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 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
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
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
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
The Xuan Dai Bay,located in Phu Yen Province,Vietnam,is one of the most traditional and important aquaculture areas of the country.Using physico-chemical methods to evaluate the environmental quality of the bay shows ...The Xuan Dai Bay,located in Phu Yen Province,Vietnam,is one of the most traditional and important aquaculture areas of the country.Using physico-chemical methods to evaluate the environmental quality of the bay shows that the area is contaminated with nutrients.However,it is necessary to clarify the level of pollution and the impact of polluting factors on biological communities and ecological status in the area.Two marine biotic indices AZTI’s marine biotic index(AMBI)and multivariate-AMBI(M-AMBI)were used to shed light on these issues.This research reveals the outcomes of applying these indicators in evaluating the ecological status in the area.The results show that the environment of the Xuan Dai Bay is being polluted.The most severe pollution level is at stations close to denser farms sites;while the lower pollution is found at stations near the mouth of the bay.The benthic community was imbalanced at all sampling stations,ranging from mild to moderate levels;while the ecological status is moderate,except good-high quality status close to the mouth.展开更多
Mangrove ecosystems along Vietnam’s coastline face significant degradation due to human activities,despite their crucial role in coastal protection against natural hazards.This study aims to assess the spatial and te...Mangrove ecosystems along Vietnam’s coastline face significant degradation due to human activities,despite their crucial role in coastal protection against natural hazards.This study aims to assess the spatial and temporal changes in mangrove coverage along Vietnam’s southern coast by integrating remote sensing techniques with hydrodynamic model simulations.The research methodology combines the Collect Earth tool analysis of Spot-4 and Planet satellite imagery(2000–2020)with Mike 21-HD two-dimensional(2D)hydrodynamic modeling to evaluate mangrove coverage changes by simulating shoreline erosion.Results analysis reveals that a significant increase of 109.83 ha in mangrove area within Vinh Chau Town of Soc Trang Province during the period 2010–2020,predominantly in the eastern region.Hydrodynamic simulations demonstrate that the coastal zone is primarily influenced by the interaction of nearshore currents,East Sea tides,and seasonal monsoon wave patterns.The model results effectively capture the complex interactions between these hydrodynamic factors and mangrove distribution.These findings not only validate the effectiveness of combining remote sensing and hydrodynamic modeling for mangrove assessment but also provide crucial insights for sustainable coastal ecosystem management.The study’s integrated approach offers a robust framework for monitoring mangrove dynamics and developing evidence-based conservation strategies,highlighting the importance of maintaining these vital ecosystems for coastal protection.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
Objective: Perfluorooctanoic acid (PFOA), an ingredient among endocrine-disrupting chemicals, leads to a decrease in fertility. Since the relationship between exposure to these compounds and disruption of the implanta...Objective: Perfluorooctanoic acid (PFOA), an ingredient among endocrine-disrupting chemicals, leads to a decrease in fertility. Since the relationship between exposure to these compounds and disruption of the implantation process has been minimally explored, this research investigated the effect of oral consumption of PFOA on endometrial receptivity.Methods: After an adaptation period, thirty 8-week-old Naval Medical Research Institute (NMRI) female mice were mated with male mice of the same breed. The morning of finding the vaginal plug was considered day 1 (GD1). The mice were randomly divided into five groups: control group, sham group (receiving saline), group 2.5 (receiving 2.5 mg/kg PFOA), group 5 (receiving 5 mg/kg PFOA), and group 10 (receiving 10 mg/kg PFOA). Gavage was performed for 4 days from GD1, after which the mice were euthanized on day 4.5. Blood samples were collected to measure progesterone levels. Endometrial tissue was used to examine pinopodesvia scanning electron microscopy (SEM) and the expression of interleukin (IL)-6 and IL-1βvia quantitative real-time polymerase chain reaction (qRT-PCR).Results: The results showed that PFOA led to a decrease in serum progesterone levels. This reduction trend was statistically significant only in group 10. The decline in the number of pinopodes was dose-dependent, and with increasing doses of PFOA, the decrease in their number and extent became more pronounced. Additionally, the expression levels of IL-6 and IL-1β decreased;this reduction was dose-dependent and statistically significant.Conclusion: The results of this study demonstrated that PFOA altered endometrial function during the implantation stage by affecting serum progesterone levels, the number of pinopodes, and the expression levels of IL-6 and IL-1β. The evidence suggests that these changes are detrimental to embryo implantation. Therefore, further studies investigating the negative effects of PFOA on the endometrium are warranted.展开更多
Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consist...Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consistently reveal a La Niña-like warming pattern[0.15℃-0.25℃(10 yr)^(−1) relative cooling in the eastern equatorial Pacific],over 80%of CMIP6 models project an erroneous El Niño-like trend.These discrepancies arise from biases in cloud feedbacks,Walker circulation strength,and oceanic upwelling processes.This review examines the key mechanisms shaping observed versus modeled warming patterns,evaluates the complex link between tropical SST patterns and TC activity,and explores the feasibility of storm-resolving models for improving TC projections.We propose that pattern-conditioned TC projections using convection-permitting models,alongside physics-informed interpretations,offer a path forward in reducing uncertainties in future climate predictions.展开更多
The purpose of this study is to evaluate the price and composition of blood glucose meters and blood glucose test papers in Hubei Province,so as to improve the affordability of blood glucose monitoring for diabetes pa...The purpose of this study is to evaluate the price and composition of blood glucose meters and blood glucose test papers in Hubei Province,so as to improve the affordability of blood glucose monitoring for diabetes patients.Using the standard survey method jointly developed by the World Health Organization(WHO)and Health Action International(HAI)for drug price composition analysis,central level data was collected through literature review,policy review,and interviews with key informants.Field research was conducted in Wuhan and Yichang to trace price data at various levels of the supply chain.At the central level,data shows that China has implemented multiple policies related to the management and pricing of blood glucose meters and test strips,but has not yet introduced price restrictions for blood glucose meters and test strips;At the supply chain level,data shows that the price composition of blood glucose meters and test strips in Hubei Province is mainly composed of manufacturer prices and retail markups,followed by supply chain taxes and wholesale markups.It can be seen from this that China has established a comprehensive medical device registration,sales,quality control and management standard system through a series of policies.At present,China has not issued price policies for blood glucose meters and blood glucose test papers.Therefore,we can reduce product prices by including medical insurance,government subsidies,competitive bidding,and reducing supply chain taxes,thus improving the affordability of blood glucose monitoring for diabetes patients.展开更多
Reducing greenhouse gas(GHG)emissions to address climate change is a global consensus,and municipal wastewater treatment plants(MWWTPs)should lead the way in low-carbon sustainable development.However,achieving efflue...Reducing greenhouse gas(GHG)emissions to address climate change is a global consensus,and municipal wastewater treatment plants(MWWTPs)should lead the way in low-carbon sustainable development.However,achieving effluent discharge standards often requires considerable energy and chemical consumption during operation,resulting in significant carbon footprints.In this study,GHG emissions are systematically accounted for,and the driving factors of carbon footprint growth in China’s MWWTPs are explored.In 2020,a total of 41.9 million tonnes(Mt)of carbon dioxide equivalent(CO_(2)-eq)were released by the sector,with nearly two-thirds being indirect emissions resulting from energy and material usage.The intensity of electricity,carbon source,and phosphorus removing agent consumption increasingly influence carbon footprint growth over time.Through statistical inference,benchmarks for electricity and chemical consumption intensity are established across all MWWTPs under various operational conditions,and the potential for mitigation through more efficient energy and material utilization is calculated.The results suggest that many MWWTPs offer significant opportunities for emission reduction.Consequently,empirical decarbonization measures,including intelligent device control,optimization of aeration equipment,energy recovery initiatives,and other enhancements to improve operational and carbon efficiency,are recommended.展开更多
A comprehensive taxonomic reassessment of the Hebius optatus species complex,integrating molecular data and morphological data,has led to the recognition and description of a previously overlooked species from norther...A comprehensive taxonomic reassessment of the Hebius optatus species complex,integrating molecular data and morphological data,has led to the recognition and description of a previously overlooked species from northern Vietnam and the Guangxi Zhuang Autonomous Region,China,herein described as Hebius vogeli sp.nov.Phylogenetic analyses reveal that Hebius vogeli sp.nov.is closely related to H.sauteri and H.optatus sensu stricto.Uncorrected p-distances based on cytochrome b sequences indicate a divergence of 10.74%-11.73%between Hebius vogeli sp.nov.and H.optatus.The new species differs from H.optatus by a combination of characters,including a higher number of subcaudal scales,a greater total number of ventral and subcaudal scales,and distinct ventral coloration.Hebius vogeli sp.nov.appears to be geographically restricted to northern Vietnam and the adjacent region of Guangxi Zhuang Autonomous Region,China,making its distribution allopatric from that of H.optatus.The Pearl River is hypothesized to serve as a biogeographic barrier separating the two taxa.Accordingly,we recommend the exclusion of H.optatus from the herpetofauna of Vietnam.Based on IUCN Red List criteria,we propose that Hebius vogeli sp.nov.be assessed as Least Concern(LC).Our results emphasize both the underestimated diversity within Hebius and the need for continued integrative taxonomic efforts,particularly in the Vietnam-China borderlands,where cryptic diversity remains largely unexplored.展开更多
Membrane technology has thus far played an essential role in promoting environmental sustainability through improving the quality of water.Taking into account the current growth rate of membrane products along with th...Membrane technology has thus far played an essential role in promoting environmental sustainability through improving the quality of water.Taking into account the current growth rate of membrane products along with the market capacity,a tremendous rise in the amount of end-of-life(EoL)membranes is inevitable.In 2022,the global records of EoL membranes reached 35,000 tons.Recycling and resource utilization of EoL membranes is a viable option and hold significant promises for energy conservation and carbon neutralization.The present work provides an extensive overview of the latest progress in the field in relation with the prominent application cases.Furthermore,the avenues for the contributions of membrane recycling treatment technology within the framework of“carbon neutrality”are discussed with emphasis on permeability,pollutant interception capacity,and other relevant factors associated with the recycled membranes.This review strives to summarize the recycling and efficient utilization of EoL membranes,aiming at providing technical support to reduce operational costs and promote the low-carbon development of membrane technology.展开更多
In order to evaluate the influence of particle size and particle concentration on the coagulation process, two kinds of particle suspensions, nanoparticles and microparticles,were employed to investigate the effect of...In order to evaluate the influence of particle size and particle concentration on the coagulation process, two kinds of particle suspensions, nanoparticles and microparticles,were employed to investigate the effect of particle size on coagulation mechanisms with varying coagulation parameters. Results showed that it is easier for nanoparticles to cause self-aggregation because of Brownian motion, while interception and sedimentation are the mainly physical processes affecting particle transport for microparticles, so they are more stable and disperse more easily. The particle size distribution and particle concentration had distinct influence on the coagulation mechanisms. Under neutral conditions, as the amount of coagulant increased, the coagulation mechanism for nanoparticles changed from charge neutralization to sweep flocculation and the nanoparticles became destabilized, re-stabilized and again destabilized. For microparticles, although the coagulation mechanism was the same as that of nanoparticles, the increased rate of aluminum hydroxide precipitation exceeded the adsorption of incipiently formed soluble alum species, resulting in the disappearance of the re-stabilization zone. Under acidic conditions, Brownian motion dominates for nanoparticles at low particle concentrations, while sweep flocculation is predominant at high particle concentrations. As for microparticles, charge neutralization and sweep flocculation are the mechanisms for low and high particle concentrations respectively.Under alkaline condition, although the mechanisms for both nano-and microparticles are the same, the morphology of flocs and the kinetics of floc formation are different. At low particle concentrations, nanoparticles have larger growth rate and final size of flocs, while at high particle concentrations, nanoparticles have higher fractal dimension and recovery factors.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
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
Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize see...Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize seed threshed at different moisture contents(MCs).Seeds of dent maize JK968 and flint maize DD2 were threshed at 12,15,18,21,and 24% MC.The damage degree was determined by iodine staining,and seed vigor was assessed by standard germination(SG),cold test germination(CTG),accelerated aging germination(AAG),seedling emergence rate,and seedling root and shoot length.The results showed that the damage percentage increased,and the seed vigor parameters decreased with increasing seed MC during threshing in both cultivars.For obtaining high seed quality,indicated by at least 90,85,and 80% of SG,AAG,and CTG,respectively,JK 968 and DD2 should be threshed at MC lower than 15 and 18%,respectively.Furthermore,the damage mainly occurred in the apical part of seeds,irrespective of the threshing MC in both cultivars.When the embryo was damaged,seedling emergence rates were significantly reduced with great influence on shoot length.Damage to the endosperm resulted in little effect on seedling performance.Flint maize DD2 was more tolerant to mechanical threshing than dent maize JK968.These results provided technical reference for the production and processing of high vigor maize seeds.展开更多
Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost...Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost.In this paper,Mg_(91.4)Ni_(7)Y_(1.6) and Mg_(92.8)Ni_(2.4)Y_(4.8) alloys were prepared by melting and ball milling.Their microstructures and phases were characterized by X-ray diffraction,scanning electron microscope and transmission electron microscope,and hydrogen absorbing and desorbing properties were tested by the high pressure gas adsorption apparatus and differential scanning calorimetry(DSC).In order to estimate the activation energy and growth mechanism of alloy hydride,the JMAK,Arrhenius and Kissinger methods were applied for calculation.The hydrogen absorption content of Mg_(92.8)Ni_(2.4)Y_(4.8) alloy reaches 3.84 wt.%within 5 min under 350℃,3 MPa,and the maximum hydrogen capacity of the alloy is 4.89 wt.%in same condition.However,the hydrogen absorption of Mg_(91.4)Ni_(7)Y_(1.6) alloy reaches 5.78 wt.%within 5 min,and the maximum hydrogen absorption of the alloy is 6.44 wt.%at 350℃and 3 MPa.The hydrogenation activation energy of Mg_(94.4)Ni_(7)Y_(1.6) alloy is 25.4 kJ/mol H_(2),and the enthalpy and entropy of hydrogen absorption are-60.6 kJ/mol H_(2) and 105.5 J/K/mol H_(2),separately.The alloy begins to dehydrogenate at 210℃,with the dehydrogenation activation energy of 87.7 kJ/mol H_(2).By altering the addition amount of Ni and Y elements,the 14 H-LPSO phase with smaller size and ternary eutectic areas with high volume fraction are obtained,which provides more phase boundaries and catalysts with better dispersion,and there are a lot of fine particles in the alloy,these structures are beneficial to enhance the hydrogen storage performance of the alloys.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
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.
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.
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 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 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A project at the Joint Vietnam-Russia Tropical Science and Technology Research Center under contract No.1113/QD-TTNDVN.
文摘The Xuan Dai Bay,located in Phu Yen Province,Vietnam,is one of the most traditional and important aquaculture areas of the country.Using physico-chemical methods to evaluate the environmental quality of the bay shows that the area is contaminated with nutrients.However,it is necessary to clarify the level of pollution and the impact of polluting factors on biological communities and ecological status in the area.Two marine biotic indices AZTI’s marine biotic index(AMBI)and multivariate-AMBI(M-AMBI)were used to shed light on these issues.This research reveals the outcomes of applying these indicators in evaluating the ecological status in the area.The results show that the environment of the Xuan Dai Bay is being polluted.The most severe pollution level is at stations close to denser farms sites;while the lower pollution is found at stations near the mouth of the bay.The benthic community was imbalanced at all sampling stations,ranging from mild to moderate levels;while the ecological status is moderate,except good-high quality status close to the mouth.
基金supported by Environmental Protection Project 2023-2024,with the Joint Vietnam-Russia Tropical Science and Technology Research Center(Southern Branch)as the lead Institution.
文摘Mangrove ecosystems along Vietnam’s coastline face significant degradation due to human activities,despite their crucial role in coastal protection against natural hazards.This study aims to assess the spatial and temporal changes in mangrove coverage along Vietnam’s southern coast by integrating remote sensing techniques with hydrodynamic model simulations.The research methodology combines the Collect Earth tool analysis of Spot-4 and Planet satellite imagery(2000–2020)with Mike 21-HD two-dimensional(2D)hydrodynamic modeling to evaluate mangrove coverage changes by simulating shoreline erosion.Results analysis reveals that a significant increase of 109.83 ha in mangrove area within Vinh Chau Town of Soc Trang Province during the period 2010–2020,predominantly in the eastern region.Hydrodynamic simulations demonstrate that the coastal zone is primarily influenced by the interaction of nearshore currents,East Sea tides,and seasonal monsoon wave patterns.The model results effectively capture the complex interactions between these hydrodynamic factors and mangrove distribution.These findings not only validate the effectiveness of combining remote sensing and hydrodynamic modeling for mangrove assessment but also provide crucial insights for sustainable coastal ecosystem management.The study’s integrated approach offers a robust framework for monitoring mangrove dynamics and developing evidence-based conservation strategies,highlighting the importance of maintaining these vital ecosystems for coastal protection.
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Iran University of Medical Sciences(1401-1-65-23281)。
文摘Objective: Perfluorooctanoic acid (PFOA), an ingredient among endocrine-disrupting chemicals, leads to a decrease in fertility. Since the relationship between exposure to these compounds and disruption of the implantation process has been minimally explored, this research investigated the effect of oral consumption of PFOA on endometrial receptivity.Methods: After an adaptation period, thirty 8-week-old Naval Medical Research Institute (NMRI) female mice were mated with male mice of the same breed. The morning of finding the vaginal plug was considered day 1 (GD1). The mice were randomly divided into five groups: control group, sham group (receiving saline), group 2.5 (receiving 2.5 mg/kg PFOA), group 5 (receiving 5 mg/kg PFOA), and group 10 (receiving 10 mg/kg PFOA). Gavage was performed for 4 days from GD1, after which the mice were euthanized on day 4.5. Blood samples were collected to measure progesterone levels. Endometrial tissue was used to examine pinopodesvia scanning electron microscopy (SEM) and the expression of interleukin (IL)-6 and IL-1βvia quantitative real-time polymerase chain reaction (qRT-PCR).Results: The results showed that PFOA led to a decrease in serum progesterone levels. This reduction trend was statistically significant only in group 10. The decline in the number of pinopodes was dose-dependent, and with increasing doses of PFOA, the decrease in their number and extent became more pronounced. Additionally, the expression levels of IL-6 and IL-1β decreased;this reduction was dose-dependent and statistically significant.Conclusion: The results of this study demonstrated that PFOA altered endometrial function during the implantation stage by affecting serum progesterone levels, the number of pinopodes, and the expression levels of IL-6 and IL-1β. The evidence suggests that these changes are detrimental to embryo implantation. Therefore, further studies investigating the negative effects of PFOA on the endometrium are warranted.
基金supported partly by the AORI visiting professorship programsupported in part by a Moonshot R&D grant(Grant No.JPMJMS2282-02)from the Japan Science and Technology Agency+1 种基金the JSPS Core-to-Core Program,“International Core-to-Core Project on Global Storm Resolving Analysis”(Grant No.JPJSCCA20220001)JSPS KAKENHI(Grant Nos.20B202,20H05728,and 24K00703)。
文摘Recent studies identify large uncertainties in the projections of tropical cyclone(TC)activity due to discrepancies in tropical Pacific sea surface temperature(SST)warming patterns.While observational datasets consistently reveal a La Niña-like warming pattern[0.15℃-0.25℃(10 yr)^(−1) relative cooling in the eastern equatorial Pacific],over 80%of CMIP6 models project an erroneous El Niño-like trend.These discrepancies arise from biases in cloud feedbacks,Walker circulation strength,and oceanic upwelling processes.This review examines the key mechanisms shaping observed versus modeled warming patterns,evaluates the complex link between tropical SST patterns and TC activity,and explores the feasibility of storm-resolving models for improving TC projections.We propose that pattern-conditioned TC projections using convection-permitting models,alongside physics-informed interpretations,offer a path forward in reducing uncertainties in future climate predictions.
基金Hubei Provincial Medical Institutions at all levels of basic drugs and drug bridging support policy projectsResearch on the Integrated Development of Disease Prevention and Control and Medical Services in the XPCC under the Background of Healthy China (Grant No. BTJKJ2024003)。
文摘The purpose of this study is to evaluate the price and composition of blood glucose meters and blood glucose test papers in Hubei Province,so as to improve the affordability of blood glucose monitoring for diabetes patients.Using the standard survey method jointly developed by the World Health Organization(WHO)and Health Action International(HAI)for drug price composition analysis,central level data was collected through literature review,policy review,and interviews with key informants.Field research was conducted in Wuhan and Yichang to trace price data at various levels of the supply chain.At the central level,data shows that China has implemented multiple policies related to the management and pricing of blood glucose meters and test strips,but has not yet introduced price restrictions for blood glucose meters and test strips;At the supply chain level,data shows that the price composition of blood glucose meters and test strips in Hubei Province is mainly composed of manufacturer prices and retail markups,followed by supply chain taxes and wholesale markups.It can be seen from this that China has established a comprehensive medical device registration,sales,quality control and management standard system through a series of policies.At present,China has not issued price policies for blood glucose meters and blood glucose test papers.Therefore,we can reduce product prices by including medical insurance,government subsidies,competitive bidding,and reducing supply chain taxes,thus improving the affordability of blood glucose monitoring for diabetes patients.
基金supported by the National Natural Science Foundation of China(52200228 and 72022004)the National Key Research and Development Program of China(2021YFC3200205 and 2022YFC3203704).
文摘Reducing greenhouse gas(GHG)emissions to address climate change is a global consensus,and municipal wastewater treatment plants(MWWTPs)should lead the way in low-carbon sustainable development.However,achieving effluent discharge standards often requires considerable energy and chemical consumption during operation,resulting in significant carbon footprints.In this study,GHG emissions are systematically accounted for,and the driving factors of carbon footprint growth in China’s MWWTPs are explored.In 2020,a total of 41.9 million tonnes(Mt)of carbon dioxide equivalent(CO_(2)-eq)were released by the sector,with nearly two-thirds being indirect emissions resulting from energy and material usage.The intensity of electricity,carbon source,and phosphorus removing agent consumption increasingly influence carbon footprint growth over time.Through statistical inference,benchmarks for electricity and chemical consumption intensity are established across all MWWTPs under various operational conditions,and the potential for mitigation through more efficient energy and material utilization is calculated.The results suggest that many MWWTPs offer significant opportunities for emission reduction.Consequently,empirical decarbonization measures,including intelligent device control,optimization of aeration equipment,energy recovery initiatives,and other enhancements to improve operational and carbon efficiency,are recommended.
基金supported by the Rufford Foundation(Grant No.45888-2:data analysis)the Russian Science Foundation(RSF Grant No.22-14-00037-P:data analysis)+3 种基金the National Natural Science Foundation of China(32300370)International Partnership Program of Chinese Academy of Sciences(071GJHZ2023041MI),ChinaPostdoctoral Science Foundation(2023M743416)the 2023 award fund of Qinghai Provincial Key Laboratory of Animal Ecological Genomics.
文摘A comprehensive taxonomic reassessment of the Hebius optatus species complex,integrating molecular data and morphological data,has led to the recognition and description of a previously overlooked species from northern Vietnam and the Guangxi Zhuang Autonomous Region,China,herein described as Hebius vogeli sp.nov.Phylogenetic analyses reveal that Hebius vogeli sp.nov.is closely related to H.sauteri and H.optatus sensu stricto.Uncorrected p-distances based on cytochrome b sequences indicate a divergence of 10.74%-11.73%between Hebius vogeli sp.nov.and H.optatus.The new species differs from H.optatus by a combination of characters,including a higher number of subcaudal scales,a greater total number of ventral and subcaudal scales,and distinct ventral coloration.Hebius vogeli sp.nov.appears to be geographically restricted to northern Vietnam and the adjacent region of Guangxi Zhuang Autonomous Region,China,making its distribution allopatric from that of H.optatus.The Pearl River is hypothesized to serve as a biogeographic barrier separating the two taxa.Accordingly,we recommend the exclusion of H.optatus from the herpetofauna of Vietnam.Based on IUCN Red List criteria,we propose that Hebius vogeli sp.nov.be assessed as Least Concern(LC).Our results emphasize both the underestimated diversity within Hebius and the need for continued integrative taxonomic efforts,particularly in the Vietnam-China borderlands,where cryptic diversity remains largely unexplored.
基金supported by the National Natural Science Foundation of China(Nos.52322001,52070183,and 52330001)the National Key R&D Program of China(No.2023YFE0113800)the Excellent Member of the Youth Innovation Promotion Association,Chinese Academy of Sciences(No.Y2023010).
文摘Membrane technology has thus far played an essential role in promoting environmental sustainability through improving the quality of water.Taking into account the current growth rate of membrane products along with the market capacity,a tremendous rise in the amount of end-of-life(EoL)membranes is inevitable.In 2022,the global records of EoL membranes reached 35,000 tons.Recycling and resource utilization of EoL membranes is a viable option and hold significant promises for energy conservation and carbon neutralization.The present work provides an extensive overview of the latest progress in the field in relation with the prominent application cases.Furthermore,the avenues for the contributions of membrane recycling treatment technology within the framework of“carbon neutrality”are discussed with emphasis on permeability,pollutant interception capacity,and other relevant factors associated with the recycled membranes.This review strives to summarize the recycling and efficient utilization of EoL membranes,aiming at providing technical support to reduce operational costs and promote the low-carbon development of membrane technology.
基金supported by the National Natural Science Foundation of China(No.51808530)
文摘In order to evaluate the influence of particle size and particle concentration on the coagulation process, two kinds of particle suspensions, nanoparticles and microparticles,were employed to investigate the effect of particle size on coagulation mechanisms with varying coagulation parameters. Results showed that it is easier for nanoparticles to cause self-aggregation because of Brownian motion, while interception and sedimentation are the mainly physical processes affecting particle transport for microparticles, so they are more stable and disperse more easily. The particle size distribution and particle concentration had distinct influence on the coagulation mechanisms. Under neutral conditions, as the amount of coagulant increased, the coagulation mechanism for nanoparticles changed from charge neutralization to sweep flocculation and the nanoparticles became destabilized, re-stabilized and again destabilized. For microparticles, although the coagulation mechanism was the same as that of nanoparticles, the increased rate of aluminum hydroxide precipitation exceeded the adsorption of incipiently formed soluble alum species, resulting in the disappearance of the re-stabilization zone. Under acidic conditions, Brownian motion dominates for nanoparticles at low particle concentrations, while sweep flocculation is predominant at high particle concentrations. As for microparticles, charge neutralization and sweep flocculation are the mechanisms for low and high particle concentrations respectively.Under alkaline condition, although the mechanisms for both nano-and microparticles are the same, the morphology of flocs and the kinetics of floc formation are different. At low particle concentrations, nanoparticles have larger growth rate and final size of flocs, while at high particle concentrations, nanoparticles have higher fractal dimension and recovery factors.
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 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 earmarked fund for China Agriculture Research System(CARS-02-10)the Special Fund for Agro-scientific Research in the Public Interest,China(201303002)the National Natural Science Foundation of China(31771891)
文摘Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize seed threshed at different moisture contents(MCs).Seeds of dent maize JK968 and flint maize DD2 were threshed at 12,15,18,21,and 24% MC.The damage degree was determined by iodine staining,and seed vigor was assessed by standard germination(SG),cold test germination(CTG),accelerated aging germination(AAG),seedling emergence rate,and seedling root and shoot length.The results showed that the damage percentage increased,and the seed vigor parameters decreased with increasing seed MC during threshing in both cultivars.For obtaining high seed quality,indicated by at least 90,85,and 80% of SG,AAG,and CTG,respectively,JK 968 and DD2 should be threshed at MC lower than 15 and 18%,respectively.Furthermore,the damage mainly occurred in the apical part of seeds,irrespective of the threshing MC in both cultivars.When the embryo was damaged,seedling emergence rates were significantly reduced with great influence on shoot length.Damage to the endosperm resulted in little effect on seedling performance.Flint maize DD2 was more tolerant to mechanical threshing than dent maize JK968.These results provided technical reference for the production and processing of high vigor maize seeds.
基金Chongqing Special Key Project of Technology Innovation and Application Development,China(Grant No.cstc2019jscx-dxwt B0029)。
文摘Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost.In this paper,Mg_(91.4)Ni_(7)Y_(1.6) and Mg_(92.8)Ni_(2.4)Y_(4.8) alloys were prepared by melting and ball milling.Their microstructures and phases were characterized by X-ray diffraction,scanning electron microscope and transmission electron microscope,and hydrogen absorbing and desorbing properties were tested by the high pressure gas adsorption apparatus and differential scanning calorimetry(DSC).In order to estimate the activation energy and growth mechanism of alloy hydride,the JMAK,Arrhenius and Kissinger methods were applied for calculation.The hydrogen absorption content of Mg_(92.8)Ni_(2.4)Y_(4.8) alloy reaches 3.84 wt.%within 5 min under 350℃,3 MPa,and the maximum hydrogen capacity of the alloy is 4.89 wt.%in same condition.However,the hydrogen absorption of Mg_(91.4)Ni_(7)Y_(1.6) alloy reaches 5.78 wt.%within 5 min,and the maximum hydrogen absorption of the alloy is 6.44 wt.%at 350℃and 3 MPa.The hydrogenation activation energy of Mg_(94.4)Ni_(7)Y_(1.6) alloy is 25.4 kJ/mol H_(2),and the enthalpy and entropy of hydrogen absorption are-60.6 kJ/mol H_(2) and 105.5 J/K/mol H_(2),separately.The alloy begins to dehydrogenate at 210℃,with the dehydrogenation activation energy of 87.7 kJ/mol H_(2).By altering the addition amount of Ni and Y elements,the 14 H-LPSO phase with smaller size and ternary eutectic areas with high volume fraction are obtained,which provides more phase boundaries and catalysts with better dispersion,and there are a lot of fine particles in the alloy,these structures are beneficial to enhance the hydrogen storage performance of the alloys.
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.
