The Key Laboratory of Drinking Water Science and Technology(DWST),a key branch of the Laboratory of Environmental Aquatic Chemistry,has been staying on the cutting edge in the field of drinking water since its establi...The Key Laboratory of Drinking Water Science and Technology(DWST),a key branch of the Laboratory of Environmental Aquatic Chemistry,has been staying on the cutting edge in the field of drinking water since its establishment in 2014.The main goal of this laboratory is to ensure drinking water safety,particularly with regard to public health.To achieve this goal,the research teams have been making great efforts to develop water quality criteria and standards for health risk control;establish stateof-the-art theoretical and technological systems for pollution control and water purification;form an innovation layout from foundation to application,from engineering to management,and from water source to tap;and provide systematic solutions to forward-looking and universal scientific problems in drinking water safety.The laboratory mainly focuses on four research fields:(1)methodology for water quality risk assessment;(2)combined pollution of water source and ecological restoration;(3)new theories and technologies for water purification;and(4)chemical/biological processes and regulations of water distribution systems.展开更多
Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficult...Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.展开更多
A wide range of compounds with various structural features can cause taste and odor(T&O)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In th...A wide range of compounds with various structural features can cause taste and odor(T&O)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction(LLE) with gas chromatography-triple quadrupole tandem mass spectrometry(GC–MS/MS)was established to simultaneously analyze 51 odor-causing compounds in drinking water,including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4,were used to correct the variations in recovery, and five isotope-labeled internal standards(4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity(R2> 0.99, level = 7),and method detection limits(MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants(0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible(RSD < 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants(DWTPs) were analyzed by this method.According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.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
Maintaining a residual disinfectant/oxidant(e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, suc...Maintaining a residual disinfectant/oxidant(e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, such as hypobromous acid(HOBr), can be formed during chlorination of bromide-containing waters. The decay of oxidants and formation of disinfection byproducts(DBPs) due to the interaction between oxidants and selected metal oxides were studied. Selected metal oxides generally enhanced the decay of these halogencontaining oxidants via three pathways:(1) catalytic disproportionation to yield an oxidized form of halogen(i.e., halate) and reduced form(halide for chlorine and bromine or chlorite for chlorine dioxide),(2) oxygen formation, and(3) oxidation of a metal in a reduced form(e.g., cuprous oxide) to a higher oxidation state. Cupric oxide(Cu O) and nickel oxide(Ni O)showed significantly strong abilities for the first pathway, and oxygen formation was a side reaction. Cuprous oxide can react with oxidants via the third pathway, while goethite was not involved in these reactions. The ability of Cu O on catalytic disproportionation of HOBr remained stable up to four cycles. In chlorination process, bromate formation tends to be important(exceeding 10 μg/L) when initial bromide concentration is above 400 μg/L in the presence of dissolved organic matter. Increasing initial bromide concentrations increased the formation of DBPs and calculated cytotoxicity, and the maximum was observed at p H8.6 during chlorination process. Therefore, the possible disinfectant loss and DBP formation should be carefully considered in drinking water distribution systems.展开更多
Shijiuyang Constructed Wetland（110 hm^2） is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water ...Shijiuyang Constructed Wetland（110 hm^2） is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond–wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the ＂hidden＂ diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited.展开更多
Many problems in drinking water distribution systems(DWDSs)are caused by microbe,such as biofilm formation,biocorrosion and opportunistic pathogens growth.More iron release from corrosion scales may induce red water.B...Many problems in drinking water distribution systems(DWDSs)are caused by microbe,such as biofilm formation,biocorrosion and opportunistic pathogens growth.More iron release from corrosion scales may induce red water.Biofilm played great roles on the corrosion.The iron-oxidizing bacteria(IOB)promoted corrosion.However,when iron-reducing bacteria(IRB)and nitrate-reducing bacteria(NRB)became the main bacteria in biofilm,they could induce iron redox cycling in corrosion process.This process enhanced the precipitation of iron oxides and formation of more Fe3 O4 in corrosion scales,which inhibited corrosion effectively.Therefore,the IRB and NRB in the biofilm can reduce iron release and red water occurrence.Moreover,there are many opportunistic pathogens in biofilm of DWDSs.The opportunistic pathogens growth in DWDSs related to the bacterial community changes due to the effects of micropollutants.Micropollutants increased the number of bacteria with antibiotic resistance genes(ARGs).Furthermore,extracellular polymeric substances(EPS)production was increased by the antibiotic resistant bacteria,leading to greater bacterial aggregation and adsorption,increasing the chlorine-resistance capability,which was responsible for the enhancement of the particle-associated opportunistic pathogens in DWDSs.Moreover,O3-biological activated carbon filtration-UV-Cl2 treatment could be used to control the iron release,red water occurrence and opportunistic pathogens growth in DWDSs.展开更多
The survival and development of human society highly depends on the water availability. Driven by the growth of population and economy, global water demand has increased more than eightfold since the 1900s. Meanwhile,...The survival and development of human society highly depends on the water availability. Driven by the growth of population and economy, global water demand has increased more than eightfold since the 1900s. Meanwhile, the commonly deteriorated freshwater quality cause a large proportion of available water resources unsuitable for human uses. This inter-coupled challenge of insufficient water quantity and inadequate water quality has rendered water scarcity a widespread problem in many parts of the world.展开更多
The cement mortar lining(CML)of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use,but the behavioral characteristics of different elements release from th...The cement mortar lining(CML)of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use,but the behavioral characteristics of different elements release from the CML in this stage is still unclear.In this study,dynamic immersion experiments with new cement mortar lined ductile iron pipe reactors were conducted under different feed water hardness and alkalinity conditions.The results showed that the release of alkaline substances from the CML at the initial stage of use could strongly influence the pH of water,which consequently greatly impacted the release/precipitation behaviors of calcium,aluminum and silicon.The pH and aluminum concentration of the effluent water could reach 11.5 and 700μg/L within 24 hr of hydraulic retention time,respectively,under conditions of relatively lower hardness and alkalinity.Due to the pH elevation,calcium carbonate precipitation could occur even at much lower feed water alkalinity.Whereas the aluminum and silicon could keep release from the CML in soluble form at different hardness and alkalinity levels,and their release rate depended on the amount of calcium carbonate precipitation.Thus,aluminum and silicon were more suitable as indicators of the corrosion intensity at the initial stage of CML use rather than the traditional calcium carbonate precipitation potential.Appropriate feed water hardness and alkalinity levels for mitigating the initial intense corrosion of CML were proposed:hardness>40 mg/L(CaCO_(3)),alkalinity>100 mg/L(CaCO_(3)).展开更多
The Acknowledgments“Thisworkwas supported by the National Natural Science Foundation of China(Nos.51878649,52030002),the National Key R&D Program of China(No.2018YFE0204100)and the Youth Innovation Promotion Asso...The Acknowledgments“Thisworkwas supported by the National Natural Science Foundation of China(Nos.51878649,52030002),the National Key R&D Program of China(No.2018YFE0204100)and the Youth Innovation Promotion Association CAS.”should be revised to“This work was supported by the National Key R&D Program of China(No.2018YFE0204101),the National Natural Science Foundation of China(Nos.51878649,52030002),and the Youth Innovation Promotion Association CAS.”展开更多
Microplastics have caused great concern worldwide recently due to their ubiquitous presence within the marine environment. Up to now, most attention has been paid to their sources,distributions, measurement methods, a...Microplastics have caused great concern worldwide recently due to their ubiquitous presence within the marine environment. Up to now, most attention has been paid to their sources,distributions, measurement methods, and especially their eco-toxicological effects. With microplastics being increasingly detected in freshwater, it is urgently necessary to evaluate their behaviors during coagulation and ultrafiltration(UF) processes. Herein, the removal behavior of polyethylene(PE), which is easily suspended in water and is the main component of microplastics, was investigated with commonly used Fe-based salts. Results showed that although higher removal efficiency was induced for smaller PE particles, low PE removal efficiency(below 15%) was observed using the traditional coagulation process, and was little influenced by water characteristics. In comparison to solution pH, PAM addition played a more important role in increasing the removal efficiency, especially anionic PAM at high dosage(with efficiency up to 90.9%). The main reason was ascribed to the dense floc formation and high adsorption ability because of the positively charged Fe-based flocs under neutral conditions. For ultrafiltration, although PE particles could be completely rejected,slight membrane fouling was caused owing to their large particle size. The membrane flux decreased after coagulation; however, the membrane fouling was less severe than that induced by flocs alone due to the heterogeneous nature of the cake layer caused by PE, even at high dosages of Fe-based salts. Based on the behavior exhibited during coagulation and ultrafiltration, we believe these findings will have potential application in drinking water treatment.展开更多
In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated ...In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated that the average numbers of gene copies of Legionella spp. and Mycobacterium spp. were significantly higher than those of Aeromonas spp.(p < 0.05). Legionella spp. and Mycobacterium spp. were 100%(44/44) positively detected while P. aeruginosa and Aeromonas spp. were 79.54%(35/44) and 77.27%(34/44) positively detected. Legionella pneumophila was only detected in 4 samples(4/44), demonstrating its occasional occurrence. No Mycobacterium avium or Naegleria fowleri was detected in any of the samples. The average gene copy numbers of target OPPPs were the highest in summer,suggesting seasonal prevalence of OPPPs. Average gene copy numbers of OPPPs in the taps of low-use-frequency were higher than in taps of high-use-frequency, but the difference was not significant for some OPPPs(p > 0.05). Moderate negative correlations between the chlorine concentration and the gene copy numbers of OPPPs were observed by Spearman analysis(rsranged from -0.311 to -0.710, p < 0.05). However, no significant correlations existed between OPPPs and AOC, BDOC, or turbidity. Moderate positive correlations were observed between the target microorganisms, especially for Acanthamoeba spp., through Spearman analysis(p < 0.05). Based on our studies, it is proposed that disinfectant concentration, season, taps with different-use frequency, OPPP species, and potential microbial correlations should be considered for control of OPPPs in tap water.展开更多
Phthalate esters(PAEs),recognized as endocrine disruptors,are released into the environment during usage,thereby exerting adverse ecological effects.This study investigates the occurrence,sources,and risk assessment o...Phthalate esters(PAEs),recognized as endocrine disruptors,are released into the environment during usage,thereby exerting adverse ecological effects.This study investigates the occurrence,sources,and risk assessment of PAEs in surface water obtained from 36 sampling points within the Yellow River and Yangtze River basins.The total concentration of PAEs in the Yellow River spans from124.5 to 836.5 ng/L,with Dimethyl phthalate(DMP)(75.4±102.7 ng/L)and Diisobutyl phthalate(DiBP)(263.4±103.1 ng/L)emerging as the predominant types.Concentrations exhibit a pattern of upstream(512.9±202.1 ng/L)>midstream(344.5±135.3 ng/L)>downstream(177.8±46.7 ng/L).In the Yangtze River,the total concentration ranges from 81.9 to 441.6 ng/L,with DMP(46.1±23.4 ng/L),Diethyl phthalate(DEP)(93.3±45.2 ng/L),and DiBP(174.2±67.6 ng/L)as the primary components.Concentration levels follow a midstream(324.8±107.3 ng/L)>upstream(200.8±51.8 ng/L)>downstream(165.8±71.6 ng/L)pattern.Attention should be directed towards the moderate ecological risks of DiBP in the upstream of HH,and both the upstream and midstream of CJ need consideration for the moderate ecological risks associated with Di-n-octyl phthalate(DNOP).Conversely,in other regions,the associated risk with PAEs is either low or negligible.The main source of PAEs in Yellow River is attributed to the release of construction land,while in the Yangtze River Basin,it stems from the accumulation of pollutants in lakes and forests discharged into the river.These findings are instrumental for pinpointing sources of PAEs pollution and formulating control strategies in the Yellow and Yangtze Rivers,providing valuable insights for global PAEs research in other major rivers.展开更多
Odor problems in source water caused by 2-methylisoborneol(MIB) have been a common issue in China recently, posing a high risk to drinking water safety. The earthy-musty odorant MIB has an extremely low odor threshol...Odor problems in source water caused by 2-methylisoborneol(MIB) have been a common issue in China recently, posing a high risk to drinking water safety. The earthy-musty odorant MIB has an extremely low odor threshold(4–16 ng/L) and is hard to remove via conventional processes in drinking water plants(DWP), and therefore could easily provoke complaints from consumers. This compound is produced by a group of filamentous cyanobacteria, mainly belonging to Oscillatoriales. Different from the well-studied surface-blooming Microcystis, filamentous cyanobacteria have specific niche characteristics that allow them to stay at a subsurface or deep layer in the water column. The underwater bloom of these MIB producers is therefore passively determined by the underwater light availability, which is governed by the cell density of surface scum. This suggests that drinking water reservoirs with relatively low nutrient contents are not able to support surface blooms, but are a fairly good fit to the specialized ecological niche of filamentous cyanobacteria;this could explain the widespread odor problems in source water. At present, MIB is mainly treated in DWP using advanced treatment processes and/or activated carbon, but these post-treatment methods have high cost, and not able to deal with water containing high MIB concentrations.Thus, in situ control of MIB producers in source water is an effective complement and is desirable. Lowering the underwater light availability is a possible measure to control MIB producers according to their niche characteristics, which can be obtained by either changing the water level or other measures.展开更多
Coagulation and precipitation is a widely applied method to remove F-from wastewater.In this work,the effect of coagulation on the removal of F-and organic matter from coking wastewater was studied using Al Cl3and Fe ...Coagulation and precipitation is a widely applied method to remove F-from wastewater.In this work,the effect of coagulation on the removal of F-and organic matter from coking wastewater was studied using Al Cl3and Fe Cl3as compound coagulants.The removal rates of F-and organic matter under different coagulant doses and p H conditions were investigated.The results show that the highest removal rates of F-by Al Cl3and Fe Cl3are 94.4%and 25.4%,respectively;when the dosage is 10 mmol/L,the TOC removal rates of Fe Cl3and Al Cl3reach 20.4%and 34.7%,respectively.Therefore,the removal rate of F-by Al Cl3is higher than that of Fe Cl3,but the removal rate of organic matter by Fe Cl3is relatively higher.The addition of Ca2+can promote the removal of F-,but the removal rate of organic matter decreases.In addition,by investigating the effects of different p H and Fe–Al ratio on the removal rate,the removal effect of adding Fe Cl3and Al Cl3at the same time was discussed.The results show that the most suitable working condition for the removal of organic matter and F-is that the p H is 6.5 and the molar ratio of Al/Fe is 8:2.Overall,the removal mechanism of F-and organic matter in coking wastewater by Fe Cl3and Al Cl3was explored in this study.The experimental results can provide reference for the advanced treatment of coking wastewater.展开更多
Pre-oxidation is widely used to reduce ultrafiltration membrane fouling. However, the variation in the composition of microbial communities and extracellular polymeric substances （EPSs） accompanying pre-oxidation in...Pre-oxidation is widely used to reduce ultrafiltration membrane fouling. However, the variation in the composition of microbial communities and extracellular polymeric substances （EPSs） accompanying pre-oxidation in drinking water treatment has received little attention. In this study, hydrogen peroxide （H2O2） was used in a coagulation- ultrafiltration process with Al2（SO4）3.18H2O. A long-term reactor experiment （60 d） showed that pre-oxidation alleviated membrane fouling, mainly due to its inhibition of microbial growth, as observed by flow cytometry measurements of the membrane tank water. Further analysis of the formed cake layer demonstrated that the corresponding levels of EPS released from the microbes were lower with than without H202 treatment. In comparison to polysaccharides, proteins dominated the EPS. 2D-electrophoresis showed little difference （p 〉 0.05, Student＇s t-test） in the composition of proteins in the cake layer between the treatments with and without H2O2. The molecular weights of proteins ranged from approximately 30-50 kDa and the majority of isoelectric points ranged from 6 to 8. Highthroughput sequencing showed that the predominant bacteria were Proteobacteria, Bacteroidetes, and Verrucomicrobia in both cake layers. However, the relative abundance of Planctomycetes was higher in the cake layer with H2O2 pre-oxidation, which was likely probably due to the strong oxidative resistance of its cell wall. Overall, our findings clarify the fundamental molecular mechanism in H2O2 pre-oxidation for ultrafiltration membrane bio-fouling alleviation in drinking water treatment.展开更多
The long term exposure of arsenic via drinking water has resulted in wide occurrence of arsenisim globally, and the oxidation of the non-ionic arsenite(As(Ⅲ)) to negatively-charged arsenate(As(Ⅴ)) is of crucial impo...The long term exposure of arsenic via drinking water has resulted in wide occurrence of arsenisim globally, and the oxidation of the non-ionic arsenite(As(Ⅲ)) to negatively-charged arsenate(As(Ⅴ)) is of crucial importance for the promising removal of arsenic. The chemical oxidants of ozone, chlorine, chlorine dioxide, and potassium permanganate may achieve this goal;however, their application in developing countries is sometimes restricted by the complicate operation and high cost. This review paper focuses on the heterogeneous oxidation of As(Ⅲ) by solid oxidants such as manganese oxide, and the adsorption of As(Ⅴ)accordingly. Manganese oxide may be prepared by both chemical and biological methods to achieve good oxidation performance towards As(Ⅲ). Additionally, manganese oxide may be combined with other metal oxides, e.g., iron oxide, to improve the adsorption capability towards As(Ⅴ). Furthermore, manganese oxide may be coated onto porous materials of metal organic frameworks to develop novel adsorbents for arsenic removal. To achieve the application in engineering works, the adsorbents granulation may be achieved by drying and calcination, agglomeration, and the active components may also be in situ coated onto the porous materials to maintain the oxidation and adsorption activities as much as possible. The novel adsorbents with heterogeneous oxidation and adsorption capability may be carefully designed for the removal of arsenic in household purifiers, community-level decentralized small systems, and the large-scale drinking water treatment plants(DWTPs).This review provides insight into the fundamental studies on novel adsorbents, the development of innovative technologies, and the demonstration engineering works involved in the heterogeneous oxidation and adsorption, and may be practically valuable for the arsenic pollution control globally.展开更多
Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the ...Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the occurrence characteristics,sources,and potential ecological risks of 13 PFASs in the Yangtze River.The results indicated that the concentrations ofΣPFASs range from 5.1 to 57.7 ng/L,with more severe pollution downstream and perfluorobutane sulfonate(PFBuS)being the main pollutant.ΣPFASs showed a positive correlation with total organic carbon and absorbance under the condition of UV wavelength 254 nm(UV_(254)),and a negative correlation with total dissolved solids.Positive matrix factorization model analysis revealed that the primary sources of PFASs in the study area are food packaging,the electroplating industry,and the manufacturing and processing of fluoropolymer-containing products.The total ecological risk value of PFASs indicated that the ecological risks to algae,invertebrates,and fish are negligible.The annual load of ΣPFASs in the Yangtze River was 39.00 t,with the highest concentrations of pollutants being PFBuS(26.41 t/year),perfluorobutanoic acid(6.47 t/year),and perfluorooctanoic acid(PFOA,3.19t/year).While PFASs have not yet posed a risk to aquatic organisms,the increase in the use of short-chain PFASs substitutes(C4-C7)due to the regulation of PFOA and perfluorooctane sulfonate highlights the need for continued monitoring of short-chain PFASs pollution.展开更多
Simulated drinking water distribution system(DWDS) treated with O_3-BAC-Cl_2(ozonebiological activated carbon-chlorine) was constructed to study its effects on the regrowth of five typical opportunistic pathogens(OPs)...Simulated drinking water distribution system(DWDS) treated with O_3-BAC-Cl_2(ozonebiological activated carbon-chlorine) was constructed to study its effects on the regrowth of five typical opportunistic pathogens(OPs). It was found that O_3-BAC-Cl_2 could significantly reduce the regrowth of target OPs in the effluents of DWDS compared with Cl_2 and O_3-Cl_2 with the same residual chlorine levels. However, the effect of O_3-BAC-Cl_2 on the average numbers of target OPs gene markers in the biofilms of DWDS was not apparent, suggesting that OPs in the biofilms of DWDS were tolerant to the upstream disinfection process. The quantification of target OPs in the BAC-filter column demonstrated that OPs decreased with the increase of depth, which was likely due to the organic nutrient gradient and microbial competition inside the BAC-filter. Increase in the ozone dose could further reduce the OPs at the bottom of the BAC-filter. Spearman correlation analysis demonstrated that some significant correlations existed between target microorganisms, suggesting potential microbial ecological relationships. Overall, our results demonstrated that the BAC-filter may act as a "battlefield"suppressing the OPs through microbial competition. O_3-BAC-Cl_2 could be an effective multibarrier process to suppress the proliferation of OPs in the bulk water of DWDS. However, OPs protected by the biofilms of DWDS should receive further attention because OPs may be detached and released from the biofilms.展开更多
The chemistry associated with the disinfection of aquarium seawater is more complicated than that of freshwater, therefore limited information is available on the formation and speciation of disinfection byproducts（D...The chemistry associated with the disinfection of aquarium seawater is more complicated than that of freshwater, therefore limited information is available on the formation and speciation of disinfection byproducts（DBPs） in marine aquaria. In this study, the effects of organic precursors, bromide（Br-） and pre-ozonation on the formation and speciation of several typical classes of DBPs, including trihalomethanes（THM4）, haloacetic acids（HAAs）,iodinated trihalomethanes（I-THMs）, and haloacetamides（HAc Ams）, were investigated during the chlorination/chloramination of aquarium seawater. Results indicate that with an increase in dissolved organic carbon concentration from 4.5 to 9.4 mg/L, the concentrations of THM4 and HAAs increased by 3.2-7.8 times under chlorination and by 1.1-2.3 times under chloramination. An increase in Br-concentration from 3 to 68 mg/L generally enhanced the formation of THM4, I-THMs and HAc Ams and increased the bromine substitution factors of all studied DBPs as well, whereas it impacted insignificantly on the yield of HAAs. Pre-ozonation with 1 mg/L O3 dose substantially reduced the formation of all studied DBPs in the subsequent chlorination and I-THMs in the subsequent chloramination. Because chloramination produces much lower amounts of DBPs than chlorination, it tends to be more suitable for disinfection of aquarium seawater.展开更多
文摘The Key Laboratory of Drinking Water Science and Technology(DWST),a key branch of the Laboratory of Environmental Aquatic Chemistry,has been staying on the cutting edge in the field of drinking water since its establishment in 2014.The main goal of this laboratory is to ensure drinking water safety,particularly with regard to public health.To achieve this goal,the research teams have been making great efforts to develop water quality criteria and standards for health risk control;establish stateof-the-art theoretical and technological systems for pollution control and water purification;form an innovation layout from foundation to application,from engineering to management,and from water source to tap;and provide systematic solutions to forward-looking and universal scientific problems in drinking water safety.The laboratory mainly focuses on four research fields:(1)methodology for water quality risk assessment;(2)combined pollution of water source and ecological restoration;(3)new theories and technologies for water purification;and(4)chemical/biological processes and regulations of water distribution systems.
基金supported by the Ministry of Science and Technology of China (Nos.2021YFC3200904,and 2022YFC3203705)the National Natural Science Foundation of China (Nos.52070184,and 52270012)the Nanning Scientific Research and Technology Development Project (No.ZC20223238).
文摘Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(Nos.2015ZX07406001 and 2017ZX07207004)the National Natural Science Foundation of China(Nos.51778602 and 21707117)the Major Project of Key Laboratory of Drinking Water Science and Technology,Research Center for EcoEnvironmental Sciences,CAS(No.17Z02KLDWST)
文摘A wide range of compounds with various structural features can cause taste and odor(T&O)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction(LLE) with gas chromatography-triple quadrupole tandem mass spectrometry(GC–MS/MS)was established to simultaneously analyze 51 odor-causing compounds in drinking water,including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4,were used to correct the variations in recovery, and five isotope-labeled internal standards(4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity(R2> 0.99, level = 7),and method detection limits(MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants(0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible(RSD < 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants(DWTPs) were analyzed by this method.According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.
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supported by the Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (Project No. 20Z01KLDWST)。
文摘Maintaining a residual disinfectant/oxidant(e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, such as hypobromous acid(HOBr), can be formed during chlorination of bromide-containing waters. The decay of oxidants and formation of disinfection byproducts(DBPs) due to the interaction between oxidants and selected metal oxides were studied. Selected metal oxides generally enhanced the decay of these halogencontaining oxidants via three pathways:(1) catalytic disproportionation to yield an oxidized form of halogen(i.e., halate) and reduced form(halide for chlorine and bromine or chlorite for chlorine dioxide),(2) oxygen formation, and(3) oxidation of a metal in a reduced form(e.g., cuprous oxide) to a higher oxidation state. Cupric oxide(Cu O) and nickel oxide(Ni O)showed significantly strong abilities for the first pathway, and oxygen formation was a side reaction. Cuprous oxide can react with oxidants via the third pathway, while goethite was not involved in these reactions. The ability of Cu O on catalytic disproportionation of HOBr remained stable up to four cycles. In chlorination process, bromate formation tends to be important(exceeding 10 μg/L) when initial bromide concentration is above 400 μg/L in the presence of dissolved organic matter. Increasing initial bromide concentrations increased the formation of DBPs and calculated cytotoxicity, and the maximum was observed at p H8.6 during chlorination process. Therefore, the possible disinfectant loss and DBP formation should be carefully considered in drinking water distribution systems.
基金upported by the National Natural Science Foundation of China (No. 51278487)the Major National Water Pollution Control and Management Project of China (Nos. 2012ZX07403-003-03, 2008ZX07421-001)+1 种基金the National Basic Research Program (973) of China (No. 2009CB421103)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX2-EW-410-05)
文摘Shijiuyang Constructed Wetland（110 hm^2） is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond–wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the ＂hidden＂ diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited.
基金funded by the National Natural Science Foundation of China(Nos.51878654,52070189,51838005)the National Key R&D Program of China(Nos.2019YFD1100105,SQ2018YFE020448)+2 种基金the project of Chinese Academy of Sciences(No.QYZDY-SSW-ZQC004)Major Science and Technology Program for Water Pollution Control and Treatment(Nos.2017ZX07108,2017ZX07501-002)。
文摘Many problems in drinking water distribution systems(DWDSs)are caused by microbe,such as biofilm formation,biocorrosion and opportunistic pathogens growth.More iron release from corrosion scales may induce red water.Biofilm played great roles on the corrosion.The iron-oxidizing bacteria(IOB)promoted corrosion.However,when iron-reducing bacteria(IRB)and nitrate-reducing bacteria(NRB)became the main bacteria in biofilm,they could induce iron redox cycling in corrosion process.This process enhanced the precipitation of iron oxides and formation of more Fe3 O4 in corrosion scales,which inhibited corrosion effectively.Therefore,the IRB and NRB in the biofilm can reduce iron release and red water occurrence.Moreover,there are many opportunistic pathogens in biofilm of DWDSs.The opportunistic pathogens growth in DWDSs related to the bacterial community changes due to the effects of micropollutants.Micropollutants increased the number of bacteria with antibiotic resistance genes(ARGs).Furthermore,extracellular polymeric substances(EPS)production was increased by the antibiotic resistant bacteria,leading to greater bacterial aggregation and adsorption,increasing the chlorine-resistance capability,which was responsible for the enhancement of the particle-associated opportunistic pathogens in DWDSs.Moreover,O3-biological activated carbon filtration-UV-Cl2 treatment could be used to control the iron release,red water occurrence and opportunistic pathogens growth in DWDSs.
文摘The survival and development of human society highly depends on the water availability. Driven by the growth of population and economy, global water demand has increased more than eightfold since the 1900s. Meanwhile, the commonly deteriorated freshwater quality cause a large proportion of available water resources unsuitable for human uses. This inter-coupled challenge of insufficient water quantity and inadequate water quality has rendered water scarcity a widespread problem in many parts of the world.
基金supported by the Beijing Municipal Science&Technology Program (No.Z201100008220003)the National Key R&D Program of China (No.2019YFD1100105)。
文摘The cement mortar lining(CML)of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use,but the behavioral characteristics of different elements release from the CML in this stage is still unclear.In this study,dynamic immersion experiments with new cement mortar lined ductile iron pipe reactors were conducted under different feed water hardness and alkalinity conditions.The results showed that the release of alkaline substances from the CML at the initial stage of use could strongly influence the pH of water,which consequently greatly impacted the release/precipitation behaviors of calcium,aluminum and silicon.The pH and aluminum concentration of the effluent water could reach 11.5 and 700μg/L within 24 hr of hydraulic retention time,respectively,under conditions of relatively lower hardness and alkalinity.Due to the pH elevation,calcium carbonate precipitation could occur even at much lower feed water alkalinity.Whereas the aluminum and silicon could keep release from the CML in soluble form at different hardness and alkalinity levels,and their release rate depended on the amount of calcium carbonate precipitation.Thus,aluminum and silicon were more suitable as indicators of the corrosion intensity at the initial stage of CML use rather than the traditional calcium carbonate precipitation potential.Appropriate feed water hardness and alkalinity levels for mitigating the initial intense corrosion of CML were proposed:hardness>40 mg/L(CaCO_(3)),alkalinity>100 mg/L(CaCO_(3)).
文摘The Acknowledgments“Thisworkwas supported by the National Natural Science Foundation of China(Nos.51878649,52030002),the National Key R&D Program of China(No.2018YFE0204100)and the Youth Innovation Promotion Association CAS.”should be revised to“This work was supported by the National Key R&D Program of China(No.2018YFE0204101),the National Natural Science Foundation of China(Nos.51878649,52030002),and the Youth Innovation Promotion Association CAS.”
基金supported by the National Key R&D Program of China (No. 2016YFC0400802)the National Natural Science Foundation for Young Scientists of China (No. 51608514)a special fund from the Key Laboratory of Drinking Water Science and Technology, Research Center for EcoEnvironmental Sciences, Chinese Academy of Sciences (No. 17Z03KLDWST)
文摘Microplastics have caused great concern worldwide recently due to their ubiquitous presence within the marine environment. Up to now, most attention has been paid to their sources,distributions, measurement methods, and especially their eco-toxicological effects. With microplastics being increasingly detected in freshwater, it is urgently necessary to evaluate their behaviors during coagulation and ultrafiltration(UF) processes. Herein, the removal behavior of polyethylene(PE), which is easily suspended in water and is the main component of microplastics, was investigated with commonly used Fe-based salts. Results showed that although higher removal efficiency was induced for smaller PE particles, low PE removal efficiency(below 15%) was observed using the traditional coagulation process, and was little influenced by water characteristics. In comparison to solution pH, PAM addition played a more important role in increasing the removal efficiency, especially anionic PAM at high dosage(with efficiency up to 90.9%). The main reason was ascribed to the dense floc formation and high adsorption ability because of the positively charged Fe-based flocs under neutral conditions. For ultrafiltration, although PE particles could be completely rejected,slight membrane fouling was caused owing to their large particle size. The membrane flux decreased after coagulation; however, the membrane fouling was less severe than that induced by flocs alone due to the heterogeneous nature of the cake layer caused by PE, even at high dosages of Fe-based salts. Based on the behavior exhibited during coagulation and ultrafiltration, we believe these findings will have potential application in drinking water treatment.
基金supported by the National Key Research and Development Plan(No.2016YFA0203200)the National Natural Science Foundation of China(No.51538013)the project of Chinese Academy of Sciences(No.QYZDY-SSW-DQC004)
文摘In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated that the average numbers of gene copies of Legionella spp. and Mycobacterium spp. were significantly higher than those of Aeromonas spp.(p < 0.05). Legionella spp. and Mycobacterium spp. were 100%(44/44) positively detected while P. aeruginosa and Aeromonas spp. were 79.54%(35/44) and 77.27%(34/44) positively detected. Legionella pneumophila was only detected in 4 samples(4/44), demonstrating its occasional occurrence. No Mycobacterium avium or Naegleria fowleri was detected in any of the samples. The average gene copy numbers of target OPPPs were the highest in summer,suggesting seasonal prevalence of OPPPs. Average gene copy numbers of OPPPs in the taps of low-use-frequency were higher than in taps of high-use-frequency, but the difference was not significant for some OPPPs(p > 0.05). Moderate negative correlations between the chlorine concentration and the gene copy numbers of OPPPs were observed by Spearman analysis(rsranged from -0.311 to -0.710, p < 0.05). However, no significant correlations existed between OPPPs and AOC, BDOC, or turbidity. Moderate positive correlations were observed between the target microorganisms, especially for Acanthamoeba spp., through Spearman analysis(p < 0.05). Based on our studies, it is proposed that disinfectant concentration, season, taps with different-use frequency, OPPP species, and potential microbial correlations should be considered for control of OPPPs in tap water.
基金supported by the Ministry of Science and Technology of China(Nos.2021YFC3200904 and 2022YFC3203705)the National Natural Science Foundation of China(Nos.52270012 and 52070184).
文摘Phthalate esters(PAEs),recognized as endocrine disruptors,are released into the environment during usage,thereby exerting adverse ecological effects.This study investigates the occurrence,sources,and risk assessment of PAEs in surface water obtained from 36 sampling points within the Yellow River and Yangtze River basins.The total concentration of PAEs in the Yellow River spans from124.5 to 836.5 ng/L,with Dimethyl phthalate(DMP)(75.4±102.7 ng/L)and Diisobutyl phthalate(DiBP)(263.4±103.1 ng/L)emerging as the predominant types.Concentrations exhibit a pattern of upstream(512.9±202.1 ng/L)>midstream(344.5±135.3 ng/L)>downstream(177.8±46.7 ng/L).In the Yangtze River,the total concentration ranges from 81.9 to 441.6 ng/L,with DMP(46.1±23.4 ng/L),Diethyl phthalate(DEP)(93.3±45.2 ng/L),and DiBP(174.2±67.6 ng/L)as the primary components.Concentration levels follow a midstream(324.8±107.3 ng/L)>upstream(200.8±51.8 ng/L)>downstream(165.8±71.6 ng/L)pattern.Attention should be directed towards the moderate ecological risks of DiBP in the upstream of HH,and both the upstream and midstream of CJ need consideration for the moderate ecological risks associated with Di-n-octyl phthalate(DNOP).Conversely,in other regions,the associated risk with PAEs is either low or negligible.The main source of PAEs in Yellow River is attributed to the release of construction land,while in the Yangtze River Basin,it stems from the accumulation of pollutants in lakes and forests discharged into the river.These findings are instrumental for pinpointing sources of PAEs pollution and formulating control strategies in the Yellow and Yangtze Rivers,providing valuable insights for global PAEs research in other major rivers.
基金supported by the National Natural Science Foundation of China(Nos.51878649,52030002)the National Key R&D Program of China(No.2018YFE0204100)+1 种基金the Youth Innovation Promotion Association CAS。
文摘Odor problems in source water caused by 2-methylisoborneol(MIB) have been a common issue in China recently, posing a high risk to drinking water safety. The earthy-musty odorant MIB has an extremely low odor threshold(4–16 ng/L) and is hard to remove via conventional processes in drinking water plants(DWP), and therefore could easily provoke complaints from consumers. This compound is produced by a group of filamentous cyanobacteria, mainly belonging to Oscillatoriales. Different from the well-studied surface-blooming Microcystis, filamentous cyanobacteria have specific niche characteristics that allow them to stay at a subsurface or deep layer in the water column. The underwater bloom of these MIB producers is therefore passively determined by the underwater light availability, which is governed by the cell density of surface scum. This suggests that drinking water reservoirs with relatively low nutrient contents are not able to support surface blooms, but are a fairly good fit to the specialized ecological niche of filamentous cyanobacteria;this could explain the widespread odor problems in source water. At present, MIB is mainly treated in DWP using advanced treatment processes and/or activated carbon, but these post-treatment methods have high cost, and not able to deal with water containing high MIB concentrations.Thus, in situ control of MIB producers in source water is an effective complement and is desirable. Lowering the underwater light availability is a possible measure to control MIB producers according to their niche characteristics, which can be obtained by either changing the water level or other measures.
基金supported by the National Natural Science Foundation of China(No.51108444)the Key Research and Development Plan of the Ministry of Science and Technology(No.2019YFD1100104)。
文摘Coagulation and precipitation is a widely applied method to remove F-from wastewater.In this work,the effect of coagulation on the removal of F-and organic matter from coking wastewater was studied using Al Cl3and Fe Cl3as compound coagulants.The removal rates of F-and organic matter under different coagulant doses and p H conditions were investigated.The results show that the highest removal rates of F-by Al Cl3and Fe Cl3are 94.4%and 25.4%,respectively;when the dosage is 10 mmol/L,the TOC removal rates of Fe Cl3and Al Cl3reach 20.4%and 34.7%,respectively.Therefore,the removal rate of F-by Al Cl3is higher than that of Fe Cl3,but the removal rate of organic matter by Fe Cl3is relatively higher.The addition of Ca2+can promote the removal of F-,but the removal rate of organic matter decreases.In addition,by investigating the effects of different p H and Fe–Al ratio on the removal rate,the removal effect of adding Fe Cl3and Al Cl3at the same time was discussed.The results show that the most suitable working condition for the removal of organic matter and F-is that the p H is 6.5 and the molar ratio of Al/Fe is 8:2.Overall,the removal mechanism of F-and organic matter in coking wastewater by Fe Cl3and Al Cl3was explored in this study.The experimental results can provide reference for the advanced treatment of coking wastewater.
基金supported by the National Key R&D Program of China(No.2016YFC0400802)the National Natural Science Foundation of China(No.51290282)the “National Water Pollution Control and Treatment Science and Technology Major Project(No.2015ZX07406006).”
文摘Pre-oxidation is widely used to reduce ultrafiltration membrane fouling. However, the variation in the composition of microbial communities and extracellular polymeric substances （EPSs） accompanying pre-oxidation in drinking water treatment has received little attention. In this study, hydrogen peroxide （H2O2） was used in a coagulation- ultrafiltration process with Al2（SO4）3.18H2O. A long-term reactor experiment （60 d） showed that pre-oxidation alleviated membrane fouling, mainly due to its inhibition of microbial growth, as observed by flow cytometry measurements of the membrane tank water. Further analysis of the formed cake layer demonstrated that the corresponding levels of EPS released from the microbes were lower with than without H202 treatment. In comparison to polysaccharides, proteins dominated the EPS. 2D-electrophoresis showed little difference （p 〉 0.05, Student＇s t-test） in the composition of proteins in the cake layer between the treatments with and without H2O2. The molecular weights of proteins ranged from approximately 30-50 kDa and the majority of isoelectric points ranged from 6 to 8. Highthroughput sequencing showed that the predominant bacteria were Proteobacteria, Bacteroidetes, and Verrucomicrobia in both cake layers. However, the relative abundance of Planctomycetes was higher in the cake layer with H2O2 pre-oxidation, which was likely probably due to the strong oxidative resistance of its cell wall. Overall, our findings clarify the fundamental molecular mechanism in H2O2 pre-oxidation for ultrafiltration membrane bio-fouling alleviation in drinking water treatment.
基金supported by the National Natural Science Foundation of China (No. 51925807)。
文摘The long term exposure of arsenic via drinking water has resulted in wide occurrence of arsenisim globally, and the oxidation of the non-ionic arsenite(As(Ⅲ)) to negatively-charged arsenate(As(Ⅴ)) is of crucial importance for the promising removal of arsenic. The chemical oxidants of ozone, chlorine, chlorine dioxide, and potassium permanganate may achieve this goal;however, their application in developing countries is sometimes restricted by the complicate operation and high cost. This review paper focuses on the heterogeneous oxidation of As(Ⅲ) by solid oxidants such as manganese oxide, and the adsorption of As(Ⅴ)accordingly. Manganese oxide may be prepared by both chemical and biological methods to achieve good oxidation performance towards As(Ⅲ). Additionally, manganese oxide may be combined with other metal oxides, e.g., iron oxide, to improve the adsorption capability towards As(Ⅴ). Furthermore, manganese oxide may be coated onto porous materials of metal organic frameworks to develop novel adsorbents for arsenic removal. To achieve the application in engineering works, the adsorbents granulation may be achieved by drying and calcination, agglomeration, and the active components may also be in situ coated onto the porous materials to maintain the oxidation and adsorption activities as much as possible. The novel adsorbents with heterogeneous oxidation and adsorption capability may be carefully designed for the removal of arsenic in household purifiers, community-level decentralized small systems, and the large-scale drinking water treatment plants(DWTPs).This review provides insight into the fundamental studies on novel adsorbents, the development of innovative technologies, and the demonstration engineering works involved in the heterogeneous oxidation and adsorption, and may be practically valuable for the arsenic pollution control globally.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750000)the National Natural Science Foundation of China(Nos.52270012 and 52470018)the Ministry of Science and Technology of China(Nos.2022YFC3203705 and2021YFC3200904)。
文摘Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the occurrence characteristics,sources,and potential ecological risks of 13 PFASs in the Yangtze River.The results indicated that the concentrations ofΣPFASs range from 5.1 to 57.7 ng/L,with more severe pollution downstream and perfluorobutane sulfonate(PFBuS)being the main pollutant.ΣPFASs showed a positive correlation with total organic carbon and absorbance under the condition of UV wavelength 254 nm(UV_(254)),and a negative correlation with total dissolved solids.Positive matrix factorization model analysis revealed that the primary sources of PFASs in the study area are food packaging,the electroplating industry,and the manufacturing and processing of fluoropolymer-containing products.The total ecological risk value of PFASs indicated that the ecological risks to algae,invertebrates,and fish are negligible.The annual load of ΣPFASs in the Yangtze River was 39.00 t,with the highest concentrations of pollutants being PFBuS(26.41 t/year),perfluorobutanoic acid(6.47 t/year),and perfluorooctanoic acid(PFOA,3.19t/year).While PFASs have not yet posed a risk to aquatic organisms,the increase in the use of short-chain PFASs substitutes(C4-C7)due to the regulation of PFOA and perfluorooctane sulfonate highlights the need for continued monitoring of short-chain PFASs pollution.
基金supported by the National Key Research and Development Plan (No.2016YFA0203200)the National Natural Science Foundation of China (No.51538013)the project of Chinese Academy of Sciences (No.QYZDY-SSW-DQC004)
文摘Simulated drinking water distribution system(DWDS) treated with O_3-BAC-Cl_2(ozonebiological activated carbon-chlorine) was constructed to study its effects on the regrowth of five typical opportunistic pathogens(OPs). It was found that O_3-BAC-Cl_2 could significantly reduce the regrowth of target OPs in the effluents of DWDS compared with Cl_2 and O_3-Cl_2 with the same residual chlorine levels. However, the effect of O_3-BAC-Cl_2 on the average numbers of target OPs gene markers in the biofilms of DWDS was not apparent, suggesting that OPs in the biofilms of DWDS were tolerant to the upstream disinfection process. The quantification of target OPs in the BAC-filter column demonstrated that OPs decreased with the increase of depth, which was likely due to the organic nutrient gradient and microbial competition inside the BAC-filter. Increase in the ozone dose could further reduce the OPs at the bottom of the BAC-filter. Spearman correlation analysis demonstrated that some significant correlations existed between target microorganisms, suggesting potential microbial ecological relationships. Overall, our results demonstrated that the BAC-filter may act as a "battlefield"suppressing the OPs through microbial competition. O_3-BAC-Cl_2 could be an effective multibarrier process to suppress the proliferation of OPs in the bulk water of DWDS. However, OPs protected by the biofilms of DWDS should receive further attention because OPs may be detached and released from the biofilms.
基金financially supported by the People Programme (Marie Curie Actions) of the European Union's Seventh Programme FP7/2007-2013 under a REA grant (No. 318926)the National Natural Science Foundation of China (No. 51221892)
文摘The chemistry associated with the disinfection of aquarium seawater is more complicated than that of freshwater, therefore limited information is available on the formation and speciation of disinfection byproducts（DBPs） in marine aquaria. In this study, the effects of organic precursors, bromide（Br-） and pre-ozonation on the formation and speciation of several typical classes of DBPs, including trihalomethanes（THM4）, haloacetic acids（HAAs）,iodinated trihalomethanes（I-THMs）, and haloacetamides（HAc Ams）, were investigated during the chlorination/chloramination of aquarium seawater. Results indicate that with an increase in dissolved organic carbon concentration from 4.5 to 9.4 mg/L, the concentrations of THM4 and HAAs increased by 3.2-7.8 times under chlorination and by 1.1-2.3 times under chloramination. An increase in Br-concentration from 3 to 68 mg/L generally enhanced the formation of THM4, I-THMs and HAc Ams and increased the bromine substitution factors of all studied DBPs as well, whereas it impacted insignificantly on the yield of HAAs. Pre-ozonation with 1 mg/L O3 dose substantially reduced the formation of all studied DBPs in the subsequent chlorination and I-THMs in the subsequent chloramination. Because chloramination produces much lower amounts of DBPs than chlorination, it tends to be more suitable for disinfection of aquarium seawater.
