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Zeng J, Zhang M, Qin X, He Y, Liu X, Zhu Y, Liu Z, Li W, Dong H, Qiang Z, Lian J. Quenching residual H 2O 2 from UV/H 2O 2 with granular activated carbon: A significant impact of bicarbonate. CHEMOSPHERE 2024; 354:141670. [PMID: 38462184 DOI: 10.1016/j.chemosphere.2024.141670] [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: 11/01/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 03/12/2024]
Abstract
UV/H2O2 has been used as an advanced oxidation process to remove organic micropollutants from drinking water. It is essential to quench residual H2O2 to prevent increased chlorine demand during chlorination/chloramination and within distribution systems. Granular activated carbon (GAC) filter can quench the residual oxidant and eliminate some of the dissolved organic matter. However, knowledge on the kinetics and governing factors of GAC quenching of residual H2O2 from UV/H2O2 and the mechanism underlying the enhancement of the process by HCO3- is limited. Therefore, this study aimed to analyse the kinetics and influential factors, particularly the significant impact of bicarbonate (HCO3-). H2O2 decomposition by GAC followed first-order kinetics, and the rate constants normalised by the GAC dosage (kn) were steady (1.6 × 10-3 L g-1 min-1) with variations in the GAC dosage and initial H2O2 concentration. Alkaline conditions favour H2O2 quenching. The content of basic groups exhibited a stronger correlation with the efficiency of GAC in quenching H₂O₂ than did the acidic groups, with their specific kn values being 8.9 and 2.4 min-1 M-1, respectively. The presence of chloride, sulfate, nitrate, and dissolved organic matter inhibited H2O2 quenching, while HCO3- promoted it. The interfacial hydroxyl radical (HO•) zones were visualised on the GAC surface, and HCO3- addition increased the HO• concentration. HCO3- increased the concentration of persistent free radicals (PFRs) on the GAC surface, which mainly contributed to HO• generation. A significant enhancement of HCO3- on H2O2 quenching by GAC was also verified in real water. This study revealed the synergistic mechanism of HCO3- and GAC on H2O2 quenching and presents the potential applications of residual H2O2 in the H2O2-based oxidation processes.
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Affiliation(s)
- Jinfeng Zeng
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China; Hydrology and Water Resources Monitoring Center for Ganjiang Upstream Watershed, 8 Zhang-jia-wei Road, Ganzhou, 341000, China
| | - Miao Zhang
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China; Guyang Water Conservancy Agricultural Machinery Management Service Station, Zhenjiang, 212100, China
| | - Xinxin Qin
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China
| | - Yi He
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China
| | - Xinyue Liu
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China
| | - Yichun Zhu
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China
| | - Zuwen Liu
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China; National-local Joint Engineering Laboratory of Water Engineering Safety and Efficient Utilization of Resources in Poyang Lake Watershed, Nanchang Institute of Technology, Nanchang, 330099, China
| | - Wentao Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing, 100085, China
| | - Huiyu Dong
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing, 100085, China
| | - Zhimin Qiang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing, 100085, China
| | - Junfeng Lian
- Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions, Jiangxi University of Science and Technology, 1958 Ke-jia Road, Ganzhou, 341000, China.
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2
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Dang AN, Rogalski MH, Pilgrim CD, Wilbanks JR, Peterman DR, Carrie JD, Zalupski PR, Mezyk SP, Horne GP. Radiolytic evaluation of a new technetium redox control reagent for advanced used nuclear fuel separations. Phys Chem Chem Phys 2024; 26:4039-4046. [PMID: 38224090 DOI: 10.1039/d3cp04987f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Technetium is a problematic radioisotope for used nuclear fuel (UNF) and subsequent waste management owing to its high environmental mobility and coextraction in reprocessing technologies as the pertechnetate anion (TcO4-). Consequently, several strategies are under development to control the transport of this radioisotope. A proposed approach is to use diaminoguanidine (DAG) for TcO4- and transuranic ion redox control. Although the initial DAG molecule is ultimately consumed in the redox process, its susceptibility to radiolysis is currently unknown under envisioned UNF reprocessing conditions, which is a critical knowledge gap for evaluating its overall suitability for this role. To this end, we report the impacts of steady-state gamma irradiation on the rate of DAG radiolysis in water, aqueous 2.0 M nitric acid (HNO3), and in a biphasic solvent system composed of aqueous 2.0 M HNO3 in contact with 1.5 M N,N-di-(2-ethylhexyl)isobutyramide (DEHiBA) dissolved in n-dodecane. Additionally, we report chemical kinetics for the reaction of DAG with key transients arising from electron pulse radiolysis, specifically the hydrated electron (eaq-), hydrogen atom (H˙), and hydroxyl (˙OH) and nitrate (NO3˙) radicals. The DAG molecule exhibited significant reactivity with the ˙OH and NO3˙ radicals, indicating that oxidation would be the predominant degradation pathway in radiation environments. This is consistent with its role as a reducing agent. Steady-state gamma irradiations demonstrated that DAG is readily degraded within a few hundred kilogray, the rate of which was found to increase upon going from water to HNO3 containing solutions and solvents systems. This was attributed to a thermal reaction between DAG and the predominant HNO3 radiolysis product, nitrous acid (HNO2), k(DAG + HNO2) = 5480 ± 85 M-1 s-1. Although no evidence was found for the radiolysis of DAG altering the radiation chemistry of the contacted DEHiBA/n-dodecane phase in the investigated biphasic system, the utility of DAG as a redox control reagent will likely be limited by significant competition with its degradation by HNO2.
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Affiliation(s)
- Anh N Dang
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach California, 90840-9507, USA.
| | - Maya H Rogalski
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach California, 90840-9507, USA.
| | - Corey D Pilgrim
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., P.O. Box 1625, Idaho Falls, ID, 83415, USA.
| | - Joseph R Wilbanks
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., P.O. Box 1625, Idaho Falls, ID, 83415, USA.
| | - Dean R Peterman
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., P.O. Box 1625, Idaho Falls, ID, 83415, USA.
| | - Jesse D Carrie
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., P.O. Box 1625, Idaho Falls, ID, 83415, USA.
| | - Peter R Zalupski
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., P.O. Box 1625, Idaho Falls, ID, 83415, USA.
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach California, 90840-9507, USA.
| | - Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., P.O. Box 1625, Idaho Falls, ID, 83415, USA.
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3
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Chuang YH, Chen TY, Chou CS, Chu LK, Hou CY, Szczuka A. Critical Role of Trichloramine Interaction with Dichloramine for N-Nitrosamine Formation during Breakpoint Chlorination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15232-15242. [PMID: 37603422 DOI: 10.1021/acs.est.3c03326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Breakpoint chlorination is prevalent in drinking water and potable reuse water treatment. Breakpoint chlorination enhances the formation of N-nitrosamines through reactions that form nitrosating agents. The most recent study suggests that nitroxyl (HNO) can react with free chlorine (HOCl) to form the nitrosyl chloride (ClNO) nitrosating agent but has not experimentally verified its importance in breakpoint chlorination. This study first assessed the formation of N-nitrosamines from model N-chloro-alkylamine precursors when they were added to a mixture of HOCl and HNO-derived nitrosating agents generated by chlorinating hydroxyurea. Results demonstrated negligible N-nitrosamine formation. Instead, we observed that the interaction of NCl3 with NHCl2 (total Cl2/total N molar ratio = 2.4-3:1) produced an intermediate capable of nitrosating N-chloro-alkylamines to N-nitrosamines at yields 8-fold higher to those observed in NHCl2 treatment alone, within a very short timescale (<3 min). We examined the stoichiometry of the reaction of NCl3 with NHCl2 using a UV-spectrum-based approach. Nitrosyl chloride was proposed as the key intermediate, likely formed alongside the reformation of NHCl2. Further isotopic experiments, byproduct measurements, and kinetic modeling supported the hypotheses. Modeling indicated that the reaction of NCl3 with NHCl2 explained ∼75% of NDMA formation during breakpoint chlorination. Because NCl3 is mainly derived from the reaction of HOCl with NHCl2, controlling NHCl2 (e.g., with additional treatment) is critical for minimizing nitrosamine formation in waters where breakpoint chlorination occurs.
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Affiliation(s)
- Yi-Hsueh Chuang
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001, University Rd., Hsinchu City 30010, Taiwan
| | - Ting-Yuan Chen
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001, University Rd., Hsinchu City 30010, Taiwan
| | - Chia-Shun Chou
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001, University Rd., Hsinchu City 30010, Taiwan
| | - Li-Kang Chu
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Rd., Hsinchu 300044, Taiwan
| | - Chun-Yao Hou
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Rd., Hsinchu 300044, Taiwan
| | - Aleksandra Szczuka
- Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Ave. Ann Arbor, Michigan 48109, United States
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Kinani S, Roumiguières A, Bouchonnet S. A Critical Review on Chemical Speciation of Chlorine-Produced Oxidants (CPOs) in Seawater. Part 2: Sampling, Sample Preparation and Non-Chromatographic and Mass Spectrometric-Based Methods. Crit Rev Anal Chem 2022:1-20. [PMID: 36288103 DOI: 10.1080/10408347.2022.2135984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Chlorination of seawater forms a range of secondary oxidative species, collectively termed "chlorine-produced oxidants" (CPOs). These compounds do not have the same biocidal efficacy, the same fate and behavior in the marine environment, the same potential formation of chlorination by-products (CBPs), nor the same effects on marine organisms. Their chemical speciation is an important step toward an accurate assessment of the effectiveness of chlorination and the potential impacts of its releases, among others. The aim of this paper - which is the second of a trilogy dedicated to the chemical speciation of CPOs in seawater - is to cover all aspects related to CPOs analysis in seawater, from sampling to instrumental determination. First, it discusses the procedures involved in synthesis, storage, and standardization of analytical standards. Second, it deals with sampling and sample preparation, addressing all relevant issues related to these two key steps. Third, it provides a comprehensive and up-to-date overview of the colorimetric, titrimetric, and electrochemical methods used for CPOs determination and thoroughly discusses their advantages and limitations. Finally, this review ends with some recommendations for progress in the field of CPO analysis with the three aforementioned approaches. Chromatographic and mass spectrometric-based methods will be covered in the third and final article (Part III).
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Affiliation(s)
- Said Kinani
- Laboratoire National d'Hydraulique et Environnement (LNHE), Division Recherche et Développement, Electricité de France (EDF), Chatou Cedex, France
| | - Adrien Roumiguières
- Laboratoire National d'Hydraulique et Environnement (LNHE), Division Recherche et Développement, Electricité de France (EDF), Chatou Cedex, France
- Laboratoire de Chimie Moléculaire, CNRS, Institut polytechnique de Paris, Route de Saclay, Palaiseau, France
| | - Stéphane Bouchonnet
- Laboratoire de Chimie Moléculaire, CNRS, Institut polytechnique de Paris, Route de Saclay, Palaiseau, France
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5
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Huang H, Zheng H, Jiao J, Lei Y, Zhou Y, Qiu J, Yang X. Trichloramine and Hydroxyl Radical Contributions to Dichloroacetonitrile Formation Following Breakpoint Chlorination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:12592-12601. [PMID: 35976682 DOI: 10.1021/acs.est.2c03701] [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] [Indexed: 06/15/2023]
Abstract
Breakpoint chlorination is applied to remove ammonia in water treatment. Trichloramine (NCl3) and transient reactive species can be present, but how they affect the formation of nitrogenous disinfection byproducts is unknown. In this study, the dichloroacetonitrile (DCAN) formation mechanisms and pathways involved during breakpoint chlorination (i.e., free chlorine to ammonia molar ratio ≥2.0) were investigated. DCAN formation during breakpoint chlorination of natural organic matter (NOM) isolates was 14.3-20.3 μg/L, which was 2-10 times that in chlorination without ammonia at similar free chlorine residual conditions (2.1-2.9 mg/L as Cl2). The probe tests and electron paramagnetic resonance spectra supported the presence of •OH, •NO, and NCl3 besides free chlorine in breakpoint chlorination. 15N-labeled ammonium-N tests indicated the incorporation of ammonium-N in DCAN formation though ammonia was eliminated during breakpoint chlorination. Aromatic non-nitrogenous moieties, such as phenols (i.e., none DCAN precursors in the free-chlorine-only system), became DCAN precursors during breakpoint chlorination. The reactions involved in reactive nitrogen species, such as •NO/•NO2 and NCl3, led to additional nitrogen sources in DCAN formation, accounting for 36-84% of total nitrogen sources in DCAN formation from NOM isolates and real water samples. Scavenging •OH by tert-butanol reduced DCAN formation by 40-56%, indicating an important role of •OH in transforming DCAN precursors. This study improves the understanding of breakpoint chlorination chemistry.
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Affiliation(s)
- 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
| | - Hangcong Zheng
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Jiajia 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
| | - Yu Lei
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yangjian Zhou
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Junlang Qiu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, 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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6
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Ciffroy P, Urien N. A probabilistic model for assessing uncertainty and sensitivity in the prediction of monochloramine loss in French river waters. WATER RESEARCH 2021; 202:117383. [PMID: 34237692 DOI: 10.1016/j.watres.2021.117383] [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: 03/01/2021] [Revised: 06/03/2021] [Accepted: 06/20/2021] [Indexed: 06/13/2023]
Abstract
Monochloramine (NH2Cl) is increasingly used as alternative disinfectant to free chlorine in industrial plants. After use in cooling systems, the waters are released to the environment and residual NH2Cl may be discharged into the receiving waters. As NH2Cl is suspected to exhibit toxicity towards aquatic organisms, a proper risk assessment of its occurrence in environmental waters is needed to prevent adverse effects on wildlife. For this purpose, a comprehensive model simulating monochloramine loss in natural riverine waters was developed. This model incorporates the following processes: (i) autodecomposition; (ii) reaction with nitrite and bromide; (iii) oxidation with Dissolved Organic Carbon (DOC); (iv) oxidation with organic fraction of Suspended Particulate Matter (SPM); (v) reactions in bottom sediments and (vi) volatilization. The model was also designed to conduct uncertainty and sensitivity analysis. It was tested on several French rivers submitted to discharges of monochloraminated effluents and on several seasonal conditions. Uncertainty analysis allowed evaluation of confidence intervals related to NH2Cl half-lives in natural waters. It was shown that simulation intervals are in good agreement with experimental data obtained on the same rivers. Sensitivity analysis using an EFAST variance decomposition approach allowed identification of the most influential parameters on half-life determination. It was shown that the kinetic rate describing rapid reaction of NH2Cl with DOC is by far the most sensitive parameter, demonstrating the predominance of such reactions in the loss process. Variables or parameters involved in temperature dependence (temperature and activation energy) can also significantly influence model results. To a lesser extent, wind velocity is the most sensitive parameter explaining uncertainty in the prediction of volatilization, with a high level of interactions with other parameters, showing that loss through volatilization can be essential in some specific conditions only. This study then identified the most important research priorities for improving the prediction of NH2Cl half-lives in natural rivers.
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Affiliation(s)
- P Ciffroy
- EDF, Division Recherche et Développement, Laboratoire National dHydraulique et Environnement 6 quai Watier, 78401 Chatou, France
| | - N Urien
- EDF, Division Recherche et Développement, Laboratoire National dHydraulique et Environnement 6 quai Watier, 78401 Chatou, France
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7
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Pham HT, Wahman DG, Fairey JL. Updated Reaction Pathway for Dichloramine Decomposition: Formation of Reactive Nitrogen Species and N-Nitrosodimethylamine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1740-1749. [PMID: 33448793 PMCID: PMC7951990 DOI: 10.1021/acs.est.0c06456] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The N-nitrosodimethylamine (NDMA) formation pathway in chloraminated drinking water remains unresolved. In pH 7-10 waters amended with 10 μM total dimethylamine and 800 μeq Cl2·L-1 dichloramine (NHCl2), NDMA, nitrous oxide (N2O), dissolved oxygen (DO), NHCl2, and monochloramine (NH2Cl) were kinetically quantified. NHCl2, N2O, and DO profiles indicated that reactive nitrogen species (RNS) formed during NHCl2 decomposition, including nitroxyl/nitroxyl anion (HNO/NO-) and peroxynitrous acid/peroxynitrite anion (ONOOH/ONOO-). Experiments with uric acid (a ONOOH/ONOO- scavenger) implicated ONOOH/ONOO- as a central node for NDMA formation, which were further supported by the concomitant N-nitrodimethylamine formation. A kinetic model accurately simulated NHCl2, NH2Cl, NDMA, and DO concentrations and included (1) the unified model of chloramine chemistry revised with HNO as a direct product of NHCl2 hydrolysis; (2) HNO/NO- then reacting with (i) HNO to form N2O, (ii) DO to form ONOOH/ONOO-, or (iii) NHCl2 or NH2Cl to form nitrogen gas; and (3) NDMA formation via ONOOH/ONOO- or their decomposition products reacting with (i) dimethylamine (DMA) and/or (ii) chlorinated unsymmetrical dimethylhydrazine (UDMH-Cl), the product of NHCl2 and DMA. Overall, updated NHCl2 decomposition pathways are proposed, yielding (1) RNS via NHCl2→HNO/NO-→O2ONOOH/ONOO- and (2) NDMA via ONOOH/ONOO-→UDMH-ClorDMANDMA.
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Affiliation(s)
- Huong T Pham
- Department of Civil Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - David G Wahman
- U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, United States
| | - Julian L Fairey
- Department of Civil Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
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8
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Herraiz-Carboné M, Cotillas S, Lacasa E, Moratalla Á, Cañizares P, Rodrigo MA, Sáez C. Improving the biodegradability of hospital urines polluted with chloramphenicol by the application of electrochemical oxidation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 725:138430. [PMID: 32298888 DOI: 10.1016/j.scitotenv.2020.138430] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/22/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
This work focuses on improving the biodegradability of hospital urines polluted with antibiotics by electrochemical advanced oxidation processes (EAOPs). To do this, chloramphenicol (CAP) has been used as a model compound and the influence of anodic material (Boron Doped Diamond (BDD) and Mixed Metal Oxide (MMO)) and current density (1.25-5 mA cm-2) on the toxicity and the biodegradability was evaluated. Results show that a complete CAP removal was attained using BDD anodes, being the process more efficient at the lowest current density tested (1.25 mA cm-2). Conversely, after passing 4 Ah dm-3, only 35% of CAP removal is reached using MMO anodes, regardless of the current density applied. Furthermore, a kinetic study demonstrated that there is a clear competitive oxidation between the target antibiotic and the organic compounds naturally contained in urine, regardless the current density and the anode material used. During the first stages of the electrolysis, acute toxicity is around 1% EC50 but it increases once CAP and its organic intermediates have been degraded. The formation and accumulation of inorganic oxidants may justify the remaining acute toxicity. This also helps to explain the trend observed in the rapid biodegradability assays. Finally, a 60% of standard biodegradability (Zahn-Wellens test) was achieved which suggests that electrochemical oxidation with BDD anodes could be the most appropriate technology to reduce the hazard of hospital urines at the operating conditions tested.
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Affiliation(s)
- Miguel Herraiz-Carboné
- Department of Chemical Engineering, School of Industrial Engineering, University of Castilla-La Mancha, 02071 Albacete, Spain
| | - Salvador Cotillas
- Department of Chemical Engineering, School of Industrial Engineering, University of Castilla-La Mancha, 02071 Albacete, Spain
| | - Engracia Lacasa
- Department of Chemical Engineering, School of Industrial Engineering, University of Castilla-La Mancha, 02071 Albacete, Spain
| | - Ángela Moratalla
- Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, 13005 Ciudad Real, Spain
| | - Pablo Cañizares
- Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, 13005 Ciudad Real, Spain
| | - Manuel A Rodrigo
- Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, 13005 Ciudad Real, Spain
| | - Cristina Sáez
- Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, 13005 Ciudad Real, Spain.
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9
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Wang C, Hofmann M, Safari A, Viole I, Andrews S, Hofmann R. Chlorine is preferred over bisulfite for H 2O 2 quenching following UV-AOP drinking water treatment. WATER RESEARCH 2019; 165:115000. [PMID: 31465994 DOI: 10.1016/j.watres.2019.115000] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/13/2019] [Accepted: 08/18/2019] [Indexed: 06/10/2023]
Abstract
Drinking water treatment using UV/H2O2 advanced oxidation typically results in residual H2O2 that requires quenching to minimize its interference with downstream processes. Chemical quenching using chlorine or bisulfite are options, but there is some uncertainty in the literature about the kinetics of the bisulfite reaction, with some reports quoting the reaction as fast, and others as slow. Part of the contradictory information may be due to interference in H2O2 analysis by bisulfite. An analytical method was developed to avoid this interference, in which monochloramine first selectively quenched bisulfite, and then H2O2 was measured spectrometrically using titanium(IV) oxysulfate for color development. The confirmatory experiments suggested that the bisulfite reaction with H2O2 is actually relatively slow, with a half-life in the order of hours to days depending on the pH and the reagent concentrations. As a result, within the typical pH range of drinking water treatment (e.g., 6-9), chlorine is preferred over bisulfite as the H2O2 quenching agent on the basis of reaction kinetics. However, a decrease in pH will lead to an increase in the bisulfite-H2O2 reaction rate along with a decrease in the Cl2-H2O2 reaction rate, such that at pH < 5.7 bisulfite is the faster reagent. Both bisulfite and chlorine were observed to react with H2O2 following a stoichiometric ratio of 1:1 in the natural water matrix tested.
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Affiliation(s)
- Chengjin Wang
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada.
| | - Michael Hofmann
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada
| | - Armin Safari
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada
| | - Isabelle Viole
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada
| | - Susan Andrews
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada
| | - Ron Hofmann
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada
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10
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Yu L, Ling R, Chen JP, Reinhard M. Quantitative assessment of the iron-catalyzed degradation of a polyamide nanofiltration membrane by hydrogen peroxide. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2019.05.078] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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11
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Skibinski B, Uhlig S, Müller P, Slavik I, Uhl W. Impact of Different Combinations of Water Treatment Processes on the Concentration of Disinfection Byproducts and Their Precursors in Swimming Pool Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8115-8126. [PMID: 31180210 DOI: 10.1021/acs.est.9b00491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
To mitigate microbial activity in swimming pools and to ensure hygienic safety for bathers, pool systems have a recirculating water system ensuring continuous water treatment and disinfection by chlorination. A major drawback associated with the use of chlorine as disinfectant is its potential to react with precursor substances present in pool water to form harmful disinfection byproducts (DBPs). In this study, different combinations of conventional and advanced treatment processes were applied to lower the concentration of DBPs and their precursors in pool water by using a pilot-scale swimming pool model operated under reproducible and fully controlled conditions. The quality of the pool water was determined after stationary concentrations of dissolved organic carbon (DOC) were reached. The relative removal of DOC (Δc cin-1) across the considered treatment trains ranged between 0.1 ± 2.9% and 7.70 ± 4.5%, where conventional water treatment (coagulation and sand filtration combined with granular activated carbon (GAC) filtration) was revealed to be the most effective. Microbial processes in the deeper, chlorine-free regions of the GAC filter have been found to play an important role in the degradation of organic substances. Almost all treatment combinations were capable of removing trihalomethanes to some degree and trichloramine and dichloroacetonitrile almost completely. However, the results demonstrated that effective removal of DBPs across the treatment train does not necessarily result in low DBP concentrations in the basin of a pool. This raises the importance of the DBP formation potential of the organic precursors, which has been shown to depend strongly on the treatment concept applied. Irrespective of the filtration technique employed, treatment combinations employing UV irradiation as a second treatment step revealed higher concentrations of volatile DBPs in the pool compared to those employing GAC filtration as a second treatment step. In the particular case of trichloramine, results confirm that its removal across the treatment train is not a feasible mitigation strategy because it cannot compensate for the fast formation in the basin.
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Affiliation(s)
- Bertram Skibinski
- Chair of Urban Water Systems Engineering , Technical University of Munich , 85748 Garching , Germany
- Chair of Water Supply Engineering , Technische Universität Dresden , 01062 Dresden , Germany
| | - Stephan Uhlig
- Chair of Water Supply Engineering , Technische Universität Dresden , 01062 Dresden , Germany
| | - Pascal Müller
- Chair of Water Supply Engineering , Technische Universität Dresden , 01062 Dresden , Germany
| | - Irene Slavik
- Chair of Water Supply Engineering , Technische Universität Dresden , 01062 Dresden , Germany
- Wahnbachtalsperrenverband , 53721 Siegburg , Germany
| | - Wolfgang Uhl
- Chair of Water Supply Engineering , Technische Universität Dresden , 01062 Dresden , Germany
- Norwegian Institute for Water Research (NIVA) , 0349 Oslo , Norway
- Norwegian University of Science and Technology (NTNU) , Institute of Civil and Environmental Engineering , 7491 Trondheim , Norway
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12
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Patton S, Romano M, Naddeo V, Ishida KP, Liu H. Photolysis of Mono- and Dichloramines in UV/Hydrogen Peroxide: Effects on 1,4-Dioxane Removal and Relevance in Water Reuse. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11720-11727. [PMID: 29791794 DOI: 10.1021/acs.est.8b01023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Growing demands and increasing scarcity of fresh water resources necessitate potable water reuse, which has been implemented with the aid of UV-based advanced oxidation processes (UV/AOPs) that remove potentially hazardous trace organic contaminants from reclaimed water. During the potable reuse treatment process, chloramines are added to prevent membrane fouling that are carried over to the UV/AOP, where hydrogen peroxide (H2O2) is commonly added. However, the impact of chloramines on the photolysis of H2O2 and the overall performance of the UV/AOP remains unknown. This study investigated the impacts of the photochemistry of monochloramine (NH2Cl) and dichloramine (NHCl2) associated with the photolysis of H2O2 on the degradation of 1,4-dioxane (1,4-D), a trace organic contaminant ubiquitous in recycled water. Results indicated that NH2Cl and NHCl2 alone functioned as oxidants upon UV photolysis, which produced HO• and Cl2•- as the two primary oxidative radicals. The speciation of chloramines did not have a significant impact on the degradation kinetics. The inclusion of monochloramine in UV/H2O2 greatly decreased 1,4-D removal efficiency. HO• was the major radical in the mixed H2O2/chloramine system. Results from this study suggest that recognizing the existence of chloramines in UV/H2O2 systems is important for predicting UV/AOP performance in the treatment train of potable reuse.
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Affiliation(s)
- Samuel Patton
- Department of Chemical and Environmental Engineering , University of California , Riverside , California 92521 United States
- Program of Environmental Toxicology , University of California , Riverside , California 92521 United States
| | - Mariano Romano
- Department of Civil Engineering , University of Salerno , Fisciano , Salerno 84084 , Italy
| | - Vincenzo Naddeo
- Department of Civil Engineering , University of Salerno , Fisciano , Salerno 84084 , Italy
| | - Kenneth P Ishida
- Research & Development Department , Orange County Water District , Fountain Valley , California 92708 , United States
| | - Haizhou Liu
- Department of Chemical and Environmental Engineering , University of California , Riverside , California 92521 United States
- Program of Environmental Toxicology , University of California , Riverside , California 92521 United States
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13
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Influence of Ammonium Ions, Organic Load and Flow Rate on the UV/Chlorine AOP Applied to Effluent of a Wastewater Treatment Plant at Pilot Scale. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15061276. [PMID: 29914154 PMCID: PMC6025302 DOI: 10.3390/ijerph15061276] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/14/2018] [Accepted: 06/14/2018] [Indexed: 01/01/2023]
Abstract
This work investigates the influence of ammonium ions and the organic load (chemical oxygen demand (COD)) on the UV/chlorine AOP regarding the maintenance of free available chlorine (FAC) and elimination of 16 emerging contaminants (ECs) from wastewater treatment plant effluent (WWTE) at pilot scale (UV chamber at 0.4 kW). COD inhibited the FAC maintenance in the UV chamber influent at a ratio of 0.16 mg FAC per mg COD (kHOCl–COD = 182 M−1s−1). An increase in ammonium ion concentration led to a stoichiometric decrease of the FAC concentration in the UV chamber influent. Especially in cold seasons due to insufficient nitrification, the ammonium ion concentration in WWTE can become so high that it becomes impossible to achieve sufficiently high FAC concentrations in the UV chamber influent. For all ECs, the elimination effect by the UV/combined Cl2 AOP (UV/CC) was not significantly higher than that by sole UV treatment. Accordingly, the UV/chlorine AOP is very sensitive and loses its effectiveness drastically as soon as there is no FAC but only CC in the UV chamber influent. Therefore, within the electrical energy consumption range tested (0.13–1 kWh/m3), a stable EC elimination performance of the UV/chlorine AOP cannot be maintained throughout the year.
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14
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Gleason JM, McKay G, Ishida KP, Mezyk SP. Temperature dependence of hydroxyl radical reactions with chloramine species in aqueous solution. CHEMOSPHERE 2017; 187:123-129. [PMID: 28843670 PMCID: PMC6865285 DOI: 10.1016/j.chemosphere.2017.08.053] [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: 05/22/2017] [Revised: 08/08/2017] [Accepted: 08/11/2017] [Indexed: 05/10/2023]
Abstract
The absolute temperature-dependent kinetics for the reaction between hydroxyl radicals and the chloramine water disinfectant species monochloramine (NH2Cl), as well as dichloramine (NHCl2) and trichloramine (NCl3), have been determined using electron pulse radiolysis and transient absorption spectroscopy. These radical reaction rate constants were fast, with values of 6.06 × 108, 2.57 × 108, and 1.67 × 108 M-1 s-1 at 25 °C for NH2Cl, NHCl2, and NCl3, respectively. The corresponding temperature dependence of these reaction rate constants, measured over the range 10-40 °C, is well-described by the transformed Arrhenius equations:giving activation energies of 8.57 ± 0.58, 6.11 ± 0.40, and 5.77 ± 0.72 kJ mol-1 for these three chloramines, respectively. These data will aid water utilities in predicting hydroxyl radical partitioning and chemical contaminant removal efficiencies under real-world advanced oxidation process treatment conditions.
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Affiliation(s)
- Jamie M Gleason
- Department of Chemistry and Biochemistry, California State University at Long Beach, Long Beach, CA 90820, USA
| | - Garrett McKay
- Department of Chemistry and Biochemistry, California State University at Long Beach, Long Beach, CA 90820, USA
| | - Kenneth P Ishida
- Research and Development Department, Orange County Water District, 18700 Ward Street, Fountain Valley, CA 92708, USA
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University at Long Beach, Long Beach, CA 90820, USA.
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15
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Song M, Wang J, Chen B, Wang L. A Facile, Nonreactive Hydrogen Peroxide (H2O2) Detection Method Enabled by Ion Chromatography with UV Detector. Anal Chem 2017; 89:11537-11544. [DOI: 10.1021/acs.analchem.7b02831] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mingrui Song
- Shenzhen Key Laboratory of Organic Pollution
Prevention and Control, State Key Laboratory of Urban Water Resource
and Environment, Harbin Institute of Technology (Shenzhen) China, 518055
| | - Junli Wang
- Shenzhen Key Laboratory of Organic Pollution
Prevention and Control, State Key Laboratory of Urban Water Resource
and Environment, Harbin Institute of Technology (Shenzhen) China, 518055
| | - Baiyang Chen
- Shenzhen Key Laboratory of Organic Pollution
Prevention and Control, State Key Laboratory of Urban Water Resource
and Environment, Harbin Institute of Technology (Shenzhen) China, 518055
| | - Lei Wang
- Shenzhen Key Laboratory of Organic Pollution
Prevention and Control, State Key Laboratory of Urban Water Resource
and Environment, Harbin Institute of Technology (Shenzhen) China, 518055
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16
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Ling R, Yu L, Pham TPT, Shao J, Chen JP, Reinhard M. The tolerance of a thin-film composite polyamide reverse osmosis membrane to hydrogen peroxide exposure. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.11.041] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Spahr S, Cirpka OA, von Gunten U, Hofstetter TB. Formation of N-Nitrosodimethylamine during Chloramination of Secondary and Tertiary Amines: Role of Molecular Oxygen and Radical Intermediates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:280-290. [PMID: 27958701 DOI: 10.1021/acs.est.6b04780] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
N-Nitrosodimethylamine (NDMA) is a carcinogenic disinfection byproduct from water chloramination. Despite the identification of numerous NDMA precursors, essential parts of the reaction mechanism such as the incorporation of molecular O2 are poorly understood. In laboratory model systems for the chloramination of secondary and tertiary amines, we investigated the kinetics of precursor disappearance and NDMA formation, quantified the stoichiometries of monochloramine (NH2Cl) and aqueous O2 consumption, derived 18O-kinetic isotope effects (18O-KIE) for the reactions of aqueous O2, and studied the impact of radical scavengers on NDMA formation. Although the molar NDMA yields from five N,N-dimethylamine-containing precursors varied between 1.4% and 90%, we observed the stoichiometric removal of one O2 per N,N-dimethylamine group of the precursor indicating that the oxygenation of N atoms did not determine the molar NDMA yield. Small 18O-KIEs between 1.0026 ± 0.0003 and 1.0092 ± 0.0009 found for all precursors as well as completely inhibited NDMA formation in the presence of radical scavengers (ABTS and trolox) imply that O2 reacted with radical species. Our study suggests that aminyl radicals from the oxidation of organic amines by NH2Cl and N-peroxyl radicals from the reaction of aminyl radicals with aqueous O2 are part of the NDMA formation mechanism.
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Affiliation(s)
- Stephanie Spahr
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
| | - Olaf A Cirpka
- Center for Applied Geoscience, University of Tübingen , D-72074 Tübingen, Germany
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich , CH-8092 Zürich, Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich , CH-8092 Zürich, Switzerland
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18
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Wang F, Gao B, Ma D, Li R, Sun S, Yue Q, Wang Y, Li Q. Effects of operating conditions on trihalomethanes formation and speciation during chloramination in reclaimed water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:1576-1583. [PMID: 26377970 DOI: 10.1007/s11356-015-5409-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Abstract
In this study, a hybrid powdered activated carbon-membrane bioreactor (PAC-MBR) system was used to treat municipal wastewater in northern China intended for recycle. In order to control microbiological hazards in PAC-MBR effluent, chloramine was chosen as the disinfectant which could reduce the disinfection by-product yields. Effects of reaction time, chloramines dose, pH value, and bromide ion concentration on trihalomethanes (THMs) formation and speciation during chloramination of the reclaimed effluent were investigated. Study results indicated that the yield of total THMs (TTHM) increased at higher reaction time and chloramines dose. The trend of growth showed that slow reacting precursors were the main components of dissolved organic matter (DOM) in PAC-MBR effluent. THMs formation potential of PAC-MBR effluent achieved the maximum at chloramines dosage of 20 mg/L. Meanwhile, THMs formation was enhanced evidently under alkaline conditions. The yields of THMs species were in following order: CHCl3 > CHBrCl2 > CHBr2Cl > CHBr3, although in different reaction time, chloramines dose, and pH value. Furthermore, the formation of Br-THMs was promoted by the increasing concentration of bromide ion.
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Affiliation(s)
- Fang Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China
| | - Baoyu Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China.
| | - Defang Ma
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China
| | - Ruihua Li
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China
| | - Shenglei Sun
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China
| | - Qinyan Yue
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China
| | - Yan Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China
| | - Qian Li
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Ji' nan, 250100, China
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19
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Soltermann F, Canonica S, von Gunten U. Trichloramine reactions with nitrogenous and carbonaceous compounds: kinetics, products and chloroform formation. WATER RESEARCH 2015; 71:318-329. [PMID: 25655201 DOI: 10.1016/j.watres.2014.12.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/01/2014] [Accepted: 12/06/2014] [Indexed: 06/04/2023]
Abstract
Trichloramine is a hazardous disinfection by-product that is of particular relevance in indoor swimming pools. To better understand its fate in pool waters, apparent second order rate constants (kapp) at pH 7 for its reaction with several model compounds were determined. kapp values at pH 7 for nitrogenous compounds were found to increase in the following order: ammonia ∼ amides (∼10(-2)-10(-1) M(-1) s(-1)) < primary amines (∼10(-1)-10(0) M(-1) s(-1)) < relevant body fluid compounds (l-histidine, creatinine) (∼10(0)-10(1) M(-1) s(-1)) < secondary amines (∼10(1)-10(2) M(-1) s(-1)) < trimethylamine (∼10(3) M(-1) s(-1)). kapp values at pH 7 of trichloramine with hydroxylated aromatic compounds (∼10(2)-10(5) M(-1) s(-1)) are higher than for the nitrogenous compounds and depend on the number and position of the hydroxyl groups (phenol < hydroquinone < catechol < resorcinol). The measurement of kapp as a function of pH revealed that mainly the deprotonated species react with trichloramine. The reaction of trichloramine with Suwannee River and Pony Lake fulvic acid standards showed a decrease of their reactivity upon chlorination, which can be related to the electron donating capacity and the SUVA254. Chlorinated nitrogenous compounds (e.g. uric acid) also have a reduced reactivity with trichloramine. Hence, the residual chlorine in pool water hinders a fast consumption of trichloramine. This explains why trichloramine degradation in pool water is lower than expected from the reactivity with the estimated bather input. Trichloramine also has the potential to form secondary disinfection by-products such as chlorinated aromatic compounds or chloroform by electron transfer or Cl(+)-transfer reactions. The chloroform formation from the reaction of trichloramine with resorcinol occurs with a similar yield and rate as for chlorination of resorcinol. Since the trichloramine concentration in pool water is commonly about one order of magnitude lower than the free chlorine concentration, its contribution to the disinfection by-product formation is assumed to be minor in most cases but might be relevant for few precursors (e.g. phenols) that react faster with trichloramine than with free chlorine.
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Affiliation(s)
- Fabian Soltermann
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Silvio Canonica
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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20
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Sgroi M, Roccaro P, Oelker GL, Snyder SA. N-nitrosodimethylamine (NDMA) formation at an indirect potable reuse facility. WATER RESEARCH 2015; 70:174-183. [PMID: 25528547 DOI: 10.1016/j.watres.2014.11.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/26/2014] [Accepted: 11/27/2014] [Indexed: 06/04/2023]
Abstract
Full-scale experiments to evaluate N-nitrosodimethylamine (NDMA) formation and attenuation were performed within an advanced indirect potable reuse (IPR) treatment system, which includes, sequentially: chloramination for membrane fouling control, microfiltration (MF), reverse osmosis (RO), ultraviolet irradiation with hydrogen peroxide (UV/H₂O₂), final chloramination, and pH stabilization. Results of the study demonstrate that while RO does effectively remove the vast majority of NDMA precursors, RO permeate can still contain significant concentrations of NDMA precursors resulting in additional NDMA formation during chloramination. Thus, it is possible for this advanced treatment system to produce water with NDMA levels higher than regional requirements for potable applications (10 ng/L). The presence of H2O2 during UV oxidation reduced NDMA photolysis efficiency and increased NDMA formation (∼22 ng/L) during the secondary chloramination and lime stabilization. This is likely due to formation of UV/H₂O₂ degradation by-products with higher NDMA formation rate than the parent compounds. However, this effect was diminished with higher UV doses. Bench-scale experiments confirmed an enhanced NDMA formation during chloramination after UV/H2O2 treatment of dimethylformamide, a compound detected in RO permeate and used as model precursor in this study. The effect of pre-ozonation for membrane fouling control on NDMA formation was also evaluated at pilot- (ozone-MF-RO) and bench-scale. Relatively large NDMA formation (117-227 ng/L) occurred through ozone application that was dose dependent, whereas chloramination under typical dosages and contact times of IPR systems resulted in only a relatively small increase of NDMA (∼20 ng/L). Thus, this research shows that NDMA formation within a potable water reuse facility can be challenging and must be carefully evaluated and controlled.
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Affiliation(s)
- Massimiliano Sgroi
- Department of Civil Engineering and Architecture, University of Catania, Viale A. Doria 6, 95125 Catania, Italy; Department of Chemical & Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721, USA
| | - Paolo Roccaro
- Department of Civil Engineering and Architecture, University of Catania, Viale A. Doria 6, 95125 Catania, Italy; Department of Chemical & Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721, USA
| | - Gregg L Oelker
- United Water, Edward C. Little Water Reclamation Facility, 1935 South Hughes Way, El Segundo, CA 90245, USA
| | - Shane A Snyder
- Department of Chemical & Environmental Engineering, University of Arizona, 1133 E. James E. Rogers Way, Tucson, AZ 85721, USA; National University of Singapore, NUS Environmental Research Institute (NERI), 5A Engineering Drive 1; T-Lab Building, #02-01, 117411 Singapore, Singapore.
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Soltermann F, Widler T, Canonica S, von Gunten U. Photolysis of inorganic chloramines and efficiency of trichloramine abatement by UV treatment of swimming pool water. WATER RESEARCH 2014; 56:280-291. [PMID: 24699420 DOI: 10.1016/j.watres.2014.02.034] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/12/2014] [Accepted: 02/16/2014] [Indexed: 06/03/2023]
Abstract
Trichloramine, one of the three inorganic chloramines (mono-, di- and trichloramine), is a problematic disinfection by-product in recreational pool water since it causes skin and eye irritations as well as irritations of the respiratory tract. The most commonly used chloramine mitigation strategy in pool water is UV treatment. Experiments with membrane inlet mass spectrometry (MIMS) confirmed that inorganic chloramines are effectively degraded by UV irradiation with low-pressure (LP) and medium-pressure (MP) mercury lamps (apparent quantum yields (QY): NH2Cl = 0.50 (LP) and 0.31 (MP) mol einstein(-1), NHCl2: 1.06 (LP) and 0.85 (MP) mol einstein(-1)). Trichloramine showed the fastest depletion with a quantum yield slightly above 2 mol einstein(-1) in purified (LP and MP) and pool water (MP). This high quantum yield can partly be explained by reactions involving OH radicals (purified water) and the reaction of trichloramine with moieties formed during UV irradiation of pool water. The presence of free chlorine affects trichloramine degradation (QY: ∼1.5 mol einstein(-1)) since it scavenges OH radicals and competes with trichloramine for reactive species (e.g. organic amines). Measurements in a pool facility revealed that the installed UV reactors degraded trichloramine by 40-50% as expected from laboratory experiments. However, trichloramine reduction in the pools was less pronounced than in the UV reactors. Model calculations combining pool hydraulics with formation/abatement of trichloramine showed that there was a fast trichloramine formation in the pool from the residual chlorine and nitrogenous precursors. The main factors influencing trichloramine concentrations in pool water are the free chlorine concentration and the UV treatment in combination with the recirculation rate through the water treatment system.
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Affiliation(s)
- Fabian Soltermann
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Tobias Widler
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Silvio Canonica
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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