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Zhou X, Diao Y, Zhu Y, Quan G, Yan J, Zhang W. Release of biochar-derived dissolved organic matter and the formation of chlorination disinfection by-products: Effects of pH and chlorine dosage. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123025. [PMID: 38040185 DOI: 10.1016/j.envpol.2023.123025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/23/2023] [Accepted: 11/21/2023] [Indexed: 12/03/2023]
Abstract
Transformation, fragmentation, dissolution, and oxidation of biochar are inevitable in the environment, which will undoubtedly accelerate the release of biochar-derived dissolved organic matter (BDOM) into various water bodies. In addition, biochar may affect disinfection by-products (DBPs) during water treatment and subsequent disinfection. In this study, biochars were derived at three selected pyrolysis temperatures (350 °C, 500 °C, and 650 °C) from rice husk, wheat straw, and shrimp shell, and BDOM was extracted from biochar-derived in artificial seawater and ultrapure water. The TOC analyzer results showed that the concentrations of three BDOM decreased with increasing pyrolysis temperature. The BDOM derived from rice husk biochar and wheat straw biochar in seawater was lower than that in ultrapure water, while that of shrimp shell biochar showed an opposite trend, being released in seawater at nearly twice the extent of that in ultrapure water at 350 °C. Moreover, BDOM showed a catalytic effect on chlorination, and GC analysis showed that the concentrations of its DBPs were affected by pH. The concentration of halogenated acetic acid reached the highest value (54.51 μg/L) in weak acidic environment, while the concentrations of trihalomethane and halogenated acetonitrile had the highest values (23.63 and 47.53 μg/L, respectively) in alkaline conditions. The concentrations of all the three DBPs were lowest under neutral pH conditions. In addition, the volatile halogenated DBPs such as dichloroacetone and trichloroacetone were easily hydrolyzed under alkaline conditions. Therefore, it is something be aware of the release of BDOM and the effects of chlorination DBPs when biochar is used for water treatment or water purification.
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Affiliation(s)
- Xiangqian Zhou
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China
| | - Yusen Diao
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China
| | - Yun Zhu
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China
| | - Guixiang Quan
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China; Jiangsu Engineering Research Center of Biomass Waste Pyrolytic Carbonization & Application, Yancheng, 224051, China
| | - Jinlong Yan
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China; Jiangsu Engineering Research Center of Biomass Waste Pyrolytic Carbonization & Application, Yancheng, 224051, China; Industrial Technology Research Institute of YCIT, Yancheng, 224051, China.
| | - Wei Zhang
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China
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2
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Ma X, Cheng J, Zhang P, Wu Y, Deng J, Dong F, Li X, Dietrich AM. Impact of boiling on chemical and physical processes for reduction of halomethanes, haloacetonitriles, and haloacetic acids in drinking water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167657. [PMID: 37806591 DOI: 10.1016/j.scitotenv.2023.167657] [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: 07/24/2023] [Revised: 09/29/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Tap water is boiled by families across the globe in their daily life for cooking food and beverages, as well as for controlling some chlorine-resistant organisms to improve the water quality. However, the effects of boiling methods (heating temperature, heating modes, open or closed containers) on water quality, in particular the reduction of disinfection byproducts (DBPs), are unclear. This comprehensive research demonstrates that during the heating process, trihalomethanes (THMs) were markedly decreased, haloacetonitriles (HANs) were drastically reduced and sometimes completely removed, while haloacetic acids (HAAs) were reduced the least. Heating to boiling in open containers reduced DBPs concentrations more than heating in the closed containers. Residual chlorine from 0.1 to 5.0 mg/L did not affect the removal of HANs, but could increase concentrations of HAAs likely due to reaction of organic matter with chlorine at elevated temperatures. THMs demonstrated good removal at 0.1-1 mg/L residual chlorine, but less removal at 5 mg/L residual chlorine. Sodium chloride (salt), often added as seasoning agent in the process of family cooking, was found to have little effect on the removal of DBPs during cooking and boiling. Compared with the toxicity of DBPs in tap water, boiling could greatly reduce both the cytotoxicity and carcinogenicity through removal of DBPs. Consequently, boiling of tap water had a significant effect on reducing human exposure to DBPs and their associated toxicities.
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Affiliation(s)
- Xiaoyan Ma
- College of Civil Engineering, Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiayi Cheng
- College of Civil Engineering, Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Peifeng Zhang
- College of Civil Engineering, Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yifei Wu
- College of Civil Engineering, Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jing Deng
- College of Civil Engineering, Zhejiang Key Laboratory of Civil Engineering Structures & Disaster Prevention and Mitigation Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Feilong Dong
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; Shaoxing Research Institute, Zhejiang University of Technology, Shaoxing 312085, China.
| | - Xueyan Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Andrea M Dietrich
- Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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3
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Okoji AI, Okoji CN, Awarun OS. Performance evaluation of artificial intelligence with particle swarm optimization (PSO) to predict treatment water plant DBPs (haloacetic acids). CHEMOSPHERE 2023; 344:140238. [PMID: 37788747 DOI: 10.1016/j.chemosphere.2023.140238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/17/2023] [Accepted: 09/19/2023] [Indexed: 10/05/2023]
Abstract
The prevention of water-borne diseases requires the disinfection of water consumed. Disinfection by-products, however, are an increasing concern, and they require advanced knowledge of water treatment plants before their release for human consumption. In this study, multivariate non-linear regression (MNR) and adaptive neuro-fuzzy inference system (ANFIS: Grid partition - GP and Sub-clustering - SC) integrated with particle swarm optimization (PSO) were proposed for the prediction of haloacetic acids (HAAs) in actual distribution systems. PSO-ANFIS-GP and PSO-ANFIS-SC were trained and verified for a total of 64 sets of data with eight parameters (pH, Temperature, UVA254, DOC, Br-; NH4+-N; NO2--N, residual free chlorine). With MNR, R2 is 0.5184
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Affiliation(s)
- Anthony I Okoji
- Department of Chemical Engineering, Covenant University, Ota, Ogun state, Nigeria.
| | - Comfort N Okoji
- Department of Biology and Forensic, Admiralty University, Ibusa, Delta state, Nigeria
| | - Olorunfemi S Awarun
- Department of Microbiology, Landmark University, Omu-Aran, Kwara state, Nigeria
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4
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Wang Y, Peng F, Zhao R, Dong X, Yang Z, Li H. Removal and transformation of disinfection by-products in water during boiling treatment. CHEMOSPHERE 2023; 326:138426. [PMID: 36931400 DOI: 10.1016/j.chemosphere.2023.138426] [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: 12/08/2022] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Disinfection by-products (DBPs) remain an ongoing issue because of their widespread occurrence and toxicity. Boiling is the most popular household water treatment method and can effectively remove some DBPs. However, the transformation behavior of DBPs during boiling is still unclear, and the key contributors to toxicity have not been identified. In this study, the changes in the concentrations of DBPs in the single-DBP systems and the multi-DBP systems during boiling were monitored, and in-depth discussions on the removal and transformation of DBPs in both systems were carried out. The results showed that boiling was effective in removing volatile DBPs (over 90% for TCAL, TCAN, and DCAN, and over 60% for TCM), but ineffective for non-volatile DBPs (around 20% for TCAA and below 10% for DCAA and MCAA). By hydrolysis and decarboxylation, the transformation occurred among DBPs, i.e., 55% TCAL to TCM, followed by 23% DCAN to DCAA, 22% TCAN to TCAA, and 10% TCAA to TCM. The transformations were found to be significantly influenced by other co-existing DBPs. In multi-DBP systems, the transformations of DCAN to DCAA and TCAN to TCAA were both promoted, while the transformation of TCAN to TCAA was inhibited. Transformation and volatilization are the two processes responsible for DBP removal. Toxicity estimates indicated that boiling was effective in reducing the toxicity of DBPs and improving the safety of the water, despite the interconversion of DBPs in drinking water during boiling. This study emphasized the importance of studying the interconversion behaviors of DBPs in drinking water during boiling and provided practical information for end-use drinking water safety.
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Affiliation(s)
- Yingyang Wang
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China
| | - Fangyuan Peng
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China
| | - Ruiyang Zhao
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China
| | - Xuelian Dong
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China
| | - Zhaoguang Yang
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China
| | - Haipu Li
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China.
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5
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Gan J, Zhu T, Zhang Y, Li D, Li T, Zhao M, Zhao Z, Wang L. Degradation and dechlorination of trichloroacetic acid induced by an in situ 222 nm KrCl* excimer radiation. CHEMOSPHERE 2023; 331:138753. [PMID: 37100246 PMCID: PMC10122990 DOI: 10.1016/j.chemosphere.2023.138753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/08/2023] [Accepted: 04/20/2023] [Indexed: 05/07/2023]
Abstract
Since the coronavirus disease 2019 (COVID-19) pandemic epidemic, the excessive usage of chlorinated disinfectants raised the substantial risks of disinfection by-products (DBPs) exposure. While several technologies may remove the typical carcinogenic DBPs, trichloroacetic acid (TCAA), their application for continuous treatment is limited due to their complexity and expensive or hazardous inputs. In this study, degradation and dechlorination of TCAA induced by an in situ 222 nm KrCl* excimer radiation as well as role of oxygen in the reaction pathway were investigated. Quantum chemical calculation methods were used to help predict the reaction mechanism. Experimental results showed that UV irradiance increased with increasing input power and decreased when the input power exceeded 60 W. Decomposition and dechlorination were simultaneously achieved, where around 78% of TCAA (0.62 mM) can be eliminated and 78% dechlorination within 200 min. Dissolved oxygen showed little effect on the TCAA degradation but greatly boosted the dechlorination as it can additionally generate hydroxyl radical (•OH) in the reaction process. Computational results showed that under 222 nm irradiation, TCAA was excited from S0 to S1 state and then decayed by internal crossing process to T1 state, and a reaction without potential energy barrier followed, resulting in the breaking of C-Cl bond and finally returning to S0 state. Subsequent C-Cl bond cleavage occurred by a barrierless •OH insertion and HCl elimination (27.9 kcal/mol). Finally, the •OH attacked (14.6 kcal/mol) the intermediate byproducts, leading to complete dechlorination and decomposition. The KrCl* excimer radiation has obvious advantages in terms of energy efficiency compared to other competitive methods. These results provide insight into the mechanisms of TCAA dechlorination and decomposition under KrCl* excimer radiation, as well as important information for guiding research toward direct and indirect photolysis of halogenated DBPs.
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Affiliation(s)
- Jiaming Gan
- School of Environmental Science & Engineering, Xiamen University of Technology, Xiamen, 361024, PR China
| | - Ting Zhu
- School of Electrical Engineering and Automation, Xiamen University of Technology, Xiamen, 361024, PR China
| | - Yizhan Zhang
- School of Environmental Science & Engineering, Xiamen University of Technology, Xiamen, 361024, PR China
| | - Dailin Li
- School of Environmental Science & Engineering, Xiamen University of Technology, Xiamen, 361024, PR China
| | - Ting Li
- School of Environmental Science & Engineering, Xiamen University of Technology, Xiamen, 361024, PR China
| | - Min Zhao
- School of Environmental Science & Engineering, Xiamen University of Technology, Xiamen, 361024, PR China
| | - ZengXia Zhao
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, 130023, PR China
| | - Lei Wang
- School of Environmental Science & Engineering, Xiamen University of Technology, Xiamen, 361024, PR China.
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6
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Dong H, Nordhorn ID, Lamann K, Westerman DC, Liberatore HK, Forster ALB, Aziz MT, Richardson SD. Overlooked Iodo-Disinfection Byproduct Formation When Cooking Pasta with Iodized Table Salt. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:3538-3548. [PMID: 36802504 DOI: 10.1021/acs.est.2c05234] [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: 06/18/2023]
Abstract
Iodized table salt provides iodide that is essential for health. However, during cooking, we found that chloramine residuals in tap water can react with iodide in table salt and organic matter in pasta to form iodinated disinfection byproducts (I-DBPs). While naturally occurring iodide in source waters is known to react with chloramine and dissolved organic carbon (e.g., humic acid) during the treatment of drinking water, this is the first study to investigate I-DBP formation from cooking real food with iodized table salt and chloraminated tap water. Matrix effects from the pasta posed an analytical challenge, necessitating the development of a new method for sensitive and reproducible measurements. The optimized method utilized sample cleanup with Captiva EMR-Lipid sorbent, extraction with ethyl acetate, standard addition calibration, and analysis using gas chromatography (GC)-mass spectrometry (MS)/MS. Using this method, seven I-DBPs, including six iodo-trihalomethanes (I-THMs) and iodoacetonitrile, were detected when iodized table salt was used to cook pasta, while no I-DBPs were formed with Kosher or Himalayan salts. Total I-THM levels of 11.1 ng/g in pasta combined with cooking water were measured, with triiodomethane and chlorodiiodomethane dominant, at 6.7 and 1.3 ng/g, respectively. Calculated cytotoxicity and genotoxicity of I-THMs for the pasta with cooking water were 126- and 18-fold, respectively, compared to the corresponding chloraminated tap water. However, when the cooked pasta was separated (strained) from the pasta water, chlorodiiodomethane was the dominant I-THM, and lower levels of total I-THMs (retaining 30% of the I-THMs) and calculated toxicity were observed. This study highlights an overlooked source of exposure to toxic I-DBPs. At the same time, the formation of I-DBPs can be avoided by boiling the pasta without a lid and adding iodized salt after cooking.
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Affiliation(s)
- Huiyu Dong
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ilona D Nordhorn
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- Institute of Inorganic and Analytical Chemistry, University of Muenster, Muenster D-48149, Germany
| | - Karsten Lamann
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- Institute of Inorganic and Analytical Chemistry, University of Muenster, Muenster D-48149, Germany
| | - Danielle C Westerman
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Hannah K Liberatore
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- Currently at Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park North Carolina 27711, United States
| | - Alexandria L B Forster
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Md Tareq Aziz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Susan D Richardson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
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7
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Zhao J, Han L, Tan S, Chu W, Dong H, Zhou Q, Pan Y. Revisiting the effect of boiling on halogenated disinfection byproducts, total organic halogen, and cytotoxicity in simulated tap water. CHEMOSPHERE 2022; 309:136577. [PMID: 36155016 DOI: 10.1016/j.chemosphere.2022.136577] [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: 07/12/2022] [Revised: 09/10/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Boiling is a widely adopted household tap water treatment method because of its ability to inactivate chlorine-resistant pathogenic bacteria, and to reduce certain groups of disinfection byproducts (DBPs). From a more comprehensive point of view, this study revisited the effect of boiling on four groups of 17 aliphatic DBPs and six groups of 44 aromatic DBPs in both simulated chlorinated and chloraminated tap water samples, with a special focus on the changes of total organic halogen (TOX) and cytotoxicity. Results showed that the concentrations of aliphatic DBPs substantially decreased during boiling via volatilization (trihalomethanes and chloral hydrate) and hydrolysis (haloacetamides) in chlorinated and chloraminated tap water samples. The concentrations of aromatic DBPs during boiling generally followed an increasing trend due to decarboxylation of polycarboxylic precursors in chlorinated tap water samples, and showed a first increasing and then decreasing trend in chloraminated tap water samples. A sharp decreasing of TOX occurred in the heating process of tap water samples from room temperature to 100 °C, and a relatively gentle decreasing was kept in the prolonged boiling process till 5 min. The most abundant DBP group in the tap water samples without boiling was trihalomethanes, and was replaced by haloacetic acids with boiling for 5 min. Continuous boiling for 5 min substantially reduced the cytotoxicity of chlorinated and chloraminated water samples by 52.6% and 21.3%, respectively. Reduction of cytotoxicity matched well with the reduction of TOCl (r = 0.907, P < 0.01), TOBr (r = 0.885, P < 0.01) and TOX (r = 0.905, P < 0.01), suggesting that the cytotoxicity reduction during boiling was mainly ascribed to the reduction of halogenated DBPs. Therefore, boiling of tap water to 100 °C was strongly recommended to reduce the potential health risks induced by tap water ingestion.
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Affiliation(s)
- Jiayan Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Liangliang Han
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Suo Tan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Huiyu Dong
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Qing Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Yang Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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8
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Kanchan Arsenic Filters for Household Water Treatment: Unsuitable or Unsustainable? WATER 2022. [DOI: 10.3390/w14152318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This article critically evaluates the conventional Kanchan Arsenic Filter (KAF) in order to determine the main reasons for its reported poor performance. The KAF was introduced in 2004 in Nepal and makes use of non-galvanized nails as a Fe0 source for As removal. As early as 2009, the KAF was demonstrated to be ineffective for As removal in many cases. This was unambiguously attributed to the Fe0 layer which is placed on top of a sand filter instead of being incorporated into a sand matrix. Despite this conceptual mistake, the conventional KAF has been largely distributed in Asia, and recent articles have assessed its sustainability. This study reiterates that the suitability of the technology, rather than its sustainability, should be addressed. Evidence shows that the KAF has the following design limitations: (i) uses iron nails of unknown reactivity, and (ii) operates on the principle of a wet/dry cycle. The latter causes a decrease in the corrosion rate of the used nails, thereby limiting the availability of the iron corrosion products which act as contaminant scavengers. Taken together, these results confirm the unsuitability of the conventional KAF. Besides correcting the design mistakes, more attention should be paid to the intrinsic reactivity of the used iron nails, including using alternative Fe0 materials (e.g., iron filings, steel wool) for filters lasting for just 6 or 18 months. Specific design considerations to be addressed in the future are highlighted.
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9
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Jiang H, Kaw HY, Zhu L, Wang W. Halonaphthoquinones: A group of emerging disinfection byproducts of high toxicity in drinking water. WATER RESEARCH 2022; 217:118421. [PMID: 35429882 DOI: 10.1016/j.watres.2022.118421] [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: 01/27/2022] [Revised: 03/23/2022] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
Aromatic halogenated disinfection byproducts (DBPs) have received particular attention in recent years due to their high toxicity. However, most relevant researches at present focused merely on halo-monocyclic DBPs, while halo-polycyclic DBPs were scarcely explored. In this study, a new group of halo-bicyclic DBPs termed as halonaphthoquinones (HNQs) was systematically studied. By coupling with vacuum centrifugal concentrator, a SPE-UPLC-MS/MS method with high accuracy and sensitivity was developed to detect five semi-volatile HNQs in drinking water, which achieved the detection limits in the range of 0.05-0.24 ng/L. Five HNQs were identified using this method with 100% detection frequency at concentrations up to 136.7 ng/L in drinking water originated from seven water treatment plants. The cytotoxicity of the five tested HNQs in CHO-K1 cells (IC50 from 3.17 to 13.18 μM) was comparable to the most toxic known carbonaceous DBP in drinking water, iodoacetic acid (IC50=2.95 μM). Meanwhile, the cytotoxicity of five tested HNQs were also higher than 2,6-dichloro-1,4-benzoquinone (IC50=21.73 μM) which is hundreds to thousands of times more toxic than regulated DBPs, indicating the significant toxicity risk of HNQ DBPs. To the best of our knowledge, this study presents the first analytical method for analysis of HNQ DBPs, and the first set of data on the occurrence and cytotoxicity of HNQ DBPs in drinking water. These findings are meaningful for probing deeply into the presence of varied halo-polycyclic DBPs in the aqueous environment.
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Affiliation(s)
- Hangcheng Jiang
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Han Yeong Kaw
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Lizhong Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Wei Wang
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China.
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Samonte PRV, Li Z, Mao J, Chaplin BP, Xu W. Pyrogenic carbon-promoted haloacetic acid decarboxylation to trihalomethanes in drinking water. WATER RESEARCH 2022; 210:117988. [PMID: 34959066 PMCID: PMC9195562 DOI: 10.1016/j.watres.2021.117988] [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: 10/05/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Drinking water disinfection by chlorination or chloramination can result in the formation of disinfection byproducts (DBPs) such as haloacetic acids (HAAs) and trihalomethanes (THMs). Pyrogenic carbonaceous matter (PCM), such as activated carbon (AC), is commonly used as an ostensibly inert adsorbent to remove HAAs from water. HAA degradation has been mainly attributed to biological factors. This study, for the first time, revealed that abiotic HAA degradation in the presence of PCM could be important under water treatment conditions. Specifically, we observed complete destruction of Br3AA, a model HAA, in the presence of powder AC at pH 7 within 30 min. To understand the role of PCM and the reaction mechanism, we performed a systematic study using a suite of HAAs and various PCM types. We found that PCM significantly accelerated the transformation of three HAAs (Br3AA, BrCl2AA, Br2ClAA) at pH 7. Product characterization indicated an approximately 1:1 HAA molar transformation into their respective THMs following a decarboxylation pathway with PCM. The Br3AA activation energy (Ea) was measured by kinetic experiments at 15-45 °C with and without a model PCM, wherein a significant decrease in Ea from 25.7 ± 3.2 to 13.6 ± 2.2 kcal•mol-1 was observed. We further demonstrated that oxygenated functional groups on PCM (e.g., -COOH) can accelerate HAA decarboxylation using synthesized polymers to resemble PCM. Density functional theory simulations were performed to determine the enthalpy of activation (ΔH‡) for Br3AA decarboxylation with H3O+ and formic acid (HCOOH). The presence of HCOOH significantly lowered the overall ΔH‡ value for Br3AA decarboxylation, supporting the hypothesis that -COOH catalyzes the C-C bond breaking in Br3AA. Overall, our study demonstrated the importance of a previously overlooked abiotic reaction pathway, where HAAs can be quickly converted to THMs with PCM under water treatment relevant conditions. These findings have substantial implications for DBP mitigation in water quality control, particularly for potable water reuse or pre-chlorinated water that allow direct contact between HAAs and AC during filtration as well as PAC fines traveling with finished water in water distribution systems. As such, the volatilization and relative low toxicity of volatile THMs may be considered as a detoxification process to mitigate adverse DBP effects in drinking water, thereby lowering potential health risks to consumers.
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Affiliation(s)
- Pamela Rose V Samonte
- Department of Civil and Environmental Engineering, Villanova University, 800 E. Lancaster Ave., Villanova, PA 19085, United States
| | - Zhao Li
- Department of Civil and Environmental Engineering, Villanova University, 800 E. Lancaster Ave., Villanova, PA 19085, United States
| | - Jingdong Mao
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529, United States
| | - Brian P Chaplin
- Department of Chemical Engineering, University of Illinois at Chicago, 929 W. Taylor St., Chicago, IL 60607, United States; Institute of Environmental Science and Policy, University of Illinois at Chicago, 1603 W. Taylor St., Chicago, IL 60612, United States; Department of Civil, Materials, and Environmental Engineering, University of Illinois at Chicago, 842 W. Taylor St., Chicago, IL 60607, United States
| | - Wenqing Xu
- Department of Civil and Environmental Engineering, Villanova University, 800 E. Lancaster Ave., Villanova, PA 19085, United States.
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11
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A Review on the Use of Membrane Technology Systems in Developing Countries. MEMBRANES 2021; 12:membranes12010030. [PMID: 35054556 PMCID: PMC8779680 DOI: 10.3390/membranes12010030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/21/2021] [Accepted: 11/22/2021] [Indexed: 11/30/2022]
Abstract
Fulfilling the demand of clean potable water to the general public has long been a challenging task in most developing countries due to various reasons. Large-scale membrane water treatment systems have proven to be successful in many advanced countries in the past two decades. This paves the way for developing countries to study the feasibility and adopt the utilization of membrane technology in water treatment. There are still many challenges to overcome, particularly on the much higher capital and operational cost of membrane technology compared to the conventional water treatment system. This review aims to delve into the progress of membrane technology for water treatment systems, particularly in developing countries. It first concentrates on membrane classification and its application in water treatment, including membrane technology progress for large-scale water treatment systems. Then, the fouling issue and ways to mitigate the fouling will be discussed. The feasibility of membrane technologies in developing countries was then evaluated, followed by a discussion on the challenges and opportunities of the membrane technology implementation. Finally, the current trend of membrane research was highlighted to address future perspectives of the membrane technologies for clean water production.
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12
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Chen B, Jiang J, Yang X, Zhang X, Westerhoff P. Roles and Knowledge Gaps of Point-of-Use Technologies for Mitigating Health Risks from Disinfection Byproducts in Tap Water: A Critical Review. WATER RESEARCH 2021; 200:117265. [PMID: 34091221 PMCID: PMC8634687 DOI: 10.1016/j.watres.2021.117265] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 05/19/2023]
Abstract
Due to rising concerns about water pollution and affordability, there is a rapidly-growing public acceptance and global market for a variety of point-of-use (POU) devices for domestic uses. However, the efficiencies and mechanisms of POU technologies for removing regulated and emerging disinfection byproducts (DBPs) are still not systematically known. To facilitate the development of this field, we summarized performance trends of four common technologies (i.e., boiling, adsorption, membrane filtration, and advanced oxidation) on mitigating preformed DBPs and identified knowledge gaps. The following highest priority knowledge gaps include: 1) data on DBP levels at the tap or cup in domestic applications; 2) certainty regarding the controls of DBPs by heating processes as DBPs may form and transform simultaneously; 3) standards to evaluate the performance of carbon-based materials on varying types of DBPs; 4) long-term information on the membrane performance in removing DBPs; 5) knowledge of DBPs' susceptibility toward advanced redox processes; 6) tools to monitor/predict the toxicity and diversity of DBPs formed in waters with varying precursors and when implementing different treatment technologies; and 7) social acceptance and regulatory frameworks of incorporating POU as a potential supplement to current centralized-treatment focused DBP control strategies. We conclude by identifying research needs necessary to assure POU systems protect the public against regulated and emerging DBPs.
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Affiliation(s)
- Baiyang Chen
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology (Shenzhen), 518055, China.
| | - Jingyi Jiang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
| | - Paul Westerhoff
- NSF Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, School of Sustainable Engineering and the Built Environment, Ira A. Fulton Schools of Engineering, Arizona State University, Tempe, AZ 85287-3005, United States.
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13
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Gao J, Proulx F, Rodriguez MJ. Effects of domestic handling of drinking water on halogenated acetaldehydes. CHEMOSPHERE 2020; 261:127531. [PMID: 32707319 DOI: 10.1016/j.chemosphere.2020.127531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Halogenated acetaldehydes (HALs) are widely considered to be the third largest group of identified disinfection by-products (DBPs) by weight in drinking water. In this study, we evaluated various scenarios for the domestic handling of drinking water and their effects on HALs. Two drinking water systems (DS1 and DS2) were selected for this case study. First, tap water samples that were collected in DS1 at different time and from different locations were subjected to three domestic handling scenarios: boiling, domestic filtration using a point-of-use device with a new filter followed by refrigeration, and refrigeration in a covered glass pitcher. In the last two scenarios, the maximum storage (refrigeration) time was 24 h. Second, two water samples each from DS1 and DS2 were collected to investigate the effects that heating water to different temperatures has on HALs. According to the results, boiling the water effectively removed most HALs except dichloroacetaldehyde (DCAL), which increased. In contrast to the variable behaviors of HALs after boiling, all HALs were consistently and significantly reduced by domestic filtration. However, the overall removal efficiency of HALs from filtration (65%) was considerably lower than that from boiling (85%). Finally, refrigeration had no significant impact on the overall concentration of total HALs. However, chloral hydrate levels increased in unfiltered water after refrigeration, likely due to the reaction of chlorine residuals and precursors present in water. Therefore, boiling and domestic filtering of tap water may be recommended for the removal of HALs prior to consuming tap water.
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Affiliation(s)
- Jianan Gao
- ÉSAD, Université Laval, Pavillon Félix-Antoine-Savard, 2325, Rue des Bibliothèques, Québec, G1V 0A6, Canada.
| | - Francois Proulx
- Ville de Québec, 214, Avenue Saint-Sacrement, Suite 210, Québec, G1N 3X6, Canada.
| | - Manuel J Rodriguez
- ÉSAD, Université Laval, Pavillon Félix-Antoine-Savard, 2325, Rue des Bibliothèques, Québec, G1V 0A6, Canada.
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14
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Chowdhury S, Mazumder MAJ, Alhooshani K, Al-Suwaiyan MS. Reduction of DBPs in synthetic water by indoor techniques and its implications on exposure and health risk. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 691:621-630. [PMID: 31325862 DOI: 10.1016/j.scitotenv.2019.07.185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/12/2019] [Accepted: 07/12/2019] [Indexed: 06/10/2023]
Abstract
Disinfection byproducts (DBPs) in municipal supply water have been a concern. Many DBPs have been characterized as possible and probable human carcinogens, which can pose elevated cancer risks through lifetime exposure to municipal supply water. Few DBPs are regulated in many countries to control human exposure and risk from DBPs. In risk assessment studies, concentration of DBPs in water distribution systems is often used, whereas populations are typically exposed to indoor tap water. Through employing several techniques, DBPs can be reduced prior to water consumption, which is likely to reduce human exposure and risk of DBPs. This study investigated six indoor techniques in reducing trihalomethanes (THMs) and haloacetic acids (HAAs) in synthetic water and the effects of these techniques on exposure and risk. The techniques are: S1, S2: storing water in a refrigerator with and without lids respectively; S3, S4: boiling water for 1 min followed by storing in a refrigerator with and without lids respectively; S5, S6: filtering water using new and used granular activated carbon (GAC) filters and storing in a refrigerator without lids. Storing of water (S1, S2) reduced THMs in the range of 14.8-47.2% while boiling (S3, S4) and filtration (S5, S6) reduced THMs in the range of 77.3-92.8%. In S1-S4 techniques, HAAs were not reduced significantly while in S5 - S6 techniques, HAAs were reduced in the range of 64.7-69.8%. In S3-S6 techniques, overall cancer and non-cancer risks were reduced by 45.5-82.6% and 26.3-80.0% respectively. The findings might prove useful in understanding DBPs exposure, associated risks, strategies to minimize exposure to these contaminants and updating regulatory guidelines for better protection of health risks from DBPs.
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Affiliation(s)
- Shakhawat Chowdhury
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
| | | | - Khalid Alhooshani
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - Mohammad S Al-Suwaiyan
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
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15
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Padhi RK, Subramanian S, Satpathy KK. Formation, distribution, and speciation of DBPs (THMs, HAAs, ClO 2-,andClO 3-) during treatment of different source water with chlorine and chlorine dioxide. CHEMOSPHERE 2019; 218:540-550. [PMID: 30500715 DOI: 10.1016/j.chemosphere.2018.11.100] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/11/2018] [Accepted: 11/15/2018] [Indexed: 06/09/2023]
Abstract
Formation potential and speciation characteristics of two important groups of disinfection byproducts (DBPs), namely, trihalomethanes (THMs) and haloacetic acids (HAAS), during Cl2 and ClO2 treatment of water samples collected from three different sources, namely, sea, river, and reservoir, were investigated with reference to key controlling parameters. Formation of inorganic DBPs such as chlorate and chlorite was evaluated. Dissolved organic carbon (DOC) and UV absorbance (UV254) of the sea, river, and reservoir samples were 3.35 ± 0.05, 3.12 ± 0.05, and 3.23 ± 0.05 mg/L and 0.062 ± 0.01, 0.074 ± 0.01, and 0.055 ± 0.01 cm-1, respectively. For Cl2 and ClO2 treatments, the respective formation potential of THMs and HAAs from the three water sources studied exhibited unidentical trend suggesting that higher THM formation was not necessarily associated with higher HAA formation. On chlorination, the concentrations of total HAAs formed were 9.8 μg/L (sea), 12.8 μg/L (river), and 20.6 μg/L (reservoir) and total THM yields were 38.3 μg/L (sea), 18.8 μg/L (river), and 21.5 μg/L (reservoir) for a Cl2 dose of 1 mg/L and 30 min reaction time. The trend of formation of THMs and HAAs for Cl2 treatment was similar to that for ClO2 treatment. However, the amount of HAAs (3.5 μg/L (sea), 1.8 μg/L (river), and 1.9 μg/L (reservoir)) and THMs (not detected) formed was much lower than that formed during chlorination. Regardless of source water type, di-HAAs were the most favored HAAs, followed by tri-HAAs with a small amount of mono-HAAs formed for both Cl2 and ClO2 treatment. Chlorination yielded more THMs than HAAs, whereas it was reverse for chlorine dioxide treatment. Irrespective of treatment with ClO2 or Cl2, seawater samples showed the highest bromine incorporation percentage (BIP) in both THMs and HAAs followed by that for river and reservoir water samples. HAAs were found to be always associated with lower amount of BIP than THMs.
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Affiliation(s)
- R K Padhi
- Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, 603102, India; Health Safety and Environment Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, 603 102, India.
| | - S Subramanian
- Health Safety and Environment Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, 603 102, India
| | - K K Satpathy
- Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, 603102, India; Health Safety and Environment Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, 603 102, India.
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16
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Chowdhury S. Disinfection by-products in desalinated and blend water: formation and control strategy. JOURNAL OF WATER AND HEALTH 2019; 17:1-24. [PMID: 30758300 DOI: 10.2166/wh.2018.204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Desalinated seawater is the major source of drinking water in many countries. During desalination, several activities including pretreatment, desalination, stabilization, mixing, storage and distribution are performed. Few disinfectants are used during these activities to control the biofouling agents and microbiological regrowth. The reactions between the disinfectants and natural organic matter (NOM), bromide and iodide form disinfection by-products (DBPs) in product water. The product water is stabilized and mixed with treated freshwater (e.g., groundwater) to meet the domestic water demands. The DBPs in desalinated and blend water are an issue due to their possible cancer and non-cancer risks to humans. In this paper, formation and distribution of DBPs in different steps of desalination and water distribution systems prior to reaching the consumer tap were reviewed. The variability of DBPs among different sources and desalination processes was explained. The toxicities of DBPs were compared and the strategies to control DBPs in desalinated water were proposed. Several research directions were identified to achieve comprehensive control on DBPs in desalinated water, which are likely to protect humans from the adverse consequences of DBPs.
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Affiliation(s)
- Shakhawat Chowdhury
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia E-mail:
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17
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Fakour H, Lo SL. Formation and risk assessment of trihalomethanes through different tea brewing habits. Int J Hyg Environ Health 2018; 222:117-124. [PMID: 30181027 DOI: 10.1016/j.ijheh.2018.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/03/2018] [Accepted: 08/21/2018] [Indexed: 11/26/2022]
Abstract
Trihalomethanes (THMs) are suspected carcinogens and reproductive toxicants commonly found in chlorinated drinking water. This study investigates the formation of THMs and their associated risks during different tea brewing habits. Three main categories of tea (black, oolong, and green) under various brewing conditions and drinking water sources were tested. Tea samples prepared in ordinary thermos flask formed significant levels of total THM (TTHM). The highest TTHM formation came from black tea made with tap water, plausibly due to higher concentrations of reactive THM precursors. Compared with tap water, when the background solution is bottled water or distilled water, less TTHM was observed in prepared tea infusions. The results also revealed that unlike the traditional teapot-based tea serving habit, the removal of THMs is significantly reduced when tea infusion is stored in enclosed containers. Risk assessment analysis based on the survey among tea shop costumers also revealed that cancer risks induced by ingestion of THMs through drinking tea infusions prepared in thermos flask exceeded the tolerable level. Data obtained in this research demonstrated that drinking tea infusions directly from enclosed containers can be a significant source of exposure to THMs.
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Affiliation(s)
- Hoda Fakour
- Graduate Institute of Environmental Engineering National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Shang-Lien Lo
- Graduate Institute of Environmental Engineering National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan.
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18
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Brown KW, Gessesse B, Butler LJ, MacIntosh DL. Potential Effectiveness of Point-of-Use Filtration to Address Risks to Drinking Water in the United States. ENVIRONMENTAL HEALTH INSIGHTS 2017; 11:1178630217746997. [PMID: 29270018 PMCID: PMC5731620 DOI: 10.1177/1178630217746997] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/16/2017] [Indexed: 05/25/2023]
Abstract
Numerous contemporary incidents demonstrate that conventional control strategies for municipal tap water have limited ability to mitigate exposures to chemicals whose sources are within distribution systems, such as lead, and chemicals that are not removed by standard treatment technologies, such as perfluorooctanoic acid (PFOA)/perfluorooctanesulfonic acid (PFOS). In these situations, point-of-use (POU) controls may be effective in mitigating exposures and managing health risks of chemicals in drinking water, but their potential utility has not been extensively examined. As an initial effort to fill this information gap, we conducted a critical review and analysis of the existing literature and data on the effectiveness of POU drinking water treatment technologies for reducing chemical contaminants commonly found in tap water in the United States. We found that many types of water treatment devices available to consumers in the United States have undergone laboratory testing and often certification for removal of chemical contaminants in tap water, but in most cases their efficacy in actual use has yet to be well characterized. In addition, the few studies of POU devices while "in use" focus on traditional contaminants regulated under the Safe Drinking Water Act, but do not generally consider nontraditional contaminants of concern, such as certain novel human carcinogens, industrial chemicals, pesticides, pharmaceuticals, personal care products, and flame retardants. Nevertheless, the limited information available at present suggests that POU devices can be highly effective when used prophylactically and when deployed in response to contamination incidents. Based on these findings, we identify future areas of research for assessing the ability of POU filters to reduce health-related chemical contaminants distributed through public water systems and private wells.
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Affiliation(s)
| | | | - Lindsey J Butler
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA
| | - David L MacIntosh
- Environmental Health & Engineering Inc., Needham, MA, USA
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
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19
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Hong H, Yan X, Song X, Qin Y, Sun H, Lin H, Chen J, Liang Y. Bromine incorporation into five DBP classes upon chlorination of water with extremely low SUVA values. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 590-591:720-728. [PMID: 28302307 DOI: 10.1016/j.scitotenv.2017.03.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/03/2017] [Accepted: 03/04/2017] [Indexed: 06/06/2023]
Abstract
The main objective of this study was to assess the effects of disinfection conditions on bromine incorporation into disinfection by-products (DBPs) during chlorination of water with low specific UV absorbance (SUVA). Five classes of DBPs were included: trihalomethanes (THMs), dihaloacetic acids (di-HAAs), trihaloacetic acids (tri-HAAs), dihaloacetonitriles (DHANs) and trihalonitromethanes (THNMs). Results showed that the bromine utilization in DBPs formation was positive related with reaction time, pH and temperature. On the other hand, the bromine substitution factors (BSFs) of DBPs were generally increased with pH (except tri-HAAs) and bromide concentration, but decreased with the reaction time, temperature and chlorine dose. Moreover, the BSFs values varied with DBP classes with the ranking being as following: THNMs≫DHANs≫tri-HAAs>THM≈di-HAAs. These results were mostly similar with the references, yet the pH effect on BSFs as well as the rank of BSFs for different DBP classes may differ with the specific UV absorbance of organic matter.
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Affiliation(s)
- Huachang Hong
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, P. R. China.
| | - Xiaoqing Yan
- Laboratory for Food Safety and Environmental Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen 518055, P. R. China.
| | - Xuhui Song
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, P. R. China
| | - Yanyan Qin
- Shenzhen Polytechnic, Guangdong Province, Shenzhen 518055, P. R. China
| | - Hongjie Sun
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, P. R. China
| | - Hongjun Lin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, P. R. China
| | - Jianrong Chen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, P. R. China
| | - Yan Liang
- Laboratory for Food Safety and Environmental Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen 518055, P. R. China
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20
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Yan M, Li M, Han X. Behaviour of I/Br/Cl-THMs and their projected toxicities under simulated cooking conditions: Effects of heating, table salt and residual chlorine. JOURNAL OF HAZARDOUS MATERIALS 2016; 314:105-112. [PMID: 27107240 DOI: 10.1016/j.jhazmat.2016.04.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/22/2016] [Accepted: 04/10/2016] [Indexed: 06/05/2023]
Abstract
This study examined the effects of heating, residual chlorine and concentration of table salt on the generation of iodine-, bromine- and chlorine-containing trihalomethanes (THMs) under simulated cooking conditions. In the case of addition of either KI- or KIO3-fortified salt, total I-THM concentrations increased with increasing iodine concentration, while total Cl/Br-THM concentrations decreased. CHCl2I, CHBrClI, CHBrI2, CHBr2I and CHI3 were formed in the presence of KI salt, while only CHCl2I was formed in the presence of KIO3 salt. CHCl2I was unstable under cooking conditions, and >90% of this DBP was removed during heating, which in some cases increased the concentrations of the other I-THMs. The calculated cytotoxicity increased with addition of KI- or KIO3-fortified salt due to the generation of I-THMs, whose impact on the cytotoxicity at room temperature was equal to or five times higher, respectively, than the cytotoxicity of the simultaneously formed Cl/Br-THMs for the cases of salts. Heating decreased the cytotoxicity, except for the case of addition of KI salt, in which the calculated cytotoxicity of I-THMs increased above 150% as the temperature was increased up to 100°C. The reported results may have important implications for epidemiologic exposure assessments and, ultimately, for public health protection.
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Affiliation(s)
- Mingquan Yan
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
| | - Mingyang Li
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China
| | - Xuze Han
- Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China
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21
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Fakour H, Lo SL, Lin TF. Impacts of Typhoon Soudelor (2015) on the water quality of Taipei, Taiwan. Sci Rep 2016; 6:25228. [PMID: 27125312 PMCID: PMC4850432 DOI: 10.1038/srep25228] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 04/12/2016] [Indexed: 11/09/2022] Open
Abstract
Typhoon Soudelor was one of the strongest storms in the world in 2015. The category 5 hurricane made landfall in Taiwan on August 8, causing extensive damage and severe impacts on the environment. This paper describes the changes of trihalomethane (THM) concentrations in tap and drinking fountain water in selected typhoon-affected areas in Taipei before and after the typhoon. Samples were taken from water transmission mains at various distances from the local water treatment plant. The results showed that organic matter increased between pre- and post-typhoon periods with a greater proportion of aromatic compounds. Although drinking fountains showed moderately less total trihalomethane (TTHM) levels than that of tap water, the intake of high turbidity water considerably diminished the efficiency of their purification systems after the typhoon. The percentage distribution of THM species increased throughout the distribution network, probably due to a longer contact time between chlorine and the organic matter in the pipelines. After 2 to 5 min of boiling, THM reduction was considerable in all cases with the greater extent in post-typhoon samples. It is evident that extreme weather conditions may have a severe impact on water quality, and thus more cautious strategies should be adopted in such cases.
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Affiliation(s)
- Hoda Fakour
- Graduate Institute of Environmental Engineering National Taiwan University No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (R.O.C.)
| | - Shang-Lien Lo
- Graduate Institute of Environmental Engineering National Taiwan University No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (R.O.C.)
| | - Tsair-Fuh Lin
- Department of Environmental Engineering and Global Water Quality Research Center, National Cheng Kung University, Tainan City, Taiwan
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22
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Chen H, Cao Y, Wei E, Gong T, Xian Q. Facile synthesis of graphene nano zero-valent iron composites and their efficient removal of trichloronitromethane from drinking water. CHEMOSPHERE 2016; 146:32-39. [PMID: 26706929 DOI: 10.1016/j.chemosphere.2015.11.095] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/22/2015] [Accepted: 11/24/2015] [Indexed: 06/05/2023]
Abstract
Halonitromethanes (HNMs), as an emerging class of disinfection by-products containing nitrogen (N-DBPs) in drinking water, have possessed public health concerns. Two most studied materials, graphene and nanometer-sized zero-valent iron, have been successfully combined into binary nanocomposites (G-nZVI) via facile carbonization and calcinations of glucose and ferric chloride, which was used in the removal of HNMs from drinking water in this study. When the Fe/C mass ratio was 1:5, the as-prepared G-nZVI hybrids comprised numerous dispersed Fe(0) nanoparticles with a range of 5-10 nm in diameter. Batch experimental results indicated that the as-prepared G-nZVI could effectively remove trichloronitromethane (TCNM), a dominant in the group of HNMs from drinking water. About 99% of initial TCNM could be adsorbed and degraded under 60 mg/L G-nZVI dosage within 120 min. Kinetic studies indicated that the removal of TCNM by G-nZVI followed a pseudo first order rate (R(2) > 0.9). The degradation pathways of TCNM by G-nZVI nanocomposites might include dechlorination and denitration of TCNM. The Fe was in the form of iron oxides in the graphene material shape which was then restored to Fe(0) again via calcinations. These results indicated that the synthesized G-nZVI nanocomposites could be a powerful material to remove HNMs from drinking water.
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Affiliation(s)
- Haifeng Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Yu Cao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Enze Wei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Tingting Gong
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Qiming Xian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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Single-step microwave assisted headspace liquid-phase microextraction of trihalomethanes and haloketones in biological samples. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 1007:43-8. [DOI: 10.1016/j.jchromb.2015.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 10/30/2015] [Accepted: 11/01/2015] [Indexed: 11/16/2022]
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Kanchanamayoon W. Sample Preparation Methods for the Determination of Chlorination Disinfection Byproducts in Water Samples. Chromatographia 2015. [DOI: 10.1007/s10337-015-2934-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Ali A, Kurzawa-Zegota M, Najafzadeh M, Gopalan RC, Plewa MJ, Anderson D. Effect of drinking water disinfection by-products in human peripheral blood lymphocytes and sperm. Mutat Res 2014; 770:136-43. [PMID: 25771880 DOI: 10.1016/j.mrfmmm.2014.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 07/30/2014] [Accepted: 08/20/2014] [Indexed: 05/15/2023]
Abstract
BACKGROUND Drinking water disinfection by-products (DBPs) are generated by the chemical disinfection of water and may pose hazards to public health. Two major classes of DBPs are found in finished drinking water: haloacetic acids (HAAs) and trihalomethanes (THMs). HAAs are formed following disinfection with chlorine, which reacts with iodide and bromide in the water. Previously the HAAs were shown to be cytotoxic, genotoxic, mutagenic, teratogenic and carcinogenic. OBJECTIVES To determine the effect of HAAs in human somatic and germ cells and whether oxidative stress is involved in genotoxic action. In the present study both somatic and germ cells have been examined as peripheral blood lymphocytes and sperm. METHODS The effects of three HAA compounds: iodoacetic acid (IAA), bromoacetic acid (BAA) and chloroacetic acid (CAA) were investigated. After determining appropriate concentration responses, oxygen radical involvement with the antioxidants, butylated hydroxanisole (BHA) and the enzyme catalase, were investigated in the single cell gel electrophoresis (Comet) assay under alkaline conditions, >pH 13 and the micronucleus assay. RESULTS In the Comet assay, BHA and catalase were able to reduce DNA damage in each cell type compared to HAA alone. In the micronucleus assay, micronuclei (MNi) were found in peripheral lymphocytes exposed to all three HAAs and catalase and BHA were in general, able to reduce MNi induction, suggesting oxygen radicals play a role in both assays. CONCLUSION These observations are of concern to public health since both human somatic and germ cells show similar genotoxic responses.
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Affiliation(s)
- Aftab Ali
- Genetic & Reproductive Toxicology Group, Medical Sciences Division, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Malgorzata Kurzawa-Zegota
- Genetic & Reproductive Toxicology Group, Medical Sciences Division, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Mojgan Najafzadeh
- Genetic & Reproductive Toxicology Group, Medical Sciences Division, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Rajendran C Gopalan
- Genetic & Reproductive Toxicology Group, Medical Sciences Division, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Michael J Plewa
- Department of Crop Sciences and NSF Science and Technology Center of Advanced Materials for the Purification of Water with Systems, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Diana Anderson
- Genetic & Reproductive Toxicology Group, Medical Sciences Division, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK.
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Pan Y, Zhang X, Wagner ED, Osiol J, Plewa MJ. Boiling of simulated tap water: effect on polar brominated disinfection byproducts, halogen speciation, and cytotoxicity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 48:149-156. [PMID: 24308807 DOI: 10.1021/es403775v] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Tap water typically contains numerous halogenated disinfection byproducts (DBPs) as a result of disinfection, especially of chlorination. Among halogenated DBPs, brominated ones are generally significantly more toxic than their chlorinated analogues. In this study, with the aid of ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry by setting precursor ion scans of m/z 79/81, whole spectra of polar brominated DBPs in simulated tap water samples without and with boiling were revealed. Most polar brominated DBPs were thermally unstable and their levels were substantially reduced after boiling via decarboxylation or hydrolysis; the levels of a few aromatic brominated DBPs increased after boiling through decarboxylation of their precursors. A novel adsorption unit for volatile total organic halogen was designed, which enabled the evaluation of halogen speciation and mass balances in the simulated tap water samples during boiling. After boiling for 5 min, the overall level of brominated DBPs was reduced by 62.8%, of which 39.8% was volatilized and 23.0% was converted to bromide; the overall level of chlorinated DBPs was reduced by 61.1%, of which 44.4% was volatilized and 16.7% was converted to chloride; the overall level of halogenated DBPs was reduced by 62.3%. The simulated tap water sample without boiling was cytotoxic in a chronic (72 h) exposure to mammalian cells; this cytotoxicity was reduced by 76.9% after boiling for 5 min. The reduction in cytotoxicity corresponded with the reduction in overall halogenated DBPs. Thus, boiling of tap water can be regarded as a "detoxification" process and may reduce human exposure to halogenated DBPs through tap water ingestion.
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Affiliation(s)
- Yang Pan
- Environmental Engineering Program, Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology , Hong Kong SAR, China
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Smith RB, Nieuwenhuijsen MJ, Wright J, Raynor P, Cocker J, Jones K, Kappaostopoulou-Karadanelli M, Toledano MB. Validation of trichloroacetic acid exposure via drinking water during pregnancy using a urinary TCAA biomarker. ENVIRONMENTAL RESEARCH 2013; 126:145-151. [PMID: 23769186 DOI: 10.1016/j.envres.2013.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 12/24/2012] [Accepted: 05/13/2013] [Indexed: 06/02/2023]
Abstract
Disinfection by-product (DBP) exposure during pregnancy may be related to reduced fetal growth, but the evidence is inconclusive and improved DBP exposure assessment is required. The authors conducted a nested exposure study on a subset (n=39) of pregnant women in the Born in Bradford cohort to assess validity of TCAA exposure assessment based on tap water sampling and self-reported water-use; water-use questionnaire validity; and use of a one-time urinary TCAA biomarker. TCAA levels in urine and home tap water supply were quantified, and water use was measured via a questionnaire and 7-day diary, at 28 weeks gestation. Diary and urine measures were repeated later in pregnancy (n=14). TCAA level in home tap water supply was not correlated with urinary TCAA (0.18, P=0.29). Cold unfiltered tap water intake at home measured by questionnaire was correlated with urinary TCAA (0.44, P=0.007), but correlation was stronger still for cold unfiltered tap water intake reported over the 3 days prior to urine sampling (0.60, P<0.001). For unemployed women TCAA ingestion at home, derived from tap water sampling and self-reported water-use, correlated strongly with urinary TCAA (0.78, P<0.001), but for employed women the correlation was weak (0.31, P=0.20). Results suggest individual tap water intake is most influential in determining TCAA exposure variability in this cohort, and that TCAA ingestion at home is a valid proxy for TCAA exposure for unemployed women but less satisfactory for employed women.
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Affiliation(s)
- Rachel B Smith
- MRC-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, Imperial College London, London W2 1PG, UK
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Lee J, Kim ES, Roh BS, Eom SW, Zoh KD. Occurrence of disinfection by-products in tap water distribution systems and their associated health risk. ENVIRONMENTAL MONITORING AND ASSESSMENT 2013; 185:7675-91. [PMID: 23446885 DOI: 10.1007/s10661-013-3127-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 02/05/2013] [Indexed: 05/09/2023]
Abstract
The concentrations of trihalomethanes (THMs), including chloroform, bromodichloromethane, dibromochloromethane, and bromoform, and haloacetic acids (HAAs; monochloroacetic acid, monobromoacetic acid, dibromoacetic acid, dichloroacetic acid, and trichloroacetic acid) were measured in tap waters passing through water distribution systems of six water treatment plants in Seoul, Korea, and their associated health risks from exposure to THMs through ingestion, dermal contact, and inhalation were estimated using a probabilistic approach. The concentration ranges for total THMs and HAA5 were 3.9-53.5 and <LOD-49.5 μg/L, respectively. Among DBPs, chloroform, bromodichloromethane, dichloroacetic acid, and trichloroacetic acid were the most frequently detected. Spatial and seasonal variations in concentrations of THMs and HAAs in the six water distribution systems were significant (P < 0.001).The mean lifetime cancer risks through ingestion, dermal contact, and inhalation during showering ranged as 7.23-10.06 × 10(-6), 2.19-3.63 × 10(-6), and 5.22-7.35 × 10(-5), respectively. The major exposure route to THMs was inhalation during showering. Sensitivity analysis showed that shower time and shower frequency had a great impact on the lifetime cancer risk by the exposure to THMs in tap water.
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Affiliation(s)
- Jin Lee
- Seoul Metropolitan Government Research Institute of Public Health and Environment, Gwacheon, Gyeonggi Province 427070, South Korea
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Hong H, Xiong Y, Ruan M, Liao F, Lin H, Liang Y. Factors affecting THMs, HAAs and HNMs formation of Jin Lan Reservoir water exposed to chlorine and monochloramine. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 444:196-204. [PMID: 23271145 DOI: 10.1016/j.scitotenv.2012.11.086] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/25/2012] [Accepted: 11/26/2012] [Indexed: 06/01/2023]
Abstract
The formations of THMs, HAAs, and HNMs from chlorination and chloramination of water from Jinlan Reservoir were investigated in this study. Results showed that monochloramine rather than chlorine generally resulted in lower concentration of DBPs, and the DBPs formation varied greatly as the treatment conditions changed. Specifically, the yields of THMs, HAAs and HNMs all increased with the high bromide level and high disinfectant dose both during chlorination and chloramination. The longer reaction time had a positive effect on the formation of THMs, HAAs and HNMs during chlorination and HNMs during chloramination. However, no time effect was observed on the formation of THMs and HAAs during chloramination. An increase in pH enhanced the levels of THMs and HNMs upon chlorination but reduced levels of HNMs upon chloramination. As for the THMs in chloramination and HAAs in chlorination and chloramination, no obvious pH effect was observed. The elevated temperature significantly increased the yields of THMs during chlorination and HNMs during chloramination, but has no effect on THMs and HAAs yields during chloramination. In the same temperature range, the formation of HAAs and HNMs in chlorination showed a first increasing and then a decreasing trend. In chloramination study, addition of nitrite markedly increased the formation of HNMs but had little impact on the formation of THMs and HAAs. While in chlorination study, the presence of high nitrite levels significantly reduced the yields of THMs, HAAs and HNMs. Range analysis revealed that the bromide and disinfectant levels were the major factors affecting THMs, HAAs and HNMs formation, in both chlorination and chloramination. Finally, comparisons of the speciation of mono-halogenated, di-halogenated, tri-halogenated HAAs and HNMs between chlorination and monochloramination were also conducted, and factors influencing the speciation pattern were identified.
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Affiliation(s)
- Huachang Hong
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
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Legay C, Rodriguez MJ, Sadiq R, Sérodes JB, Levallois P, Proulx F. Spatial variations of human health risk associated with exposure to chlorination by-products occurring in drinking water. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2011; 92:892-901. [PMID: 21093977 DOI: 10.1016/j.jenvman.2010.10.056] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 07/14/2010] [Accepted: 10/21/2010] [Indexed: 05/09/2023]
Abstract
During disinfection, chlorine reacts with organic matter present in drinking water and forms various undesirable chlorinated by-products (CBPs). This paper describes a study of the spatial variability of human health risk (i.e., cancer effects) from CBP exposure through drinking water in a specific region. The region under study involves nine drinking water distribution systems divided into several zones based on their characteristics. The spatial distribution of cancer risk (CR) was estimated using two years of data (2006-2008) on various CBP species. In this analysis, trihalomethanes (THMs) and haloacetic acids (HAAs) served as surrogates for CBPs. Three possible routes of exposure (i.e., via ingestion, inhalation and dermal contact) were considered for each selected compound. The cancer risk assessment involved estimating a unit risk (R(T)) in each zone of the selected distribution systems. A probabilistic analysis based on Monte Carlo simulations was employed. Risk assessment results showed that cancer risk varied between systems, but also within individual systems. As a result, the population of the same region was not exposed to the same risk associated with CBPs in drinking water. Unacceptable levels (i.e., R(T) > 10(-4)) for the estimated CR were determined for several zones in the studied region. This study demonstrates that a spatial-based analysis performed to represent the spatial distribution of risk estimates can be helpful in identifying suitable risk management strategies. Suggestions for improving the risk analysis procedure are also presented.
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Affiliation(s)
- Christelle Legay
- École supérieure d'aménagement du territoire, Université Laval, Pavillon Antoine Savard, Québec City, QC., Canada
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Chowdhury S, Rodriguez MJ, Serodes J. Model development for predicting changes in DBP exposure concentrations during indoor handling of tap water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:4733-4743. [PMID: 20655096 DOI: 10.1016/j.scitotenv.2010.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Revised: 06/29/2010] [Accepted: 07/01/2010] [Indexed: 05/29/2023]
Abstract
Disinfection by-products (DBPs) in municipal drinking water are a matter of concern because of their possible risks to human health. Risk assessment studies often use measurements of DBPs in water distribution systems, whereas populations are typically exposed to the indoor tap water. Further to this, consumers often employ several indoor strategies to handle tap water (e.g., storing in a refrigerator, boiling, filtering, etc.) prior to use. The indoor handling of municipal water may have implications on DBPs' exposure assessment. This study investigates and develops models to predict the effects of various indoor handling strategies on trihalomethanes (THMs) and haloacetic acids (HAAs). Linear and nonlinear models are developed to predict changes in THM and HAA concentrations due to various indoor water manipulation strategies. The models are capable of assessing representative exposure concentrations of THMs and HAAs as a result of indoor handling, which might be useful in gaining a better understanding of exposure and risks from DBPs in municipal drinking water.
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Affiliation(s)
- Shakhawat Chowdhury
- Ecole supérieure d'aménagement du territoire, Université Laval, 1628 Pavillon Félix-Antoine-Savard, Québec City, QC, Canada.
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Kim H. Seasonal variations in the household exposures of Korean housewives to volatile tap water disinfection by-products. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 403:59-67. [PMID: 18571218 DOI: 10.1016/j.scitotenv.2008.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 05/02/2008] [Accepted: 05/07/2008] [Indexed: 05/26/2023]
Abstract
This study was conducted to compare housewives' winter and summer exposures to volatile disinfection by-products (DBPs) in chlorinated tap water. A total of 60 households were visited for this purpose: 27 in winter and 33 in summer. Each subject was given a questionnaire regarding general tap water use, household ventilation time, and activities related to water use. Tap water, household air, and exhaled breath samples were also collected during the visits. All of the subjects answered that they consumed tap water after either thermal treatment or purification through filtration systems. A longer ventilation time in winter than in summer resulted in a higher inhalation exposure for housewives during that season. Estimated chronic daily intakes calculated for winter and summer showed that in winter, the greatest risk at home is inhalation exposure while resting at home, whereas in summer, it is showering. In both seasons, the ingestion route can be discounted, because tap water is processed before consumption, eliminating the volatile DBPs. From this study, it is evident that the inhalation of household air while resting at home cannot be ignored in risk assessment. Moreover, the fact that water is normally boiled or filtered before use should also be considered.
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Affiliation(s)
- Hekap Kim
- Department of Environmental Science, College of Natural Sciences, Kangwon National University, Hyoja 2-dong, Chuncheon, Kangwon-do 200-701, Republic of Korea.
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