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Ardila A, Rodriguez MJ, Pelletier G. Optimizing sampling location for water quality degradation monitoring in distribution systems: Assessing global representativeness and potential health risk. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121505. [PMID: 38908156 DOI: 10.1016/j.jenvman.2024.121505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 04/02/2024] [Accepted: 06/15/2024] [Indexed: 06/24/2024]
Abstract
Selecting the optimal monitoring points in a water distribution network is challenging due to the complex spatiotemporal variability of water quality degradation. The lack of a standardized methodology for monitoring point selection forces operators to rely on general recommendations, historical data and professional experience, which can mask water quality problems and increase the risk to consumers. This study proposes a new methodology to optimize the selection of monitoring points in distribution networks. The method considers the spatiotemporal degradation of water quality, the definition of representative zones and two selection criteria: global representativeness and potential health risk. Representative zones were determined for each node of the network based on hydraulic paths and their water quality spatial variability. Part of the distribution network in Quebec City, Canada was used as the case study, in which four water quality parameters were investigated: free chlorine residual (FRC), heterotrophic plate counts (HPC), trihalomethanes (THMs) and haloacetic acids (HAAs). Seasonal variabilities (summer and winter) were also analyzed. The results obtained for the two criteria and for both seasons were compared, and methodological and practical recommendations were established for dynamic monitoring programs that respond to the needs of operators.
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Affiliation(s)
- Andres Ardila
- Graduate School of Land Planning and Regional Development, Faculty of Planning, Architecture, Art and Design, Université Laval, Québec City, Québec, G1V 0A6, Canada.
| | - Manuel J Rodriguez
- Graduate School of Land Planning and Regional Development, Faculty of Planning, Architecture, Art and Design, Université Laval, Québec City, Québec, G1V 0A6, Canada.
| | - Genevieve Pelletier
- Department of Civil and Water Engineering, Faculty of Sciences and Engineering, Université Laval, Québec City, Québec, G1V 0A6, Canada.
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2
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Ardila A, Rodriguez MJ, Pelletier G. Spatiotemporal optimization of water quality degradation monitoring in water distribution systems supplied by surface sources: A chronological and critical review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 337:117734. [PMID: 36996548 DOI: 10.1016/j.jenvman.2023.117734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/14/2023] [Accepted: 03/10/2023] [Indexed: 06/19/2023]
Abstract
Drinking water may undergo spatiotemporal changes in quality as it leaves the treatment plant and enters the distribution system. This variability means that not all consumers receive water of the same quality. Monitoring water quality in distribution networks makes it possible to verify the compliance of current regulations and reduce consumption risks associated with water quality degradation. An inaccurate interpretation of the spatiotemporal variability of water quality affects the selection of monitoring locations and the sampling frequency, which may conceal problems with the water quality and increase consumers' risk. This paper presents a chronological and critical review of the literature on the evolution, benefits and limitations of methodologies for the optimization of water quality degradation monitoring in water distribution systems supplied by surface sources. This review compares the different methodologies and examines the types of approaches, optimization objectives, variables, and types of spatial and temporal analysis, as well as the main advantages and limitations. A cost-benefit analysis was conducted to assess applicability in different-sized municipalities (small, medium and large). Future research recommendations for optimal water quality monitoring in distribution networks are also provided.
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Affiliation(s)
- Andres Ardila
- Graduate School of Land Planning and Regional Development, Faculty of Planning, Architecture, Art and Design, Université Laval, CA, Québec, G1V 0A6, Canada.
| | - Manuel J Rodriguez
- Graduate School of Land Planning and Regional Development, Faculty of Planning, Architecture, Art and Design, Université Laval, CA, Québec, G1V 0A6, Canada.
| | - Geneviève Pelletier
- Department of Civil and Water Engineering, Faculty of Sciences and Engineering, Université Laval, CA, Québec, G1V 0A6, Canada.
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3
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Wang Z, Li L, Ariss RW, Coburn KM, Behbahani M, Xue Z, Seo Y. The role of biofilms on the formation and decay of disinfection by-products in chlor(am)inated water distribution systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:141606. [PMID: 32890868 DOI: 10.1016/j.scitotenv.2020.141606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/07/2020] [Accepted: 08/08/2020] [Indexed: 06/11/2023]
Abstract
This study investigated the role of biofilms on the formation and decay of disinfection by-products (DBPs) in chlorine (Cl2) or monochloramine (NH2Cl) disinfected reactors under the conditions related to drinking water distribution systems (DWDSs). Biofilm analysis results revealed that at 0.5 mg/L of disinfectant residual, both Cl2 and NH2Cl were not effective to remove biofilms. As the disinfectant residual increased, biofilms could be eradicated by Cl2, while remaining biofilms were still present even under the highest allowable NH2Cl dose (4 mg/L) for 25 days. Low DBP formation was observed under the recommended minimum Cl2 residual (0.5 mg/L), which could be attributed to limited Cl2 reactions with biofilms, as well as a combination of the volatilization and biodegradation of DBPs. However, when Cl2 residuals reached 2 mg/L, DBP concentrations in bulk water increased sharply beyond the DBP formation of the feed solution, with trihalomethanes and haloacetic acids being the most prevalent DBP species. The sharp increase was temporary for 15 days because of the removal of biofilms. For unregulated DBPs, high levels of haloacetonitriles were observed as attached biofilms reacted with the increased Cl2 dose and provided an additional organic nitrogen source for nitrogenous DBP formation. When maximum Cl2 residual (4 mg/L) was applied, no further increase of DBPs was observed because of biofilm eradication. For NH2Cl disinfection, the DBP levels were much lower than those of Cl2 disinfection, with small differences in DBP formation for different NH2Cl residuals. Overall, this study provides insights into optimizing disinfection protocols for water utilities by balancing the benefits of disinfection application for biofilm control with minimized toxic DBP formation in DWDSs.
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Affiliation(s)
- Zhikang Wang
- College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, Guizhou Province 550025, PR China; Department of Chemical Engineering, University of Toledo, 3048 Nitschke Hall, 2801 W. Bancroft St., Toledo, OH 43606-3390, USA
| | - Lei Li
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, 2801 W. Bancroft St., Toledo, OH 43606-3390, USA
| | - Robert W Ariss
- College of Medicine and Life Sciences, University of Toledo, 3000 Arlington Ave, Toledo, OH 43614-2595, USA
| | - Kimberly M Coburn
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, 2801 W. Bancroft St., Toledo, OH 43606-3390, USA
| | - Mohsen Behbahani
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, 2801 W. Bancroft St., Toledo, OH 43606-3390, USA
| | - Zheng Xue
- Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, 2801 W. Bancroft St., Toledo, OH 43606-3390, USA
| | - Youngwoo Seo
- Department of Chemical Engineering, University of Toledo, 3048 Nitschke Hall, 2801 W. Bancroft St., Toledo, OH 43606-3390, USA; Department of Civil and Environmental Engineering, University of Toledo, 3006 Nitschke Hall, 2801 W. Bancroft St., Toledo, OH 43606-3390, USA.
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Legay C, Leduc S, Dubé J, Levallois P, Rodriguez MJ. Chlorination by-product levels in hot tap water: Significance and variability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 651:1735-1741. [PMID: 30316091 DOI: 10.1016/j.scitotenv.2018.10.075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/04/2018] [Accepted: 10/06/2018] [Indexed: 06/08/2023]
Abstract
People are exposed to chlorinated by-products (CBPs) through the consumption of cold tap water (CTW) (ingestion, inhalation, dermal contact) but also through the use of hot tap water (HTW) in such activities as showering and bathing (inhalation, dermal contact). This study focuses on the impact of residential water heating on CBP levels in tap water. Trihalomethane (THM) and haloacetic acid (HAA) levels were measured in the CTW and HTW of 50 residences located in two distribution systems supplied by chlorinated surface water during summer and winter. Results show important differences between CBP levels measured in cold and hot tap water. However, the magnitude of changes differs according to the specific species of THMs and HAAs, the season, the distribution system and the location within the same distribution system. Residential water heating led to an increase in average THM levels for the two distribution systems studied, which tended to be greater in winter. Residential water heating affected the two main HAA species found in the area studied (dichloroacetic (DCAA) and trichloroacetic (TCAA) acids) differently. In fact, the average DCAA levels increased due to water residential heating while a small change in average levels was observed for TCAA. However, the water heating impact on HAAs (in terms of importance and sometimes of tendency (increase vs. decrease)) may also differed between residences. The influence of seasons on the change in the average DCAA and TCAA levels (in μg/L) from residential water heating was not statistically significant except for TCAA levels in one distribution system. Results show the importance of considering site-specific characteristics of CTW (CBP level, temperature, residual chlorine, etc.) to estimate the levels of CBPs in HTW in CBP exposure assessment studies (and not to generalize for an entire population). The reported data can thus be useful in assessing for exposure to DBPs in epidemiological studies.
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Affiliation(s)
- Christelle Legay
- NSERC Industrial Research Chair on Drinking Water Quality, Université Laval, QC, Canada
| | - Sylvie Leduc
- Canada Research Chair on Water Quality Modeling, Université Laval, QC, Canada
| | - Jean Dubé
- School of Urban and Regional Planning, Université Laval, QC, Canada
| | | | - Manuel J Rodriguez
- NSERC Industrial Research Chair on Drinking Water Quality, Université Laval, QC, Canada.
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5
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Bu Y, Wang L, Chen B, Niu R, Chen Y. Effects of typical water components on the UV 254 photodegradation kinetics of haloacetic acids in water. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2018.02.045] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Marcoux A, Pelletier G, Legay C, Bouchard C, Rodriguez MJ. Behavior of non-regulated disinfection by-products in water following multiple chlorination points during treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 586:870-878. [PMID: 28238378 DOI: 10.1016/j.scitotenv.2017.02.066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/07/2017] [Accepted: 02/07/2017] [Indexed: 06/06/2023]
Abstract
In this study, the behavior of regulated (trihalomethanes-THMs, haloacetic acids-HAAs) and non-regulated (haloacetonitriles-HANs, haloketones-HKs, chloropicrin-CPK) disinfection by-products (DBPs) was investigated during treatment and distribution in a municipal drinking water system that adds chlorine at multiple points within the water treatment plant (WTP). Three to eight locations in the WTP and four locations in the distribution network were sampled weekly for DBP measurements during the warmest period of the year. The results show that most DBPs found in the study area are formed during treatment, not distribution. However, the DBP species studied behave differently during treatment and distribution. Moreover, the location where DBP concentration is the highest in the distribution network differs among species of the same family, especially HAAs and HKs, and between the sampling campaigns. As a result, the relevance of using the sum of the concentrations of the species of the same DBP family to select sampling sites for DBP monitoring is questionable. This study illustrates the difficulties that drinking water supply managers must face to control and monitor the presence of DBPs.
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7
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Serrano M, Montesinos I, Cardador MJ, Silva M, Gallego M. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 517:246-58. [PMID: 25771439 DOI: 10.1016/j.scitotenv.2015.02.070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/19/2015] [Accepted: 02/19/2015] [Indexed: 05/03/2023]
Abstract
In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15-50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%).
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Affiliation(s)
- Maria Serrano
- Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain
| | - Isabel Montesinos
- Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain
| | - M J Cardador
- Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain
| | - Manuel Silva
- Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain
| | - Mercedes Gallego
- Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
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8
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Mercier Shanks C, Sérodes JB, Rodriguez MJ. Spatio-temporal variability of non-regulated disinfection by-products within a drinking water distribution network. WATER RESEARCH 2013; 47:3231-3243. [PMID: 23582352 DOI: 10.1016/j.watres.2013.03.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/19/2013] [Accepted: 03/18/2013] [Indexed: 06/02/2023]
Abstract
The non-regulated disinfection by-products (NrDBP) targeted in this study include four haloacetonitriles (trichloroacetonitrile (TCAN); dichloroacetonitrile (DCAN); bromochloroacetonitrile (BCAN) and dibromoacetonitrile (DBAN)); one halonitromethane (trichloronitromethane, better known under the name chloropicrin (CPK)); and two haloketones (1,1-dichloro-2-propanone (11DCPone) and 1,1,1-trichloro-2-propanone (111TCPone)). This study provides a detailed picture of the spatial and temporal variability of these NrDBP concentrations throughout a drinking water distribution system located in a region with major seasonal climate variations. The results obtained show that the concentrations of the investigated NrDBPs varied significantly according to time and location. The average concentrations of TCAN, DCAN, CKP and 111TCPone were significantly higher in summer. Surprisingly, the average concentrations of 11DCPone were significantly higher in winter. For BCAN and DBAN, the average concentrations observed in winter were higher, but not in a statistically significant way. On the other hand, the four HANs, CPK and 111TCPone generally had spatial profiles involving an increase of the concentrations along the network according to increasing water residence times, whereas 11DCPone overall had a profile where concentrations increased at the beginning of the network, followed by a drop in the concentrations towards the ends of the network. In spite of certain disparities in the individual spatio-temporal variation profiles, strong correlations were generally observed between NrDBPs, and trihalomethanes (THMs) and haloacetic acids (HAAs). Therefore, THMs and HAAs could be good statistical indicators of the presence of NrDBPs in the drinking water of the system under study.
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9
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Ramavandi B, Dobaradaran S, Asgari G, Masoumbeigi H. High potential for the formation of haloacetic acids in the Karoon River water in Iran. ENVIRONMENTAL MONITORING AND ASSESSMENT 2013; 185:3711-3720. [PMID: 22899461 DOI: 10.1007/s10661-012-2822-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Accepted: 08/02/2012] [Indexed: 06/01/2023]
Abstract
The impact of the total organic carbon (TOC), chlorine dosage, water temperature, reaction time, pH, and seasonal variation on the formation of haloacetic acids (HAAs) in the Karoon River in Iran was studied. The results showed that dichloroacetic acid and trichloroacetic acid were the most detected HAA5. The HAA5 formation potential (HAA5FP) levels in the Karoon River water in spring time, when the water TOC content exceeded 4 mg/L, were 1.38 times higher than during the winter season, when the water TOC content was below 3.5 mg/L. There was not a strong correlation between the HAA5FP and the residence time for the Karoon River water. For the range of the water temperatures studied, there was little variation in the HAA5FP in cold water, but in warmer water, the values of the HAA5FP varied quickly.
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Affiliation(s)
- Bahman Ramavandi
- Department of Environmental Health Engineering, Faculty of Health, Bushehr University of Medical Sciences, Bushehr, Iran
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Jang HJ, Choi YJ, Ro HM, Ka JO. Effects of phosphate addition on biofilm bacterial communities and water quality in annular reactors equipped with stainless steel and ductile cast iron pipes. J Microbiol 2012; 50:17-28. [DOI: 10.1007/s12275-012-1040-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 09/16/2011] [Indexed: 10/28/2022]
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Chuang YH, Wang GS, Tung HH. Chlorine residuals and haloacetic acid reduction in rapid sand filtration. CHEMOSPHERE 2011; 85:1146-1153. [PMID: 21974919 DOI: 10.1016/j.chemosphere.2011.08.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 08/15/2011] [Accepted: 08/18/2011] [Indexed: 05/31/2023]
Abstract
It is quite rare to find biodegradation in rapid sand filtration for drinking water treatment. This might be due to frequent backwashes and low substrate levels. High chlorine concentrations may inhibit biofilm development, especially for plants with pre-chlorination. However, in tropical or subtropical regions, bioactivity on the sand surface may be quite significant due to high biofilm development--a result of year-round high temperature. The objective of this study is to explore the correlation between biodegradation and chlorine concentration in rapid sand filters, especially for the water treatment plants that practise pre-chlorination. In this study, haloacetic acid (HAA) biodegradation was found in conventional rapid sand filters practising pre-chlorination. Laboratory column studies and field investigations were conducted to explore the association between the biodegradation of HAAs and chlorine concentrations. The results showed that chlorine residual was an important factor that alters bioactivity development. A model based on filter influent and effluent chlorine was developed for determining threshold chlorine for biodegradation. From the model, a temperature independent chlorine concentration threshold (Cl(threshold)) for biodegradation was estimated at 0.46-0.5mgL(-1). The results imply that conventional filters with adequate control could be conducive to bioactivity, resulting in lower HAA concentrations. Optimizing biodegradable disinfection by-product removal in conventional rapid sand filter could be achieved with minor variation and a lower-than-Cl(threshold) influent chlorine concentration. Bacteria isolation was also carried out, successfully identifying several HAA degraders. These degraders are very commonly seen in drinking water systems and can be speculated as the main contributor of HAA loss.
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Affiliation(s)
- Yi-Hsueh Chuang
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei, Taiwan
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12
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Legay C, Rodriguez MJ, Miranda-Moreno L, Sérodes JB, Levallois P. Multi-level modelling of chlorination by-product presence in drinking water distribution systems for human exposure assessment purposes. ENVIRONMENTAL MONITORING AND ASSESSMENT 2011; 178:507-524. [PMID: 20862540 DOI: 10.1007/s10661-010-1709-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 09/06/2010] [Indexed: 05/29/2023]
Abstract
During drinking water treatment and distribution, chlorine reacts with organic matter occurring in water to form various chlorination by-products (CBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs). This paper presents the occurrence of THMs and HAAs in different water distribution systems (DS) of the same region and their modelling for exposure assessment purposes. This study was conducted in eight DS supplying chlorinated water to the population of Québec City, Canada. These systems differ in type of water source (i.e. surface, ground or mixed water), in treatment applied at the plant, and in size and structure of the DS. Two spatio-temporal databases for THMs and HAAs were implemented, one for model development and the other for model validation. The analysis of the data demonstrates significant seasonal and spatial variations of these compounds. A multi-level statistical modelling approach was applied to estimate the ranges for occurrence of THMs and HAAs in the eight DS (i.e. a single model for the study region for each CBP species). The modelling approach integrates available or easily measurable parameters. For both THMs and HAAs, a two-level model considering a sampling-site random effect was selected among various models initially developed. The model capacity for estimating the presence of THMs and HAAs in drinking water and its usefulness for exposure assessment purposes in the studied region was demonstrated.
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Affiliation(s)
- Christelle Legay
- École supérieure d'aménagement du territoire de l'Université Laval, Pavillon Antoine Savard, Université Laval, Québec City, Québec, Canada, G1K 7P4
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13
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Kristiana I, Joll C, Heitz A. Powdered activated carbon coupled with enhanced coagulation for natural organic matter removal and disinfection by-product control: application in a Western Australian water treatment plant. CHEMOSPHERE 2011; 83:661-667. [PMID: 21353285 DOI: 10.1016/j.chemosphere.2011.02.017] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 02/07/2011] [Accepted: 02/07/2011] [Indexed: 05/30/2023]
Abstract
The removal of organic precursors of disinfection by-products (DBPs), i.e. natural organic matter (NOM), prior to disinfection and distribution is considered as the most effective approach to minimise the formation of DBPs. This study investigated the impact of the addition of powdered activated carbon (PAC) to an enhanced coagulation treatment process at an existing water treatment plant on the efficiency of NOM removal, the disinfection behaviour of the treated water, and the water quality in the distribution system. This is the first comprehensive assessment of the efficacy of plant-scale application of PAC combined with enhanced coagulation on an Australian source water. As a result of the PAC addition, the removal of NOM improved by 70%, which led to a significant reduction (80-95%) in the formation of DBPs. The water quality in the distribution system also improved, indicated by lower concentrations of DBPs in the distribution system and better maintenance of disinfectant residual at the extremities of the distribution system. The efficacy of the PAC treatment for NOM removal was shown to be a function of the characteristics of the NOM and the quality of the source water, as well as the PAC dose. PAC treatment did not have the capacity to remove bromide ion, resulting in the formation of more brominated DBPs. Since brominated DBPs have been found to be more toxic than their chlorinated analogues, their preferential formation upon PAC addition must be considered, especially in source waters containing high concentrations of bromide.
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Affiliation(s)
- Ina Kristiana
- Curtin Water Quality Research Centre, Curtin University, Perth, Western Australia, Australia.
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14
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Jr. GES, Kannappan R, Bayer BM. The nitrification index: A unified concept for quantifying the risk of distribution system nitrification. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/j.1551-8833.2011.tb11383.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Grigorescu AS, Hozalski RM. Modeling HAA biodégradation in biofilters and distribution systems. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/j.1551-8833.2010.tb10150.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Chang HH, Tung HH, Chao CC, Wang GS. Occurrence of haloacetic acids (HAAs) and trihalomethanes (THMs) in drinking water of Taiwan. ENVIRONMENTAL MONITORING AND ASSESSMENT 2010; 162:237-50. [PMID: 19277887 DOI: 10.1007/s10661-009-0792-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Accepted: 01/27/2009] [Indexed: 05/27/2023]
Abstract
In this study, water samples were collected from 86 water treatment plants for analysis of haloacetic acids (HAAs) and trihalomethanes (THMs) from February to March, 2007 and from July to August, 2007. Both seasonal and geographical variations of disinfection by-products (DBPs) in drinking water of Taiwan were presented. The results showed that the five HAA concentrations (HAA5) were 1.0-38.9 microg/L in the winter and 0.2-46.7 microg/L in the summer; and the total THMs were ND-99.4 microg/L in the winter and ND-133.2 microg/L in the summer. For samples taken from the main Taiwan island, dichloroacetic acid (29.4-31.7%) and trichloroacetic acid (25.3-27.6%) were the two major HAA species, and trichloromethane was the major THM species (49.9-62.2%) in finished water. For water treatment plants located on the offshore islands outside of Taiwan, high bromide concentration was found in raw water, and higher percentage of brominated THMs and HAAs were formed in the overall formation. A statistically significant (P < 0.005) logarithmic linear regression model was found to be useful to describe the correlations between TTHM and HAA5 or nine HAAs (HAA5 = 1.219 x TTHM (0.754), R(2) = 0.658; HAA9 = 1.824 x TTHM (0.735), R(2) = 0.678). No apparent difference was observed for DBPs concentrations between finished water and distribution samples in this study.
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Affiliation(s)
- H H Chang
- Institute of Environmental Health, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
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Legay C, Rodriguez MJ, Sérodes JB, Levallois P. Estimation of chlorination by-products presence in drinking water in epidemiological studies on adverse reproductive outcomes: a review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:456-472. [PMID: 19910022 DOI: 10.1016/j.scitotenv.2009.10.047] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 10/13/2009] [Accepted: 10/16/2009] [Indexed: 05/28/2023]
Abstract
Chlorination of drinking water is essential to prevent waterborne disease. However, chlorine reacts with organic matter present in surface waters to form various by-products. In the last decade, several epidemiological studies have been conducted to determine the connection between exposure to these chlorination by-products (CBPs) and human health defects, such as adverse reproductive outcomes. However, the methodology used to assess exposure of pregnant women in these studies had serious limitations, particularly in relation to determining CBP presence in the subject's tap water. The purpose of this paper is to critically review of methods used to evaluate the CBP presence in a subject's tap water for exposure assessment purposes in epidemiological studies focused on adverse reproductive outcomes and CBPs in drinking water. Interest is directed more precisely at space-time features related to CBPs for an optimal estimation of their presence in a subject's tap water.
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Affiliation(s)
- Christelle Legay
- Ecole supérieure d'aménagement du territoire de l'Université Laval, Pavillon Antoine Savard, Université Laval, Québec City, Québec, Canada
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Ye B, Wang W, Yang L, Wei J, E X. Factors influencing disinfection by-products formation in drinking water of six cities in China. JOURNAL OF HAZARDOUS MATERIALS 2009; 171:147-152. [PMID: 19540042 DOI: 10.1016/j.jhazmat.2009.05.117] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 04/16/2009] [Accepted: 05/25/2009] [Indexed: 05/27/2023]
Abstract
Based on the measured chemical and physical data in drinking water from six cities in China, the factors including total organic carbon (TOC), ultraviolet absorbance at 254 nm (UV(254)), pH, applied chlorine dosage, temperature, concentrations of bromide ion and several chemical elements which possibly affect the formation of trihalomethane (THM) and haloacetic acid (HAA) have been studied. The results showed that: in all factors, TOC and UV(254) have definite correlations with total THM, but have nonsignificant relationships with total HAA. In the studied pH range of 6.5-8.5 for drinking water, the total THM concentration increased with the increasing of pH value, but the total HAA concentration slightly decreased. A low but significant relationship (r=0.26, p<0.01) occurred between total THM and applied chlorine dosage. Similar relationship (r=0.21, p<0.01) was found between total HAA and applied chlorine dosage. When the water temperature was low, the variation of THMs and HAAs was little, but in warmer water, the concentration of THMs and HAAs varied quickly. The extent of bromine incorporation into the DBPs increases with increasing bromide ion concentration. Based on the effect of chemical elements for the DBPs remove effect, the polyferric chloride could be a preferred flocculant agent in waterworks.
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Affiliation(s)
- Bixiong Ye
- Institute of Geographical Sciences and Natural Resources Research, CAS, Beijing 100101, China
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Zhang P, Lapara TM, Goslan EH, Xie Y, Parsons SA, Hozalski RM. Biodegradation of haloacetic acids by bacterial isolates and enrichment cultures from drinking water systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:3169-3175. [PMID: 19534130 DOI: 10.1021/es802990e] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Biodegradation is a potentially important loss process for haloacetic acids (HAAs), a class of chlorination byproducts, in water treatment and distribution systems, but little is known about the organisms involved (i.e., identity, substrate range, biodegradation kinetics). In this research, 10 biomass samples (i.e., tap water, distribution system biofilms, and prechlorinated granular activated carbon filters) from nine drinking water systems were used to inoculate a total of thirty enrichment cultures fed monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), or trichloroacetic (TCAA) as sole carbon and energy source. HAA degraders were successfully enriched from the biofilm samples (GAC and distribution system) but rarely from tap water. Half of the MCAA and DCAA enrichment cultures were positive, whereas only one TCAA culture was positive (two were inconclusive). Eight unique HAA-degrading isolates were obtained including several Afipia spp. and a Methylobacterium sp.; all isolates were members of the phylum Proteobacteria. MCAA, monobromoacetic acid (MBAA), and monoiodoacetic acid (MIAA) were rapidly degraded by all isolates, and DCAA and tribromoacetic (TBAA) were also relatively labile. TCAA and dibromoacetic acid (DBAA)were degraded by only three isolates and degradation lagged behind the other HAAs. Detailed DCAA biodegradation kinetics were obtained for two selected isolates and two enrichment cultures. The maximum biomass-normalized degradation rates (Vm) were 0.27 and 0.97 microg DCAA/ microg protein/h for Methylobacterium fujisawaense strain PAWDI and Afipia felis strain EMD2, respectively, which were comparable to the values obtained for the enrichment cultures from which those organisms were isolated (0.39 and 1.37 microg DCAN/microg protein/h, respectively). The half-saturation constant (Km) values ranged from 4.38 to 77.91 microg DCAA/L and the cell yields ranged from 14.4 to 36.1 mg protein/g DCAA.
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Affiliation(s)
- Ping Zhang
- Microbiology and Molecular Genetics, 6120 Biomedical and Physical Sciences, Michigan State University, East Lansing, Michigan 48824, USA
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20
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Chen B, Nam SN, Westerhoff PK, Krasner SW, Amy G. Fate of effluent organic matter and DBP precursors in an effluent-dominated river: a case study of wastewater impact on downstream water quality. WATER RESEARCH 2009; 43:1755-1765. [PMID: 19243808 DOI: 10.1016/j.watres.2009.01.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 12/25/2008] [Accepted: 01/14/2009] [Indexed: 05/27/2023]
Abstract
The impact of treated wastewater discharges on downstream water quality was evaluated in an effluent-dominated stream in the Southwest USA. The fate and transport of effluent organic matter (EfOM) and disinfection by-product (DBP) precursors was studied. Nitrification and biodegradation were important mechanisms. Changes in DBP formation potential along the river appeared to correlate with dissolved organic carbon (DOC) and organic nitrogen concentrations and specific ultraviolet absorbance. The mean oxidation state of carbon (MOC) decreased in value along the river. MOC decreases paralleled decreases in the biodegradability of residual DOC (i.e., lower biodegradable DOC/DOC ratio). The EfOM was biodegradable by up to 40 percent, both in the stream and in a laboratory reactor, and many DBP precursors (e.g., haloacetonitriles, certain nitrosamines) decreased in concentration. Alternatively, the DBP yields for trihalomethanes or haloacetic acids either remained the same or increased slightly, suggesting that these precursors were part of the recalcitrant organic matter (OM).
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Affiliation(s)
- Baiyang Chen
- Chinese Environmental Scholars and Professionals Network, 3004 S 101st Drive, Phoenix, AZ 85353, United States.
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21
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Tung HH, Xie YF. Association between haloacetic acid degradation and heterotrophic bacteria in water distribution systems. WATER RESEARCH 2009; 43:971-978. [PMID: 19070347 DOI: 10.1016/j.watres.2008.11.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 10/19/2008] [Accepted: 11/26/2008] [Indexed: 05/27/2023]
Abstract
The occurrences of trihalomethanes (THMs), haloacetic acids (HAAs) and heterotrophic bacteria were monitored in five small water systems over a nine-month period to investigate the association between HAA degradation and heterotrophic bacteria populations. The sampling sites were chosen to cover the entire distribution network for each system. An inverse association between heterotrophic bacteria and HAA concentrations was found at some locations where chlorine residuals were around or less than 0.3mgL(-1). At other sample locations, where chlorine residuals were higher (over 0.7mgL(-1)), no HAA reduction was observed. A high heterotrophic bacteria count accompanied with a low chlorine residual could be used as an indicator for HAA degradation in distribution systems.
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Affiliation(s)
- Hsin-Hsin Tung
- Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei 10673, Taiwan
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22
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Kim J. Fate of THMs and HAAs in low TOC surface water. ENVIRONMENTAL RESEARCH 2009; 109:158-165. [PMID: 19135189 DOI: 10.1016/j.envres.2008.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Revised: 11/09/2008] [Accepted: 11/11/2008] [Indexed: 05/27/2023]
Abstract
A total of 30 conventional surface water treatment plants (WTPs) implementing prechlorination and postchlorination simultaneously from different regions in Korea were investigated to assess formation and removal of THMs and HAA(5). All water was low in total organic carbon (TOC) ranging from 0.74 to 6.20 mg/L with an average of 1.63 mg/L. The ranges of THMs and HAA(5) levels were 4.5-84.3 microg/L and 1.5-90.8 microg/L, respectively. THMs concentration was more sensitive to water temperature than HAA(5) and the ratio of THMs in summer over winter was 2.06. The sum of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) was 97% of HAA(5). The extent of formation and speciation of DBPs varied greatly by season and geography. The concentration of DCAA and TCAA of the finished water was comparable on a yearly base, but more TCAA was noticed in summer and the opposite trend was noticed in winter. This can be caused by different biodegradability in the sand filter between DCAA and TCAA that formed through prechlorination. Investigation on the removal of preformed DBPs in the GAC filter-adsorber (FA) revealed that breakthrough of THMs and HAA(5) was noticed after 3 months of operation. However, gradual improvement (>90%) in HAA(5) removal was observed again after breakthrough, which could be attributable to biodegradation. Heterotrophic plate counts confirmed active biological activity in the GAC FA.
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Affiliation(s)
- Jinkeun Kim
- Department of Water Supply Operations and Maintenance, K-water (Korea Water Resources Corporation), Daejeon 306-711, Republic of Korea.
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Onstad GD, Weinberg HS, Krasner SW. Occurrence of halogenated furanones in U.S. drinking waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:3341-3348. [PMID: 18522116 DOI: 10.1021/es071374w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Chlorinated and brominated forms of MX (3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone) were detected in the disinfected waters of six pairs of U.S. drinking watertreatment plants, with MX as high as approximately 310 ng/L in finished water. The strength of this study is in its comparison between pairs of plants that drew water from the same or similar watersheds and treated the raw source water with two contrasting disinfection and/or treatment schemes. As expected, the brominated MX-analogues were produced in greater abundance than MX from raw source waters with high bromide concentrations. Disinfection of waters with free chlorine produced more MX-analogues than disinfection with monochloramine. Use of chloramines as the residual disinfectant appeared to stabilize MX-analogues once they were formed. Pretreatment with ozone and biologically active granular activated carbon minimized MX-analogue formation upon subsequent chlorination or chloramination, either because MX precursors were altered by ozone, removed by granular activated carbon, or degraded by biological filtration. Pretreatment with chlorine dioxide did not minimize MX-analogue formation. In plant effluent samples, MX and chloroform were positively correlated (molar R = 0.7, N = 6). Similar formation patterns of MX-analogues, trihalomethanes, and haloacetic acids in these water treatment plants suggest that the three classes of disinfection byproduct follow a common formation mechanism from natural organic matter and chlorine.
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Affiliation(s)
- Gretchen D Onstad
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7431, USA
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Kim J, Kang B. DBPs removal in GAC filter-adsorber. WATER RESEARCH 2008; 42:145-52. [PMID: 17706265 DOI: 10.1016/j.watres.2007.07.040] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 07/20/2007] [Accepted: 07/24/2007] [Indexed: 05/16/2023]
Abstract
A rapid sand filter and granular activated carbon filter-adsorber (GAC FA) were compared in terms of dissolved organic carbon (DOC) and disinfection by-products (DBPs) removal. A water treatment plant (WTP) that had a high ammonia concentration and DOC in raw water, which, in turn, led to a high concentration of DBPs because of a high dose of pre-chlorination, was investigated. To remove DBPs and DOC simultaneously, a conventional rapid sand filter had been retrofitted to a GAC FA at the Buyeo WTP in Korea. The overall removal efficiency of DBPs and DOC was higher in the GAC FA than in the sand filter, as expected. Breakthrough of trihalomethanes (THMs) was noticed after 3 months of GAC FA operation, and then removal of THMs was minimal (<10%). On the other hand, the removal efficiency of five haloacetic acids (HAA(5)) in the GAC FA was better than that of THMs, though adsorption of HAA(5) decreased rapidly after 3.5 months of GAC FA operation. And then, gradual improvement (>90%) in HAA(5) removal efficiency was again observed, which could be attributed to biodegradation. At the early stage of GAC FA operation, HAA(5) removal was largely due to physical adsorption, but later on biodegradation appeared to prevail. Biodegradation of HAA(5) was significantly influenced by water temperature. Similar turbidity removal was noticed in both filters, while better manganese removal was confirmed in the sand filter rather than in the GAC FA.
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Affiliation(s)
- Jinkeun Kim
- Kwater Academy, Kwater (Korea Water Resources Corporation), Daejeon 305-730, Republic of Korea.
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