Despite significant Brazilian social programs to expand energy access,approximately one million people in rural Amazonia still lack electricity.Moreover,the existing rural electricity grid in the region is inadequate ...Despite significant Brazilian social programs to expand energy access,approximately one million people in rural Amazonia still lack electricity.Moreover,the existing rural electricity grid in the region is inadequate for supporting efficient small-scale production systems due to both the poor quality and high cost of supplied energy.In parallel,traditional wooden bridges in the Amazon have been progressively replaced by more durable concrete structures in recent years.In this context,this study explores the application of very low-head hydropower installations in the Amazon,focusing on integrating axial-flow turbines beneath small concrete bridges.The methodology involves analyzing flow duration curves and key hydraulic parameters upstream and downstream to design a micro-hydropower system comprising two or more units,thereby maximizing annual energy generation.Additionally,the study assesses the applicability of the minimum pressure coefficient criterion to improve the efficiency of very low-head turbines.This design criterion is first validated against an existing experimental study featuring a propeller turbine with a simple curved plate blade.The proposed methodology is then applied to a case study involving a small dam-bridge with a head variation from 1.4 to 2.4 m and a flow rate ranging from 0.23 to 0.92 m^(3)/s.The optimal configuration achieves an energy output of 26.2 MWh/year with an efficiency of up to 86%.展开更多
Xylitol,one of the top twelve chemical building blocks,is commercially synthesized through the xylose hy-drogenation reaction using a metal catalyst.Biochar has emerged as an eco-efficient catalyst support material.In...Xylitol,one of the top twelve chemical building blocks,is commercially synthesized through the xylose hy-drogenation reaction using a metal catalyst.Biochar has emerged as an eco-efficient catalyst support material.In this study,biochar derived from corn stover(BCS)was first used as a metal catalyst support material for xylose hydrogenation into xylitol.The catalyst was prepared by carbonizing corn stover(CS),impregnating the resulting biochar with metal,and reducing the metal-impregnated BCS.The catalyst characteristics were comprehensively explored.The Ru/BCS catalyst was employed in xylose conversion to xylitol at different process temperatures(100-160℃),retention times(3-12 h),H_(2)pressures(2-5 MPa),and Ru contents(1-5%).The highest xylitol yield(87.0 wt.%)and selectivity(91.6%)were derived at 120℃ for 6 h under 4 MPa H_(2)using 5%Ru.Interestingly,the Ru/BCS catalyst showed high stability under the promising process condition.Additionally,xylitol production from hydrolysates enriched with CS xylose was subsequently explored.On the other hand,the catalyst characterization results revealed that the superior catalytic efficiency of 5Ru/BCS was mainly due to the metal nanoparticles embedded in the biochar.Additionally,BCS proved to be an outstanding support material for a bimetallic hydrogenation catalyst(Ru-Ni/BCS).Therefore,these results indicate that BCS can be a competitive support material for metal hydrogenation catalysts,enhancing environmental friendliness and potentially being employed in industrial-scale xylitol production.展开更多
Advanced oxidation processes have been widely studied for organic pollutants treatment in water,but the degradation performance of radical-dominated pathway was severely inhibited by the side reactions between the ani...Advanced oxidation processes have been widely studied for organic pollutants treatment in water,but the degradation performance of radical-dominated pathway was severely inhibited by the side reactions between the anions and radicals,especially in high salinity conditions.Here,a singlet oxygen(^(1)O_(2))-dominated non-radical process was developed for organic pollutants degradation in high salinity wastewater,with layered crednerite(CuMnO_(2))as catalysts and peroxymonosulfate(PMS)as oxidant.Based on the experiments and density functional theory calculations,^(1)O_(2)was the dominating reactive species and the constructed Cu-O-Mn with electron-deficient Mn captured electron from PMS promoting the generation of^(1)O_(2).The rapid degradation of bisphenol A(BPA)was achieved by CuMnO_(2)/PMS system,which was 5-fold and 21-fold higher than that in Mn_(2)O_(3)/PMS system and Cu_(2)O/PMS system.The CuMnO_(2)/PMS system shown prominent BPA removal performance under high salinity conditions,prominent PMS utilization efficiency,outstanding total organic carbon removal rate,wide range of applicable pH and good stability.This work unveiled that the^(1)O_(2)-dominated non-radical process of CuMnO_(2)/PMS system overcame the inhibitory effect of anions in high salinity conditions,which provided a promising technique to remove organic pollutants from high saline wastewater.展开更多
The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,wh...The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,while comorbidities(e.g.,hypertension and diabetes)and mental shock(e.g.,insomnia and anxiety)are nonnegligible.Nevertheless,little is known about the long-term impacts of comorbidities and mental shock on organic micropollutants(OMPs)in surface waters.Herein,we monitored 114 OMPs in surface water and wastewater treatment plants(WWTPs)in Wuhan,China,between 2019 and 2021.The pandemic-induced OMP pollution in surface water was confirmed by significant increases in 26 OMP concentrations.Significant increases in four antihypertensives and one diabetic drug suggest that the treatment of comorbidities may induce OMP pollution.Notably,cotinine(a metabolite of nicotine)increased 155 times to 187 ngL1,which might be associated with increased smoking.Additionally,the increases in zolpidem and sulpiride might be the result of worsened insomnia and depression.Hence,it is reasonable to note that mental-health protecting drugs/behavior also contributed to OMP pollution.Among the observed OMPs,telmisartan,lopinavir,and ritonavir were associated with significantly higher ecological risks because of their limited WWTP-removal rate and high ecotoxicity.This study provides new insights into the effects of comorbidities and mental shock on OMPs in surface water during a pandemic and highlights the need to monitor the fate of related pharmaceuticals in the aquatic environment and to improve their removal efficiencies in WWTPs。展开更多
The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an M...The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(～2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.展开更多
Coagulation is the best available method for removing intracellular organic matter(IOM),which is released from algae cells and is an important precursor to disinfection by-products in drinking water treatment. To gain...Coagulation is the best available method for removing intracellular organic matter(IOM),which is released from algae cells and is an important precursor to disinfection by-products in drinking water treatment. To gain insight into the best strategy to optimize IOM removal, the coagulation performance of two Al salts, i.e., aluminum chloride(AlCl_3) and polyaluminum chloride(PACl, containing 81.2% Al_(13)), was investigated to illuminate the effect of Al species distribution on IOM removal. PACl showed better removal efficiency than AlCl_3 with regard to the removal of turbidity and dissolved organic carbon(DOC), owing to the higher charge neutralization effect and greater stability of pre-formed Al_(13) species. High pressure size exclusion chromatography analysis indicated that the superiority of PACl in DOC removal could be ascribed to the higher binding affinity between Al_(13) polymer and the low and medium molecular weight(MW) fractions of IOM. The results of differential log-transformed absorbance at 254 and 350 nm indicated more significant formation of complexes between AlCl_3 and IOM, which benefits the removal of tryptophan-like proteins thereafter. Additionally,PACl showed more significant superiority compared to AlCl_3 in the removal of <5 kD a and hydrophilic fractions, which are widely viewed as the most difficult to remove by coagulation.This study provides insight into the interactions between Al species and IOM, and advances the optimization of coagulation for the removal of IOM in eutrophic water.展开更多
In recent years,volatile fatty acid(VFA)production through anaerobic fermentation of sewage sludge,instead of methane production,has been regarded as a high-value and promising roadmap for sludge stabilization and res...In recent years,volatile fatty acid(VFA)production through anaerobic fermentation of sewage sludge,instead of methane production,has been regarded as a high-value and promising roadmap for sludge stabilization and resource recovery.This review first presents the effects of some essential factors that influence VFA production and composition.In the second part,we present an extensive analysis of conventional pretreatment and co-fermentation strategies ultimately addressed to improving VFA production and composition.Also,the effectiveness of these approaches is summarized in terms of sludge degradation,hydrolysis rate,and VFA production and composition.According to published studies,it is concluded that some pretreatments such as alkaline and thermal pretreatment are the most effective ways to enhance VFA production from sewage sludge.The possible reasons for the improvement of VFA production by different methods are also discussed.Finally,this review also highlights several current technical challenges and opportunities in VFA production with spectrum control,and further related research is proposed.展开更多
The survival and development of human society highly depends on the water availability. Driven by the growth of population and economy, global water demand has increased more than eightfold since the 1900s. Meanwhile,...The survival and development of human society highly depends on the water availability. Driven by the growth of population and economy, global water demand has increased more than eightfold since the 1900s. Meanwhile, the commonly deteriorated freshwater quality cause a large proportion of available water resources unsuitable for human uses. This inter-coupled challenge of insufficient water quantity and inadequate water quality has rendered water scarcity a widespread problem in many parts of the world.展开更多
The water sector needs to address viral-related public health issues,because water is a virus carrier,which not only spreads viruses(e.g.,via drinking water),but also provides information about the circu-lation of vir...The water sector needs to address viral-related public health issues,because water is a virus carrier,which not only spreads viruses(e.g.,via drinking water),but also provides information about the circu-lation of viruses in the community(e.g.,via sewage).It has been widely reported that waterborne viral pathogens are abundant,diverse,complex,and threatening the public health in both developed and developing countries.Meanwhile,there is great potential for viral monitoring that can indicate biosafety,treatment performance and community health.New developments in technology have been rising to meet the emerging challenges over the past decades.Under the current coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the world’s attention is directed to the urgent need to tackle the most challenging public health issues related to waterborne viruses.Based on critical analysis of the water viral knowledge progresses and gaps,this article offers a roadmap for managing COVID-19 and other viruses in the water environments for ensur-ing public health.展开更多
The presence of newly emerging pollutants in the aquatic environment poses great challenges for drink-ing water treatment plants.Due to their low concentrations and unknown characteristics,emerging pol-lutants cannot ...The presence of newly emerging pollutants in the aquatic environment poses great challenges for drink-ing water treatment plants.Due to their low concentrations and unknown characteristics,emerging pol-lutants cannot be efficiently removed by conventional water treatment processes,making technically,economically,and environmentally friendly water purification technologies increasingly important.This article introduces a one-step reverse osmosis(OSRO)concept consisting of riverbank filtration(RBF)and reverse osmosis(RO)for drinking water treatment.The OSRO concept combines the relatively low-cost natural pretreatment of river water with an advanced engineered purification system.RBF pro-vides a continuous natural source of water with stable water quality and a robust barrier for contami-nants.With the pre-removal of particles,organic matter,organic micro-pollutants(OMPs),and microbes,RBF becomes an ideal source for a purification system based on RO membranes,in comparison with the direct intake of surface water.OSRO treatment removes almost 99.9%of the particles,pathogens,viruses,and OMPs,as well as the vast majority of nutrients,and thus meets the requirements for the chlorine-free delivery of drinking water with high biostability.The OSRO treatment is cost effective com-pared with the standard conventional series of purification steps involving sprinkling filters,softening,and activated carbon.Artificial bank filtration(ABF),which functions as an artificial recharge in combi-nation with a sand filtration system,is proposed as an alternative for RBF in the OSRO concept to supply drinking water from locally available resources.It is also suggested that the OSRO concept be imple-mented with wind power as an alternative energy source in order to be more sustainable and renewable.An OSRO-based decentralized water system is proposed for water reclaiming and reuse.It is suggested that future water treatment focus on the combination of natural and engineered systems to provide drinking water through technically efficient,financially feasible,resource reusable,and environmentally relevant means.展开更多
The pursuit of alternative safe water has increased dramatically the world trade in bottled water. Events happened in Canada which changed the population’s perception about the quality of tap water, despite all gover...The pursuit of alternative safe water has increased dramatically the world trade in bottled water. Events happened in Canada which changed the population’s perception about the quality of tap water, despite all government efforts. Media has an important role to pass on information because there is value judgment in its reports. As a result, this study aims to present recent data from two Canadian newspapers of national circulation, which refer to tap water and bottled water. It used quantitative and qualitative data for this analysis. The study concludes that the media, taken into consideration, provides its readers with important information, but the information can also be ambiguous. Nevertheless, it arouses interest in further research about this subject matter and about protecting water resources.展开更多
Electrochemical oxidation of water to produce highly reactive hydroxyl radicals(·OH)is the dominant factor that accounts for the organic compounds removal efficiency in water treatment.As an emerging carbon-based...Electrochemical oxidation of water to produce highly reactive hydroxyl radicals(·OH)is the dominant factor that accounts for the organic compounds removal efficiency in water treatment.As an emerging carbon-based material,the investigation of electrocatalytic of water to produce·OH on Graphdiyne(GDY)anode is firstly evaluated by using first-principles calculations.The theoretical calculation results demonstrated that the GDY anode owns a large oxygen evolution reaction(OER)overpotential(η^(OER)=1.95 V)and a weak sorptive ability towards oxygen evolution intermediates(HO^(*),not·OH).The high Gibbs energy change of HO^(*)(3.18 e V)on GDY anode makes the selective production of·OH(△G=2.4 eV)thermodynamically favorable.The investigation comprises the understanding of the relationship between OER to electrochemical advanced oxidation process(EAOP),and give a proof-of-concept of finding the novel and robust environmental EAOP anode at quantum chemistry level.展开更多
Drinking water quality deteriorates from treatment plant to customer taps, especially in the plumbing system. There is no direct evidence about what the differences are contributed by plumbing system. This study compa...Drinking water quality deteriorates from treatment plant to customer taps, especially in the plumbing system. There is no direct evidence about what the differences are contributed by plumbing system. This study compared the water quality in the water main and at customer tap by preparing a sampling tap on the water main. The biomass was quantified by adenosine triphosphate(ATP) and the microbial community was profiled by 454 pyrosequencing.The results showed that in distribution pipes, biofilm contributed >94% of the total biomass,while loose deposits showed little contribution(< 2%) because of the low amount of loose deposits. The distribution of biological stable water had minor effects on the microbiocidal water quality regarding both quantity(ATP 1 ng/L vs. 1.7 ng/L) and community of the bacteria. Whereas the plumbing system has significant contribution to the increase of active biomass(1.7 ng/L vs. 2.9 ng/L) and the changes of bacterial community. The relative abundance of Sphingomonas spp. at tap(22%) was higher than that at water main(2%), while the relative abundance of Pseudomonas spp. in tap water(15%) was lower than that in the water from street water main(29%). Though only one location was prepared and studied, the present study showed that the protocol of making sampling tap on water main offered directly evidences about the impacts of plumbing system on tap water quality, which makes it possible to distinguish and study the processes in distribution system and plumbing system separately.展开更多
Most of developing countries suffer from decreasing and poor quality of drinking water which led to emergence of many dangerous diseases. In addition, there isn’t any methodology followed to predict and disinfect dri...Most of developing countries suffer from decreasing and poor quality of drinking water which led to emergence of many dangerous diseases. In addition, there isn’t any methodology followed to predict and disinfect drinking water by using advanced software program. Maintaining water quality in the water distribution system has become a prominent issue in the study of the water network. Residual chlorine concentration is the indicator to ensure the quality of water in the water network because it eliminates contaminants in the distribution network beginning of the treatment plant down to the consumer. In collaboration with Alexandria (Egypt) Water Company, samples were taken from El-NOZHA water plant station and El-HADARA water distribution network to know the free residual chlorine. In this paper, WaterCAD software has been used to make hydraulic analysis and calibration of residual chlorine in water distribution network to know the ideal chlorine dose that should be added at the water treatment plant and to know the areas of strength and weakness in the concentration of free residual chlorine in the water distribution network. In addition different scenarios have been found to know the free residual chlorine at the weakness areas after injecting chlorine in some junctions and the impact of a fire case or breaking in the water pipe distribution network on the residual chlorine. Results showed ensuring in the water quality in the distribution network by adding chlorine dose in water less than the existing dose which has been added in the El-NOZHA water treatment plant. It is possible to maintain the percentage of free residual chlorine concentration at different locations without relying on adding chlorine only in water treatment plant by injecting low percentage of chlorine dose in the junctions.展开更多
The aim of this study was to assess the runoff amount from a catchment characterized by diverse land uses by using the Soil Conservation Service Curve Number(SCS-CN) method based on Curve Number(CN) defined for domina...The aim of this study was to assess the runoff amount from a catchment characterized by diverse land uses by using the Soil Conservation Service Curve Number(SCS-CN) method based on Curve Number(CN) defined for dominant homogeneous elementary sub-regions.The calculations employed the SCS-CN method,involving the division of the catchment in two homogeneous parts and determining the runoff amount.The obtained results were compared with the results provided by three other CN determination methods,i.e.the Hawkins function,the kinetics equation,and a complementary error function peak.The catchment is located in a mountain dominated by forest land cover.Empirical CN-Precipitation(CN_(emp)-P) data pairs were analyzed using the mentioned methods,and the highest quality score was achieved from model 1.The results suggest that dividing a catchment into two homogeneous areas and determining their separate CN parameters,used later on to calculate the runoff by means of the presented approach,could be an alternative to the standard methods.The described method is relatively easy,and as it does not require an adoption of numerous parameters,and it can be employed for designing hydraulic facilities.展开更多
Mathematical models and simulation are considered a powerful tool in engineering practice. Those tools are becoming increasingly used for the improvement of wastewater treatment plants design because the conceptual de...Mathematical models and simulation are considered a powerful tool in engineering practice. Those tools are becoming increasingly used for the improvement of wastewater treatment plants design because the conceptual design is complex and ill-defined. In this paper, three alternatives: 1) complete mix activated sludge without nitrogen removal (CAS);2) complete mix activated sludge with nitrogen removal (CAS-N) and;3) membrane bioreactor (MBR) processes were designed into two steps: first concept design to calculate the size of process units, then second implement modeling and simulation to improve the accuracy of the conceptual design. In brief, the treatment process design has been verified by using the activated sludge model No. 1 (ASM1) in GPS-X (v.7) simulation software. This application helps not only in sizing the treatment units but also in understanding the plant’s capacity. In the same time, it can assist in studying the future expansion works required for increased hydraulic and organic loadings. For this purpose, Tikrit WWTP was selected as a case study. The used model was validated by comparing the designed values of the plant and the modeling data. The verification of the obtained results from both hand calculations and the results of the program showed a good agreement. A significant difference in the volume of secondary treatment was obtained from design calculations, where the CAS without denitrification system was 9244 m3 (aerobic and secondary tanks), CAS with denitrification system was 11,324 m3 (anoxic, aerobic and secondary tanks) and for MBR system was 7468 m3 (anoxic, aerobic and immersed membrane tanks). From the obtained results point of view, it can be concluded that mathematical models can be considered as worthy tools to complement the established wastewater treatment plant design procedures.展开更多
The Rio Grande do Sul-RS State, even with average annual rainfall of 1.721 mm, has shown a lack of water in the soil for crop production. The study aimed to determine the variation of annual and seasonal precipitation...The Rio Grande do Sul-RS State, even with average annual rainfall of 1.721 mm, has shown a lack of water in the soil for crop production. The study aimed to determine the variation of annual and seasonal precipitation over the time;determine the year seasons that can provide the recharge of water into the soil profile and estimate the time needed to fulfill the soil pore space with water from effective rainfall with different scenarios of water infiltration. The soil uses were: oxisol;Red Yellow Podzolic and Planosolo Hydromorphic Eutrophic respectively in the North, Centre and South of RS State. We determined the total variation of annual rainfall, mean annual potential evapotranspiration and the time required to refill the soil profile for three infiltration scenarios: with fractions 1/2, 2/3 and 3/4 of effective rainfall. In the regions of Passo Fundo, Santa Maria and Santa Vitóriado Palmar, from 1914 to 2004 there was no reduction in the annual volume of rainfall. Considering that 50% of soil volume and water storage are met and that the fraction 1/2, 2/3 and 3/4 of the effective rainfall infiltrates into the soil, the recharging time profile varies from 3.7 to 16.6 years, infiltrating 2/3 range from 1.8 to 6.6 years and infiltrating 3/4 of effective precipitation range from 1.2 to 5.1 years, the time required to refill the entire soil porous space. The recovery of water storage in the soil profile must occur mainly during winter, followed by spring and fall.展开更多
A new in situ treatment technique was being utilized on a part of the Dorfweiher landfill in Konstanz, Germany to reduce the aftercare period. From 2010 to 2012, the landfill was aerated intermittently with low pressu...A new in situ treatment technique was being utilized on a part of the Dorfweiher landfill in Konstanz, Germany to reduce the aftercare period. From 2010 to 2012, the landfill was aerated intermittently with low pressure. Outgoing air was treated passively in an open biofilter which covers the landfill surface. The landfill was aerated by means of 80 air injection wells arranged area-wide in a 10 m grid. An elaborate measuring process and technological controls are being utilized in the pilot scheme. The data collected offer interesting insights about the processes during aeration, allowing optimization of the aeration strategy depending on changes of the conditions in the landfill. During the three-year aeration phase, conditions have changed inside the landfill section in various ways. In numerous zones of the landfill body, the aeration caused aerobic conditions with a decline of methane production. Accelerated settlings are measured up to 11%. The effects of the aerobic stabilization on the landfill are evaluated in a two-year monitoring phase started in 2013.展开更多
The intense mobilization of the soil inappropriately causes a reduction in the percentage of macropores and in the rate of soil water infiltration with reduction of crop yield. Due to the difficulty of using the Muntz...The intense mobilization of the soil inappropriately causes a reduction in the percentage of macropores and in the rate of soil water infiltration with reduction of crop yield. Due to the difficulty of using the Muntz concentric ring method, researchers have used mathematical models to estimate infiltration based on soil physical parameters such as, soil texture that does not reflect physical reality in relation to infiltration rate, leading to errors. To automate the use of the infiltrometer ring method, there are no hydrometers that record small flows in non-pressurized hydraulic systems, making it difficult to automate the method for field determination. For this purpose, six Muntz double rings were instrumented with an electromechanical system coupled to the “Tipin Buked” (weighbridge) with the ability to record flows from 8 cm<sup>3</sup><span style="white-space:nowrap;">∙</span>minute<sup><span style="white-space:nowrap;">−</span>1</sup> on a memory card. The results indicate that the models of the regression equations describe 93% to 99% of the real values, showing the accuracy of the equipment. This work aimed to modify the Muntz method to reduce field work and automate the determination of water infiltration rate in the soil.展开更多
基金funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq),project number 408034/2022−0.
文摘Despite significant Brazilian social programs to expand energy access,approximately one million people in rural Amazonia still lack electricity.Moreover,the existing rural electricity grid in the region is inadequate for supporting efficient small-scale production systems due to both the poor quality and high cost of supplied energy.In parallel,traditional wooden bridges in the Amazon have been progressively replaced by more durable concrete structures in recent years.In this context,this study explores the application of very low-head hydropower installations in the Amazon,focusing on integrating axial-flow turbines beneath small concrete bridges.The methodology involves analyzing flow duration curves and key hydraulic parameters upstream and downstream to design a micro-hydropower system comprising two or more units,thereby maximizing annual energy generation.Additionally,the study assesses the applicability of the minimum pressure coefficient criterion to improve the efficiency of very low-head turbines.This design criterion is first validated against an existing experimental study featuring a propeller turbine with a simple curved plate blade.The proposed methodology is then applied to a case study involving a small dam-bridge with a head variation from 1.4 to 2.4 m and a flow rate ranging from 0.23 to 0.92 m^(3)/s.The optimal configuration achieves an energy output of 26.2 MWh/year with an efficiency of up to 86%.
基金supported by Specific League Funds from Mahidol University,and partially supported by Office of the Permanent Secretary,Ministry of Higher Education,Science,Research and Inno-vation(OPS MHESI),Thailand Science Research and Innovation(TSRI)(Grant No.RGNS 63-167).
文摘Xylitol,one of the top twelve chemical building blocks,is commercially synthesized through the xylose hy-drogenation reaction using a metal catalyst.Biochar has emerged as an eco-efficient catalyst support material.In this study,biochar derived from corn stover(BCS)was first used as a metal catalyst support material for xylose hydrogenation into xylitol.The catalyst was prepared by carbonizing corn stover(CS),impregnating the resulting biochar with metal,and reducing the metal-impregnated BCS.The catalyst characteristics were comprehensively explored.The Ru/BCS catalyst was employed in xylose conversion to xylitol at different process temperatures(100-160℃),retention times(3-12 h),H_(2)pressures(2-5 MPa),and Ru contents(1-5%).The highest xylitol yield(87.0 wt.%)and selectivity(91.6%)were derived at 120℃ for 6 h under 4 MPa H_(2)using 5%Ru.Interestingly,the Ru/BCS catalyst showed high stability under the promising process condition.Additionally,xylitol production from hydrolysates enriched with CS xylose was subsequently explored.On the other hand,the catalyst characterization results revealed that the superior catalytic efficiency of 5Ru/BCS was mainly due to the metal nanoparticles embedded in the biochar.Additionally,BCS proved to be an outstanding support material for a bimetallic hydrogenation catalyst(Ru-Ni/BCS).Therefore,these results indicate that BCS can be a competitive support material for metal hydrogenation catalysts,enhancing environmental friendliness and potentially being employed in industrial-scale xylitol production.
基金supported by the Open Fund of Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling (No.2020B121201003)the National Natural Science Foundation of China (Nos.21876099,22106088,and 22276110)+1 种基金the Key Research&Developmental Program of Shandong Province (No.2021CXGC011202)the Fundamental Research Funds of Shandong University (No.zy202102)。
文摘Advanced oxidation processes have been widely studied for organic pollutants treatment in water,but the degradation performance of radical-dominated pathway was severely inhibited by the side reactions between the anions and radicals,especially in high salinity conditions.Here,a singlet oxygen(^(1)O_(2))-dominated non-radical process was developed for organic pollutants degradation in high salinity wastewater,with layered crednerite(CuMnO_(2))as catalysts and peroxymonosulfate(PMS)as oxidant.Based on the experiments and density functional theory calculations,^(1)O_(2)was the dominating reactive species and the constructed Cu-O-Mn with electron-deficient Mn captured electron from PMS promoting the generation of^(1)O_(2).The rapid degradation of bisphenol A(BPA)was achieved by CuMnO_(2)/PMS system,which was 5-fold and 21-fold higher than that in Mn_(2)O_(3)/PMS system and Cu_(2)O/PMS system.The CuMnO_(2)/PMS system shown prominent BPA removal performance under high salinity conditions,prominent PMS utilization efficiency,outstanding total organic carbon removal rate,wide range of applicable pH and good stability.This work unveiled that the^(1)O_(2)-dominated non-radical process of CuMnO_(2)/PMS system overcame the inhibitory effect of anions in high salinity conditions,which provided a promising technique to remove organic pollutants from high saline wastewater.
基金supported by the National Natural Science Foundation of China(52221004,52091542,and 51820105011)the Scientific Research Project of China Three Gorges Corporation(201903139)the Research Fund of Vanke School of Public Health(2021JC009),Tsinghua University.
文摘The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,while comorbidities(e.g.,hypertension and diabetes)and mental shock(e.g.,insomnia and anxiety)are nonnegligible.Nevertheless,little is known about the long-term impacts of comorbidities and mental shock on organic micropollutants(OMPs)in surface waters.Herein,we monitored 114 OMPs in surface water and wastewater treatment plants(WWTPs)in Wuhan,China,between 2019 and 2021.The pandemic-induced OMP pollution in surface water was confirmed by significant increases in 26 OMP concentrations.Significant increases in four antihypertensives and one diabetic drug suggest that the treatment of comorbidities may induce OMP pollution.Notably,cotinine(a metabolite of nicotine)increased 155 times to 187 ngL1,which might be associated with increased smoking.Additionally,the increases in zolpidem and sulpiride might be the result of worsened insomnia and depression.Hence,it is reasonable to note that mental-health protecting drugs/behavior also contributed to OMP pollution.Among the observed OMPs,telmisartan,lopinavir,and ritonavir were associated with significantly higher ecological risks because of their limited WWTP-removal rate and high ecotoxicity.This study provides new insights into the effects of comorbidities and mental shock on OMPs in surface water during a pandemic and highlights the need to monitor the fate of related pharmaceuticals in the aquatic environment and to improve their removal efficiencies in WWTPs。
基金the DAAD Sandwich Model Scholarships for Master's Students of the IITs and IIMs, 2016/17, who funded the research stay of Mr.Pravesh Tamang in Germany (Personal Ref No: 91635161)
文摘The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(～2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.
基金supported by the Natural Key R&D Program of China (No.2016YFC0400802)the Natural Science Foundation of China (No.51225805)
文摘Coagulation is the best available method for removing intracellular organic matter(IOM),which is released from algae cells and is an important precursor to disinfection by-products in drinking water treatment. To gain insight into the best strategy to optimize IOM removal, the coagulation performance of two Al salts, i.e., aluminum chloride(AlCl_3) and polyaluminum chloride(PACl, containing 81.2% Al_(13)), was investigated to illuminate the effect of Al species distribution on IOM removal. PACl showed better removal efficiency than AlCl_3 with regard to the removal of turbidity and dissolved organic carbon(DOC), owing to the higher charge neutralization effect and greater stability of pre-formed Al_(13) species. High pressure size exclusion chromatography analysis indicated that the superiority of PACl in DOC removal could be ascribed to the higher binding affinity between Al_(13) polymer and the low and medium molecular weight(MW) fractions of IOM. The results of differential log-transformed absorbance at 254 and 350 nm indicated more significant formation of complexes between AlCl_3 and IOM, which benefits the removal of tryptophan-like proteins thereafter. Additionally,PACl showed more significant superiority compared to AlCl_3 in the removal of <5 kD a and hydrophilic fractions, which are widely viewed as the most difficult to remove by coagulation.This study provides insight into the interactions between Al species and IOM, and advances the optimization of coagulation for the removal of IOM in eutrophic water.
基金supported by the National Natural Science Foundation of China(No.51578068)"One Thousand Talent Plan" Youth Program
文摘In recent years,volatile fatty acid(VFA)production through anaerobic fermentation of sewage sludge,instead of methane production,has been regarded as a high-value and promising roadmap for sludge stabilization and resource recovery.This review first presents the effects of some essential factors that influence VFA production and composition.In the second part,we present an extensive analysis of conventional pretreatment and co-fermentation strategies ultimately addressed to improving VFA production and composition.Also,the effectiveness of these approaches is summarized in terms of sludge degradation,hydrolysis rate,and VFA production and composition.According to published studies,it is concluded that some pretreatments such as alkaline and thermal pretreatment are the most effective ways to enhance VFA production from sewage sludge.The possible reasons for the improvement of VFA production by different methods are also discussed.Finally,this review also highlights several current technical challenges and opportunities in VFA production with spectrum control,and further related research is proposed.
文摘The survival and development of human society highly depends on the water availability. Driven by the growth of population and economy, global water demand has increased more than eightfold since the 1900s. Meanwhile, the commonly deteriorated freshwater quality cause a large proportion of available water resources unsuitable for human uses. This inter-coupled challenge of insufficient water quantity and inadequate water quality has rendered water scarcity a widespread problem in many parts of the world.
基金support from the National Key Research and Development (R&D) program of China (2018YFE0204100)the National Natural Science Foundation of China for International Cooperation and Exchange (51820105011)
文摘The water sector needs to address viral-related public health issues,because water is a virus carrier,which not only spreads viruses(e.g.,via drinking water),but also provides information about the circu-lation of viruses in the community(e.g.,via sewage).It has been widely reported that waterborne viral pathogens are abundant,diverse,complex,and threatening the public health in both developed and developing countries.Meanwhile,there is great potential for viral monitoring that can indicate biosafety,treatment performance and community health.New developments in technology have been rising to meet the emerging challenges over the past decades.Under the current coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the world’s attention is directed to the urgent need to tackle the most challenging public health issues related to waterborne viruses.Based on critical analysis of the water viral knowledge progresses and gaps,this article offers a roadmap for managing COVID-19 and other viruses in the water environments for ensur-ing public health.
基金support from the National Key Research and Development(R&D)program of China(2018YFE0204100)the National Natural Science Foundation of China for International Cooperation and Exchange(51820105011).
文摘The presence of newly emerging pollutants in the aquatic environment poses great challenges for drink-ing water treatment plants.Due to their low concentrations and unknown characteristics,emerging pol-lutants cannot be efficiently removed by conventional water treatment processes,making technically,economically,and environmentally friendly water purification technologies increasingly important.This article introduces a one-step reverse osmosis(OSRO)concept consisting of riverbank filtration(RBF)and reverse osmosis(RO)for drinking water treatment.The OSRO concept combines the relatively low-cost natural pretreatment of river water with an advanced engineered purification system.RBF pro-vides a continuous natural source of water with stable water quality and a robust barrier for contami-nants.With the pre-removal of particles,organic matter,organic micro-pollutants(OMPs),and microbes,RBF becomes an ideal source for a purification system based on RO membranes,in comparison with the direct intake of surface water.OSRO treatment removes almost 99.9%of the particles,pathogens,viruses,and OMPs,as well as the vast majority of nutrients,and thus meets the requirements for the chlorine-free delivery of drinking water with high biostability.The OSRO treatment is cost effective com-pared with the standard conventional series of purification steps involving sprinkling filters,softening,and activated carbon.Artificial bank filtration(ABF),which functions as an artificial recharge in combi-nation with a sand filtration system,is proposed as an alternative for RBF in the OSRO concept to supply drinking water from locally available resources.It is also suggested that the OSRO concept be imple-mented with wind power as an alternative energy source in order to be more sustainable and renewable.An OSRO-based decentralized water system is proposed for water reclaiming and reuse.It is suggested that future water treatment focus on the combination of natural and engineered systems to provide drinking water through technically efficient,financially feasible,resource reusable,and environmentally relevant means.
文摘The pursuit of alternative safe water has increased dramatically the world trade in bottled water. Events happened in Canada which changed the population’s perception about the quality of tap water, despite all government efforts. Media has an important role to pass on information because there is value judgment in its reports. As a result, this study aims to present recent data from two Canadian newspapers of national circulation, which refer to tap water and bottled water. It used quantitative and qualitative data for this analysis. The study concludes that the media, taken into consideration, provides its readers with important information, but the information can also be ambiguous. Nevertheless, it arouses interest in further research about this subject matter and about protecting water resources.
基金the support from the National Key Research and Development Program of China(No.2017YFE9133400)Preresearch Fund of Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment(No.XTCXSZ2020-3)。
文摘Electrochemical oxidation of water to produce highly reactive hydroxyl radicals(·OH)is the dominant factor that accounts for the organic compounds removal efficiency in water treatment.As an emerging carbon-based material,the investigation of electrocatalytic of water to produce·OH on Graphdiyne(GDY)anode is firstly evaluated by using first-principles calculations.The theoretical calculation results demonstrated that the GDY anode owns a large oxygen evolution reaction(OER)overpotential(η^(OER)=1.95 V)and a weak sorptive ability towards oxygen evolution intermediates(HO^(*),not·OH).The high Gibbs energy change of HO^(*)(3.18 e V)on GDY anode makes the selective production of·OH(△G=2.4 eV)thermodynamically favorable.The investigation comprises the understanding of the relationship between OER to electrochemical advanced oxidation process(EAOP),and give a proof-of-concept of finding the novel and robust environmental EAOP anode at quantum chemistry level.
基金the support from the National Key R&D program of China(No.2018YFE0204100)the National Natural Science Foundation of China(No.52022103)the National Natural Science Foundation of China for International Cooperation and Exchange(No.51820105011)。
文摘Drinking water quality deteriorates from treatment plant to customer taps, especially in the plumbing system. There is no direct evidence about what the differences are contributed by plumbing system. This study compared the water quality in the water main and at customer tap by preparing a sampling tap on the water main. The biomass was quantified by adenosine triphosphate(ATP) and the microbial community was profiled by 454 pyrosequencing.The results showed that in distribution pipes, biofilm contributed >94% of the total biomass,while loose deposits showed little contribution(< 2%) because of the low amount of loose deposits. The distribution of biological stable water had minor effects on the microbiocidal water quality regarding both quantity(ATP 1 ng/L vs. 1.7 ng/L) and community of the bacteria. Whereas the plumbing system has significant contribution to the increase of active biomass(1.7 ng/L vs. 2.9 ng/L) and the changes of bacterial community. The relative abundance of Sphingomonas spp. at tap(22%) was higher than that at water main(2%), while the relative abundance of Pseudomonas spp. in tap water(15%) was lower than that in the water from street water main(29%). Though only one location was prepared and studied, the present study showed that the protocol of making sampling tap on water main offered directly evidences about the impacts of plumbing system on tap water quality, which makes it possible to distinguish and study the processes in distribution system and plumbing system separately.
文摘Most of developing countries suffer from decreasing and poor quality of drinking water which led to emergence of many dangerous diseases. In addition, there isn’t any methodology followed to predict and disinfect drinking water by using advanced software program. Maintaining water quality in the water distribution system has become a prominent issue in the study of the water network. Residual chlorine concentration is the indicator to ensure the quality of water in the water network because it eliminates contaminants in the distribution network beginning of the treatment plant down to the consumer. In collaboration with Alexandria (Egypt) Water Company, samples were taken from El-NOZHA water plant station and El-HADARA water distribution network to know the free residual chlorine. In this paper, WaterCAD software has been used to make hydraulic analysis and calibration of residual chlorine in water distribution network to know the ideal chlorine dose that should be added at the water treatment plant and to know the areas of strength and weakness in the concentration of free residual chlorine in the water distribution network. In addition different scenarios have been found to know the free residual chlorine at the weakness areas after injecting chlorine in some junctions and the impact of a fire case or breaking in the water pipe distribution network on the residual chlorine. Results showed ensuring in the water quality in the distribution network by adding chlorine dose in water less than the existing dose which has been added in the El-NOZHA water treatment plant. It is possible to maintain the percentage of free residual chlorine concentration at different locations without relying on adding chlorine only in water treatment plant by injecting low percentage of chlorine dose in the junctions.
基金Dean of the Faculty of Environmental Engineering and Land Surveying, University of Agriculture in Krakow, for financial support
文摘The aim of this study was to assess the runoff amount from a catchment characterized by diverse land uses by using the Soil Conservation Service Curve Number(SCS-CN) method based on Curve Number(CN) defined for dominant homogeneous elementary sub-regions.The calculations employed the SCS-CN method,involving the division of the catchment in two homogeneous parts and determining the runoff amount.The obtained results were compared with the results provided by three other CN determination methods,i.e.the Hawkins function,the kinetics equation,and a complementary error function peak.The catchment is located in a mountain dominated by forest land cover.Empirical CN-Precipitation(CN_(emp)-P) data pairs were analyzed using the mentioned methods,and the highest quality score was achieved from model 1.The results suggest that dividing a catchment into two homogeneous areas and determining their separate CN parameters,used later on to calculate the runoff by means of the presented approach,could be an alternative to the standard methods.The described method is relatively easy,and as it does not require an adoption of numerous parameters,and it can be employed for designing hydraulic facilities.
文摘Mathematical models and simulation are considered a powerful tool in engineering practice. Those tools are becoming increasingly used for the improvement of wastewater treatment plants design because the conceptual design is complex and ill-defined. In this paper, three alternatives: 1) complete mix activated sludge without nitrogen removal (CAS);2) complete mix activated sludge with nitrogen removal (CAS-N) and;3) membrane bioreactor (MBR) processes were designed into two steps: first concept design to calculate the size of process units, then second implement modeling and simulation to improve the accuracy of the conceptual design. In brief, the treatment process design has been verified by using the activated sludge model No. 1 (ASM1) in GPS-X (v.7) simulation software. This application helps not only in sizing the treatment units but also in understanding the plant’s capacity. In the same time, it can assist in studying the future expansion works required for increased hydraulic and organic loadings. For this purpose, Tikrit WWTP was selected as a case study. The used model was validated by comparing the designed values of the plant and the modeling data. The verification of the obtained results from both hand calculations and the results of the program showed a good agreement. A significant difference in the volume of secondary treatment was obtained from design calculations, where the CAS without denitrification system was 9244 m3 (aerobic and secondary tanks), CAS with denitrification system was 11,324 m3 (anoxic, aerobic and secondary tanks) and for MBR system was 7468 m3 (anoxic, aerobic and immersed membrane tanks). From the obtained results point of view, it can be concluded that mathematical models can be considered as worthy tools to complement the established wastewater treatment plant design procedures.
文摘The Rio Grande do Sul-RS State, even with average annual rainfall of 1.721 mm, has shown a lack of water in the soil for crop production. The study aimed to determine the variation of annual and seasonal precipitation over the time;determine the year seasons that can provide the recharge of water into the soil profile and estimate the time needed to fulfill the soil pore space with water from effective rainfall with different scenarios of water infiltration. The soil uses were: oxisol;Red Yellow Podzolic and Planosolo Hydromorphic Eutrophic respectively in the North, Centre and South of RS State. We determined the total variation of annual rainfall, mean annual potential evapotranspiration and the time required to refill the soil profile for three infiltration scenarios: with fractions 1/2, 2/3 and 3/4 of effective rainfall. In the regions of Passo Fundo, Santa Maria and Santa Vitóriado Palmar, from 1914 to 2004 there was no reduction in the annual volume of rainfall. Considering that 50% of soil volume and water storage are met and that the fraction 1/2, 2/3 and 3/4 of the effective rainfall infiltrates into the soil, the recharging time profile varies from 3.7 to 16.6 years, infiltrating 2/3 range from 1.8 to 6.6 years and infiltrating 3/4 of effective precipitation range from 1.2 to 5.1 years, the time required to refill the entire soil porous space. The recovery of water storage in the soil profile must occur mainly during winter, followed by spring and fall.
文摘A new in situ treatment technique was being utilized on a part of the Dorfweiher landfill in Konstanz, Germany to reduce the aftercare period. From 2010 to 2012, the landfill was aerated intermittently with low pressure. Outgoing air was treated passively in an open biofilter which covers the landfill surface. The landfill was aerated by means of 80 air injection wells arranged area-wide in a 10 m grid. An elaborate measuring process and technological controls are being utilized in the pilot scheme. The data collected offer interesting insights about the processes during aeration, allowing optimization of the aeration strategy depending on changes of the conditions in the landfill. During the three-year aeration phase, conditions have changed inside the landfill section in various ways. In numerous zones of the landfill body, the aeration caused aerobic conditions with a decline of methane production. Accelerated settlings are measured up to 11%. The effects of the aerobic stabilization on the landfill are evaluated in a two-year monitoring phase started in 2013.
文摘The intense mobilization of the soil inappropriately causes a reduction in the percentage of macropores and in the rate of soil water infiltration with reduction of crop yield. Due to the difficulty of using the Muntz concentric ring method, researchers have used mathematical models to estimate infiltration based on soil physical parameters such as, soil texture that does not reflect physical reality in relation to infiltration rate, leading to errors. To automate the use of the infiltrometer ring method, there are no hydrometers that record small flows in non-pressurized hydraulic systems, making it difficult to automate the method for field determination. For this purpose, six Muntz double rings were instrumented with an electromechanical system coupled to the “Tipin Buked” (weighbridge) with the ability to record flows from 8 cm<sup>3</sup><span style="white-space:nowrap;">∙</span>minute<sup><span style="white-space:nowrap;">−</span>1</sup> on a memory card. The results indicate that the models of the regression equations describe 93% to 99% of the real values, showing the accuracy of the equipment. This work aimed to modify the Muntz method to reduce field work and automate the determination of water infiltration rate in the soil.
