The effects of disinfectants and plasmid-based antibiotic resistance genes(ARGs)on the growth of microorganisms and the plasmid-mediated transfer of ARGs in the water and biofilm of the drinkingwater distribution syst...The effects of disinfectants and plasmid-based antibiotic resistance genes(ARGs)on the growth of microorganisms and the plasmid-mediated transfer of ARGs in the water and biofilm of the drinkingwater distribution system under simulated conditionswere explored.The heterotrophic plate count of the water in reactors with 0.1 mg/L NaClO and NH_(2)Cl was higher than in the control groups.Therewas no similar phenomenon in biofilm.In thewater of reactors containing NaClO,the aphA and bla geneswere lower than in the antibiotic resistant bacteria group,while both genes were higher in the water of reactors with NH_(2)Cl than in the control group.Chloramine may promote the transfer of ARGs in the water phase.Both genes in the biofilm of the reactors containing chlorine were lower than the control group.Correlation analysis between ARGs and water quality parameters revealed that the copy numbers of the aphA gene were significantly positively correlated with the copy numbers of the bla gene in water and significantly negatively correlated in biofilm(p<0.05).The results of the sequencing assay showed that bacteria in the biofilm,in the presence of disinfectant,were primarily Gram-negative.1.0 mg/L chlorine decreased the diversity of the community in the biofilm.The relative abundance of some bacteria that may undergo transfer increased in the biofilm of the reactor containing 0.1 mg/L chlorine.展开更多
Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environme...Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.展开更多
Pharmaceuticals and personal care products(PPCPs)are receiving attention as emerging pollutants due to their extensive applications and persistent emissions.The Qiantang River Basin,a representative region in eastern ...Pharmaceuticals and personal care products(PPCPs)are receiving attention as emerging pollutants due to their extensive applications and persistent emissions.The Qiantang River Basin,a representative region in eastern China that relies on surface water for drinking purposes,experiences the movement and accumulation of PPCPs in its water and sediment,which can directly affect the safety of drinking water in the basin.This study focuses on the Qiantang River Basin’s surface water,sediment,and drinking water to determine the occurrence and potential risks of 31 PPCPs.It aims to address whether PPCPs in the environment could migrate and accumulate,thereby affecting human health.The findings indicated that PPCPs are ubiquitous in various environmental media,with surface and pore water showing distinct spatial distribution characteristics,specifically,concentrations escalated with urban scale expansion,indicating that domestic sewage discharge is the primary source of PPCP input.Bisphenol A(BPA),ketoprofen(KTP),and diethyltoluamide(DEET)were the primary contaminants.The movement of PPCPs within the surface water-sediment-pore water system was affected by various circumstances.Substances like Sulfamethoxazole(SMX)(RQ>103)and KTP(RQ=22.3)present in surface water and sediment pose significant ecological concerns,and KTP and atrazine(ATZ)(0.6<RQ<2.1)also pose a high risk in drinking water.This study performed an extensive analysis of the distribution and risks associated with typical PPCPs in the Qiantang River Basin,offering a scientific foundation and theoretical support for research on the environmental behavior of PPCPs in this area and the development of targeted pollution control strategies.展开更多
Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking wa...Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.展开更多
The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region w...The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region was investigated using a method combining Google Earth with the field survey.The gaps between management practices and legislation requirements were analyzed.Finally,several countermeasures for water resource protection were proposed as follows:to promote delineation in a more scientific way,to safeguard the sanctity of the law,to make better plan on water saving,and to encourage public participation in supervision and management.展开更多
Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinkin...Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water and are mainly caused by the presence of two semi-volatile compounds - 2-methyl isobomeol （MIB） and geosmin. A review of these two taste and odor causing compounds in drinking water is presented. The sources for the formation of these compounds in water are discussed alongwith the health and regulatory implications. The recent developments in the analysis of MIB/geosmin in water which have allowed for rapid measurements in the nanogram per liter concentrations are also discussed. This review focuses on the relevant treatment alternatives, that are described in detail with emphasis on their respective advantages and problems associated with their implementation in a full- scale facility. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ineffective for removal of M1B/geosmin. Studies have shown powdered activated carbon, ozonation and biofiltration to be effective in treatment of these two compounds. Although some of these technologies are more effective and show more promise than the others, much work remains to be done to optimize these technologies so that they can be retrofitted or installed with minimal impact on the overall operation and effectiveness of the treatment system.展开更多
In recent years, membrane ultrafiltration （UF） of surface water for drinking water treatment has become a more attractive technology worldwide as a possible alternative treatment to conventional clarification. To ev...In recent years, membrane ultrafiltration （UF） of surface water for drinking water treatment has become a more attractive technology worldwide as a possible alternative treatment to conventional clarification. To evaluate the performance of ultrafiltration membranes for treatment of surface water in North China, a 48-m^2 low pressure hollow fiber membrane ultrafiltration pilot plant was constructed. Ultrafiltration was operated in cross-flow and with powdered activated carbon （PAC） adsorption. Turbidity was almost completely removed to less than 0.2 NTU （below Chinese standard 1 NTU）. It was found that PAC addition enhanced organic matter removal. The combined process of PAC/UF allowed to 41% removal of CODMn, 46% removal of DOC and 57% decrease in UV254 absorbance. The elimination of particles, from average 12000/ml in the raw water to approximately 15/ml in the permeated, was observed. When PAC concentration was below 30 mg/L, backwashing could recovery the membrane flux with backwash interval/backwashing duration of 1/30.展开更多
Taste and odor （T＆O） problems in drinking water frequently occur because of many compounds present in the water, of which trans-1,10-dimethyl-trans-9-decalol （geosrnin） and 2-methylisoborneol （MIB） are well-kno...Taste and odor （T＆O） problems in drinking water frequently occur because of many compounds present in the water, of which trans-1,10-dimethyl-trans-9-decalol （geosrnin） and 2-methylisoborneol （MIB） are well-known. In this study, a fast and effective method was established for simultaneous determination of 10 T＆O compounds, including geosmin, MIB, 2,4,6-trichloroanisole （TCA）, 2-methylbenzofuran, 2-isopropyl-3-methoxypyrazine （IPMP）, 2-isobutyl-3-methoxypyrazine （IBMP）, cis-3-hexenyl acetate, trans,trans-2,4-heptadienal, trans, cis-2,6-nonadienal, and trans-2-decenal in water samples by headspace solid-phase microextraction （SPME） coupled with gas chromatography-mass spectrometry. An orthogonal array experimental design was used to optimize the effects of SPME fiber, extraction temperature, stirring rate, NaC1 content, extraction time, and desorption time. The limits of detection ranged from 0.1 to 73 ng/L were lower than or close to the odor threshold concentrations （OTCs）. All the 10 T＆O compounds were detected in the 14 water samples including surface water, treatment process water and tap water, taken from a waterworks in Lianyungang City, China. MIB and geosmin were detected in most samples at low concentration. Six T＆O compounds （IPMP, IBMP, trans,cis-2,6-nonadienal, 2-methylbenzofuran, trans-2-decenal, and TCA） were effectively decreased in water treatment process （sedimentation and filtration） that is different from cis-3-hexenyl acetate, MIB and geosmin. It is noted that the TCA concentrations at 15.9-122.3 ng/L and the trans,cis-2,6-nonadienal concentrations at 79.9-190.1 ng/L were over 10 times higher than their OTCs in tap water. The variation of the analytes in the all water samples, especially distribution system indicated that distribution system cannot be ignored as a T＆O compounds source.展开更多
The method for detecting N-nitrosodimethylamine （NDMA） in drinking water using ultra performance liquid chromatography （UPLC） coupled with tandem mass spectrometry （MS/MS） was improved by optimizing the clean-up...The method for detecting N-nitrosodimethylamine （NDMA） in drinking water using ultra performance liquid chromatography （UPLC） coupled with tandem mass spectrometry （MS/MS） was improved by optimizing the clean-up procedure to remove the matrix interference in pretreatment process, and was then applied to a survey of NDMA in both raw and finished water samples from five water treatment plants in South China. The NDMA concentrations ranged from 4.7 to 15.1 ng/L in raw water samples, and from 4.68 to 46.9 ng/L in finished water. The NDMA concentration in raw water was found to be related with nitrite concentration, and during the treatment, the NDMA concentration increased following ozonation but decreased after subsequent activated carbon treatment.展开更多
The characteristics of ammonia in drinking water sources in China were evaluated during 2005-2009. The spatial distribution and seasonal changes of ammonia in different types of drinking water sources of 22 provinces,...The characteristics of ammonia in drinking water sources in China were evaluated during 2005-2009. The spatial distribution and seasonal changes of ammonia in different types of drinking water sources of 22 provinces, 5 autonomous regions and 4 municipalities were investigated. The levels of ammonia in drinking water sources follow the order of fiver 〉 lake/reservoir 〉 groundwater. The levels of ammonia concentration in river sources gradually decreased from 2005 to 2008, while no obvious change was observed in the lakes/reservoirs and groundwater drinking water sources. The proportion of the type of drinking water sources is different in different regions. In river drinking water sources, the ammonia level was varied in different regions and changed seasonally. The highest value and wide range of annual ammonia was found in South East region, while the lowest value was found in Southwest region. In lake/reservoir drinking water sources, the ammonia levels were not varied obviously in different regions. In underground drinking water sources, the ammonia levels were varied obviously in different regions due to the geological permeability and the natural features of regions. In the drinking water sources with higher ammonia levels, there are enterprises and wastewater drainages in the protected areas of the drinking water sources.展开更多
The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources （surface and groundwater） collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential ...The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources （surface and groundwater） collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake （CDI） and health risk index （HRI） were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr 〉 Mn 〉 Ni 〉 Zn 〉 Cd 〉 Cu 〉 Pb and Cd 〉 Ni 〉 Mn 〉 Cr 〉 Cu 〉 Pb 〉 Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.展开更多
The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors （ARs）. The corrosion process and most probable num...The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors （ARs）. The corrosion process and most probable number （MPN） analysis indicated that the higher content of iron-oxidizing bacteria and iron-reducing bacteria in biofilms of the AR treated with O3/Cl2 induced higher Fe304 formation in corrosion scales. These corrosion scales became more stable than the ones that formed in the AR treated with Cl2 alone. O3/Cl2 disinfection inhibited corrosion and iron release efficiently by changing the content of corrosion-related bacteria. Moreover, ozone disinfection inactivated or damaged the opportunistic pathogens due to its strong oxidizing properties. The damaged bacteria resulting from initial ozone treatment were inactivated by the subsequent chlorine disinfection. Compared with the AR treated with Cl2 alone, the opportunistic pathogens M. auium and L. pneumophila were not detectable in effluents of the AR treated with O3/Cl2, and decreased to （4.60 ± 0.14） and （3.09 ± 0.12） loglo （gene copies/g corrosion scales） in biofilms, respectively. The amoeba counts were also lower in the AR treated with O3/Cl2. Therefore, O3/Cl2 disinfection can effectively control opportunistic pathogens in effluents and biofilms of an AR used as a model for a drinking water distribution system.展开更多
Objective To investigate the association of microcystin (MC) in drinking water with the incidence of colorectal cancer. Methods The study was designed as a retrospective cohort. Eight townships or towns were random...Objective To investigate the association of microcystin (MC) in drinking water with the incidence of colorectal cancer. Methods The study was designed as a retrospective cohort. Eight townships or towns were randomly selected as the study sites in Haining City of Zhejiang Province, China. 408 cases of colon and rectum carcinomas diagnosed from 1977 to 1996 in the study sites were included, and a survey on types of drinking water of these patients was conducted. Samples of different water sources (well, tap, river and pond) were collected separately and microcystin concentrations were determined by indirect competitive ELISA method. Results The incidence rate of colorectal cancer was significantly higher in population who drank river and pond water than those who drank well and tap water. Compared to well water, the relative risk (RR) for colorectal cancer was 1.88 (tap), 7.94 (river) and 7.70 (pond) respectively. The positive rate (>50 pg/mL) of microcystin in samples of well, tap, river and pond water was 0, 0, 36.23% and 17.14% respectively. The concentration of microcystin in river and pond water was significantly higher than that in well and tap water (P<0.01). Spearman rank correlation analysis showed that in the study sites, the microcystin concentration of river and pond water was positively associated with the incidence of colorectal cancer (rs= 0.881, P<0.01). Conclusions The types of drinking water are positively associated with the incidence of colorectal cancer in the study sites, and this may be related to microcystin contamination of drinking water. Further biological study is needed to support the possible causative role of mycrocystin in carcinogenesis of colon and rectum.展开更多
An embedded reservoir that provides an efficient nutrient removal system protects drinking water.However,embedded reservoirs are rarely used in eutrophic shallow lakes because of their undetermined nutrient retention ...An embedded reservoir that provides an efficient nutrient removal system protects drinking water.However,embedded reservoirs are rarely used in eutrophic shallow lakes because of their undetermined nutrient retention efficiency and unknown effects by the phytoplankton community.In this study,we aim to investigate the nutrient retention and algae succession in an embedded reservoir and adjacent wetland from April 2017 to September 2018 in the eastern part of Lake Taihu,China.More than 40%of total phosphorus(TP)and 45%of particulate phosphorous entering the reservoir were retained semiannually,and the highest TP removal efficiency was achieved in the reservoir during autumn with an average value of 53.3%±9.9%.The overall nitrogen retention efficiency(21.7%±37.8%)was lower than that of TP(41.8%±27.8%).Similar trends were obtained in the wetland area.An important pathway for phosphorus removal is through particulate matter retention.Our study revealed that nutrient retention mechanisms in the reservoir were primarily via macrophyte absorption,particulate substance sedimentation,and prolonged water residence time.Consequently,the phytoplankton biomass(Chl-a)in the reservoir decreased(from 48.0 to 25.2μg/L)and water transparency improved,due to the decreased P level and transformation of the phytoplankton group into simple structures with good ecological status.Therefore,the combination of embedded reservoir and constructed wetland ecosystem can be used successfully to protect surface water.The results will be advantageous to groups seeking to preserve drinking water sources.展开更多
Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to de...Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to detect the possible presence of these substances in drinking water, aiming to define the most relevant parameters to detect these substances, which particularly affect the development and reproduction of zebrafish. To this end, batches of30 embryos with the chorion intact were cultured in drinking waters from different sources,throughout their full life-cycle up to 5 months, in 20 L tanks. Six replicates were performed in all water groups, with a total of 24 aquariums. Two generations（F0 and F1） were studied and the following parameters were tested： in the F0 generation, survival and abnormality rates evaluated at 5 dpf（days post-fertilization） and at 5 mpf（months post-fertilization）,the onset of spawning and the fertility rate from 3 mpf to 5 mpf, and the sex ratio and underdeveloped specimens at 5 mpf. Furthermore, in the F0 offspring（F1）, survival and abnormality rates were evaluated at 5 dpf and the hatching rate at 72 hpf. These results revealed that the hatching rate is the most sensitive parameter to distinguish different levels of effects between waters during the early life stages, whereas the rate of underdeveloped specimens is more suitable at later life stages. Regarding adult reproduction, fertility rate was the most sensitive parameter. The possible reversibility or accumulative nature of such effects will be studied in future work.展开更多
An increasing number of industrial, agricultural, and commercial chemicals in the aquatic environment leads to various deleterious effects on organisms, which is becoming an increasingly serious problem in China. In t...An increasing number of industrial, agricultural, and commercial chemicals in the aquatic environment leads to various deleterious effects on organisms, which is becoming an increasingly serious problem in China. In this study, the comet assay was conducted to investigate the genotoxicity to human body caused by organic concentrates in the drinking water sources of Nanjing City from Yangtze River of China, and health and ecology risk due to expose to these organic pollutants were evaluated with the multimedia environmental assessment system （MEAS）. For all the water samples, they were collected from four different locations in the drinking water sourcr samples, es of Nanjing City. The results of the comet assay showed that all the organic concentrates from the water samples could induce different levels DNA damages on human peripheral blood lymphocytes, and a statistically significant difference （p〈0.01） was observed compared with the solvent control, which demonstrated the genotoxicity was in existence. According to the ambient severity （AS） of individual compound, we had sorted out the main organic pollutants in the drinking water source of the four waterworks, and the results showed that there was some potential hazard to human body for all the source water, namely the total ambient severity （TAS） of health for each water source was more than 1. However, the TAS of ecology for each water source was less than 1, which indicated that it was safe to ecology. The results of this investigation demonstrate the application of the comet assay and the MEAS in aquatic environmental monitoring studies, and the comet assay found to be fast, sensitive, and suitable for genotoxicity monitoring programs of drinking water source.展开更多
Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are c...Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are critical to manage the risks posed by ARGs.This study summarizes the prevalence of ARGs in raw water sources and treated drinking water worldwide.In addition,the removal efficiency of ARGs and related mechanisms by different DWTPs are reviewed.Abiotic and biotic factors that affect ARGs elimination are also discussed.The data on presence of ARGs in drinking water help come to the conclusion that ARGs pollution is prevalent and deserves a high priority.Generally,DWTPs indeed achieve ARGs removal,but some biological treatment processes such as biological activated carbon filtration may promote antibiotic resistance due to the enrichment of ARGs in the biofilm.The finding that disinfection and membrane filtration are superior to other DWTPs adds weight to the advice that DWTPs should adopt multiple disinfection barriers,as well as keep sufficient chlorine residuals to inhibit re-growth of ARGs during subsequent distribution.Mechanistically,DWTPs obtain direct and inderect ARGs reduction through DNA damage and interception of host bacterias of ARGs.Thus,escaping of intracellular ARGs to extracellular environment,induced by DWTPs,should be advoided.This review provides the theoretical support for developping efficient reduction technologies of ARGs.Future study should focus on ARGs controlling in terms of transmissibility or persistence through DWTPs due to their biological related nature and ubiquitous presence of biofilm in the treatment unit.展开更多
This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species...This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the effects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L （calculated as TOC）. Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5-7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the effects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5-7.5 were recommended during drinking water treatment.展开更多
The elemental composition and bacteria attached in particles were investigated during granular activated carbon （GAC） filtration.The experimental results showed that trapped influent particles could form new,larger ...The elemental composition and bacteria attached in particles were investigated during granular activated carbon （GAC） filtration.The experimental results showed that trapped influent particles could form new,larger particles on GAC surface.The sloughing of individuals off GAC surface caused an increase in effluent particles in the size range from 5 to 25 μm.The selectivity for element removal in GAC filters caused an increasing proportion of metallic elements in the effluent particles.The distribution of molar ratio indicated a complicated composition for large particles,involving organic and inorganic substances.The organic proportion accounted for 40% of total carbon attached to the particles.Compared with dissolved carbon,there was potential for the formation of trihalomethanes by organic carbon attached to particles,especially for those with size larger than 10 μm.The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 μm.The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection.The residual attached bacteria after chorine disinfection was increased to 10 2-10 3 CFU/mL within 24 hours at 25°C.展开更多
基金supported by the Natural Science Foundation of China(No.52070145,51778453).
文摘The effects of disinfectants and plasmid-based antibiotic resistance genes(ARGs)on the growth of microorganisms and the plasmid-mediated transfer of ARGs in the water and biofilm of the drinkingwater distribution system under simulated conditionswere explored.The heterotrophic plate count of the water in reactors with 0.1 mg/L NaClO and NH_(2)Cl was higher than in the control groups.Therewas no similar phenomenon in biofilm.In thewater of reactors containing NaClO,the aphA and bla geneswere lower than in the antibiotic resistant bacteria group,while both genes were higher in the water of reactors with NH_(2)Cl than in the control group.Chloramine may promote the transfer of ARGs in the water phase.Both genes in the biofilm of the reactors containing chlorine were lower than the control group.Correlation analysis between ARGs and water quality parameters revealed that the copy numbers of the aphA gene were significantly positively correlated with the copy numbers of the bla gene in water and significantly negatively correlated in biofilm(p<0.05).The results of the sequencing assay showed that bacteria in the biofilm,in the presence of disinfectant,were primarily Gram-negative.1.0 mg/L chlorine decreased the diversity of the community in the biofilm.The relative abundance of some bacteria that may undergo transfer increased in the biofilm of the reactor containing 0.1 mg/L chlorine.
基金supported by the Shanghai 3-year Public Health Action Plan(grant number:GWVI-11.1-39).
文摘Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.
基金jointly supported by the Open Research Fund of State Environmental Protection Key Laboratory of Drinking Water Source Protection,Chinese Research Academy of Environmental Sciences(2022YYSYKFYB07)the Fundamental Research Funds for the Central Publicinterest Scientific Institution(2022YSKY-07)the China Geological Survey Project(DD20211414).
文摘Pharmaceuticals and personal care products(PPCPs)are receiving attention as emerging pollutants due to their extensive applications and persistent emissions.The Qiantang River Basin,a representative region in eastern China that relies on surface water for drinking purposes,experiences the movement and accumulation of PPCPs in its water and sediment,which can directly affect the safety of drinking water in the basin.This study focuses on the Qiantang River Basin’s surface water,sediment,and drinking water to determine the occurrence and potential risks of 31 PPCPs.It aims to address whether PPCPs in the environment could migrate and accumulate,thereby affecting human health.The findings indicated that PPCPs are ubiquitous in various environmental media,with surface and pore water showing distinct spatial distribution characteristics,specifically,concentrations escalated with urban scale expansion,indicating that domestic sewage discharge is the primary source of PPCP input.Bisphenol A(BPA),ketoprofen(KTP),and diethyltoluamide(DEET)were the primary contaminants.The movement of PPCPs within the surface water-sediment-pore water system was affected by various circumstances.Substances like Sulfamethoxazole(SMX)(RQ>103)and KTP(RQ=22.3)present in surface water and sediment pose significant ecological concerns,and KTP and atrazine(ATZ)(0.6<RQ<2.1)also pose a high risk in drinking water.This study performed an extensive analysis of the distribution and risks associated with typical PPCPs in the Qiantang River Basin,offering a scientific foundation and theoretical support for research on the environmental behavior of PPCPs in this area and the development of targeted pollution control strategies.
基金supported by the National Key Research and Development Program of China(No.2019YFD1100203).
文摘Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.
文摘The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region was investigated using a method combining Google Earth with the field survey.The gaps between management practices and legislation requirements were analyzed.Finally,several countermeasures for water resource protection were proposed as follows:to promote delineation in a more scientific way,to safeguard the sanctity of the law,to make better plan on water saving,and to encourage public participation in supervision and management.
文摘Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water and are mainly caused by the presence of two semi-volatile compounds - 2-methyl isobomeol （MIB） and geosmin. A review of these two taste and odor causing compounds in drinking water is presented. The sources for the formation of these compounds in water are discussed alongwith the health and regulatory implications. The recent developments in the analysis of MIB/geosmin in water which have allowed for rapid measurements in the nanogram per liter concentrations are also discussed. This review focuses on the relevant treatment alternatives, that are described in detail with emphasis on their respective advantages and problems associated with their implementation in a full- scale facility. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ineffective for removal of M1B/geosmin. Studies have shown powdered activated carbon, ozonation and biofiltration to be effective in treatment of these two compounds. Although some of these technologies are more effective and show more promise than the others, much work remains to be done to optimize these technologies so that they can be retrofitted or installed with minimal impact on the overall operation and effectiveness of the treatment system.
基金Project supported by the Hi-Tech Research and Development Program (863) of China (No. 2002AA601140)the Science and Technology Commission of Shanghai Municipality (No. 052312008)the National Eleven Five-Year Scientific and Technical Support Plans (No. 2006BAJ08B06, 2006BAJ08B02).
文摘In recent years, membrane ultrafiltration （UF） of surface water for drinking water treatment has become a more attractive technology worldwide as a possible alternative treatment to conventional clarification. To evaluate the performance of ultrafiltration membranes for treatment of surface water in North China, a 48-m^2 low pressure hollow fiber membrane ultrafiltration pilot plant was constructed. Ultrafiltration was operated in cross-flow and with powdered activated carbon （PAC） adsorption. Turbidity was almost completely removed to less than 0.2 NTU （below Chinese standard 1 NTU）. It was found that PAC addition enhanced organic matter removal. The combined process of PAC/UF allowed to 41% removal of CODMn, 46% removal of DOC and 57% decrease in UV254 absorbance. The elimination of particles, from average 12000/ml in the raw water to approximately 15/ml in the permeated, was observed. When PAC concentration was below 30 mg/L, backwashing could recovery the membrane flux with backwash interval/backwashing duration of 1/30.
基金supported by the National Natural Science Foundation of China(No.21007077,51290283)the Ministry of Water Resources’ Special Funds for Scientific Research on Public Causes(No.201201032)
文摘Taste and odor （T＆O） problems in drinking water frequently occur because of many compounds present in the water, of which trans-1,10-dimethyl-trans-9-decalol （geosrnin） and 2-methylisoborneol （MIB） are well-known. In this study, a fast and effective method was established for simultaneous determination of 10 T＆O compounds, including geosmin, MIB, 2,4,6-trichloroanisole （TCA）, 2-methylbenzofuran, 2-isopropyl-3-methoxypyrazine （IPMP）, 2-isobutyl-3-methoxypyrazine （IBMP）, cis-3-hexenyl acetate, trans,trans-2,4-heptadienal, trans, cis-2,6-nonadienal, and trans-2-decenal in water samples by headspace solid-phase microextraction （SPME） coupled with gas chromatography-mass spectrometry. An orthogonal array experimental design was used to optimize the effects of SPME fiber, extraction temperature, stirring rate, NaC1 content, extraction time, and desorption time. The limits of detection ranged from 0.1 to 73 ng/L were lower than or close to the odor threshold concentrations （OTCs）. All the 10 T＆O compounds were detected in the 14 water samples including surface water, treatment process water and tap water, taken from a waterworks in Lianyungang City, China. MIB and geosmin were detected in most samples at low concentration. Six T＆O compounds （IPMP, IBMP, trans,cis-2,6-nonadienal, 2-methylbenzofuran, trans-2-decenal, and TCA） were effectively decreased in water treatment process （sedimentation and filtration） that is different from cis-3-hexenyl acetate, MIB and geosmin. It is noted that the TCA concentrations at 15.9-122.3 ng/L and the trans,cis-2,6-nonadienal concentrations at 79.9-190.1 ng/L were over 10 times higher than their OTCs in tap water. The variation of the analytes in the all water samples, especially distribution system indicated that distribution system cannot be ignored as a T＆O compounds source.
基金supported by the National Special Funding Project for Water Pollution Control and Management of China(No.2009ZX07419-001,2008ZX07421-004)the Chinese Academy of Sciences Major Projects of Knowledge Innovation Program(No.kzcx-yw-06-02)the Special Co-construction Project of Beijing Municipal Commission of Education
文摘The method for detecting N-nitrosodimethylamine （NDMA） in drinking water using ultra performance liquid chromatography （UPLC） coupled with tandem mass spectrometry （MS/MS） was improved by optimizing the clean-up procedure to remove the matrix interference in pretreatment process, and was then applied to a survey of NDMA in both raw and finished water samples from five water treatment plants in South China. The NDMA concentrations ranged from 4.7 to 15.1 ng/L in raw water samples, and from 4.68 to 46.9 ng/L in finished water. The NDMA concentration in raw water was found to be related with nitrite concentration, and during the treatment, the NDMA concentration increased following ozonation but decreased after subsequent activated carbon treatment.
基金supported by the Water Pollution Control and Management (No. 2009ZX07419-002-2,2009ZX07419-003)the International Science and Technology Cooperation Program of China (No.2007DFA90510)
文摘The characteristics of ammonia in drinking water sources in China were evaluated during 2005-2009. The spatial distribution and seasonal changes of ammonia in different types of drinking water sources of 22 provinces, 5 autonomous regions and 4 municipalities were investigated. The levels of ammonia in drinking water sources follow the order of fiver 〉 lake/reservoir 〉 groundwater. The levels of ammonia concentration in river sources gradually decreased from 2005 to 2008, while no obvious change was observed in the lakes/reservoirs and groundwater drinking water sources. The proportion of the type of drinking water sources is different in different regions. In river drinking water sources, the ammonia level was varied in different regions and changed seasonally. The highest value and wide range of annual ammonia was found in South East region, while the lowest value was found in Southwest region. In lake/reservoir drinking water sources, the ammonia levels were not varied obviously in different regions. In underground drinking water sources, the ammonia levels were varied obviously in different regions due to the geological permeability and the natural features of regions. In the drinking water sources with higher ammonia levels, there are enterprises and wastewater drainages in the protected areas of the drinking water sources.
基金provided by the Chinese Academy of Sciences and the World Academy of Sciences under FR Number:3240255020
文摘The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources （surface and groundwater） collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake （CDI） and health risk index （HRI） were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr 〉 Mn 〉 Ni 〉 Zn 〉 Cd 〉 Cu 〉 Pb and Cd 〉 Ni 〉 Mn 〉 Cr 〉 Cu 〉 Pb 〉 Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.
基金supported by the National Natural Science Foundation of China(No.51290281)the project of Chinese Academy of Sciences(No.QYZDY-SSW-DQC004)the Federal Department of Chinese Water Control and Treatment(Nos.2017ZX07108,2017ZX07501002)
文摘The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors （ARs）. The corrosion process and most probable number （MPN） analysis indicated that the higher content of iron-oxidizing bacteria and iron-reducing bacteria in biofilms of the AR treated with O3/Cl2 induced higher Fe304 formation in corrosion scales. These corrosion scales became more stable than the ones that formed in the AR treated with Cl2 alone. O3/Cl2 disinfection inhibited corrosion and iron release efficiently by changing the content of corrosion-related bacteria. Moreover, ozone disinfection inactivated or damaged the opportunistic pathogens due to its strong oxidizing properties. The damaged bacteria resulting from initial ozone treatment were inactivated by the subsequent chlorine disinfection. Compared with the AR treated with Cl2 alone, the opportunistic pathogens M. auium and L. pneumophila were not detectable in effluents of the AR treated with O3/Cl2, and decreased to （4.60 ± 0.14） and （3.09 ± 0.12） loglo （gene copies/g corrosion scales） in biofilms, respectively. The amoeba counts were also lower in the AR treated with O3/Cl2. Therefore, O3/Cl2 disinfection can effectively control opportunistic pathogens in effluents and biofilms of an AR used as a model for a drinking water distribution system.
基金This project was supported by the Scientific Foundation of Ministry of Health China (No. 96-1-350)
文摘Objective To investigate the association of microcystin (MC) in drinking water with the incidence of colorectal cancer. Methods The study was designed as a retrospective cohort. Eight townships or towns were randomly selected as the study sites in Haining City of Zhejiang Province, China. 408 cases of colon and rectum carcinomas diagnosed from 1977 to 1996 in the study sites were included, and a survey on types of drinking water of these patients was conducted. Samples of different water sources (well, tap, river and pond) were collected separately and microcystin concentrations were determined by indirect competitive ELISA method. Results The incidence rate of colorectal cancer was significantly higher in population who drank river and pond water than those who drank well and tap water. Compared to well water, the relative risk (RR) for colorectal cancer was 1.88 (tap), 7.94 (river) and 7.70 (pond) respectively. The positive rate (>50 pg/mL) of microcystin in samples of well, tap, river and pond water was 0, 0, 36.23% and 17.14% respectively. The concentration of microcystin in river and pond water was significantly higher than that in well and tap water (P<0.01). Spearman rank correlation analysis showed that in the study sites, the microcystin concentration of river and pond water was positively associated with the incidence of colorectal cancer (rs= 0.881, P<0.01). Conclusions The types of drinking water are positively associated with the incidence of colorectal cancer in the study sites, and this may be related to microcystin contamination of drinking water. Further biological study is needed to support the possible causative role of mycrocystin in carcinogenesis of colon and rectum.
基金supported by the Bureau of Water Resource of Wujiang District(No.SZSY2018WJG032A)the Joint Innovative and Technological Research Projects from the Ministry of Science and Technology of the People’s Republic of China(No.2016YFE0115800)+1 种基金the China Major Science and Technology Program for Water Pollution Control and Treatment(No.2017ZX07205002)Shanghai Institute of Pollution Control and Ecological Security and the Key Laboratory of Yangtze River Water Environment,Ministry of Education,China
文摘An embedded reservoir that provides an efficient nutrient removal system protects drinking water.However,embedded reservoirs are rarely used in eutrophic shallow lakes because of their undetermined nutrient retention efficiency and unknown effects by the phytoplankton community.In this study,we aim to investigate the nutrient retention and algae succession in an embedded reservoir and adjacent wetland from April 2017 to September 2018 in the eastern part of Lake Taihu,China.More than 40%of total phosphorus(TP)and 45%of particulate phosphorous entering the reservoir were retained semiannually,and the highest TP removal efficiency was achieved in the reservoir during autumn with an average value of 53.3%±9.9%.The overall nitrogen retention efficiency(21.7%±37.8%)was lower than that of TP(41.8%±27.8%).Similar trends were obtained in the wetland area.An important pathway for phosphorus removal is through particulate matter retention.Our study revealed that nutrient retention mechanisms in the reservoir were primarily via macrophyte absorption,particulate substance sedimentation,and prolonged water residence time.Consequently,the phytoplankton biomass(Chl-a)in the reservoir decreased(from 48.0 to 25.2μg/L)and water transparency improved,due to the decreased P level and transformation of the phytoplankton group into simple structures with good ecological status.Therefore,the combination of embedded reservoir and constructed wetland ecosystem can be used successfully to protect surface water.The results will be advantageous to groups seeking to preserve drinking water sources.
文摘Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to detect the possible presence of these substances in drinking water, aiming to define the most relevant parameters to detect these substances, which particularly affect the development and reproduction of zebrafish. To this end, batches of30 embryos with the chorion intact were cultured in drinking waters from different sources,throughout their full life-cycle up to 5 months, in 20 L tanks. Six replicates were performed in all water groups, with a total of 24 aquariums. Two generations（F0 and F1） were studied and the following parameters were tested： in the F0 generation, survival and abnormality rates evaluated at 5 dpf（days post-fertilization） and at 5 mpf（months post-fertilization）,the onset of spawning and the fertility rate from 3 mpf to 5 mpf, and the sex ratio and underdeveloped specimens at 5 mpf. Furthermore, in the F0 offspring（F1）, survival and abnormality rates were evaluated at 5 dpf and the hatching rate at 72 hpf. These results revealed that the hatching rate is the most sensitive parameter to distinguish different levels of effects between waters during the early life stages, whereas the rate of underdeveloped specimens is more suitable at later life stages. Regarding adult reproduction, fertility rate was the most sensitive parameter. The possible reversibility or accumulative nature of such effects will be studied in future work.
基金The Society Development Foundation of Jiangsu Province (No. BS2001039)
文摘An increasing number of industrial, agricultural, and commercial chemicals in the aquatic environment leads to various deleterious effects on organisms, which is becoming an increasingly serious problem in China. In this study, the comet assay was conducted to investigate the genotoxicity to human body caused by organic concentrates in the drinking water sources of Nanjing City from Yangtze River of China, and health and ecology risk due to expose to these organic pollutants were evaluated with the multimedia environmental assessment system （MEAS）. For all the water samples, they were collected from four different locations in the drinking water sourcr samples, es of Nanjing City. The results of the comet assay showed that all the organic concentrates from the water samples could induce different levels DNA damages on human peripheral blood lymphocytes, and a statistically significant difference （p〈0.01） was observed compared with the solvent control, which demonstrated the genotoxicity was in existence. According to the ambient severity （AS） of individual compound, we had sorted out the main organic pollutants in the drinking water source of the four waterworks, and the results showed that there was some potential hazard to human body for all the source water, namely the total ambient severity （TAS） of health for each water source was more than 1. However, the TAS of ecology for each water source was less than 1, which indicated that it was safe to ecology. The results of this investigation demonstrate the application of the comet assay and the MEAS in aquatic environmental monitoring studies, and the comet assay found to be fast, sensitive, and suitable for genotoxicity monitoring programs of drinking water source.
基金supported by the National Science and Technology Major Projects for Water Pollution Control and Treatment(No.2017ZX07201-003)the Science and Technology Program of Zhejiang Province(No.LQ19E080023)the Zhejiang Public welfare technology research program(No.GG21E080021)。
文摘Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are critical to manage the risks posed by ARGs.This study summarizes the prevalence of ARGs in raw water sources and treated drinking water worldwide.In addition,the removal efficiency of ARGs and related mechanisms by different DWTPs are reviewed.Abiotic and biotic factors that affect ARGs elimination are also discussed.The data on presence of ARGs in drinking water help come to the conclusion that ARGs pollution is prevalent and deserves a high priority.Generally,DWTPs indeed achieve ARGs removal,but some biological treatment processes such as biological activated carbon filtration may promote antibiotic resistance due to the enrichment of ARGs in the biofilm.The finding that disinfection and membrane filtration are superior to other DWTPs adds weight to the advice that DWTPs should adopt multiple disinfection barriers,as well as keep sufficient chlorine residuals to inhibit re-growth of ARGs during subsequent distribution.Mechanistically,DWTPs obtain direct and inderect ARGs reduction through DNA damage and interception of host bacterias of ARGs.Thus,escaping of intracellular ARGs to extracellular environment,induced by DWTPs,should be advoided.This review provides the theoretical support for developping efficient reduction technologies of ARGs.Future study should focus on ARGs controlling in terms of transmissibility or persistence through DWTPs due to their biological related nature and ubiquitous presence of biofilm in the treatment unit.
基金supported by the National Natural Science Foundation of China (No.50838005)the Changjiang Scholars and Innovative Research Team in University(No.IRT0853)the American Aluminum Foundation
文摘This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the effects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L （calculated as TOC）. Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5-7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the effects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5-7.5 were recommended during drinking water treatment.
基金supported by the National Natural Science Foundation of China (No. 50778062)the Hi-Tech Research and Development Program (863) of China (No.2006AA06Z311)
文摘The elemental composition and bacteria attached in particles were investigated during granular activated carbon （GAC） filtration.The experimental results showed that trapped influent particles could form new,larger particles on GAC surface.The sloughing of individuals off GAC surface caused an increase in effluent particles in the size range from 5 to 25 μm.The selectivity for element removal in GAC filters caused an increasing proportion of metallic elements in the effluent particles.The distribution of molar ratio indicated a complicated composition for large particles,involving organic and inorganic substances.The organic proportion accounted for 40% of total carbon attached to the particles.Compared with dissolved carbon,there was potential for the formation of trihalomethanes by organic carbon attached to particles,especially for those with size larger than 10 μm.The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 μm.The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection.The residual attached bacteria after chorine disinfection was increased to 10 2-10 3 CFU/mL within 24 hours at 25°C.
