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Digital Twins for Wastewater Treatment:A Technical Review
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作者 Ai-Jie Wang Hewen Li +6 位作者 Zhejun He Yu Tao Hongcheng Wang Min Yang Dragan Savic Glen TDaigger nanqi ren 《Engineering》 SCIE EI CAS CSCD 2024年第5期21-35,共15页
The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domai... The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domains,and key technologies.More specifically,we investigate the transformative potential of digital twins for the wastewater treatment engineering sector.Our discussion highlights the application of digital twins to wastewater treatment plants(WWTPs)and sewage networks,hardware(i.e.,facilities and pipes,sensors for water quality and activated sludge,hydrodynamics,and power consumption),and software(i.e.,knowledge-based and data-driven models,mechanistic models,hybrid twins,control methods,and the Internet of Things).Furthermore,two cases are provided,followed by an assessment of current challenges in and perspectives on the application of digital twins in WWTPs.This review serves as an essential primer for wastewater engineers navigating the digital paradigm shift. 展开更多
关键词 Digital twins Urban water systems Wastewater treatment
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Biodegradation of phenol and m-cresol by mutated Candida tropicalis 被引量:11
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作者 Yan Jiang Xun Cai +1 位作者 Di Wu nanqi ren 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第4期621-626,共6页
The phenol and m-cresol biodegradations were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that C. tropicalis exhibited the increased... The phenol and m-cresol biodegradations were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that C. tropicalis exhibited the increased capacity of phenolic compounds degradation after laser irradiation. It could degrade 2600 mg/L phenol and 300 mg/L m-cresol by 5% inoculum concentration, respectively. In the dual-substrate biodegradation system, 0-500 mg/L phenol could accelerate m-cresol biodegradation, and 300 mg/L m-cresol could be completely utilized within 46 hr at the presence of 350 mg/L phenol. Besides, the maximum biodegradation of m-cresol could reach 350 mg/L with 80 mg/L phenol within 61 hr. Obviously, phenol, as a growth substrate, could promote CTM 2 to degrade m-cresol, and was always preferentially utilized as carbon source. Comparatively, low-concentration m-cresol could result in a great inhibition on phenol degradation. In addition, the kinetic behaviors of cell growth and substrate biodegradation were described by kinetic model proposed in our laboratory. 展开更多
关键词 BIODEGRADATION the mutant strain CTM 2 PHENOL M-CRESOL KINETIC
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Electrochemical Removal of Chlorophenol Pollutants by Reactive Electrode Membranes: Scale-Up Strategy for Engineered Applications 被引量:3
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作者 Shuzhao Pei Yi Wang +2 位作者 Shijie You Zhanguo Li nanqi ren 《Engineering》 SCIE EI 2022年第2期77-84,共8页
Chlorophenols(CPs)are significant refractory pollutants that are highly toxic to humans and other organ-isms.Reactive electrode membranes(REMs)show considerable potential in the electrochemical removal of refractory p... Chlorophenols(CPs)are significant refractory pollutants that are highly toxic to humans and other organ-isms.Reactive electrode membranes(REMs)show considerable potential in the electrochemical removal of refractory pollutants by allowing flow-through operations with convection-enhanced mass transfer.However,relevant studies are commonly performed on the laboratory scale,and there is no straightfor-ward method that guarantees success in scaling up engineered REM reactors.In this study,we demon-strated that a tubular concentric electrode(TCE)configuration with a titanium suboxide ceramic anode and a stainless-steel cathode is suitable for large-scale CPs removal.Both theoretical and experi-mental results showed that the TCE configuration not only allows the electrode surface to be orthogonal to electric field lines everywhere,but also has an ohmic resistance that is inversely proportional to the length of the electrode.In addition,the TCE configuration can be operated in either the anode-to-cathode(AC)or the cathode-to-anode(CA)mode based on the flow direction,creating adjustable condi-tions for selective degradation of CPs.This was confirmed by 98%removal of 2,4-dichlorophenol(2,4-DCP)and 72.5%removal of chemical oxygen demand(COD)in the CA mode,in which the kinetic constant was one order of magnitude higher than that for the AC mode under flow-through single-pass operations.This can be explained by the lower activation energy and free energy in the CA mode,as revealed by the-oretical calculations and experimental measurements.The TCE configuration is also suitable for a numbering-up strategy to scale up the electrochemical reactor without increasing the ohmic resistance or decreasing the specific electrode area,achieving 99.4%removal of 2,4-DCP with an energy consump-tion of 1.5 kW·h·m^(-3) when three TCE modules were employed.This study presents a suitable electrode design configuration for the REM reactor,offering effective strategies to bridge the“Valley of Death”encountered when scaling up the electrochemical removal of CP pollutants. 展开更多
关键词 CHLOROPHENOLS Reactive electrode membrane Tubular concentric electrode Scale-up
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Biological hydrogen production from organic wastewater with a novel strain B49 isolated from anaerobic sewage sludge
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作者 Liying XU nanqi ren +1 位作者 Xingzu WANG Yongfeng JIA 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期153-153,共1页
关键词 废水 发酵 微生物 水体污染 水质
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Sustainable Generation of Sulfate Radicals and Decontamination of Micropollutants via Sequential Electrochemistry
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作者 Wentian Zheng Shijie You +4 位作者 Yuan Yao nanqi ren Bin Ding Fang Li Yanbiao Liu 《Engineering》 SCIE EI CAS CSCD 2023年第11期144-152,共9页
The removal of emerging micropollutants in the aquatic environment remains a global challenge.Conventional routes are often chemically,energetically,and operationally intensive,which decreases their sustainability dur... The removal of emerging micropollutants in the aquatic environment remains a global challenge.Conventional routes are often chemically,energetically,and operationally intensive,which decreases their sustainability during applications.Herein,we develop an advanced chemical-free strategy for micropollutants decontamination that is solely based on sequential electrochemistry involving ubiquitous sulfate anions in natural and engineered waters.This can be achieved via a chain reaction initiated by electrocatalytic anodic sulfate(SO_(4)^(2-))oxidation to produce persulfate(S_(2)O_(8)^(2-))and followed by a cathodic persulfate reduction to produce sulfate radicals(SO_(4)^(·-)).These SO_(4)^(·-)are powerful reactive species that enable the unselective degradation of micropollutants and yield SO_(4)^(2-)again in the treated water.The proposed flow-through electrochemical system achieves the efficient degradation(100.0%)and total organic carbon removal(65.0%)of aniline under optimized conditions with a single-pass mode.We also reveal the effectiveness of the proposed system for the degradation of a wide array of emerging micropollutants over a broad pH range and in complex matrices.This work provides the first proof-ofconcept demonstration using ubiquitous sulfate for micropollutants decontamination,making water purification more sustainable and more economical. 展开更多
关键词 Advanced oxidation Chain reaction Sulfate radical MICROPOLLUTANTS Sequential electrochemistry
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Evaluation of In-situ Sludge Reduction and Enhanced Nutrient Removal in an Integrated Repeatedly Coupling Aerobic and Anaerobic and Oxic-setting-anaerobic System
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作者 Shanshan Yang Wanqian Guo +5 位作者 Qinglian Wu Haichao Luo Simai Peng Heshan Zheng Xiaochi Feng nanqi ren 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第5期17-24,共8页
Aiming to achieve simultaneous good performances of in-situ sludge reduction and effluent quality,an integrated repeatedly coupling aerobic and anaerobic and oxic-setting-anaerobic system( r CAA + OSA) is developed to... Aiming to achieve simultaneous good performances of in-situ sludge reduction and effluent quality,an integrated repeatedly coupling aerobic and anaerobic and oxic-setting-anaerobic system( r CAA + OSA) is developed to reduce sludge production and enhance nutrient removal. Considering the mechanism of in-situ sludge reduction in this r CAA +OSA system,the combined effect of energy uncoupling metabolism and sludge cryptic growth maybe attributed to the higher reduction of biomass. Results show that the maximal sludge reduction in this r CAA + OSA system is obtained when the hydraulic retention time( HRT) is controlled at6. 5 h,which an increase in 16. 67% reduction in excess sludge is achieved compared with OSA system( HRT of 6. 5 h). When compared the performances of effluent qualities,the enhanced nutrient removal efficiencies also can be observed in this r CAA + OSA system. Three-dimensional excitation emission matrix( 3D-EEM)fluorescence spectroscopy is applied to characterize the effluent organic matters( Ef OM) under different HRTs in the OSA and the r CAA+OSA systems. Analyses of 3D-EEM spectra show that more refractory humic-like and fulvic-like components are observed in the effluent of the OSA system. On the basis of these results,simultaneous enhanced in-situ sludge reduction and improved nutrient removal can be obtained in the r CAA +OSA systems. 展开更多
关键词 in-situ sludge reduction BNPR Ef OM EEM r CAA OSA
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Degradation Pathway of Benzothiazole and Microbial Community Structure in Microbial Electrolysis Cells
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作者 Xianshu Liu Jie Ding +4 位作者 nanqi ren Shuangyang Zhao Luyan Zhang Yan Li Qingyue Tong 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2019年第6期1-7,共7页
In this study, benzothiazole was entirely mineralized by an up-flow internal circulation microbial electrolysis reactor. The bioelectrochemical system was operated at ambient temperature under continuous-flow mode. Th... In this study, benzothiazole was entirely mineralized by an up-flow internal circulation microbial electrolysis reactor. The bioelectrochemical system was operated at ambient temperature under continuous-flow mode. The analysis of metabolite which was extracted by HPLC-MS from the bioreactor indicated that benzothiazole derivative ( BTH ) was firstly converted into 2-hydroxybenzothiazole in the microbial electrolysis cell (MEC) and then mineralized within three steps, i.e., the fracture of thiazole-ring through a series of oxidation and hydrolysis, the deamination and hydroxylation of 2-aminobenzenesulfonic acid, and the mineralization of various carboxylic acids to CO2 and H2O. Bacterial community analysis indicated that the applied electric field could selectively enrich certain species and the dominate bacteria on the electrodes belonged to Proteobacteria, Bacteroidetes, and Firmicutes. Results show that MEC can improve the degradation efficiency of BTH in wastewater, enable the microbiological reactor to satisfy the requirements of high loading rate, thereby fulfilling the scale-up of whole process in the future. 展开更多
关键词 BENZOTHIAZOLE microbial electrolysis cell intermediate product biodegradation pathway high-throughput sequencing
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Effects of Ultrasonic and Acid Pretreatment on Food Waste Disintegration and Volatile Fatty Acid Production
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作者 Qinglian Wu Wanqian Guo +3 位作者 Shanshan Yang Haichao Luo Simai Peng nanqi ren 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第3期1-6,共6页
This study aims at investigating the effects of ultrasonic and acid pretreatment on food waste( FW)disintegration and volatile fatty acid( VFA) production. Single-factor experiments are carried out to obtain optimal c... This study aims at investigating the effects of ultrasonic and acid pretreatment on food waste( FW)disintegration and volatile fatty acid( VFA) production. Single-factor experiments are carried out to obtain optimal conditions of individual ultrasonic and acid pretreatment,and response surface method( RSM) is applied to optimize the conditions of the combination of ultrasonic and acid( UA) pretreatment. Results show that the optimal acid,ultrasonic and UA pretreatments conditions are individual pH 2,individual ultrasonic energy density of 1. 0 W / mL and the combination of ultrasonic energy density1. 11 W / mL and pH 1. 43,respectively. Correspondingly,the maximum disintegration degrees( DD) of 46. 90%,57. 38% and68. 83%are obtained by acid,ultrasonic and UA pretreatments,respectively. After optimizing pretreatment conditions,batch experiments are operated to produce VFA from raw and pretreated FW under anaerobic fermentation process. Both the maximum VFA production( 976. 17 mg COD / gV S) and VFA / SCOD( 72. 89%) are obtained with ultrasonic pretreatment, followed by UA pretreatment, non-pretreatment and acid pretreatment,respectively. This observation demonstrates that a higher acidity on acid and UA pretreatments inhibits the generation of VFA. Results suggest that ultrasonic pretreatment is preferable to promote the disintegration degree of FW and VFA production. 展开更多
关键词 food waste(FW) ultrasonic and acid pretreatment response surface method(RSM) anaerobic fermentation volatile fatty acid(VFA)
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Microbial community structure in different wastewater treatment processes characterized by single-strand conformation polymorphism (SSCP) technique 被引量:2
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作者 Yangguo ZHAO Aijie WANG +1 位作者 nanqi ren Yan ZHAO 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2008年第1期116-121,共6页
In order to investigate microbial community structures in different wastewater treatment processes and understand the relationship between the structures and the status of processes,the microbial community diversity,v... In order to investigate microbial community structures in different wastewater treatment processes and understand the relationship between the structures and the status of processes,the microbial community diversity,variety and distribution in five wastewater treatment pro cesses were studied by a culture-independent genetic fingerprinting technique single-strand conformation poly-morphism(SSCP).The five processes included denitrifying and phosphate-removal system(diminished N),Chinese traditional medicine wastewater treatment system(P),beer wastewater treatment system(W),fermentative biohydrogen-producing system(H),and sulfate-reduction system(S).The results indicated that the microbial community profiles in the wastewater bioreactors with the uniform status were very similar.The diversity of microbial populations was correlated with the complexity of organic contaminants in wastewater.Chinese traditional medicine wastewater contained more complex organic components;hence,the population diversity was higher than that of simple nutrient bioreactors fed with molasses wastewater.Compared with the strain bands in a simulated community,the relative proportion of some functional microbial populations in bioreactors was not dom-inant.Fermentative biohydrogen producer Ethanoligenens harbinense in the better condition bioreactor had only a 5% band density,and the Desulfovibrio sp.in the sulfate-reducing bioreactor had less than 1.5%band density.The SSCP profiles could identify the difference in microbial community structures in wastewater treatment processes,monitor some of the functional microbes in these processes,and consequently provide useful guidance for improving their efficiency. 展开更多
关键词 wastewater treatment process microbial community structure community diversity single-strand conformation polymorphism(SSCP)
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Kinetics and mechanisms of non-radically and radically induced degradation of bisphenol A in a peroxymonosulfate-chloride system
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作者 Zhao Song Yu Zhang +3 位作者 Yanhu Yang Yidi Chen nanqi ren Xiaoguang Duan 《Environmental Science and Ecotechnology》 SCIE 2024年第6期191-197,共7页
Bisphenol A,a hazardous endocrine disruptor,poses significant environmental and human health threats,demanding efficient removal approaches.Traditional biological methods struggle to treat BPA wastewater with high chl... Bisphenol A,a hazardous endocrine disruptor,poses significant environmental and human health threats,demanding efficient removal approaches.Traditional biological methods struggle to treat BPA wastewater with high chloride(Cl^(-))levels due to the toxicity of high Cl^(-)to microorganisms.While persulfate-based advanced oxidation processes(PS-AOPs)have shown promise in removing BPA from high Cl^(-)wastewater,their widespread application is always limited by the high energy and chemical usage costs.Here we show that peroxymonosulfate(PMS)degrades BPA in situ under high Cl^(-)concentrations.BPA was completely removed in 30 min with 0.3 mM PMS and 60 mM Cl^(-).Non-radical reactive species,notably free chlorine species,including dissolved Cl2(l),HClO,and ClO−dominate the removal of BPA at temperatures ranging from 15 to 60°C.Besides,free radicals,including•OH and Cl_(2)^(•−),contribute minimally to BPA removal at 60°C.Based on the elementary kinetic models,the production rate constant of Cl2(l)(32.5 M^(−1) s^(−1))is much higher than HClO(6.5×10^(−4) M^(−1) s^(−1)),and its degradation rate with BPA(2×10^(7) M^(−1) s^(−1))is also much faster than HClO(18 M^(−1) s^(−1)).Furthermore,the degradation of BPA by Cl2(l)and HClO were enlarged by 10-and 18-fold at 60°C compared to room temperature,suggesting waste heat utilization can enhance treatment performance.Overall,this research provides valuable insights into the effectiveness of direct PMS introduction for removing organic micropollutants from high Cl^(-)wastewater.It further underscores the critical kinetics and mechanisms within the PMS/Cl⁻system,presenting a cost-effective and environmentally sustainable alternative for wastewater treatment. 展开更多
关键词 BPA removal Saline wastewater PEROXYMONOSULFATE Free chlorine Kinetic model
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Advanced wastewater treatment with microalgae-indigenous bacterial interactions
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作者 Xue Li Shengnan Li +7 位作者 Peng Xie Xi Chen Yuhao Chu Haixing Chang Jian Sun Qing Li nanqi ren Shih-Hsin Ho 《Environmental Science and Ecotechnology》 SCIE 2024年第4期198-207,共10页
Microalgal-indigenous bacterial wastewater treatment(MBWT)emerges as a promising approach for the concurrent removal of nitrogen(N)and phosphorus(P).Despite its potential,the prevalent use of MBWT in batch systems lim... Microalgal-indigenous bacterial wastewater treatment(MBWT)emerges as a promising approach for the concurrent removal of nitrogen(N)and phosphorus(P).Despite its potential,the prevalent use of MBWT in batch systems limits its broader application.Furthermore,the success of MBWT critically depends on the stable self-adaptation and synergistic interactions between microalgae and indigenous bacteria,yet the underlying biological mechanisms are not fully understood.Here we explore the viability and microbial dynamics of a continuous flow microalgae-indigenous bacteria advanced wastewater treatment system(CFMBAWTS)in processing actual secondary effluent,with a focus on varying hydraulic retention times(HRTs).The research highlights a stable,mutually beneficial relationship between indigenous bacteria and microalgae.Microalgae and indigenous bacteria can create an optimal environment for each other by providing essential cofactors(like iron,vitamins,and indole-3-acetic acid),oxygen,dissolved organic matter,and tryptophan.This collaboration leads to effective microbial growth,enhanced N and P removal,and energy generation.The study also uncovers crucial metabolic pathways,functional genes,and patterns of microbial succession.Significantly,the effluent NH4 t-N and P levels complied with the Chinese national Class-II,Class-V,Class-IA,and Class-IB wastewater discharge standards when the HRT was reduced from 15 to 6 h.Optimal results,including the highest rates of CO_(2) fixation(1.23 g L^(-1)),total energy yield(32.35 kJ L^(-1)),and the maximal lipid(33.91%)and carbohydrate(41.91%)content,were observed at an HRT of 15 h.Overall,this study not only confirms the feasibility of CFMBAWTS but also lays a crucial foundation for enhancing our understanding of this technology and propelling its practical application in wastewater treatment plants. 展开更多
关键词 Continuous flow systems Microalgal-indigenous bacterial interactions Advanced treatment Self-adaptation mechanisms Nutrient removal mechanisms
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Methane and nitrous oxide emissions from municipal wastewater treatment plants in China:A plant-level and technology-specific study
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作者 Haiyan Li Liangfang You +6 位作者 He Du Bowen Yu Lu Lu Bo Zheng Qiang Zhang Kebin He nanqi ren 《Environmental Science and Ecotechnology》 SCIE 2024年第4期123-130,共8页
Wastewater treatment is an important source of greenhouse gases(GHGs).Yet large uncertainties remain in the quantification of GHG emissions from municipal wastewater treatment plants(MWWTPs)in China.A high-resolution ... Wastewater treatment is an important source of greenhouse gases(GHGs).Yet large uncertainties remain in the quantification of GHG emissions from municipal wastewater treatment plants(MWWTPs)in China.A high-resolution and technology-specific emission inventory is still lacking to support mitigation strategies of MWWTPs.Here we develop a plant-level and technology-based MWWTP emission inventory for China covering 8703 plants and 19 treatment technology categories by compiling and harmonizing the most up-to-date facility-level databases.China's methane(CH_(4))and nitrous oxide(N_(2)O)emissions from MWWTPs in 2020 are estimated to be 150.6 Gg and 22.0 Gg,respectively,with the uncertainty range of-30%to 37%and-30%to 26%at 95%confidence interval.We find an emission inequality across cities,with the richest cities emitting two times more CH_(4)and N_(2)O per capita from municipal wastewater treatment than the poorest cities.The emitted CH_(4)and N_(2)O are dominated by Anaerobic/Anoxic/Oxic-,Sequencing Batch Reactor-,Oxidation Ditch-,and Anoxic/Oxic-based MWWTPs of less than 20 years old.Considering the relatively young age structure of China's MWWTPs,the committed emissions highlight the importance of reducing on-site GHG emissions by optimization of operating conditions and innovation management.The emission differences among our estimates,previous studies,and the Intergovernmental Panel on Climate Change guidelines are largely attributed to the uncertainties in emission factors,implying the urgent need for more plant-integrated measurements to improve the accuracy of emission accounting. 展开更多
关键词 METHANE Nitrous oxide EMISSIONS Municipal wastewater treatment plants
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Sustainable Seawater Desalination and Energy Management:Mechanisms,Strategies,and the Way Forward
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作者 Meng Wang Yen Wei +4 位作者 Ruoxin Li Xin Wang Chengyu Wang nanqi ren Shih-Hsin Ho 《Research》 SCIE EI CSCD 2024年第3期595-611,共17页
Solar-driven desalination systems have been recognized as an effective technology to address the water crisis.Recently,evaporators prepared based on advanced manufacturing technologies have emerged as a promising tool... Solar-driven desalination systems have been recognized as an effective technology to address the water crisis.Recently,evaporators prepared based on advanced manufacturing technologies have emerged as a promising tool in enhancing ocean energy utilization.In this review,we discussed the thermal conversion,energy flow,salt deposition mechanisms,and design strategies for solar-driven desalination systems,and explored how to improve the desalination performance and energy use efficiency of the systems through advanced manufacturing technologies.In future perspectives,we determined the feasibility of coupling solar-driven solar desalination systems with multi-stage energy utilization systems and emerging artificial intelligence technologies,for which conclusions are given and new directions for future desalination system development are envisioned.Finally,exciting opportunities and challenges in the face of basic research and practical implementation are discussed,providing promising solutions and blueprints for green and novel desalination technologies while achieving sustainable development. 展开更多
关键词 SUSTAINABLE SOLAR DIRECTIONS
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Preparation of excellent building materials using geopolymer instead of traditional cement
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作者 Yuanchuan ren Shanqisong Huang +6 位作者 Yan Hu nanqi ren Lingrui Kuang Fenghui Wu Dandan Chen Xuejun Zhu Qiang Niu 《Particuology》 SCIE EI CAS 2024年第12期333-342,共10页
In order to improve the resource utilization rate of aluminum ash,high-quality building materials were prepared by replacing traditional cement with aluminum ash,and the performance of building materials under differe... In order to improve the resource utilization rate of aluminum ash,high-quality building materials were prepared by replacing traditional cement with aluminum ash,and the performance of building materials under different conditions and factors was studied.The experimental results show that when the pressure was 300 MPa and the natural curing time was 3 days,the comprehensive performance of the brick reaches its optimum(compressive strength of 60 MPa,flexural strength of 1.3 MPa,and softening coefficient of about 0.9),far superior to other reported methods for preparing building materials.SEM-EDS,Particle size analysis and XRD confirmed that the crystal structure in aluminum ash undergoes a transformation under high-intensity mechanical pressure,forming cement-based active substances.This study not only obtained a new method for preparing building materials,but also further promoted the research on the resource utilization of aluminum ash,providing a new approach for the treatment and disposal of hazardous waste. 展开更多
关键词 Aluminum ash Hazardous solid waste Extreme high value Densification Super building materials
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Bulking sludge for PHA production:Energy saving and comparative storage capacity with well-settled sludge 被引量:16
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作者 Qinxue Wen Zhiqiang Chen +1 位作者 Changyong Wang nanqi ren 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第10期1744-1752,共9页
Two acetate-fed sequencing batch reactors (SBR) were operated under an aerobic dynamic feeding (ADF) model (SBR#2) and with anaerobic phase before aerobic phase (SBR#1) to select mixed cultures with a high pol... Two acetate-fed sequencing batch reactors (SBR) were operated under an aerobic dynamic feeding (ADF) model (SBR#2) and with anaerobic phase before aerobic phase (SBR#1) to select mixed cultures with a high polyhydroxyalkanoates (PHA) storage response. Although kinetic selection based on storage response should bring about a predominance of floc-formers, a bulking sludge with storage response comparable to well-settled sludge was steadily established. An anaerobic phase was introduced before the aerobic phase in the ADF model to improve the sludge settleability (SBR #1), however, due to the consequent increased feast/famine ratio, the performance of SBR #1, in terms of both the maximum PHB (polyhydroxybutyrate) cell content and APHB, was lower than that of SBR #2. SBR #2 gradually reached a steady state while SBR #1 failed suddenly after 50 days of operation. The maximum specific substrate uptake rate and storage rate for the selected bulking sludge were 0.4 Cmol Ae/(Cmol X.hr) and 0.18 Cmol Ac/(Cmol PHB.hr), respectively, resulting a yield of 0.45 Cmol PHB/(Cmol Ae) in SBR #2 in the culture enrichment phase. A maximum PHB content of 53% of total suspended solids and PHB storage rate of 1.36 Cmol Ac/(Cmol PHB.hr) was achieved at 10.2 hr in batch accumulation tests under nitrogen starvation. The results indicated that it was feasible to utilize filamentous bacteria to accumulate PHA with a rate comparable to well-settled sludge, Furthermore, the lower dissolved oxygen demand of filamentous bacteria would save energy required for aeration in the culture enrichment stage. 展开更多
关键词 POLYHYDROXYALKANOATES mixed cultures aerobic dynamic feeding bulking sludge feast/famine ratio
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Effect of seed sludge on characteristics and microbial community of aerobic granular sludge 被引量:18
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作者 Zhiwei Song Yuejun Pan +2 位作者 Kun Zhang nanqi ren Aijie Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第9期1312-1318,共7页
Aerobic granular sludge was cultivated by using different kinds of seed sludge in sequencing batch airlift reactor. The influence of seed sludge on physical and chemical properties of granular sludge was studied; the ... Aerobic granular sludge was cultivated by using different kinds of seed sludge in sequencing batch airlift reactor. The influence of seed sludge on physical and chemical properties of granular sludge was studied; the microbial community structure was probed by using scanning electron microscope and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that seed sludge played an important role on the formation of aerobic granules. Seed sludge taken from beer wastewater treatment plant (inoculum A) was more suitable for cultivating aerobic granules than that of sludge from municipal wastewater treatment plant (inoculurn B). Cultivated with inoculum A, large amount of mature granules formed after 35 days operation, its SVI reached 32.75 mL/g, and SOUR of granular sludge was beyond 1.10 mg/(g.min). By contrast, it needed 56 days obtaining mature granules using inoculum B. DGGE profiles indicated that the dominant microbial species in mature granules were 18 and 11 OTU when inoculum A and B were respectively employed as seed sludge. The sequencing results suggested that dominant species in mature granules cultivated by inoculum A were Paracoccus sp., Devosia hwasunensi, Pseudoxanthomonas sp., while the dominant species were Lactococcus raffinolactis and Pseudomonas sp. in granules developed from inoculum B. 展开更多
关键词 aerobic granular sludge seed sludge microbial community PCR-DGGE
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Effect of temperature switchover on the degradation of antibiotic chloramphenicol by biocathode bioelectrochemical system 被引量:10
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作者 Deyong Kong Bin Liang +2 位作者 Duu-Jong Lee Aijie Wang nanqi ren 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第8期1689-1697,共9页
Exposure to chloramphenicol(CAP),a chlorinated nitroaromatic antibiotic,can induce CAP-resistant bacteria/genes in diverse environments. A biocathode bioelectrochemical system(BES) was applied to reduce CAP under ... Exposure to chloramphenicol(CAP),a chlorinated nitroaromatic antibiotic,can induce CAP-resistant bacteria/genes in diverse environments. A biocathode bioelectrochemical system(BES) was applied to reduce CAP under switched operational temperatures.When switching from 25 to 10°C,the CAP reduction rate(kCAP) and the maximum amount of the dechlorinated reduced amine product(AMCl,with no antibacterial activity) by the biocathode communities were both markedly decreased. The acetate and ethanol yield from cathodophilic microbial glucose fermentation(with release of electrons) was also reduced. Formation of the product AMCl was enhanced by the biocathode dechloridation reaction compared with that produced from pure electrochemical or microbial dechloridation processes. The electrochemical and morphological analyses of cathode biofilms demonstrated that some cathodophilic microbes could adapt to low temperature and play a key role in CAP degradation. The resilient biocathode BES has a potential for the treatment of CAP-containing wastewater in temperature fluctuating environments. 展开更多
关键词 Chloramphenicol degradation BIOCATHODE Dechloridation Temperature switchover
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Denitrification and phosphorus uptake by DPAOs using nitrite as an electron acceptor by step-feed strategies 被引量:8
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作者 Bin MA Shuying WANG +4 位作者 Guibing ZHU Shijian GE Junmin WANG nanqi ren Yongzhen PENG 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2013年第2期267-272,共6页
Denitrifying phosphorus accumulating organ- isms (DPAOs) using nitrite as an electron acceptor can reduce more energy. However, nitrite has been reported to have an inhibition on denitrifying phosphorus removal. In ... Denitrifying phosphorus accumulating organ- isms (DPAOs) using nitrite as an electron acceptor can reduce more energy. However, nitrite has been reported to have an inhibition on denitrifying phosphorus removal. In this study, the step-feed strategy was proposed to achieve low nitrite concentration, which can avoid or relieve nitrite inhibition. The results showed that denitrification rate, phosphorus uptake rate and the ratio of the phosphorus uptaken to nitrite denitrified (anoxic P/N ratio) increased when the nitrite concentration was 15 rag. L-1 after step- feeding nitrite. The maximum denitrification rate and phosphorus uptake rate was 12.73 mg NO2-N.g MLSS- 1· h- 1 and 18.75 mg PO34--P- g MLSS- 1. h- 1, respec- tively. These rates were higher than that using nitrate (15 mg. L-l) as an electron acceptor. The maximum anoxic P/N ratio was 1.55 mg PO43- -Pmg NO2-N-1. When the nitrite concentration increased from 15 to 20 mg NO2 -N ~ L-I after addition of nitrite, the anoxic phosphorus uptake was inhibited by 64.85%, and the denitrification by DPAOs was inhibited by 61.25%. Denitrification rate by DPAOs decreased gradually when nitrite (about 20 mg · L-1) was added in the step-feed SBR. These results indicated that the step-feed strategy can be used to achieve denitrifying phosphorus removal using nitrite as an electron acceptor, and nitrite concentration should be maintained at low level ( 〈 15 mg. L-1 in this study). 展开更多
关键词 denitrifying phosphate accumulating organ-isms (DPAOs) DENITRIFICATION phosphorus uptake nitrite step-feed enhanced biological phosphorus removal
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One-pot hydrothermal fabrication of BiVO_(4)/Fe_(3)O_(4)/rGO composite photocatalyst for the simulated solar light-driven degradation of Rhodamine B 被引量:7
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作者 Shuangyang Zhao Chengxin Chen +3 位作者 Jie Ding Shanshan Yang Yani Zang nanqi ren 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2022年第3期105-120,共16页
Fabrication of easily recyclable photocatalyst with excellent photocatalytic activity for degradation of organic pollutants in wastewater is highly desirable for practical application.In this study,a novel ternary mag... Fabrication of easily recyclable photocatalyst with excellent photocatalytic activity for degradation of organic pollutants in wastewater is highly desirable for practical application.In this study,a novel ternary magnetic photocatalyst BiVO_(4)/Fe_(3)O_(4)/reduced graphene oxide(BiVO_(4)/Fe_(3)O_(4)/rGO)was synthesized via a facile hydrothermal strategy.The BiVO_(4)/Fe_(3)O_(4) with 0.5 wt%of rGO(BiVO_(4)/Fe_(3)O_(4)/0.5%rGO)exhibited superior activity,degrading greater than 99%Rhodamine B(RhB)after 120 min solar light radiation.The surface morphology and chemical composition of BiVO_(4)/Fe_(3)O_(4)/rGO were studied by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,UV–visible diffuse reflectance spectroscopy,Fourier transform infrared spectroscopy,and Raman spectroscopy.The free radicals scavenging experiments demonstrated that hole(h^(+))and superoxide radical(O_(2)•^(−))were the dominant species for RhB degradation over BiVO_(4)/Fe_(3)O_(4)/rGO under solar light.The reusability of this composite catalyst was also investigated after five successive runs under an external magnetic field.The BiVO_(4)/Fe_(3)O_(4)/rGO composite was easily separated,and the recycled catalyst retained high photocatalytic activity.This study demonstrates that catalyst BiVO_(4)/Fe_(3)O_(4)/rGO possessed high dye removal efficiency in water treatment with excellent recyclability from water after use.The current study provides a possibility for more practical and sustainable photocatalytic process. 展开更多
关键词 Photocatalysis Ternary magnetic photocatalyst Visible-light-driven Free radicals trapping REUSABILITY Recycling
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Trophic mode and organics metabolic characteristic of fungal community in swine manure composting 被引量:5
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作者 Jing Peng Ke Wang +6 位作者 Xiangbo Yin Xiaoqing Yin Mengfei Du Yingzhi Gao Philip Antwi nanqi ren Aijie Wang 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2019年第6期137-146,共10页
The succession of fungal community,trophic mode and metabolic characteristics were evaluated in 60 days composting of swine manure by high-throughput sequencing,FUNGuild and Biolog method,respectively.The result showe... The succession of fungal community,trophic mode and metabolic characteristics were evaluated in 60 days composting of swine manure by high-throughput sequencing,FUNGuild and Biolog method,respectively.The result showed that the ftingal community diversity reached to the highest level(76 OTUs)in the thermophilic phase of composting,then sustained decline to 15 OTUs after incubation.There were 10 fungal function groups in the raw swine manure.Pathotroph-saprotroph fungi reached to 15.91%on Day-10but disappeared on Day-60.Dung saprotroph-undefined saprotroph fungi grown from 0.19%to 52.39%during the treatment.The ftmgal community had more functional groups but the lower substrate degradation rates in the thermophilic phase.The fungal communities on Day-0 and Day-60 had the highest degradation rates of amino acids and polymers,respectively.Redundancy analysis showed that ORP(49.6%),VS/Ash(45.3%)and moisture(39.2%)were the main influence factors on the succession of fungal community in the swine manure composting process. 展开更多
关键词 FUNGUS FUNGuild BIOLOG Trophic mode COMPOSTING Oxidation reduction potential
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