[ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmenta...[ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmental change and ecological security for a river basin, DPSIR model as framework, the basic framework, principle and related method of index system of the environmental change and ecological security for a river basin under influence of the multi-level development were put forward. [ ]Result] Index system of the environmental change and ecological se- curity for a river basin based on DPSIR model included driving force indicator, pressure indicator, state indicator, influence indicator and response indicator. Each indicator type also had many sub-indicators. [ Conclusion] The research provided theoretical support and method reference for as- sessment of the ecological security and execution of the ecological environment management for a river basin in China.展开更多
Two hybrid processes including ozonation-ceramic membrane-biological activated carbon （BAC） （Process A） and ceramic membrane-BAC （Process B） were compared to treat polluted raw water. The performance of hybrid p...Two hybrid processes including ozonation-ceramic membrane-biological activated carbon （BAC） （Process A） and ceramic membrane-BAC （Process B） were compared to treat polluted raw water. The performance of hybrid processes was evaluated with the removal efficiencies of turbidity, ammonia and organic matter. The results indicated that more than 99% of particle count was removed by both hybrid processes and ozonation had no significant effect on its removal. BAC filtration greatly improved the removal of ammonia. Increasing the dissolved oxygen to 30.0 mg/L could lead to a removal of ammonia with concentrations as high as 7.80 mg/L and 8.69 mg/L for Processes A and B, respectively. The average removal efficiencies of total organic carbon and ultraviolet absorbance at 254 nm （UV254, a parameter indicating organic matter with aromatic structure） were 49% and 52% for Process A, 51% and 48% for Process B, respectively. Some organic matter was oxidized by ozone and this resulted in reduced membrane fouling and increased membrane flux by 25%-30%. However, pre-ozonation altered the components of the raw water and affected the microorganisms in the BAC, which may impact the removals of organic matter and nitrite negatively.展开更多
Antibiotic resistance,which is encoded by antibiotic-resistance genes(ARGs),has proliferated to become a growing threat to public health around the world.With technical advances,especially in the popularization of met...Antibiotic resistance,which is encoded by antibiotic-resistance genes(ARGs),has proliferated to become a growing threat to public health around the world.With technical advances,especially in the popularization of metagenomic sequencing,scientists have gained the ability to decipher the profiles of ARGs in diverse samples with high accuracy at an accelerated speed.To analyze thousands of ARGs in a highthroughput way,standardized and integrated pipelines are needed.The new version(v3.0)of the widely used ARGs online analysis pipeline(ARGs-OAP)has made significant improvements to both the reference database-the structured ARG(SARG)database-and the integrated analysis pipeline.SARG has been enhanced with sequence curation to improve annotation reliability,incorporate emerging resistance genotypes,and determine rigorous mechanism classification.The database has been further organized and visualized online in the format of a tree-like structure with a dictionary.It has also been divided into sub-databases for different application scenarios.In addition,the ARGs-OAP has been improved with adjusted quantification methods,simplified tool implementation,and multiple functions with userdefined reference databases.Moreover,the online platform now provides a diverse biostatistical analysis workflow with visualization packages for the efficient interpretation of ARG profiles.The ARGs-OAP v3.0 with an improved database and analysis pipeline will benefit academia,governmental management,and consultation regarding risk assessment of the environmental prevalence of ARGs.展开更多
Particle surface characteristics, floc recoverability and fractal structure of alum-kaolin flocs were investigated using in situ particle image velocimetry （PIV） and microbalance with or without humic acid. Experime...Particle surface characteristics, floc recoverability and fractal structure of alum-kaolin flocs were investigated using in situ particle image velocimetry （PIV） and microbalance with or without humic acid. Experimental results indicated that the zeta potential of kaolin particle surface after adsorption of humic acid was related with humic acid concentration and its acid-base buffering capacity. Adsorption of humic acid resulted in more negative electrophoresis on the particle surface. Coagulant dosages for particles to form flocs would increase with increasing humic concentration. PIV was used to evaluate floc structural fragmentation, floc surface erosion as well as recoverability after high shear. It was found that the floc size during the steady phase of growth was small, while the regrowing capability decreased in the presence of humic acid. The recoverability was closely related with floc breakage modes including floc structural fragmentation and floc surface erosion. The fractal dimensions of alum-kaolin flocs by mass-size method based on microbalance would decrease with increasing humic concentration. This study proved that humic acid had adverse influences on the performance of coagulation process.展开更多
We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters--from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles w...We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters--from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases. Other environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles.展开更多
The maximum specific methanogenic activity （SMA） of a sludge originating from a brewery wastewater treatment plant on the degradation of glucose was investigated at various levels of sulfate on a specific loading ba...The maximum specific methanogenic activity （SMA） of a sludge originating from a brewery wastewater treatment plant on the degradation of glucose was investigated at various levels of sulfate on a specific loading basis. Batch experiments were conducted in serum bottles at pH 7 and 35℃. A comparison of the values indicates that the SMA of this mixed culture was increased and reached its highest level of 0.128 g CH4 gas COD/（g VSS.d） when biomass was in contact with sulfate at a ratio of 1：0.114 by weight.展开更多
Arsenic is one of the most common inorganic contaminants in groundwater worldwide,mainly due to the release of naturally occurring arsenic from aquifer sediments（Amini et al.,2008;Li and Cai,2015;Rahman et al.,2015）...Arsenic is one of the most common inorganic contaminants in groundwater worldwide,mainly due to the release of naturally occurring arsenic from aquifer sediments（Amini et al.,2008;Li and Cai,2015;Rahman et al.,2015）.Naturally occurring arsenic exists predominantly in arsenate and arsenite species in groundwater.展开更多
Dolomite lime（DL）（CaMg（OH）4） was used as an economical source of Mg^2＋for the removal and recovery of phosphate from an anaerobic digester effluent of a municipal wastewater treatment plant（MWWTP） wastewater....Dolomite lime（DL）（CaMg（OH）4） was used as an economical source of Mg^2＋for the removal and recovery of phosphate from an anaerobic digester effluent of a municipal wastewater treatment plant（MWWTP） wastewater. Batch precipitation results determined that phosphate was effectively reduced from 87 to less than 4 mg-P/L when the effluent water was mixed with 0.3 g/L of DL. The competitive precipitation mechanisms of different solids in the treatment system consisting of Ca^2＋–Mg^2＋–NH4^＋–PO4^3-CO3^2-were determined by comparing model predictions with experimental results. Thermodynamic model calculations indicated that hydroxyapatite（Ca10（PO4）6（OH）2）, Ca4H（PO4）3·3H2O, Ca3（PO4）2（beta）, and Ca3（PO4）2（am2）were more stable than struvite（MgNH4PO36·H2O） and calcite（CaCO3）. However, X-ray diffraction（XRD） analysis determined the formation of struvite and calcite minerals in the treated effluent. Kinetic experimental results showed that most of the phosphate was removed from synthetic effluent containing NH4^＋within 2 hr, while only 20% of the PO4^3-was removed in the absence of NH4^＋after 24 hr of treatment. The formation of struvite in the DL-treated effluent was due to the rapid precipitation rate of the mineral. The final pH of the DL-treated effluent significantly influenced the mass ratio of struvite to calcite in the precipitates. Because more calcite was formed when the p H increased from 8.4 to 9.6, a pH range of 8.0–8.5 should be used to produce solid with high PO4^3-content. This study demonstrated that DL could be used for effective removal of phosphate from the effluent and that resultant precipitates contained high content of phosphate and ammonium.展开更多
Leptospirosis is a potential threat to public health. An increasing number of people infected with Leptospira were reported in Bantul District, Yogyakarta special region with a case fatality rate (CFR) of 7.8%. Infect...Leptospirosis is a potential threat to public health. An increasing number of people infected with Leptospira were reported in Bantul District, Yogyakarta special region with a case fatality rate (CFR) of 7.8%. Infected areas in the district have increased from 2 to 15 sub districts. Leptospirosis is caused by Leptospira bacteria and spread by direct contact with infected rodents and indirect contact through contaminated water or soil. Leptospira in rats, water and soil were detected using real-time quantitative polymerase chain reaction (qPCR). The sites of sampled materials were geocoded using Global Positioning System (GPS). Spatial analysis was used to predict the spread of Spira. This study aims to perform the mapping, clustering, and predicting the spread of Leptospira in Bantul Yogyakarta Indonesia. Data were collected from three sub-districts: Sedayu, Sewon and Bantul. The result showed that 38.04% from 368 samples were Spira positive. There were four significant clusters of infection spread source. Spira is predicted to spread in, and out from, Bantul District.展开更多
Objective: To detect genetic variations among pathogenic Leptospira isolated from rats using 16 S r RNA gen as chronometer. Methods: This is an observational study with cross sectional design. Rats saples were taken i...Objective: To detect genetic variations among pathogenic Leptospira isolated from rats using 16 S r RNA gen as chronometer. Methods: This is an observational study with cross sectional design. Rats saples were taken in Yogyakarta Special Region of Indonesia. Leptospira in the rats was detected by two methods ie. real time PCR(q PCR) by using primers correspond to16 S r RNA gene of Leptospira, and standard PCR by using dif erent set of primer correspond to the 16 S r RNA gene of Leptospira. The standard PCR amplicon then subjected for DNA sequencing. Analysis genetic variation was performed using MEGA 6.2. Software. Results:There were 99 DNA samples from rats included in this study. Detection of Leptospira by using q PCR revealed 25 samples positive for pathogenic Leptospira, while only 6 samples were able to be detected using standard PCR. The new primer set correspond to 16 S r RNA gene was able to detect specii cally pathogenic Leptospira in the rats. Sequencing analysis of 6 PCR amplicons showed that the Leptospira which infect the rats catched in Yogyakarta genetically close related with pathogenic Leptospira which were isolated from human, animal, rodents, and environment. Conclusions: It can be considered that rats are the most important vector and reservoir of Leptospira.展开更多
Wastewater surveillance(WWS)can leverage its wide coverage,population-based sampling,and high monitoring frequency to capture citywide pandemic trends independent of clinical surveillance.Here we conducted a nine mont...Wastewater surveillance(WWS)can leverage its wide coverage,population-based sampling,and high monitoring frequency to capture citywide pandemic trends independent of clinical surveillance.Here we conducted a nine months daily WWS for severe acute respiratory syndrome coronavirus 2(SARSCoV-2)from 12 wastewater treatment plants(WWTPs),covering approximately 80%of the population,to monitor infection dynamics in Hong Kong,China.We found that the SARS-CoV-2 virus concentration in wastewater was correlated with the daily number of reported cases and reached two pandemic peaks three days earlier during the study period.In addition,two different methods were established to estimate the prevalence/incidence rates from wastewater measurements.The estimated results from wastewater were consistent with findings from two independent citywide clinical surveillance programmes(rapid antigen test(RAT)surveillance and serology surveillance),but higher than the cases number reported by the Centre for Health Protection(CHP)of Hong Kong,China.Moreover,the effective reproductive number(R_(t))was estimated from wastewater measurements to reflect both citywide and regional transmission dynamics.Our findings demonstrate that large-scale intensive WWS from WWTPs provides cost-effective and timely public health information,especially when the clinical surveillance is inadequate and costly.This approach also provides insights into pandemic dynamics at higher spatiotemporal resolutions,facilitating the formulation of effective control policies and targeted resource allocation.展开更多
The recent outbreak of the 5th wave of COVID-19 in Hong Kong reminds us again that infectious diseases are one of the grand challenges to the public health today.The ability to rapidly monitor the spread of diseases i...The recent outbreak of the 5th wave of COVID-19 in Hong Kong reminds us again that infectious diseases are one of the grand challenges to the public health today.The ability to rapidly monitor the spread of diseases in a large scale is the key for prevention,intervention and control.Wastewater-Based Epidemiology(WBE)is based on pooled wastewater of a population.展开更多
The emergence and rapid spread of antimicrobial resistance is of global public health concern.The gut microbiota harboring diverse commensal and opportunistic bacteria that can acquire resistance via horizontal and ve...The emergence and rapid spread of antimicrobial resistance is of global public health concern.The gut microbiota harboring diverse commensal and opportunistic bacteria that can acquire resistance via horizontal and vertical gene transfers is considered an important reservoir and sink of antibiotic resistance genes(ARGs).In this review,we describe the reservoirs of gut ARGs and their dynamics in both animals and humans,use the One Health perspective to track the transmission of ARG-containing bacteria between humans,animals,and the environment,and assess the impact of antimicrobial resistance on human health and socioeconomic development.The gut resistome can evolve in an environment subject to various selective pressures,including antibiotic administration and environmental and lifestyle factors(e.g.,diet,age,gender,and living conditions),and interventions through probiotics.Strategies to reduce the abundance of clinically relevant antibiotic-resistant bacteria and their resistance determinants in various environmental niches are needed to ensure the mitigation of acquired antibiotic resistance.With the help of effective measures taken at the national,local,personal,and intestinal management,it will also result in preventing or minimizing the spread of infectious diseases.This review aims to improve our understanding of the correlations between intestinal microbiota and antimicrobial resistance and provide a basis for the development of management strategies to mitigate the antimicrobial resistance crisis.展开更多
A new neural network architecture,namely DimNet,was designed for correlating dimensionless quantities with power-law-like relations.Unlike common neural networks that are usually used as“black-boxes”,DimNet is inter...A new neural network architecture,namely DimNet,was designed for correlating dimensionless quantities with power-law-like relations.Unlike common neural networks that are usually used as“black-boxes”,DimNet is interpretable as it can be converted to an explicit algebraic piecewise power-law-like function.With DimNet,a data-driven,empirical model was developed to predict the pre-dryout heat transfer coefficient of flow boiling within microfin tubes.The model was trained on a database with 7349 experimental data points for 16 refrigerants,and then optimized by comparing different sets of dominant dimensionless quantities and by adjusting the network configuration.The model exhibits an overall mean-absolute-error of 13.8%and no systematic variation with respect to the salient parameters for most conditions.Besides being statistically accurate,the model captures parametric trends of the heat transfer coefficient.The excellent prediction performance of the model was attributed to the DimNet’s ability to automatically classify the data into optimal regions and simultaneously correlate the data of each region.Therefore,the DimNet architecture is inherently suitable for modeling complex heat transfer and flow problems where multiple distinct physical regimes exist,especially for problems where a power-law-like input–output relation is desired such as convective heat transfer.展开更多
The performance of an integrated process including coagulation, ozonation, ceramic ultrafiltration （UF） and biologic activated carbon （BAC） filtration was investigated for the removal of organic matter and disinfe...The performance of an integrated process including coagulation, ozonation, ceramic ultrafiltration （UF） and biologic activated carbon （BAC） filtration was investigated for the removal of organic matter and disinfection by-products （DBPs） precursors from micropolluted surface water. A pilot scale plant with the capacity of 120 m3 per day was set up and operated for the treatment of drinking water. Ceramic membranes were used with the filtration area of 50 m2 and a pore size of 60 nm. Dissolved organic matter was divided into five fractions including hydrophobic acid （HoA）, base （HOB） and neutral （HoN）, weakly hydrophobic acid （WHOA） and hydrophilic matter （HIM） by DAX-8 and XAD-4 resins. The experiment results showed that the removal of organic matter was significantly improved with ozonation in advance. In sum, the integrated process removed 73% of dissolved organic carbon （DOC）, 87% of UV254, 77% of trihalomethane （THMs） precursors, 76% of haloacetic acid （HAAs） precursors, 83%of trichloracetic aldehyde （CH） precursor, 77% of dichloroaeetonitrile （DCAN） precursor, 51% of trichloroacetonitrile （TCAN） precursor, 96% of 1,1,1- trichloroacetone （TCP） precursor and 63% of trichloroni- tromethane （TCNM） precursor. Hydrophobic organic matter was converted into hydrophilic organic matter during ozonation/UF, while the organic matter with molecular weight of 1000-3000 Da was remarkably decreased and converted into lower molecular weight organic matter ranged from 200-500 Da. DOC had a close linear relationship with the formation potential of DBPs.展开更多
Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation...Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation, air conditioning and refrigeration systems. A novel finless bare tube heat exchanger was studied using a validated heat exchanger modeling tool. The capacity based optimization and entransy dissipation based thermal resistance were used and compared. The applicability of using entransy dissipation based thermal resistance in this type of heat exchanger optimization has been discussed. It has been demonstrated that minimizing entransy dissipation and maximizing capacity are equivalent to optimizing evaporators with fixed flow rates and different when optimizing evaporators with variable flow rates and the deviation is negligible when heat exchanger capacity is small(~1 k W) and more obvious as heat exchanger capacity increases. Thus entransy dissipation based thermal resistance could be used as an alternative optimization index to capacity for evaporators with fixed flow rate and small capacity evaporators with variable flow rates and should be used individually with capacity as an optimization index for evaporators with large capacity and variable flow rates.展开更多
Antibiotic resistance has been recognized as a major challenge worldwide for humans.“One Health”has been recognized as a key concept for containment of antibiotic resistance.Under the framework,the role of the envir...Antibiotic resistance has been recognized as a major challenge worldwide for humans.“One Health”has been recognized as a key concept for containment of antibiotic resistance.Under the framework,the role of the environment in the development of antibiotic resistance genes(ARGs)has become increasingly obvious.Despite numerous efforts,response to antibiotic re-sistance is considered to be inadequate,which is probably due to the lack of a clear roadmap.Here,we propose a“One Health”roadmap to combat antibiotic resistance in the environment through(1)understanding environmental resistome.The environmental gene pool has long been recognized as the single largest reservoir of both known and novel ARGs.(2)Standardizing ARG quantification.Systematic joint efforts based on standardized quantification are urgently needed to un-derstand the true tempospatial profiles of the environmental resistome.(3)Identifying mechanisms of resistome development.Horizontal gene transfer and co-selection have been recognized as the two main mechanisms contributing to the environmental resistome.(4)Establishing a risk-assessment framework.The first critical step for large-scale cost-effective targeted ARG management in the environment is the risk assessment to identify the priority ARGs for control.(5)Formulating regulatory standards.By correlating the environmental ARG profile with public health,we may identify the indicator ARGs that can be integrated into current environmental quality standards.(6)Developing control strategies.Systematic analysis of available control technologies is required to identify the most feasible ones to curtail the spread of ARGs in the environment.The proposed roadmap under the“One Health”framework provides a guide to tackle antibiotic resistance in the environment.展开更多
This study mainly focused on the occurrence of pharmaceutical and personal care products(PPCPs)in sewage dewatered sludge and their discharges through sludge disposal from wastewater treatment plants(WWTPs).The data w...This study mainly focused on the occurrence of pharmaceutical and personal care products(PPCPs)in sewage dewatered sludge and their discharges through sludge disposal from wastewater treatment plants(WWTPs).The data were obtained and calculated from seven PPCPs in dewatered sludge collected from 12WWTPs in two typical cities,Beijing and Shenzhen in China.Four of seven PPCPs,diclofenac acid,carbamazepine,mefenamic acid and N,N-diethyl-m-toluamide were detectable in dewatered sludge from Beijing and Shenzhen with concentration up to 4240,11,060,92 and 219μg/kg respectively.While,the other three compounds,trimethoprim,chloramphenicol and bezafibrate were not detected in collected samples from these two cities.The highest discharge of diclofenac acid and carbamazepine were 1023 g/d and 494 g/d respectively.In addition,the total discharge of these four detected PPCPs from each plant ranged from 5 to 1092 g/d in Beijing and 4e497 g/d in Shenzhen.Thus,PPCP discharge through sludge disposal cannot be neglected,and further research on transfer of PPCPs during sludge disposal onto agriculture land and influence of sludge application is required and essential.展开更多
Recently the porous bilayer wood solar collectors have drawn increasing attention because of their potential application in solar desalination.In this paper,a thermodynamic model has been developed to analyze the perf...Recently the porous bilayer wood solar collectors have drawn increasing attention because of their potential application in solar desalination.In this paper,a thermodynamic model has been developed to analyze the performance of the wood solar collector.A modeling analysis has also been conducted to assess the performance and operating conditions of the multiple effect desalination(MED)system integrated with the porous wood solar collector.Specifically,the effects of operating parameters,such as the motive steam temperature,seawater flow rate,input solar energy and number of effects on the energy consumption for each ton of distilled water produced have been investigated in the MED desalination system combined with the bilayer wood solar steam generator.It is found that,under a given operating condition,there exists an optimum steam generation temperature of around 145℃in the wood solar collector,so that the specific power consumption in the MED system reaches a minimum value of24.88 kWh/t.The average temperature difference is significantly affected by the solar heating capacity.With the solar capacity increasing from 50 kW to 230 kW,the average temperature difference increases from 1.88℃to 6.27℃.This parametric simulation study will help the design of efficient bilayer wood solar steam generator as well as the MED desalination system.展开更多
文摘[ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmental change and ecological security for a river basin, DPSIR model as framework, the basic framework, principle and related method of index system of the environmental change and ecological security for a river basin under influence of the multi-level development were put forward. [ ]Result] Index system of the environmental change and ecological se- curity for a river basin based on DPSIR model included driving force indicator, pressure indicator, state indicator, influence indicator and response indicator. Each indicator type also had many sub-indicators. [ Conclusion] The research provided theoretical support and method reference for as- sessment of the ecological security and execution of the ecological environment management for a river basin in China.
基金supported by the National Grand Water Project(No.2008ZX07423-002)the National Natural Science Foundation of China(No.50978170)the Guangdong Provincial Funding(No.2012B030800001)
文摘Two hybrid processes including ozonation-ceramic membrane-biological activated carbon （BAC） （Process A） and ceramic membrane-BAC （Process B） were compared to treat polluted raw water. The performance of hybrid processes was evaluated with the removal efficiencies of turbidity, ammonia and organic matter. The results indicated that more than 99% of particle count was removed by both hybrid processes and ozonation had no significant effect on its removal. BAC filtration greatly improved the removal of ammonia. Increasing the dissolved oxygen to 30.0 mg/L could lead to a removal of ammonia with concentrations as high as 7.80 mg/L and 8.69 mg/L for Processes A and B, respectively. The average removal efficiencies of total organic carbon and ultraviolet absorbance at 254 nm （UV254, a parameter indicating organic matter with aromatic structure） were 49% and 52% for Process A, 51% and 48% for Process B, respectively. Some organic matter was oxidized by ozone and this resulted in reduced membrane fouling and increased membrane flux by 25%-30%. However, pre-ozonation altered the components of the raw water and affected the microorganisms in the BAC, which may impact the removals of organic matter and nitrite negatively.
基金supported by a Theme-based Research Scheme grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(T21-705/20-N)。
文摘Antibiotic resistance,which is encoded by antibiotic-resistance genes(ARGs),has proliferated to become a growing threat to public health around the world.With technical advances,especially in the popularization of metagenomic sequencing,scientists have gained the ability to decipher the profiles of ARGs in diverse samples with high accuracy at an accelerated speed.To analyze thousands of ARGs in a highthroughput way,standardized and integrated pipelines are needed.The new version(v3.0)of the widely used ARGs online analysis pipeline(ARGs-OAP)has made significant improvements to both the reference database-the structured ARG(SARG)database-and the integrated analysis pipeline.SARG has been enhanced with sequence curation to improve annotation reliability,incorporate emerging resistance genotypes,and determine rigorous mechanism classification.The database has been further organized and visualized online in the format of a tree-like structure with a dictionary.It has also been divided into sub-databases for different application scenarios.In addition,the ARGs-OAP has been improved with adjusted quantification methods,simplified tool implementation,and multiple functions with userdefined reference databases.Moreover,the online platform now provides a diverse biostatistical analysis workflow with visualization packages for the efficient interpretation of ARG profiles.The ARGs-OAP v3.0 with an improved database and analysis pipeline will benefit academia,governmental management,and consultation regarding risk assessment of the environmental prevalence of ARGs.
基金supported by the National Natural Science Foundation of China (No. 20721140019, U0773002)the National High Technology Research and Development Program (863) of China (No. 2002AA601120)
文摘Particle surface characteristics, floc recoverability and fractal structure of alum-kaolin flocs were investigated using in situ particle image velocimetry （PIV） and microbalance with or without humic acid. Experimental results indicated that the zeta potential of kaolin particle surface after adsorption of humic acid was related with humic acid concentration and its acid-base buffering capacity. Adsorption of humic acid resulted in more negative electrophoresis on the particle surface. Coagulant dosages for particles to form flocs would increase with increasing humic concentration. PIV was used to evaluate floc structural fragmentation, floc surface erosion as well as recoverability after high shear. It was found that the floc size during the steady phase of growth was small, while the regrowing capability decreased in the presence of humic acid. The recoverability was closely related with floc breakage modes including floc structural fragmentation and floc surface erosion. The fractal dimensions of alum-kaolin flocs by mass-size method based on microbalance would decrease with increasing humic concentration. This study proved that humic acid had adverse influences on the performance of coagulation process.
基金Supported by the Special Promotion Program for Guangdong Provincial Ocean and Fishery Technology(No.A201101F03)the National Natural Science Foundation of China(Nos.41176102,31100260)
文摘We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters--from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases. Other environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles.
基金Project supported by the National Research Center of Environmental and Hazardous Waste Management(NRC-EHWM), Chulalongko1 University,Thailand.
文摘The maximum specific methanogenic activity （SMA） of a sludge originating from a brewery wastewater treatment plant on the degradation of glucose was investigated at various levels of sulfate on a specific loading basis. Batch experiments were conducted in serum bottles at pH 7 and 35℃. A comparison of the values indicates that the SMA of this mixed culture was increased and reached its highest level of 0.128 g CH4 gas COD/（g VSS.d） when biomass was in contact with sulfate at a ratio of 1：0.114 by weight.
文摘Arsenic is one of the most common inorganic contaminants in groundwater worldwide,mainly due to the release of naturally occurring arsenic from aquifer sediments（Amini et al.,2008;Li and Cai,2015;Rahman et al.,2015）.Naturally occurring arsenic exists predominantly in arsenate and arsenite species in groundwater.
基金supported by the National Natural Science Foundation of China (No. 51078339)
文摘Dolomite lime（DL）（CaMg（OH）4） was used as an economical source of Mg^2＋for the removal and recovery of phosphate from an anaerobic digester effluent of a municipal wastewater treatment plant（MWWTP） wastewater. Batch precipitation results determined that phosphate was effectively reduced from 87 to less than 4 mg-P/L when the effluent water was mixed with 0.3 g/L of DL. The competitive precipitation mechanisms of different solids in the treatment system consisting of Ca^2＋–Mg^2＋–NH4^＋–PO4^3-CO3^2-were determined by comparing model predictions with experimental results. Thermodynamic model calculations indicated that hydroxyapatite（Ca10（PO4）6（OH）2）, Ca4H（PO4）3·3H2O, Ca3（PO4）2（beta）, and Ca3（PO4）2（am2）were more stable than struvite（MgNH4PO36·H2O） and calcite（CaCO3）. However, X-ray diffraction（XRD） analysis determined the formation of struvite and calcite minerals in the treated effluent. Kinetic experimental results showed that most of the phosphate was removed from synthetic effluent containing NH4^＋within 2 hr, while only 20% of the PO4^3-was removed in the absence of NH4^＋after 24 hr of treatment. The formation of struvite in the DL-treated effluent was due to the rapid precipitation rate of the mineral. The final pH of the DL-treated effluent significantly influenced the mass ratio of struvite to calcite in the precipitates. Because more calcite was formed when the p H increased from 8.4 to 9.6, a pH range of 8.0–8.5 should be used to produce solid with high PO4^3-content. This study demonstrated that DL could be used for effective removal of phosphate from the effluent and that resultant precipitates contained high content of phosphate and ammonium.
文摘Leptospirosis is a potential threat to public health. An increasing number of people infected with Leptospira were reported in Bantul District, Yogyakarta special region with a case fatality rate (CFR) of 7.8%. Infected areas in the district have increased from 2 to 15 sub districts. Leptospirosis is caused by Leptospira bacteria and spread by direct contact with infected rodents and indirect contact through contaminated water or soil. Leptospira in rats, water and soil were detected using real-time quantitative polymerase chain reaction (qPCR). The sites of sampled materials were geocoded using Global Positioning System (GPS). Spatial analysis was used to predict the spread of Spira. This study aims to perform the mapping, clustering, and predicting the spread of Leptospira in Bantul Yogyakarta Indonesia. Data were collected from three sub-districts: Sedayu, Sewon and Bantul. The result showed that 38.04% from 368 samples were Spira positive. There were four significant clusters of infection spread source. Spira is predicted to spread in, and out from, Bantul District.
文摘Objective: To detect genetic variations among pathogenic Leptospira isolated from rats using 16 S r RNA gen as chronometer. Methods: This is an observational study with cross sectional design. Rats saples were taken in Yogyakarta Special Region of Indonesia. Leptospira in the rats was detected by two methods ie. real time PCR(q PCR) by using primers correspond to16 S r RNA gene of Leptospira, and standard PCR by using dif erent set of primer correspond to the 16 S r RNA gene of Leptospira. The standard PCR amplicon then subjected for DNA sequencing. Analysis genetic variation was performed using MEGA 6.2. Software. Results:There were 99 DNA samples from rats included in this study. Detection of Leptospira by using q PCR revealed 25 samples positive for pathogenic Leptospira, while only 6 samples were able to be detected using standard PCR. The new primer set correspond to 16 S r RNA gene was able to detect specii cally pathogenic Leptospira in the rats. Sequencing analysis of 6 PCR amplicons showed that the Leptospira which infect the rats catched in Yogyakarta genetically close related with pathogenic Leptospira which were isolated from human, animal, rodents, and environment. Conclusions: It can be considered that rats are the most important vector and reservoir of Leptospira.
基金financially supported by the Health and Medical Research Fund(COVID1903015)the Food and Health Bureau,the Government of the Hong Kong Special Administrative Region(SAR),China+1 种基金supported by the AIR@InnoHK(KL,GML,and JTW)Health@InnoHK(MP and LLMP)administered by the Innovation and Technology Commission of the Government of the Hong Kong SAR.
文摘Wastewater surveillance(WWS)can leverage its wide coverage,population-based sampling,and high monitoring frequency to capture citywide pandemic trends independent of clinical surveillance.Here we conducted a nine months daily WWS for severe acute respiratory syndrome coronavirus 2(SARSCoV-2)from 12 wastewater treatment plants(WWTPs),covering approximately 80%of the population,to monitor infection dynamics in Hong Kong,China.We found that the SARS-CoV-2 virus concentration in wastewater was correlated with the daily number of reported cases and reached two pandemic peaks three days earlier during the study period.In addition,two different methods were established to estimate the prevalence/incidence rates from wastewater measurements.The estimated results from wastewater were consistent with findings from two independent citywide clinical surveillance programmes(rapid antigen test(RAT)surveillance and serology surveillance),but higher than the cases number reported by the Centre for Health Protection(CHP)of Hong Kong,China.Moreover,the effective reproductive number(R_(t))was estimated from wastewater measurements to reflect both citywide and regional transmission dynamics.Our findings demonstrate that large-scale intensive WWS from WWTPs provides cost-effective and timely public health information,especially when the clinical surveillance is inadequate and costly.This approach also provides insights into pandemic dynamics at higher spatiotemporal resolutions,facilitating the formulation of effective control policies and targeted resource allocation.
文摘The recent outbreak of the 5th wave of COVID-19 in Hong Kong reminds us again that infectious diseases are one of the grand challenges to the public health today.The ability to rapidly monitor the spread of diseases in a large scale is the key for prevention,intervention and control.Wastewater-Based Epidemiology(WBE)is based on pooled wastewater of a population.
基金supported by the National Natural Science Foundation of China(41977137 and 42307048)the International Atomic Energy Agency Research Project(D15022)+5 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB460)the China Postdoctoral Science Foundation(2023M733593)Chinese Academy of Sciences President's International Fellowship Initiative(2020DC0005)Academy of Finland,Innovation Fund Denmark and the European Commission Horizon 2020 financed under the ERA-NET Aquatic Pollutants Joint Transnational Call(REWA,GA No 869178)the Center for Health Impacts of Agriculture(CHIA)of Michigan State Universitysupported by the fellowship of Alexander von Humboldt for experienced researchers,and Shennong Young Talents of the Ministry of Agriculture and Rural Affairs,China(SNYCQN006-2022).
文摘The emergence and rapid spread of antimicrobial resistance is of global public health concern.The gut microbiota harboring diverse commensal and opportunistic bacteria that can acquire resistance via horizontal and vertical gene transfers is considered an important reservoir and sink of antibiotic resistance genes(ARGs).In this review,we describe the reservoirs of gut ARGs and their dynamics in both animals and humans,use the One Health perspective to track the transmission of ARG-containing bacteria between humans,animals,and the environment,and assess the impact of antimicrobial resistance on human health and socioeconomic development.The gut resistome can evolve in an environment subject to various selective pressures,including antibiotic administration and environmental and lifestyle factors(e.g.,diet,age,gender,and living conditions),and interventions through probiotics.Strategies to reduce the abundance of clinically relevant antibiotic-resistant bacteria and their resistance determinants in various environmental niches are needed to ensure the mitigation of acquired antibiotic resistance.With the help of effective measures taken at the national,local,personal,and intestinal management,it will also result in preventing or minimizing the spread of infectious diseases.This review aims to improve our understanding of the correlations between intestinal microbiota and antimicrobial resistance and provide a basis for the development of management strategies to mitigate the antimicrobial resistance crisis.
文摘A new neural network architecture,namely DimNet,was designed for correlating dimensionless quantities with power-law-like relations.Unlike common neural networks that are usually used as“black-boxes”,DimNet is interpretable as it can be converted to an explicit algebraic piecewise power-law-like function.With DimNet,a data-driven,empirical model was developed to predict the pre-dryout heat transfer coefficient of flow boiling within microfin tubes.The model was trained on a database with 7349 experimental data points for 16 refrigerants,and then optimized by comparing different sets of dominant dimensionless quantities and by adjusting the network configuration.The model exhibits an overall mean-absolute-error of 13.8%and no systematic variation with respect to the salient parameters for most conditions.Besides being statistically accurate,the model captures parametric trends of the heat transfer coefficient.The excellent prediction performance of the model was attributed to the DimNet’s ability to automatically classify the data into optimal regions and simultaneously correlate the data of each region.Therefore,the DimNet architecture is inherently suitable for modeling complex heat transfer and flow problems where multiple distinct physical regimes exist,especially for problems where a power-law-like input–output relation is desired such as convective heat transfer.
文摘The performance of an integrated process including coagulation, ozonation, ceramic ultrafiltration （UF） and biologic activated carbon （BAC） filtration was investigated for the removal of organic matter and disinfection by-products （DBPs） precursors from micropolluted surface water. A pilot scale plant with the capacity of 120 m3 per day was set up and operated for the treatment of drinking water. Ceramic membranes were used with the filtration area of 50 m2 and a pore size of 60 nm. Dissolved organic matter was divided into five fractions including hydrophobic acid （HoA）, base （HOB） and neutral （HoN）, weakly hydrophobic acid （WHOA） and hydrophilic matter （HIM） by DAX-8 and XAD-4 resins. The experiment results showed that the removal of organic matter was significantly improved with ozonation in advance. In sum, the integrated process removed 73% of dissolved organic carbon （DOC）, 87% of UV254, 77% of trihalomethane （THMs） precursors, 76% of haloacetic acid （HAAs） precursors, 83%of trichloracetic aldehyde （CH） precursor, 77% of dichloroaeetonitrile （DCAN） precursor, 51% of trichloroacetonitrile （TCAN） precursor, 96% of 1,1,1- trichloroacetone （TCP） precursor and 63% of trichloroni- tromethane （TCNM） precursor. Hydrophobic organic matter was converted into hydrophilic organic matter during ozonation/UF, while the organic matter with molecular weight of 1000-3000 Da was remarkably decreased and converted into lower molecular weight organic matter ranged from 200-500 Da. DOC had a close linear relationship with the formation potential of DBPs.
基金supported by the sponsors of the Energy Efficiency and Heat Pumps Consortium and Modeling and Optimization Consortium at the Center for Environmental Energy Engineering(CEEE)of the University of Maryland and Heat Transfer Technologies LLC for manufacturing the heat exchanger prototype
文摘Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation, air conditioning and refrigeration systems. A novel finless bare tube heat exchanger was studied using a validated heat exchanger modeling tool. The capacity based optimization and entransy dissipation based thermal resistance were used and compared. The applicability of using entransy dissipation based thermal resistance in this type of heat exchanger optimization has been discussed. It has been demonstrated that minimizing entransy dissipation and maximizing capacity are equivalent to optimizing evaporators with fixed flow rates and different when optimizing evaporators with variable flow rates and the deviation is negligible when heat exchanger capacity is small(~1 k W) and more obvious as heat exchanger capacity increases. Thus entransy dissipation based thermal resistance could be used as an alternative optimization index to capacity for evaporators with fixed flow rate and small capacity evaporators with variable flow rates and should be used individually with capacity as an optimization index for evaporators with large capacity and variable flow rates.
基金supported by a Theme‐based Research Scheme grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project no.T21‐705/20‐N).
文摘Antibiotic resistance has been recognized as a major challenge worldwide for humans.“One Health”has been recognized as a key concept for containment of antibiotic resistance.Under the framework,the role of the environment in the development of antibiotic resistance genes(ARGs)has become increasingly obvious.Despite numerous efforts,response to antibiotic re-sistance is considered to be inadequate,which is probably due to the lack of a clear roadmap.Here,we propose a“One Health”roadmap to combat antibiotic resistance in the environment through(1)understanding environmental resistome.The environmental gene pool has long been recognized as the single largest reservoir of both known and novel ARGs.(2)Standardizing ARG quantification.Systematic joint efforts based on standardized quantification are urgently needed to un-derstand the true tempospatial profiles of the environmental resistome.(3)Identifying mechanisms of resistome development.Horizontal gene transfer and co-selection have been recognized as the two main mechanisms contributing to the environmental resistome.(4)Establishing a risk-assessment framework.The first critical step for large-scale cost-effective targeted ARG management in the environment is the risk assessment to identify the priority ARGs for control.(5)Formulating regulatory standards.By correlating the environmental ARG profile with public health,we may identify the indicator ARGs that can be integrated into current environmental quality standards.(6)Developing control strategies.Systematic analysis of available control technologies is required to identify the most feasible ones to curtail the spread of ARGs in the environment.The proposed roadmap under the“One Health”framework provides a guide to tackle antibiotic resistance in the environment.
基金supported by Tsinghua University e Veolia Environment Joint Research Center for Advanced Environment Technology and the Program for Changjiang Scholars and Innovative Research Team in University(IRT1261).
文摘This study mainly focused on the occurrence of pharmaceutical and personal care products(PPCPs)in sewage dewatered sludge and their discharges through sludge disposal from wastewater treatment plants(WWTPs).The data were obtained and calculated from seven PPCPs in dewatered sludge collected from 12WWTPs in two typical cities,Beijing and Shenzhen in China.Four of seven PPCPs,diclofenac acid,carbamazepine,mefenamic acid and N,N-diethyl-m-toluamide were detectable in dewatered sludge from Beijing and Shenzhen with concentration up to 4240,11,060,92 and 219μg/kg respectively.While,the other three compounds,trimethoprim,chloramphenicol and bezafibrate were not detected in collected samples from these two cities.The highest discharge of diclofenac acid and carbamazepine were 1023 g/d and 494 g/d respectively.In addition,the total discharge of these four detected PPCPs from each plant ranged from 5 to 1092 g/d in Beijing and 4e497 g/d in Shenzhen.Thus,PPCP discharge through sludge disposal cannot be neglected,and further research on transfer of PPCPs during sludge disposal onto agriculture land and influence of sludge application is required and essential.
文摘Recently the porous bilayer wood solar collectors have drawn increasing attention because of their potential application in solar desalination.In this paper,a thermodynamic model has been developed to analyze the performance of the wood solar collector.A modeling analysis has also been conducted to assess the performance and operating conditions of the multiple effect desalination(MED)system integrated with the porous wood solar collector.Specifically,the effects of operating parameters,such as the motive steam temperature,seawater flow rate,input solar energy and number of effects on the energy consumption for each ton of distilled water produced have been investigated in the MED desalination system combined with the bilayer wood solar steam generator.It is found that,under a given operating condition,there exists an optimum steam generation temperature of around 145℃in the wood solar collector,so that the specific power consumption in the MED system reaches a minimum value of24.88 kWh/t.The average temperature difference is significantly affected by the solar heating capacity.With the solar capacity increasing from 50 kW to 230 kW,the average temperature difference increases from 1.88℃to 6.27℃.This parametric simulation study will help the design of efficient bilayer wood solar steam generator as well as the MED desalination system.
