Objective Since haloacetic acids (HAAs), which are nonvolatile and of high carcinogenic risk, are common species of chlorinated disinfection by-products(DBPs) in drinking water, and little has been known in China, it...Objective Since haloacetic acids (HAAs), which are nonvolatile and of high carcinogenic risk, are common species of chlorinated disinfection by-products(DBPs) in drinking water, and little has been known in China, it is necessary to make a survey about the kinds and levels of HAAs in drinking water of the nation. Method HAAs were analyzed using gas chromatography with electron capture detector(GC/ECD) and relatively complex pretreatment process of sample was applied. Five main cities in different areas of China were chosen in the survey. Results Studies showed that the main species of HAAs in drinking water in China were DCAA and TCAA, ranging from 0.4 礸/L to 12.85 礸/L and from 0.56 礸/L to 10.98 礸/L, respectively. MBAA and DBAA were also detected in one city, ranging from 2.20 礸/L to 4.95 礸/L and 1.10 礸/L to 2.81 礸/L, respectively. Therefore, the contents of HAAs varied, usually no more than 25 礸/L. Based on the acquired data to date, it is known that the concentrations of HAAs in drinking water in China were surely under the limits of Sanitary Standard for Drinking Water Quality (China, 2001). Conclusion A wider survey of HAAs in drinking water should be conducted throughout the nation to get adequate data and information, the ultimate aim of which is to control HAAs pollution and keep the balance between microbiological safety insurance and chemical risk control, minimize the formation of DBPs and ensure the safety of water supply at the same time.展开更多
The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hosp...The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples' turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 μg/L and 1.30 μg/L, respectively, and the other three acids are ranging from 0.48 to 0.82μg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid was the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively.展开更多
To guarantee the safety of drinking water quality after chlorination,the formation,distribution and factors influencing the concentrations of haloacetic acids(HAAs)in a water distribution system(WDS) were investigated...To guarantee the safety of drinking water quality after chlorination,the formation,distribution and factors influencing the concentrations of haloacetic acids(HAAs)in a water distribution system(WDS) were investigated both on a full-scale WDS(FWDS) and pilot-scale WDS(PWDS) within a city in northern China.The results of both investigations showed that trichloroacetic acid(TCAA) and dichloroacetic acid(DCAA) were the dominating types of HAAs.In the FWDS,variations in the HAA content showed negative correlations with total residual chlorine,pH and non-purgeable organic carbon(NPOC)and positive correlations with temperature and UV_(254).In the PWDS,the concentration of HAAs after rechlorination followed the rule of 'first rise and then fall';therefore,locating an appropriate rechlorination point and lowering the single chlorine dosage could be used as effective measures to control the HAA content in WDSs.展开更多
Haloacetic acids(HAAs) are formed during the chlorination of drinking water,which are harmful to people′s health due to their carcinogenic and mutagenic effects. In the present study,a detection method combining meth...Haloacetic acids(HAAs) are formed during the chlorination of drinking water,which are harmful to people′s health due to their carcinogenic and mutagenic effects. In the present study,a detection method combining methyl tert -butyl ether(MtBE) extraction with acid catalysis and gas chromatography coupled with an electron capture detector(GC/ECD) was developed for determining HAAs. The detection limit of this method(MDL) and relative standard deviation(RSD) were below 0.37 μg/L and 6.2%,respectively. The laboratory chlorination experiments were conducted with the purpose of investigating the influences of reaction time,temperature,UV_ 254 ,bromide and ammonia-nitrogen on the formation of HAAs. The results show that the formation amount of HAAs increases with increasing reaction time and temperature,respectively;and there exists a linear relationship between the formation of HAAs and UV_ 254 . The formation amount of HAAs decreases first and then increases as the bromide ion concentration increases,and adding NH +_4 is a possible way to control the formation of HAAs.展开更多
The previous research on the occurrence of disinfection by-products (DBPs) in drinking water has focused on trihalomethane (THMs) formation and evolution, in particular within distribution systems. In this study, the ...The previous research on the occurrence of disinfection by-products (DBPs) in drinking water has focused on trihalomethane (THMs) formation and evolution, in particular within distribution systems. In this study, the variability of occurrence of haloacetic acids (HAAs) before and after treatment was investigated. The investigation focused on point–to-point fluctuations of HAAs in different treatment stages within the treatment plant. The research was also carried out to find out the possible sources for the presence of HAAs before chlorination in the raw water. The results showed that the presence of HAAs from the raw water point until the filtered water occurred due to industrial waste and sewages. Subsequent formation of HAAs from treated point until service reservoir due to disinfection. The HAAs concentration was the highest and most variable in the plant where level of DBP precursor indicators and the chlorine dose were both higher. However, HAAs level and in particular dichloroacetic acids (DCAA) (the preponderant HAAs species in the waters under study), trichloroacetic acids (TCAA) decreased dramatically during filtration, very probably because of the biodegradation within the filter. An ANNOVA test was used to evaluate the level of significance of HAAs between treated water and service reservoir outlet water.展开更多
Human neural stem cells(h NSCs) are a useful tool to assess the developmental effects of various environmental contaminants; however, the application of h NSCs to evaluate water disinfection byproducts(DBPs) is sc...Human neural stem cells(h NSCs) are a useful tool to assess the developmental effects of various environmental contaminants; however, the application of h NSCs to evaluate water disinfection byproducts(DBPs) is scarce. Comprehensive toxicological results are essential to the prioritization of DBPs for further testing and regulation. Therefore, this study examines the effects of DBPs on the proliferation and differentiation of h NSCs. Prior to DBP treatment, characteristic protein markers of h NSCs from passages 3 to 6 were carefully examined and it was determined that h NSCs passaged 3 or 4 times maintained stem cell characteristics and can be used for DBP analysis. Two regulated DBPs, monobromoacetic acid(BAA) and monochloroacetic acid(CAA), and two emerging DBPs, 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ) and 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ), were chosen for h NSC treatment. Both 2,6-DBBQ and 2,6-DCBQ induced cell cycle arrest at S-phase at concentrations up to 1 μmol/L. Comparatively, BAA and CAA at 0.5 μmol/L affected neural differentiation. These results suggest DBP-dependent effects on h NSC proliferation and differentiation. The DBP-induced cell cycle arrest and inhibition of normal h NSC differentiation demonstrate the need to assess the developmental neurotoxicity of DBPs.展开更多
The objective of this study is to investigate the occurrence of haloacetic acids (HAAs), a group of disinfection byproducts, in swimming pool and spa water. The samples were collected from six indoor pools, six outd...The objective of this study is to investigate the occurrence of haloacetic acids (HAAs), a group of disinfection byproducts, in swimming pool and spa water. The samples were collected from six indoor pools, six outdoor pools and three spas in Pennsylvania, the United States, and from five outdoor pools and nine indoor pools in Beijing, China. Five HAAs (HAA5), including monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid were analyzed. Total chlorine, pH and total organic carbon concentration were analyzed as well. Results indicated that the levels of HAA5 in swimming pools and spas in the United States ranged from 70 to 3980μg·L^-1, with an arithmetic average at 1440μg·L^-1 and a median level at 1150μg·L^-1. These levels are much higher than the levels reported in chlorinated drinking water and are likely due to organic matters released from swimmers' bodies. The levels of HAA5 in swimming pools in China ranged from 13 to 332μg·L^-1, with an arithmetic average at 117μg·L^-1 and a median level at 114μg·L^-1. The lower HAA levels in swimming pools in China were due to the lower chlorine residuals. Results from this study can help water professionals to better understand the formation and stability of HAAs in chlorinated water and assess risks associated with exposures to HAAs in swimming pools and spas.展开更多
A method for sensitive determination of five priority haloacetic acids in drinking water has been developed for the first time based on electromembrane extraction(EME)prior to CZE with capacitively coupled contactless...A method for sensitive determination of five priority haloacetic acids in drinking water has been developed for the first time based on electromembrane extraction(EME)prior to CZE with capacitively coupled contactless conductivity detection(CZE-C^(4)D).The target analytes were extracted from 10 mL of the sample solution(donor phase),through the supported liquid membrane(using a polypropylene membrane supporting 1-octanol),and into 10μL of 50 mmol/L NaAc solution(acceptor phase).The extracted solution was directly analyzed by CZE-C^(4)D without de-rivatization.Several factors that affect separation,detection and extraction efficiency were investigated.Under the optimum conditions,five haloacetic acids(monochloroacetic acid,dichloroacetic acid,trichloroacetic acid,mono-bromoacetic acid,and dibromoacetic acid)could be well separated from other components coexisting in water samples within 23 min,exhibiting a linear calibration over two orders of magnitude(r≥0.9943);the enrichment factors at 430-671 were obtained in a 30 min of extraction,and the limits of detection were in the range of 0.17-0.61 ng/mL.The intraday relative standard deviations for peak areas investigated at 10 ng/mL were between 1.2%and 9.7%for the combined EME-CZE-C^(4)D procedure.This approach offers an attractive alternative to the officially proposed method for purified drinking water analysis,which requires derivatization procedure prior to gas chromatography analysis.展开更多
The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution syst...The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg.m), showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 μg/L.展开更多
Raw water from the Songhua River was treated by four types of coagulants, ferric chloride (FeC13), aluminum sulfate (A12(504)3), polyaluminum chloride (PACl) and composite polyaluminum (HPAC), in order to re...Raw water from the Songhua River was treated by four types of coagulants, ferric chloride (FeC13), aluminum sulfate (A12(504)3), polyaluminum chloride (PACl) and composite polyaluminum (HPAC), in order to remove dissolved organic matter (DOM). Considering the disinfection byproduct (DBP) precursor treatability, DOM was divided into five chemical fractions based on resin adsorption. Trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP) were measured for each fraction. The results showed that hydrophobic acids (HoA), hydrophilic matter (HIM) and hydrophobic neutral (HoN) were the dominant fractions. Although both HoN and HoA were the main THM precursors, the contribution for THMFP changed after coagulation. Additionally, HoA and HiM were the main HAA precursors, while the contribution of HoN to HAAFP significantly increased after coagulation. HoM was more easily removed than HiM, no matter which coagulant was used, especially under enhanced coagulation conditions. DOC removal was highest for enhanced coagulation using FeCl3 while DBPFP was lowest using PAC1. This could indicate that not all DOC fractions contained the precursors of DBPs. Reduction of THMFP and HAAFP by PAC1 under enhanced coagulation could reach 51% and 59% respectively.展开更多
Eight typical drinking water supplies in China were selected in this study.Both source and tap water were used to investigate the occurrence of chlorinated disinfection byproducts(DBPs),and seasonal variation in the...Eight typical drinking water supplies in China were selected in this study.Both source and tap water were used to investigate the occurrence of chlorinated disinfection byproducts(DBPs),and seasonal variation in the concentrations of trihalomethanes(THMs) of seven water sources was compared.The results showed that the pollution level for source water in China,as shown by DBP formation potential,was low.The most encountered DBPs were chloroform,dichloroacetic acid,trichloroacetic acid,and chlorodibromoacetic acid.The concentration of every THMs and haloacetic acid(HAA) compound was under the limit of standards for drinking water quality.The highest total THMs concentrations were detected in spring.展开更多
The effects of biologically active carbon(BAC)filtration on haloacetic acid(HAA)levels in plant effluents and distribution systems were investigated using the United States Environmental Protection Agency’s Informati...The effects of biologically active carbon(BAC)filtration on haloacetic acid(HAA)levels in plant effluents and distribution systems were investigated using the United States Environmental Protection Agency’s Information Collection Rule(ICR)database.The results showed that average HAA5 concentrations in all locations were 20.4μg·L^(-1)and 29.6μg·L^(-1)in ICR plants with granular activated carbon(GAC)and ICR plants without GAC process,respectively.For plants without GAC,the highest HAA levels were observed in the quarters of April to June and July to September.However,for plants with GAC,the highest HAA levels were observed in the quarters of April to June and January to March.This HAA level profile inversely correlated well with water temperature,or biologic activity.For GAC plants,simulated distribution samples matched well with distribution system equivalent samples for Cl3AA and THMs.For plants with and without GAC,simulated distribution samples overestimated readily biodegradable HAAs in distribution systems.The study indicated that through HAA biodegradation,GAC process plays an important role in lowering HAA levels in finished drinking water.展开更多
Anthropogenic organics are known to be responsible for the formation of harmful disinfection byproducts (DBPs) in swimming pool water (SPW). The research explored an important scenario of SPW with no additional anthro...Anthropogenic organics are known to be responsible for the formation of harmful disinfection byproducts (DBPs) in swimming pool water (SPW). The research explored an important scenario of SPW with no additional anthropogenic organic input. With stimulations by residual chlorine or additional chlorine and extended incubation, the formation of DBPs, especially chlorofonn, was significantly induced. Similar observations were found by investigating synthetic SPW made with sweat and urine. The presence of urine led to a massive fbmiation of chloroform, as noted by an approximate 19-fbld increase after 165-day incubation with a shock chlorine dose. The research suggests that consistent residual chlorine and long water retention as two typical features of SPW could unlock the DBP fbnnation potential of anthropogenic organics. Thus, limiting the introduction of anthropogenic organics may not have an immediate effect on reducing DBP levels, because their reactions with chlorine can be slow and long-lasting. Pool management should prioritize on control of urine and improving air ventilation. This work is useful to deepen understandings about DBP formation in SPW and provide implications for pool management and prospective legislation.展开更多
In the 1980 s, a case–control epidemiologic study was conducted in Iowa(USA) to analyze the association between exposure to disinfection by-products(DBPs) and bladder cancer risk. Trihalomethanes(THMs), the mos...In the 1980 s, a case–control epidemiologic study was conducted in Iowa(USA) to analyze the association between exposure to disinfection by-products(DBPs) and bladder cancer risk. Trihalomethanes(THMs), the most commonly measured and dominant class of DBPs in drinking water, served as a primary metric and surrogate for the full DBP mixture.Average THM exposure was calculated, based on rough estimates of past levels in Iowa. To reduce misclassification, a follow-up study was undertaken to improve estimates of past THM levels and to re-evaluate their association with cancer risk. In addition, the risk associated with haloacetic acids, another class of DBPs, was examined. In the original analysis, surface water treatment plants were assigned one of two possible THM levels depending on the point of chlorination. The re-assessment considered each utility treating surface or groundwater on a case-by-case basis. Multiple treatment/disinfection scenarios and water quality parameters were considered with actual DBP measurements to develop estimates of past levels. The highest annual average THM level in the re-analysis was156 μg/L compared to 74 μg/L for the original analysis. This allowed the analysis of subjects exposed at higher levels(〉 96 μg/L). The re-analysis established a new approach, based on case studies and an understanding of the water quality and operational parameters that impact DBP formation, for determining historical exposure.展开更多
文摘Objective Since haloacetic acids (HAAs), which are nonvolatile and of high carcinogenic risk, are common species of chlorinated disinfection by-products(DBPs) in drinking water, and little has been known in China, it is necessary to make a survey about the kinds and levels of HAAs in drinking water of the nation. Method HAAs were analyzed using gas chromatography with electron capture detector(GC/ECD) and relatively complex pretreatment process of sample was applied. Five main cities in different areas of China were chosen in the survey. Results Studies showed that the main species of HAAs in drinking water in China were DCAA and TCAA, ranging from 0.4 礸/L to 12.85 礸/L and from 0.56 礸/L to 10.98 礸/L, respectively. MBAA and DBAA were also detected in one city, ranging from 2.20 礸/L to 4.95 礸/L and 1.10 礸/L to 2.81 礸/L, respectively. Therefore, the contents of HAAs varied, usually no more than 25 礸/L. Based on the acquired data to date, it is known that the concentrations of HAAs in drinking water in China were surely under the limits of Sanitary Standard for Drinking Water Quality (China, 2001). Conclusion A wider survey of HAAs in drinking water should be conducted throughout the nation to get adequate data and information, the ultimate aim of which is to control HAAs pollution and keep the balance between microbiological safety insurance and chemical risk control, minimize the formation of DBPs and ensure the safety of water supply at the same time.
基金Project supported by the Hi-Tech Research and Development Program(863) of China (No. 2003AA601130).
文摘The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples' turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 μg/L and 1.30 μg/L, respectively, and the other three acids are ranging from 0.48 to 0.82μg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid was the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively.
基金supported by the National Natural Science Foundation of China (No.51278333)Tianjin Science Association Key Project (033113111)
文摘To guarantee the safety of drinking water quality after chlorination,the formation,distribution and factors influencing the concentrations of haloacetic acids(HAAs)in a water distribution system(WDS) were investigated both on a full-scale WDS(FWDS) and pilot-scale WDS(PWDS) within a city in northern China.The results of both investigations showed that trichloroacetic acid(TCAA) and dichloroacetic acid(DCAA) were the dominating types of HAAs.In the FWDS,variations in the HAA content showed negative correlations with total residual chlorine,pH and non-purgeable organic carbon(NPOC)and positive correlations with temperature and UV_(254).In the PWDS,the concentration of HAAs after rechlorination followed the rule of 'first rise and then fall';therefore,locating an appropriate rechlorination point and lowering the single chlorine dosage could be used as effective measures to control the HAA content in WDSs.
文摘Haloacetic acids(HAAs) are formed during the chlorination of drinking water,which are harmful to people′s health due to their carcinogenic and mutagenic effects. In the present study,a detection method combining methyl tert -butyl ether(MtBE) extraction with acid catalysis and gas chromatography coupled with an electron capture detector(GC/ECD) was developed for determining HAAs. The detection limit of this method(MDL) and relative standard deviation(RSD) were below 0.37 μg/L and 6.2%,respectively. The laboratory chlorination experiments were conducted with the purpose of investigating the influences of reaction time,temperature,UV_ 254 ,bromide and ammonia-nitrogen on the formation of HAAs. The results show that the formation amount of HAAs increases with increasing reaction time and temperature,respectively;and there exists a linear relationship between the formation of HAAs and UV_ 254 . The formation amount of HAAs decreases first and then increases as the bromide ion concentration increases,and adding NH +_4 is a possible way to control the formation of HAAs.
文摘The previous research on the occurrence of disinfection by-products (DBPs) in drinking water has focused on trihalomethane (THMs) formation and evolution, in particular within distribution systems. In this study, the variability of occurrence of haloacetic acids (HAAs) before and after treatment was investigated. The investigation focused on point–to-point fluctuations of HAAs in different treatment stages within the treatment plant. The research was also carried out to find out the possible sources for the presence of HAAs before chlorination in the raw water. The results showed that the presence of HAAs from the raw water point until the filtered water occurred due to industrial waste and sewages. Subsequent formation of HAAs from treated point until service reservoir due to disinfection. The HAAs concentration was the highest and most variable in the plant where level of DBP precursor indicators and the chlorine dose were both higher. However, HAAs level and in particular dichloroacetic acids (DCAA) (the preponderant HAAs species in the waters under study), trichloroacetic acids (TCAA) decreased dramatically during filtration, very probably because of the biodegradation within the filter. An ANNOVA test was used to evaluate the level of significance of HAAs between treated water and service reservoir outlet water.
基金supported by funding from the Natural Sciences and Engineering Research Council (NSERC) of Canada, Alberta Innovates-Energy and Environmental Solutions, and Alberta Health
文摘Human neural stem cells(h NSCs) are a useful tool to assess the developmental effects of various environmental contaminants; however, the application of h NSCs to evaluate water disinfection byproducts(DBPs) is scarce. Comprehensive toxicological results are essential to the prioritization of DBPs for further testing and regulation. Therefore, this study examines the effects of DBPs on the proliferation and differentiation of h NSCs. Prior to DBP treatment, characteristic protein markers of h NSCs from passages 3 to 6 were carefully examined and it was determined that h NSCs passaged 3 or 4 times maintained stem cell characteristics and can be used for DBP analysis. Two regulated DBPs, monobromoacetic acid(BAA) and monochloroacetic acid(CAA), and two emerging DBPs, 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ) and 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ), were chosen for h NSC treatment. Both 2,6-DBBQ and 2,6-DCBQ induced cell cycle arrest at S-phase at concentrations up to 1 μmol/L. Comparatively, BAA and CAA at 0.5 μmol/L affected neural differentiation. These results suggest DBP-dependent effects on h NSC proliferation and differentiation. The DBP-induced cell cycle arrest and inhibition of normal h NSC differentiation demonstrate the need to assess the developmental neurotoxicity of DBPs.
基金Acknowledgements This research was supported by the National Natural Science Foundation of China (Grant No. 51290284) and Ministry of Education and Science of Spain.
文摘The objective of this study is to investigate the occurrence of haloacetic acids (HAAs), a group of disinfection byproducts, in swimming pool and spa water. The samples were collected from six indoor pools, six outdoor pools and three spas in Pennsylvania, the United States, and from five outdoor pools and nine indoor pools in Beijing, China. Five HAAs (HAA5), including monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid were analyzed. Total chlorine, pH and total organic carbon concentration were analyzed as well. Results indicated that the levels of HAA5 in swimming pools and spas in the United States ranged from 70 to 3980μg·L^-1, with an arithmetic average at 1440μg·L^-1 and a median level at 1150μg·L^-1. These levels are much higher than the levels reported in chlorinated drinking water and are likely due to organic matters released from swimmers' bodies. The levels of HAA5 in swimming pools in China ranged from 13 to 332μg·L^-1, with an arithmetic average at 117μg·L^-1 and a median level at 114μg·L^-1. The lower HAA levels in swimming pools in China were due to the lower chlorine residuals. Results from this study can help water professionals to better understand the formation and stability of HAAs in chlorinated water and assess risks associated with exposures to HAAs in swimming pools and spas.
基金supported by the National Natural Science Foundation of China(No.21205042)the Open Funds of the State Key Laboratory of Electroanalytical Chemistry(No.SKLEAC201508)the Special Funds for the Development of Major Scientific Instruments and Equipment(No.2011YQ15007205).
文摘A method for sensitive determination of five priority haloacetic acids in drinking water has been developed for the first time based on electromembrane extraction(EME)prior to CZE with capacitively coupled contactless conductivity detection(CZE-C^(4)D).The target analytes were extracted from 10 mL of the sample solution(donor phase),through the supported liquid membrane(using a polypropylene membrane supporting 1-octanol),and into 10μL of 50 mmol/L NaAc solution(acceptor phase).The extracted solution was directly analyzed by CZE-C^(4)D without de-rivatization.Several factors that affect separation,detection and extraction efficiency were investigated.Under the optimum conditions,five haloacetic acids(monochloroacetic acid,dichloroacetic acid,trichloroacetic acid,mono-bromoacetic acid,and dibromoacetic acid)could be well separated from other components coexisting in water samples within 23 min,exhibiting a linear calibration over two orders of magnitude(r≥0.9943);the enrichment factors at 430-671 were obtained in a 30 min of extraction,and the limits of detection were in the range of 0.17-0.61 ng/mL.The intraday relative standard deviations for peak areas investigated at 10 ng/mL were between 1.2%and 9.7%for the combined EME-CZE-C^(4)D procedure.This approach offers an attractive alternative to the officially proposed method for purified drinking water analysis,which requires derivatization procedure prior to gas chromatography analysis.
基金supported by the High-Tech Research and Development Program (863) of China(No.2007AA06A414)the National Basic Research Development Program (973) of China(No. 2006CB403306)the Chinese Academy of Sciences Major Projects of Knowledge Innovation Program(No. KZCX1-YW-06)
文摘The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg.m), showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 μg/L.
基金supported by the National Natural Science Foundation of China (No. 51025830, 51008293)the Funds for the Creative Research Groups of China (No. 51221892)
文摘Raw water from the Songhua River was treated by four types of coagulants, ferric chloride (FeC13), aluminum sulfate (A12(504)3), polyaluminum chloride (PACl) and composite polyaluminum (HPAC), in order to remove dissolved organic matter (DOM). Considering the disinfection byproduct (DBP) precursor treatability, DOM was divided into five chemical fractions based on resin adsorption. Trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP) were measured for each fraction. The results showed that hydrophobic acids (HoA), hydrophilic matter (HIM) and hydrophobic neutral (HoN) were the dominant fractions. Although both HoN and HoA were the main THM precursors, the contribution for THMFP changed after coagulation. Additionally, HoA and HiM were the main HAA precursors, while the contribution of HoN to HAAFP significantly increased after coagulation. HoM was more easily removed than HiM, no matter which coagulant was used, especially under enhanced coagulation conditions. DOC removal was highest for enhanced coagulation using FeCl3 while DBPFP was lowest using PAC1. This could indicate that not all DOC fractions contained the precursors of DBPs. Reduction of THMFP and HAAFP by PAC1 under enhanced coagulation could reach 51% and 59% respectively.
基金supported by the National Natural Science Foundation of China(No.51025830,50921064)the S&T Research Project of Guangdong Province(No. 2009A080303007)the Hi-Tech Research and Development Program(863) of China(No.2006AA06Z312)
文摘Eight typical drinking water supplies in China were selected in this study.Both source and tap water were used to investigate the occurrence of chlorinated disinfection byproducts(DBPs),and seasonal variation in the concentrations of trihalomethanes(THMs) of seven water sources was compared.The results showed that the pollution level for source water in China,as shown by DBP formation potential,was low.The most encountered DBPs were chloroform,dichloroacetic acid,trichloroacetic acid,and chlorodibromoacetic acid.The concentration of every THMs and haloacetic acid(HAA) compound was under the limit of standards for drinking water quality.The highest total THMs concentrations were detected in spring.
基金This study was supported by“Taiwan NSC”(No.96-2221-E-002-051)and“USEPA Small Public Water Technology Assistance Center”.
文摘The effects of biologically active carbon(BAC)filtration on haloacetic acid(HAA)levels in plant effluents and distribution systems were investigated using the United States Environmental Protection Agency’s Information Collection Rule(ICR)database.The results showed that average HAA5 concentrations in all locations were 20.4μg·L^(-1)and 29.6μg·L^(-1)in ICR plants with granular activated carbon(GAC)and ICR plants without GAC process,respectively.For plants without GAC,the highest HAA levels were observed in the quarters of April to June and July to September.However,for plants with GAC,the highest HAA levels were observed in the quarters of April to June and January to March.This HAA level profile inversely correlated well with water temperature,or biologic activity.For GAC plants,simulated distribution samples matched well with distribution system equivalent samples for Cl3AA and THMs.For plants with and without GAC,simulated distribution samples overestimated readily biodegradable HAAs in distribution systems.The study indicated that through HAA biodegradation,GAC process plays an important role in lowering HAA levels in finished drinking water.
文摘Anthropogenic organics are known to be responsible for the formation of harmful disinfection byproducts (DBPs) in swimming pool water (SPW). The research explored an important scenario of SPW with no additional anthropogenic organic input. With stimulations by residual chlorine or additional chlorine and extended incubation, the formation of DBPs, especially chlorofonn, was significantly induced. Similar observations were found by investigating synthetic SPW made with sweat and urine. The presence of urine led to a massive fbmiation of chloroform, as noted by an approximate 19-fbld increase after 165-day incubation with a shock chlorine dose. The research suggests that consistent residual chlorine and long water retention as two typical features of SPW could unlock the DBP fbnnation potential of anthropogenic organics. Thus, limiting the introduction of anthropogenic organics may not have an immediate effect on reducing DBP levels, because their reactions with chlorine can be slow and long-lasting. Pool management should prioritize on control of urine and improving air ventilation. This work is useful to deepen understandings about DBP formation in SPW and provide implications for pool management and prospective legislation.
基金the Water Research Foundationthe U.S.Environmental Protection Agency (USEPA)the Division of Cancer Epidemiology and Genetics of the National Cancer Institute (NCI) and CHEEC for their support of the Iowa epidemiologic study
文摘In the 1980 s, a case–control epidemiologic study was conducted in Iowa(USA) to analyze the association between exposure to disinfection by-products(DBPs) and bladder cancer risk. Trihalomethanes(THMs), the most commonly measured and dominant class of DBPs in drinking water, served as a primary metric and surrogate for the full DBP mixture.Average THM exposure was calculated, based on rough estimates of past levels in Iowa. To reduce misclassification, a follow-up study was undertaken to improve estimates of past THM levels and to re-evaluate their association with cancer risk. In addition, the risk associated with haloacetic acids, another class of DBPs, was examined. In the original analysis, surface water treatment plants were assigned one of two possible THM levels depending on the point of chlorination. The re-assessment considered each utility treating surface or groundwater on a case-by-case basis. Multiple treatment/disinfection scenarios and water quality parameters were considered with actual DBP measurements to develop estimates of past levels. The highest annual average THM level in the re-analysis was156 μg/L compared to 74 μg/L for the original analysis. This allowed the analysis of subjects exposed at higher levels(〉 96 μg/L). The re-analysis established a new approach, based on case studies and an understanding of the water quality and operational parameters that impact DBP formation, for determining historical exposure.