingying Zhou
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Jia-Jia Jiao
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Huang Huang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yong Dong Liu
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Rugang Zhong
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Xin Yang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
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Liu T, Xiao S, Li N, Chen J, Xu Y, Yin W, Zhou X, Huang CH, Zhang Y. Selective Transformation of Micropollutants in Saline Wastewater by Peracetic Acid: The Overlooked Brominating Agents. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18940-18949. [PMID: 37207368 DOI: 10.1021/acs.est.3c00835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Peracetic acid (PAA) is an emerging alternative disinfectant for saline waters; HOBr or HOCl is known as the sole species contributing to halogenation reactions during PAA oxidation and disinfection. However, new results herein strongly indicated that the brominating agents (e.g., BrCl, Br2, BrOCl, and Br2O) are generated at concentrations typically lower than HOCl and HOBr but played significant roles in micropollutants transformation. The presence of Cl- and Br- at environmentally relevant levels could greatly accelerate the micropollutants (e.g., 17α-ethinylestraiol (EE2)) transformation by PAA. The kinetic model and quantum chemical calculations collectively indicated that the reactivities of bromine species toward EE2 follow the order of BrCl > Br2 > BrOCl > Br2O > HOBr. In saline waters with elevated Cl- and Br- levels, these overlooked brominating agents influence bromination rates of more nucleophilic constituents of natural organic matter and increase the total organic bromine. Overall, this work refines our knowledge regarding the species-specific reactivity of brominating agents and highlights the critical roles of these agents in micropollutant abatement and disinfection byproduct formation during PAA oxidation and disinfection.
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Affiliation(s)
- Tongcai Liu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Shaoze Xiao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Nan Li
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Jiabin Chen
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Yao Xu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Wenjun Yin
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Xuefei Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Ching-Hua Huang
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Yalei Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
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10
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Lau S, Feng Y, Gu AZ, Russell C, Pope G, Mitch WA. Cytotoxicity Comparison between Drinking Water Treated by Chlorination with Postchloramination versus Granular Activated Carbon (GAC) with Postchlorination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13699-13709. [PMID: 37640368 PMCID: PMC10501121 DOI: 10.1021/acs.est.3c03591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/31/2023]
Abstract
Granular activated carbon treatment with postchlorination (GAC/Cl2) and chlorination followed by chloramination (Cl2/NH2Cl) represent two options for utilities to reduce DBP formation in drinking water. To compare the total cytotoxicity of waters treated by a pilot-scale GAC treatment system with postchlorination (and in some instances with prechlorination upstream of GAC (i.e., (Cl2)/GAC/Cl2)) and chlorination/chloramination (Cl2/NH2Cl) at ambient and elevated Br- and I- levels and at three different GAC ages, we applied the Chinese hamster ovary (CHO) cell cytotoxicity assay to whole-water extracts in conjunction with calculations of the cytotoxicity contributed by the 33 (semi)volatile DBPs lost during extractions. At both ambient and elevated Br- and I- levels, GAC/Cl2 and Cl2/NH2Cl achieved comparable reductions in the formation of regulated trihalomethanes (THMs) and haloacetic acids (HAAs). Nonetheless, GAC/Cl2 always resulted in lower total cytotoxicity than Cl2/NH2Cl, even at up to 65% total organic carbon breakthrough. Prechlorination formed (semi)volatile DBPs that were removed by the GAC, yet there was no substantial difference in total cytotoxicity between Cl2/GAC/Cl2 and GAC/Cl2. The poorly characterized fraction of DBPs captured by the bioassay dominated the total cytotoxicity when the source water contained ambient levels of Br- and I-. When the water was spiked with Br- and I-, the known, unregulated (semi)volatile DBPs and the uncharacterized fraction of DBPs were comparable contributors to total cytotoxicity; the contributions of regulated THMs and HAAs were comparatively minor.
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Affiliation(s)
- Stephanie
S. Lau
- Department
of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United States
| | - Yinmei Feng
- School
of Civil and Environmental Engineering, College of Engineering, Cornell University, 220 Hollister Hall, 527 College Ave, Ithaca, New York 14853, United States
| | - April Z. Gu
- School
of Civil and Environmental Engineering, College of Engineering, Cornell University, 220 Hollister Hall, 527 College Ave, Ithaca, New York 14853, United States
| | - Caroline Russell
- Carollo
Engineers, Inc., 8911 Capital of Texas Hwy North, Suite 2200, Austin, Texas 78759, United States
| | - Greg Pope
- Carollo
Engineers, Inc., 8911 Capital of Texas Hwy North, Suite 2200, Austin, Texas 78759, United States
| | - William A. Mitch
- Department
of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United States
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11
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Zhang T, von Gunten U. Chlorination of amides: Kinetics and mechanisms of formation of N-chloramides and their reactions with phenolic compounds. WATER RESEARCH 2023; 242:120131. [PMID: 37364355 DOI: 10.1016/j.watres.2023.120131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/18/2023] [Accepted: 05/24/2023] [Indexed: 06/28/2023]
Abstract
Amides are common constituents in natural organic matter and synthetic chemicals. In this study, we investigated kinetics and mechanisms of the reactions of chlorine with seven amides, including acetamide, N-methylformamide, N-methylacetamide, benzamide, N-methylbenzamide, N-propylbenzamide, and N-(benzoylglycyl)glycine amide. Apparent second-order rate constants for the reactions of the amides with chlorine at pH 8 are in the range of 5.8 × 10-3 - 1.8 M-1s-1 and activation energies in the range of 62-88 kJ/mol. The second-order rate constants for the reactions of chlorine with different amides decrease with increasing electron donor character of the substituents on the amide-N and N-carbonyl-C in the amide structures. Hypochlorite (‒OCl) dominates the reactions of chlorine with amides yielding N-chloramides with species-specific second-order rate constants in the range of 7.3 × 10-3 - 2.3 M-1s-1. Kinetic model simulations suggest that N-chlorinated primary amides further react with HOCl with second-order rate constants in the order of 10 M-1s-1. The chlorination products of amides, N-chloramides are reactive towards phenolic compounds, forming chlorinated phenols via electrophilic aromatic substitution (phenol and resorcinol) and quinone via electron transfer (hydroquinone). Meanwhile, N-chloramides were recycled to the parent amides. At neutral pH, apparent second-order rate constants for the reactions between phenols and N-chloramides are in the order of 10-4-0.1 M-1s-1, comparable to those with chloramine. The findings of this study improve the understanding of the fate of amides and chlorine during chlorination processes.
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Affiliation(s)
- Tianqi Zhang
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Urs von Gunten
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland; Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf CH-8600, Switzerland.
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12
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Wang L, Zhou Y, Liu YD, Zhong R. Computational Investigations of Reaction Mechanisms and Transformation Products of Olefins with Hypochlorous Acid. J Phys Chem A 2023. [PMID: 37303114 DOI: 10.1021/acs.jpca.3c01244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Hypochlorous acid (HOCl) as the main component in chlorination and also as the innate immune factor relevant to immune defense has attracted considerable attention. Electrophilic addition reaction of olefins with HOCl, one of the most important prototype of chemical reactions, has been intensively studied for a long time; however, it has not been fully understood yet. In this study, addition reaction mechanisms and transformation products of model olefins with HOCl were systematically investigated by the density functional theory method. The results indicate that the traditionally believed stepwise mechanism with a chloronium-ion intermediate is only suitable for olefins substituted with electron-donating groups (EDGs) and weak electron-withdrawing groups (EWGs) but it is a carbon-cation intermediate that is favorable for EDGs featuring p-π or π-π conjugation with the C═C moiety. Moreover, olefins substituted with moderate or/and strong EWGs prefer the concerted and nucleophilic addition mechanisms, respectively. Epoxide and truncated aldehyde as the main transformation products can be generated from chlorohydrin through a series of reactions involving hypochlorite; however, their generation is kinetically not as feasible as the formation of chlorohydrin. The reactivity of three chlorinating agents (HOCl, Cl2O, and Cl2) and the case study of chlorination and degradation of cinnamic acid were also explored. Additionally, APT charge on the double-bond moiety in olefin and energy gap (ΔE) between the highest occupied molecular orbital (HOMO) energy of olefin and the lowest unoccupied molecular orbital (LUMO) energy of HOCl were found to be good parameters to distinguish the regioselectivity of chlorohydrin and reactivity of olefin, respectively. The findings of this work are helpful in further understanding the chlorination reactions of unsaturated compounds and identifying complicated transformation products.
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Affiliation(s)
- Luhong Wang
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Yingying Zhou
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Yong Dong Liu
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Rugang Zhong
- Beijing Key Laboratory of Environmental and Viral Oncology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
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13
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Hao T, Miao M, Wang T, Xiao Y, Yu B, Zhang M, Ning X, Li Y. Physicochemical changes in microplastics and formation of DBPs under ozonation. CHEMOSPHERE 2023; 327:138488. [PMID: 36963574 DOI: 10.1016/j.chemosphere.2023.138488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 06/18/2023]
Abstract
Microplastics (MPs) are substances that pose a risk to both human life and the environment. Their types and production are increasing year on year, and their potential to cause environmental pollution is a worldwide concern. Conventional water treatment processes, particularly coagulation and sedimentation, are not effective at removing all MPs. It is therefore important to assess the morphological changes in the MPs, i.e., the thermoplastic polyurethane (TPU) and polyethylene (PE), during ozonation and the dissolved organic carbon leaching as well as chloroform formation in the subsequent chlorination. The results show that the appearance and surface chemistry of the MPs changed during the ozonation process, most notably for TPU. The trichloromethane (CHCl3) generation during chlorination was 0.168 and 0.152 μmol/L for TPU and PE, respectively, and the ozone pretreatment significantly increased the CHCl3 yield of TPU, while it had a weak effect on PE. Additional disinfection byproducts (DBPs), including CHCl2Br, CHClBr2, and CHBr3, were produced in the presence of bromide ions in the water column, and the total amount of DBPs produced by PE, PE-O, TPU, and TPU-O was significantly increased to 0.787, 0.814, 0.931, and 1.391 μmol/L, respectively. The study provides useful information for the environmental risk assessment of two representative MPs, i.e., TPU and MPs, in disinfection procedures for drinking water.
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Affiliation(s)
- Tianwei Hao
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Manhong Miao
- College of Environmental Science and Engineering/Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tong Yan Road 38, Tianjin, 300350, China
| | - Tong Wang
- College of Environmental Science and Engineering/Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tong Yan Road 38, Tianjin, 300350, China
| | - Yihang Xiao
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Bingqing Yu
- College of Environmental Science and Engineering/Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tong Yan Road 38, Tianjin, 300350, China
| | - Min Zhang
- College of Environmental Science and Engineering/Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tong Yan Road 38, Tianjin, 300350, China
| | - Xiaoyu Ning
- State Environmental Protection Key Laboratory of Odor Pollution Control, Tianjin Academy of Eco-environmental Sciences, Tianjin, 300191, China.
| | - Yao Li
- College of Environmental Science and Engineering/Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tong Yan Road 38, Tianjin, 300350, China.
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14
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Yang X, Wang A, Hua Z, Wei W, Cao Y, Fu B, Chen S, Dong Z, Fang J. Overlooked roles of Cl 2O and Cl 2 in micropollutant abatement and DBP formation by chlorination. WATER RESEARCH 2023; 229:119449. [PMID: 36495855 DOI: 10.1016/j.watres.2022.119449] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/25/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
This study investigated the roles of diverse free available chlorine (FAC) species including HOCl/OCl-, H2OCl+, Cl2O, and Cl2 in the degradation of micropollutants. The degradation of 5 micropollutants was significantly affected by pH, FAC dosage, and chloride (Cl-) concentration. The reaction orders in FAC (n) of 5 micropollutants (acetaminophen, carbamazepine, naproxen, gemfibrozil, and mecoprop) ranged from 1.4 ± 0.2 to 2.1 ± 0.3 at pH 3 - 5, evidencing the importance of Cl2O and Cl2 for micropollutant abatement. A simplified method for the determination of second-order rate constants (k) of specific FAC species with micropollutants was developed. Herein, the k for neutral/dissociated forms of 5 micropollutants with Cl2 and Cl2O were determined in the ranges of 9.3 (± 0.2) × 102 ∼ 2.9 (± 0.2) × 109 M-1 s-1 and 1.8 (± 0.1) × 104 ∼ 3.7 (± 0.6) × 109 M-1 s-1, respectively. They were 4 - 7 orders of magnitude higher than those of HOCl, whereas those of OCl- and H2OCl+ were negligible. By using kinetic modeling, Cl2 was more important under acidic conditions and higher Cl- levels with contributions of 37.9 - 99.2% at pH 5 in pure water. Cl2O played a dominant role in micropollutant degradation in pure water (56.4 - 87.3%) under neutral conditions. Furthermore, both Cl2 and Cl2O played vital roles in the formation of disinfection byproducts (DBPs) during chlorination of carbamazepine and natural organic matter. This study highlights the overlooked roles of Cl2O and Cl2 in micropollutant abatement and DBP formation during chlorination.
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Affiliation(s)
- Xin Yang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Anna Wang
- Guangdong Environmental Protection Research Institute Co., Ltd., Guangzhou Guangdong 510080, China
| | - Zhechao Hua
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Wenrui Wei
- Guangzhou Environmental Protection Investment Group Co., Ltd., Guangzhou Guangdong 510170, China
| | - Yilong Cao
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Bingyue Fu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Shuping Chen
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Zijun Dong
- College of Civil and Transportation Engineering, the Underground Polis Academy, Shenzhen University, Shenzhen 518048, China
| | - Jingyun Fang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
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15
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Hu Q, Wang R, Zhang Y, Zhou J, Qu G, Wang T, Jia H. Formation of halogenated macromolecular organics induced by Br - and I - during plasma oxidation/chlorination of DOM: Highlighting competitive mechanisms. WATER RESEARCH 2023; 229:119513. [PMID: 36549187 DOI: 10.1016/j.watres.2022.119513] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 12/13/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
Understanding the effects of halogens on the production of macromolecular disinfection byproducts (DBPs) is critical for drinking water safety. The effects of Br- and I- on the chemical diversity of dissolved organic matter (DOM) during plasma preoxidation and the subsequent formation of macromolecular halogenated DBPs after chlorination were deciphered. Plasma preoxidation changed DOM diversity from aromatic component-oriented to lignin and tannin component-oriented, resulting in 62.0% and 21.2% decreases in N-DBPs (CkHnOmNzClx formulas) and C-DBPs (CkHnOmClx formulas) after chlorination, respectively. Br- could induce the formation of organobromine compounds (OBrCs) during plasma oxidation; however, the intensities of OBrCs decreased by 56.3% (CHO formulas) and 75.2% (CHON formulas) after further chlorination. OBrCs still accounted for 79.8% of the total organohalogen compounds (OXCs, X=Cl or Br) due to the higher substitutability of bromine. I-promoted OIC production in the DOM preoxidation process, and OICs acted as intermediates to form OClCs during chlorination. When Br-and I-coexisted, Br- promoted OIC production in the DOM preoxidation process; therefore, more OBrCs and OClCs were generated due to intermediates of OICs in subsequent chlorination. Connections between OXCs and their precursors were established using network computation. The precursors of OClCs were located in the aromatic structure region (0.2 < H/C ≤ 0.7; O/C ≤ 0.67); those of OBrCs and OICs were located in the lignin (0.7 < H/C ≤ 1.5; 0.1 < O/C < 0.67) and tannin (0.6 ≤ H/C ≤ 1.5, 0.67 < O/C < 1.0) regions with relatively greater H/C and O/C ratios, respectively.
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Affiliation(s)
- Qian Hu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Ruigang Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Ying Zhang
- College of Information Science and Technology, Nanjing Forestry University, Nanjing 210037, China
| | - Jian Zhou
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Guangzhou Qu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Tiecheng Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China.
| | - Hanzhong Jia
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
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16
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Zhao H, Yang L, Chen X, Wang J, Bai L, Cao G, Cai L, Tang CY. Reactivity of various brominating agents toward polyamide nanofiltration membranes. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2022.122490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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17
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Wang WL, Nong YJ, Yang ZW, Wu QY, Hübner U. Chlorination of isothiazolinone biocides: kinetics, reactive species, pathway, and toxicity evolution. WATER RESEARCH 2022; 223:119021. [PMID: 36057235 DOI: 10.1016/j.watres.2022.119021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/20/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Due to the Covid-19 pandemic, the worldwide biocides application has been increased, which will eventually result in enhanced residuals in treated wastewater. At the same time, chlorine disinfection of secondary effluents and hospital wastewaters has been intensified. With respect to predicted elevated exposure in wastewater, the chlorination kinetics, transformation pathways and toxicity evolution were investigated in this study for two typical isothiazolinone biocides, methyl-isothiazolinone (MIT) and chloro-methyl-isothiazolinone (CMIT). Second-order rate constants of 0.13 M-1·s-1, 1.95 × 105 M-1·s-1 and 5.14 × 105 M-1·s-1 were determined for the reaction of MIT with HOCl, Cl2O and Cl2, respectively, while reactivity of CMIT was around 1-2 orders of magnitude lower. While chlorination of isothiazolinone biocides at pH 7.1 was dominated by Cl2O-oxidation, acidic pH and elevated Cl- concentration favored free active chlorine (FAC) speciation into Cl2 and increased overall isothiazolinone removal. Regardless of the dominant FAC species, the elimination of MIT and CMIT resulted in an immediate loss of acute toxicity under all experimental conditions, which was attributed to a preferential attack at the S-atom resulting in subsequent formation of sulfoxides and sulfones and eventually an S-elimination. However, chlorination of isothiazolinone biocides in secondary effluent only achieved <10% elimination at typical disinfection chlorine exposure 200 mg·L-1·min, but was predicted to be remarkably increased by acidizing solution to pH 5.5. Alternative measures might be needed to minimize the discharge of these toxic chemicals into the aquatic environment.
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Affiliation(s)
- Wen-Long Wang
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Yu-Jia Nong
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Zheng-Wei Yang
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Qian-Yuan Wu
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
| | - Uwe Hübner
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, Garching 85748, Germany.
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18
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Yang Y, Ramos NC, Clark JA, Hillhouse HW. Electrochemical oxidation of pharmaceuticals in synthetic fresh human urine: Using selective radical quenchers to reveal the dominant degradation pathways and the scavenging effects of individual urine constituents. WATER RESEARCH 2022; 221:118722. [PMID: 35728493 DOI: 10.1016/j.watres.2022.118722] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/06/2022] [Accepted: 06/06/2022] [Indexed: 06/15/2023]
Abstract
Electrochemical oxidation of fresh human urine is a promising method to prevent pharmaceuticals from being discharged into the environment. Here, we evaluate the importance of electro-generated oxidants and direct anodic oxidation for degradation of four pharmaceutical (cyclophosphamide (CP), carbamazepine (CBZ), sulfamethoxazole (SMX) and ibuprofen (IBP)) accounting for the scavenging effect of urine constituents using boron-doped diamond (BDD) and IrO2 electrodes. Allyl alcohol and tert-butanol were used as selective quenchers for adsorbed and dissolved radicals, respectively. In electrolyte containing only chloride and pharmaceuticals, we found that CBZ and SMX are primarily oxidized by electro-generated Cl2 in the fluid boundary layer , and CP and IBP are primarily oxidized by physisorbed •OH or chemisorbed chlorine (IrO3-Cl). Regarding the effects of other fresh urine constituents, urea, creatinine, and uric acid quench the dissolved reactive chlorine species (Cl•/Cl2•‒, HOCl, Cl2, etc.). However, SO42‒ shows no effect on pharmaceutical degradation while H2PO4‒ and citrate ions quench IrO3-Cl resulting in a mixed kinetic and mass-transfer limiting oxidation of pharmaceuticals on IrO2. Citrate ions only quench the dissolved oxidants (surface adsorbed radicals are the dominant oxidants) leading to the pharmaceutical degradation limited by the mass transfer of pharmaceutical to BDD surface. This work provides an understanding of the significance of various pathways for pharmaceutical degradation, scavenging effect of urine constituents, and strategies for rapid pharmaceutical degradation in human urine.
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Affiliation(s)
- Yuhang Yang
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195-2120
| | - Nathanael C Ramos
- Department of Chemical Engineering, Clean Energy Institute, Molecular Engineering & Sciences Institute, University of Washington, Seattle, Washington 98195-1750
| | - James A Clark
- Department of Chemical Engineering, Clean Energy Institute, Molecular Engineering & Sciences Institute, University of Washington, Seattle, Washington 98195-1750
| | - Hugh W Hillhouse
- Department of Chemical Engineering, Clean Energy Institute, Molecular Engineering & Sciences Institute, University of Washington, Seattle, Washington 98195-1750.
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19
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Mazur DM, Lebedev AT. Transformation of Organic Compounds during Water Chlorination/Bromination: Formation Pathways for Disinfection By-Products (A Review). JOURNAL OF ANALYTICAL CHEMISTRY 2022; 77. [PMCID: PMC9924213 DOI: 10.1134/s1061934822140052] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The purity of drinking water is an important issue of the human life quality. Water disinfection has saved millions people from the diseases spread with water. However, that procedure has a certain drawback due to formation of toxic organic disinfection products. Establishing the structures of these products and the mechanisms of their formation and diminishing their levels in drinking water represent an important task for chemistry and medicine, while mass spectrometry is the most efficient tool for the corresponding studies. The current review throws light upon natural and anthropogenic sources of the formation of disinfection by-products (DBPs) and the mechanisms of their formation related to the structural peculiarities and the presence of functional groups. In addition to chlorination, bromination is discussed since it is used quite often as an alternative method of disinfection, particularly, for the purification of swimming pool water. The benefits of the contemporary GC/MS and LC/MS methods for the elucidation of DBP structures and study of the mechanisms of their formation are discussed. The reactions characteristic for various functional groups and directions of transformation of certain classes of organic compounds in conditions of aqueous chlorination/bromination are also covered in the review.
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Affiliation(s)
- D. M. Mazur
- Organic Chemistry Department, Moscow State University, 119991 Moscow, Russia
| | - A. T. Lebedev
- M.V. Lomonosov Northern (Arctic) Federal University, 163002 Arkhangelsk, Russia
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20
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Liu Q, Xu X, Fu J, Du Y, Lin L, Bai L, Wang D. Role of hypobromous acid in the transformation of polycyclic aromatic hydrocarbons during chlorination. WATER RESEARCH 2021; 207:117787. [PMID: 34731666 DOI: 10.1016/j.watres.2021.117787] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
Hypobromous acid (HOBr), a highly reactive active species, can be formed and impact reaction processes with organic pollutants in source water during chlorination disinfection of the water containing bromide (Br-). In this study, we investigated the transformation kinetics of 10 parent polycyclic aromatic hydrocarbons (PAHs) and formation mechanisms of transformation products in the presence of Br- during chlorination. The results indicated that HOBr can accelerate the processes of electrophilic substitution (ES) and single electron transfer (ET) reactions in PAHs, and the second-order rate constants of HOBr are 102-103 times higher than those of hypochlorous acid (HOCl) with PAHs. HOBr was more conductive to induce ES reactions than HOCl. In water containing Br-, HOBr and HOCl dominate the reaction processes with PAHs, although other active bromine species may still affect reaction processes. In terms of transformation products, higher reactivity of HOBr results from faster formation of oxygenated PAHs (OPAHs) and halogenated PAHs (HPAHs) than HOCl. As an example of 3 model PAHs, anthracene transforms faster to its oxygenated products at a higher concentration, while pyrene and fluorene transform faster to halogenated products. These fundamental results were essential to understanding the transformation kinetics of PAHs and the formation of toxic disinfection by-products in the presence of Br-.
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Affiliation(s)
- Quanzhen Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiong Xu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jianjie Fu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Yanjun Du
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lihua Lin
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lu Bai
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Donghong Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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21
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Houska J, Salhi E, Walpen N, von Gunten U. Oxidant-reactive carbonous moieties in dissolved organic matter: Selective quantification by oxidative titration using chlorine dioxide and ozone. WATER RESEARCH 2021; 207:117790. [PMID: 34740166 DOI: 10.1016/j.watres.2021.117790] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
The application of oxidants for disinfection or micropollutant abatement during drinking water and wastewater treatment is accompanied by oxidation of matrix components such as dissolved organic matter (DOM). To improve predictions of the efficiency of oxidation processes and the formation of oxidation products, methods to determine concentrations of oxidant-reactive phenolic, olefinic or amine-type DOM moieties are critical. Here, a novel selective oxidative titration approach is presented, which is based on reaction kinetics of oxidation reactions towards certain DOM moieties. Phenolic moieties were determined by oxidative titration with ClO2 and O3 for five DOM isolates and two secondary wastewater effluent samples. The determined concentrations of phenolic moieties correlated with the electron-donating capacity (EDC) and the formation of inorganic ClO2-byproducts (HOCl, ClO2-, ClO3-). ClO2-byproduct yields from phenol and DOM isolates and changes due to the application of molecular tagging for phenols revealed a better understanding of oxidant-reactive structures within DOM. Overall, oxidative titrations with ClO2 and O3 provide a novel and promising tool to quantify oxidant-reactive moieties in complex mixtures such as DOM and can be expanded to other matrices or oxidants.
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Affiliation(s)
- Joanna Houska
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Elisabeth Salhi
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland
| | - Nicolas Walpen
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland
| | - Urs von Gunten
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zurich, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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Marron EL, Van Buren J, Cuthbertson AA, Darby E, von Gunten U, Sedlak DL. Reactions of α,β-Unsaturated Carbonyls with Free Chlorine, Free Bromine, and Combined Chlorine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3305-3312. [PMID: 33565865 PMCID: PMC9255599 DOI: 10.1021/acs.est.0c07660] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Chemical disinfectants employed in water and wastewater treatment can produce a variety of transformation products, including carbonyl compounds (e.g., saturated and unsaturated aldehydes and ketones). Experiments conducted under conditions relevant to chlorination at drinking water treatment plants and residual chlorine application in distribution systems indicate that α,β-unsaturated carbonyl compounds readily react with free chlorine and free bromine over a wide pH range but react slowly with combined chlorine (i.e., NH2Cl). For nearly all of the 11 α,β-unsaturated carbonyl compounds studied, the apparent second-order rate constants for the reaction with free chlorine increased in a linear manner with hypochlorite (OCl-) concentrations, yielding species-specific second-order rate constants for the reaction with OCl- ranging from 0.21 to 12 M-1 s-1. Predictions based on the second-order rate constants indicate that a substantial fraction (i.e., >60%) of several of the more prominent α,β-unsaturated carbonyls (e.g., acrolein, crotonaldehyde) will be transformed to an appreciable extent in distribution systems by free chlorine. Products from the reaction of chlorine with acrolein, crotonaldehyde, and methyl vinyl ketone were tentatively identified using nuclear magnetic resonance (NMR) and gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC-HRT-MS). These products lacked unsaturated carbons and, in some cases, contained multiple halogens.
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Affiliation(s)
- Emily L. Marron
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720
- NSF Engineering Research Center for Reinventing the Nation’s Urban Water Infrastructure (ReNUWIt)
| | - Jean Van Buren
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720
| | - Amy A. Cuthbertson
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720
| | - Emily Darby
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - David L. Sedlak
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720
- NSF Engineering Research Center for Reinventing the Nation’s Urban Water Infrastructure (ReNUWIt)
- corresponding author:
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