Active fault-tolerant control utilizes information obtained from fault diagnosis to reconfigure the control law to compensate for faults in the wastewater treatment process. However, since the similarity of fault char...Active fault-tolerant control utilizes information obtained from fault diagnosis to reconfigure the control law to compensate for faults in the wastewater treatment process. However, since the similarity of fault characteristic in the incipient stage can result in misdiagnosis, it is a challenge for fault-tolerant control to ensure system safety and reliability. Therefore, to address this issue, a fault diagnosis and fault-tolerant control with a knowledge transfer strategy(KT-FDFTC) is proposed in this paper. First, a knowledge reasoning diagnosis strategy using multi-source transfer learning is designed to distinguish the similar characteristic of incipient faults. Then, the multi-source knowledge can assist in the diagnosis strategy to strengthen the fault information for fault-tolerant control. Second, a knowledge adaptive compensation mechanism, which makes knowledge and data coupled into the output trajectory regarded as an objective function, is employed to dynamically compute the control law. Then, KT-FDFTC can ensure the stable operation to adapt to various fault conditions. Third, the Lyapunov function is established to demonstrate the stability of KT-FDFTC. Then, the theoretical basis can offer the successful application of KTFDFTC. Finally, the proposed method is validated through a real WWTP and a simulation platform. The experimental results confirm that KT-FDFTC can provide good diagnosis performance and fault tolerance ability.展开更多
The abundance of microplastics(MPs)in wastewater from three wastewater treatment plants(WWTPs)were determined in Hangzhou,Zhejiang Province,China.The MPs abundance was 140-350 particles per litre in the influent and 1...The abundance of microplastics(MPs)in wastewater from three wastewater treatment plants(WWTPs)were determined in Hangzhou,Zhejiang Province,China.The MPs abundance was 140-350 particles per litre in the influent and 10-30 particles per litre in the effluent.Four shapes of MPs in the influent were observed,while mainly only debris was left in the effluent.The percentage of small(<100μm),medium(100-500μm),and large-sized(≥500μm)plastics in the raw leachate of the three WWTPs were 54.3%,8.6%,and 37.1%,28.6%,64.3%,and 7.1%,and 41.4%,24.1%,and 34.5%,respectively.Mainly only the size of≤100μm was left in the effluent of all.The removal efficiencies of MPs in a range of 78.6%to 96.6%were achieved.Polypropylene,polystyrene,polyethylene,polyethylene terephthalate and polyvinyl chloride were the main types and detected in all wastewater samples,accounting for over 75%of all types.The plastic components contained in different industrial wastewater were more complex.The distribution of MPs was significantly positively correlated with most conventional indicators such as chemical oxygen demead,ammonia nitrogen,and total phosphorus,but not with heavy metals.Similar wastewater,different treatment processes,or similar processes but different wastewater(industrial wastewater proportion varied)could all lead to differences in MPs removal.The MPs abundance measured in this experiment was similar to some previous studies,but relatively high.The three WWTPs can discharge up to 6.0×10^(-8)-1.8×10^(-9) plastics of MPs per day,which poses potential ecological risks.This study indicates that the source control of MPs and optimizing the process design of existing WWTPs are crucial for preventing and controlling MPs pollution.展开更多
The uptake of biochar from sewage sludge has developed into a critical avenue for resource reclamation whilst solving waste disposal concerns.However,despite the latter side in environmental palliative,the use of this...The uptake of biochar from sewage sludge has developed into a critical avenue for resource reclamation whilst solving waste disposal concerns.However,despite the latter side in environmental palliative,the use of this biochar for remediation,recovery of nutrients,or adsorption of pollutants is often suboptimal due to poor surface area,high percentage of ash and functional group scarcity.Sewage sludge-derived biochar(SSB)has emerged as a promising material for resource recovery,environmental remediation,and sustainable waste management.This review paper scopes out the recent developments in the field of sludge derived biochar and focuses on the advances in hydrothermal carbonization biochar and its modified forms.Pretreatment methods such as hydrothermal carbonization,enzymatic treatment,ultrasonic,and acid/base wash are looked into in order to improve the purity and the characteristics of the feedstock.Post the structural adjustments some of the molecular modification methods are implemented using KOH,ZnCl2 and H3PO4 for chemical activation,doping with Fe/Mn or Mg,and thermal and microwave processes which are aimed at increasing porosity,adsorption and catalytic activity.The review also evaluates the combination of various methods to fabricate multifunctional biochar for applications such as phosphate recycling,heavy metals and carbon absorption and utilization,as well as the application of biochar as catalysts in advanced oxidation processes.展开更多
In this study,the efects of diferent heat treatment process parameters on the microstructure and mechanical properties of Al-12Si-5Cu-1.1Mg-2.3Ni-0.3La alloy were explored.Research showed that eutectic Si underwent th...In this study,the efects of diferent heat treatment process parameters on the microstructure and mechanical properties of Al-12Si-5Cu-1.1Mg-2.3Ni-0.3La alloy were explored.Research showed that eutectic Si underwent three stages during solution treatment:difusing,spheroidization and coarsening.As the solution temperature and time increased,the size of eutectic Si showed a trend of frst decreasing and then increasing.Compared with the heat treatment time,the heat treatment temperature had a more signifcant efect on the mechanical properties.The coarsening of microstructure was the main reason for the deterioration of mechanical properties.The Al_(3)Ti and Al_(3)CuNiLa in the microstructure after aging can signifcantly improve the mechanical properties of the alloy.The Al_(11)La_(3) with secondary precipitation occurred in the La-rich phase.The addition of La inhibited the growth of coherent/semi-coherentθandβphases,which was very benefcial for the improvement of high-temperature strength.Under the optimal heat treatment process parameters of 500℃×4 h+190℃×4 h,the ultimate tensile strength(UTS)of the alloy reached 366.65 MPa.The high-temperature strength and elongation of the alloy reached 101.98 MPa and 13.77%at 350℃,respectively.展开更多
Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are c...Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are critical to manage the risks posed by ARGs.This study summarizes the prevalence of ARGs in raw water sources and treated drinking water worldwide.In addition,the removal efficiency of ARGs and related mechanisms by different DWTPs are reviewed.Abiotic and biotic factors that affect ARGs elimination are also discussed.The data on presence of ARGs in drinking water help come to the conclusion that ARGs pollution is prevalent and deserves a high priority.Generally,DWTPs indeed achieve ARGs removal,but some biological treatment processes such as biological activated carbon filtration may promote antibiotic resistance due to the enrichment of ARGs in the biofilm.The finding that disinfection and membrane filtration are superior to other DWTPs adds weight to the advice that DWTPs should adopt multiple disinfection barriers,as well as keep sufficient chlorine residuals to inhibit re-growth of ARGs during subsequent distribution.Mechanistically,DWTPs obtain direct and inderect ARGs reduction through DNA damage and interception of host bacterias of ARGs.Thus,escaping of intracellular ARGs to extracellular environment,induced by DWTPs,should be advoided.This review provides the theoretical support for developping efficient reduction technologies of ARGs.Future study should focus on ARGs controlling in terms of transmissibility or persistence through DWTPs due to their biological related nature and ubiquitous presence of biofilm in the treatment unit.展开更多
In wastewater treatment process(WWTP), the accurate and real-time monitoring values of key variables are crucial for the operational strategies. However, most of the existing methods have difficulty in obtaining the r...In wastewater treatment process(WWTP), the accurate and real-time monitoring values of key variables are crucial for the operational strategies. However, most of the existing methods have difficulty in obtaining the real-time values of some key variables in the process. In order to handle this issue, a data-driven intelligent monitoring system, using the soft sensor technique and data distribution service, is developed to monitor the concentrations of effluent total phosphorous(TP) and ammonia nitrogen(NH_4-N). In this intelligent monitoring system, a fuzzy neural network(FNN) is applied for designing the soft sensor model, and a principal component analysis(PCA) method is used to select the input variables of the soft sensor model. Moreover, data transfer software is exploited to insert the soft sensor technique to the supervisory control and data acquisition(SCADA) system. Finally, this proposed intelligent monitoring system is tested in several real plants to demonstrate the reliability and effectiveness of the monitoring performance.展开更多
Real-time and reliable measurements of the effluent quality are essential to improve operating efficiency and reduce energy consumption for the wastewater treatment process.Due to the low accuracy and unstable perform...Real-time and reliable measurements of the effluent quality are essential to improve operating efficiency and reduce energy consumption for the wastewater treatment process.Due to the low accuracy and unstable performance of the traditional effluent quality measurements,we propose a selective ensemble extreme learning machine modeling method to enhance the effluent quality predictions.Extreme learning machine algorithm is inserted into a selective ensemble frame as the component model since it runs much faster and provides better generalization performance than other popular learning algorithms.Ensemble extreme learning machine models overcome variations in different trials of simulations for single model.Selective ensemble based on genetic algorithm is used to further exclude some bad components from all the available ensembles in order to reduce the computation complexity and improve the generalization performance.The proposed method is verified with the data from an industrial wastewater treatment plant,located in Shenyang,China.Experimental results show that the proposed method has relatively stronger generalization and higher accuracy than partial least square,neural network partial least square,single extreme learning machine and ensemble extreme learning machine model.展开更多
Dry sliding wear tests of a Cr-Mo-V cast hot-forging die steel was carried out within a load range of 50--300 N at 400℃ by a pin-on-disc high temperature wear machine. The effect of heat treatment process on wear res...Dry sliding wear tests of a Cr-Mo-V cast hot-forging die steel was carried out within a load range of 50--300 N at 400℃ by a pin-on-disc high temperature wear machine. The effect of heat treatment process on wear resistance was systematically studied in order to select heat treatment processes of the steel with high wear resistance. The morphology, structure and composition were analyzed using scanning electron microscopy （SEM）, X-ray diffraction （XRD） and energy dispersive spectroscopy （EDS） ; wear mechanism was also discussed. Tribo-oxide layer was found to form on worn surfaces to reduce wear under low loads, but appear inside the matrix to increase wear under high loads. The tribo-oxides were mainly consisted of Fe3O4 and Fe2O3, FeO only appeared under a high load. Oxidative mild wear, transition of mild-severe wear in oxidative wear and extrusive wear took turns to operate with increasing the load. The wear resistance strongly depended on the selection of heat treatment processes or microstructures. It was found that bainite presented a better wear resistance than martensite plus bainite duplex structure, martensite structure was of the poorest wear resistance. The wear resistance increased with increasing austenizing temperature in the range of 920 to 1 120 ℃, then decreased at up to 1 220 ℃. As for tempering temperature and microstructure, the wear resistance increased in following order： 700℃ （tempered sorbite）, 200 ℃ （tempered martensite）, 440 to 650 ℃ （tempered troostite）. An appropriate combination of hardness, toughness, microstructural thermal stability was re- quired for a good wear resistance in high-temperature wear. The optimized heat treatment process was suggested for the cast hot-forging steel to be austenized at 1020 to 1 120 ℃, quenched in oil, then tempered at 440 to 650℃ for 2 h.展开更多
Thermal Barrier Coatings(TBCs)technology is key to improving the service temperature and the productivity of aircraft engines.The performance and failure life of TBCs are strongly influenced by surface integrity and m...Thermal Barrier Coatings(TBCs)technology is key to improving the service temperature and the productivity of aircraft engines.The performance and failure life of TBCs are strongly influenced by surface integrity and microstructure.Therefore,recognizing failure mechanisms and developing effective surface treatment processes are crucial for further improving the reliability and durability of TBCs.This paper explains the primary reasons for TBC failure,emphasizing on how integrity of surface and interface influences interfacial oxidation,high-temperature erosion,and Calcium-Magnesium-Alumina-Silicate(CMAS)corrosion.Furthermore,this paper completely and rigorously evaluates the research status of TBCs surface treatment processes,including the characteristics and effects of various processes,and describes the requirements and goals of pretreatment and post-treatment.In addition,a potential direction for the development and application of TBCs surface treatment is suggested.展开更多
Waste water treatment process(WWTP)control has been attracting more and more attention.However,various undesired factors,such as disturbance,uncertainties,and strong nonlinear couplings,propose big challenges to the c...Waste water treatment process(WWTP)control has been attracting more and more attention.However,various undesired factors,such as disturbance,uncertainties,and strong nonlinear couplings,propose big challenges to the control of a WWTP.In order to improve the control performance of the closed-loop system and guarantee the discharge requirements of the effluent quality,rather than take the model dependent control approaches,an active disturbance rejection control(ADRC)is utilized.Based on the control signal and system output,a phase optimized ADRC(POADRC)is designed to control the dissolved oxygen and nitrate concentration in a WWTP.The phase advantage of the phase optimized extended state observer(POESO),convergence of the POESO,and stability of the closed-loop system are analyzed from the theoretical point of view.Finally,a commonly accepted benchmark simulation model no.1.(BSM1)is utilized to test the POESO and POADRC.Linear active disturbance rejection control(LADRC)and the suggested proportion-integration(PI)control are taken to make a comparative research.Both system responses and performance index values confirm the advantage of the POADRC over the LADRC and the suggested PI control.Numerical results show that,as a result of the leading phase of the total disturbance estimation,the POESO based POADRC is an effective and promising way to control the dissolved oxygen and nitrate concentration so as to ensure the effluent quality of a WWTP.展开更多
It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotox...It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotoxicity reduction of industrial wastewater are still limited.In this study,the toxic organics removal and biotoxicity reduction of coal chemical wastewater(CCW)along a novel full-scale treatment process based on the pretreatment process-anaerobic process-biological enhanced(BE)process-anoxic/oxic(A/O)process-advanced treatment process was evaluated.This process performed great removal efficiency of COD,total phenol,NH_(4)^(+)-N and total nitrogen.And the biotoxicity variation along the treatment units was analyzed from the perspective of acute biotoxicity,genotixicity and oxidative damage.The results indicated that the effluent of pretreatment process presented relatively high acute biotoxicity to Tetrahymena thermophila.But the acute biotoxicity was significantly reduced in BE-A/O process.And the genotoxicity and oxidative damage to Tetrahymena thermophila were significantly decreased after advanced treatment.The polar organics in CCW were identified as the main biotoxicity contributors.Phenols were positively correlated with acute biotoxicity,while the nitrogenous heterocyclic compounds and polycyclic aromatic hydrocarbons were positively correlated with genotoxicity.Although the biotoxicity was effectively reduced in the novel full-scale treatment process,the effluent still performed potential biotoxicity,which need to be further explored in order to reduce environmental risk.展开更多
In order to explore the biodegradation behavior of nonylphenolic compounds during wastewater treatment processing, two full-scale wastewater treatment plants were investigated and batch biodegradation experiments were...In order to explore the biodegradation behavior of nonylphenolic compounds during wastewater treatment processing, two full-scale wastewater treatment plants were investigated and batch biodegradation experiments were conducted. The biodegradation pathways under the various operational conditions were identified from batch experiments： shortening of ethoxy-chains dominated under the anaerobic condition, whereas oxidizing of the terminal alcoholic group prevailed over the other routes under the aerobic condition. Results showed that the anoxic condition could accelerate the biodegradation rates of nonylphenolic compounds, but had no influence on the biodegradation pathway. The biodegradation rates of nonylphenol （NP） and short-chain nonylphenol polyethoxylates （NPnEOs, n： number of ethoxy units） increased from the anaerobic condition, then the anoxic, finally to the aerobic condition, while those of long-chain NPnEOs and nonylphenoxy carboxylates （NPECs） seemed similar under the various conditions. Under every operational condition, long-chain NPnEOs showed the highest biodegradation activity, followed by NPECs and short-chain NPnEOs, whereas NP showed relatively recalcitrant characteristics especially under the anaerobic condition. In addition, introducing sulfate and nitrate to the anaerobic condition could enhance the biodegradation of NP and short-chain NPnEOs by supplying more positive redox potentials.展开更多
The process characteristics of heat treatment of aluminum alloy auto body sheet and the working principle of air cushion furnace were introduced.The process position and irreplaceable role of air cushion furnace in th...The process characteristics of heat treatment of aluminum alloy auto body sheet and the working principle of air cushion furnace were introduced.The process position and irreplaceable role of air cushion furnace in the aluminum alloy auto body sheet production was pointed out after the difficulty and key points in the whole production process of auto body sheet were studied.Then the development process of air cushion furnace line of aluminum alloy sheet was reviewed,summarized and divided to two stages.Based on the research of air cushion furnace,the key technology of it was analyzed,then the key points on process,equipment and control models of air cushion furnace for aluminum alloy auto body sheet in future were put forward.With the rapid development of automotive industry,there will be certainly a new upsurge of research and application of air cushion furnace for heat treatment of aluminum alloy auto body sheet.展开更多
In this study, we investigated the occurrence and fate of nonylphenol（NP）, nonylphenol monoethoxylate（NP1EO） and nonylphenol diethoxylate（NP2EO） in a full scale sewage treatment plant, which applied an Anaerobic...In this study, we investigated the occurrence and fate of nonylphenol（NP）, nonylphenol monoethoxylate（NP1EO） and nonylphenol diethoxylate（NP2EO） in a full scale sewage treatment plant, which applied an Anaerobic/Oxic process. Concentrations of NP, NP1 EO and NP2 EO in the wastewater were measured during the period spanning a whole year.The results showed remarkable seasonal variation in the concentrations of the compounds.The NPn EO compounds were most abundant in winter, with the total concentrations of influent NP, NP1 EO and NP2 EO ranging from 3900 to 7000 ng/L, 4000 to 4800 ng/L and 5200 to 7200 ng/L, respectively. Regarding the total removal efficiencies of the three types of short-chain NPn EO compounds, different trends were exhibited according to different seasons. The average removal efficiency of NP for the different seasons ranked as follows：winter 〉 summer 〉 autumn 〉 spring; NP2 EO concentrations decreased as follows： summer 〉autumn 〉 winter 〉 spring, while NP1 EO concentrations reduced according to： spring 〉summer 〉 autumn 〉 winter. We also investigated the contribution ratio of individual treatment units in the A/O process, with the findings suggesting that the anaerobic treatment unit plays an important role in the elimination of short-chain NPn EOs from the wastewater.展开更多
An as-cast Al-Zn-Mg-Sc alloy was friction stir processed varying tool related parameters, yielding microstructures with different grain sizes （0.68, 1.8 and 5.5 μm）. Significant increases in room temperature ductil...An as-cast Al-Zn-Mg-Sc alloy was friction stir processed varying tool related parameters, yielding microstructures with different grain sizes （0.68, 1.8 and 5.5 μm）. Significant increases in room temperature ductility were obtained in these materials with reasonable enhancement in strength. It is demonstrated that the type of microstructure produced by friction stir processing （FSP） has a significant influence on the choice of post-FSP heat treatment design for achieving improved tensile properties. It is also found that the ultrafine grained FSP material could not achieve the desired high strength during the post-FSP heat treatment without grain coarsening, whereas the micro-grained FSP materials could reach such strength levels （〉560 MPa） under conventional age hardening heat treatment conditions.展开更多
In wastewater treatment systems,extracting meaningful features from process data is essential for effective monitoring and control.However,the multi-time scale data generated by different sampling frequencies pose a c...In wastewater treatment systems,extracting meaningful features from process data is essential for effective monitoring and control.However,the multi-time scale data generated by different sampling frequencies pose a challenge to accurately extract features.To solve this issue,a multi-timescale feature extraction method based on adaptive entropy is proposed.Firstly,the expert knowledge graph is constructed by analyzing the characteristics of wastewater components and water quality data,which can illustrate various water quality parameters and the network of relationships among them.Secondly,multiscale entropy analysis is used to investigate the inherent multi-timescale patterns of water quality data in depth,which enables us to minimize information loss while uniformly optimizing the timescale.Thirdly,we harness partial least squares for feature extraction,resulting in an enhanced representation of sample data and the iterative enhancement of our expert knowledge graph.The experimental results show that the multi-timescale feature extraction algorithm can enhance the representation of water quality data and improve monitoring capabilities.展开更多
According to different mechanism of microbial degradation of organics, this article divided the treatment processes of garbage landfill into four kinds, analyzed each kind of the treatment leachate process and present...According to different mechanism of microbial degradation of organics, this article divided the treatment processes of garbage landfill into four kinds, analyzed each kind of the treatment leachate process and presented a better improved process. (Author abstract) 4 Refs.展开更多
The characteristics and harm of high concentrations of organic wastewater were introducecl firstly, and then several treatment processes and effects of high concentrations of organic wastewater were summarized, which ...The characteristics and harm of high concentrations of organic wastewater were introducecl firstly, and then several treatment processes and effects of high concentrations of organic wastewater were summarized, which can provide theoretical references for the choice of wastewater treatment process.展开更多
[Objectives]To detect the protective effects of six protopanaxatriols(PPTs)on hypoxia/reoxygenation(H/R)induced cardiomyocyte injury by different treatments.[Methods]The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetra...[Objectives]To detect the protective effects of six protopanaxatriols(PPTs)on hypoxia/reoxygenation(H/R)induced cardiomyocyte injury by different treatments.[Methods]The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide(MTT)assay was used for detecting the protective effects of six PPTs including ginsenoside Rg1,Re,Rf,Rg2,(R)Rh1 and(S)Rh1 on cell viability reduced by H/R in different treatments.And the adenosine triphosphate(ATP)content and mitochondrial membrane potential(MMP)were used for detecting the mitochondrial function change during PPTs treatment.[Results]Among six PPTs,ginsenoside Rg1,Re,Rf,Rg2 and(R)Rh1 at the concentration of 12.5μM significantly increased the cell survival when treated before and during H/R.These five PPTs also significantly increased the ATP content and MMP reduced by H/R in the same manner.In comparison,only Rg1 significantly increased the cell viability compared with H/R group by pretreating and treating the cells during hypoxia process.[Conclusions]Different treatments affect the protective effects of PPTs.When treated before and during H/R,ginsenoside Rg1,Re,Rf,Rg2 and(R)Rh1 protect the cardiomyocyte against H/R injury mitochondrial function,and only ginsenoside Rg1 has protective effects when treated before and during hypoxia process.展开更多
The sour gas sweetening is one of the main processes in gas industries. Gas sweetening is done through chemical processes. Therefore, it requires high cost and energy. The results show that increasing the operating te...The sour gas sweetening is one of the main processes in gas industries. Gas sweetening is done through chemical processes. Therefore, it requires high cost and energy. The results show that increasing the operating temperature increases the mass transfer coefficient and increases the mass transfer rate. Theoretical and experimental data show that sulfur removal in 4.5 W magnetic field is desirable. The increase in sulfur removal percentage in the magnetic field of 4.5 W and 6.75 W is about 16.4% and 15.2%, respectively. According to the obtained results, the effect of temperature increase from 18.8°C to 23.4°C is more evident than the effect of temperature change from 23.4°C to 32.2°C. Because more thermal energy is needed to provide higher temperatures. Therefore, the temperature of 23.4°C is reported as the optimal temperature. The results of this research show that the percentage of sulfur removal is also high at this temperature.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.62125301,62021003,62303024,U24A20275,62522302,62473011,92467205)the National Key Research and Development Project (Grant Nos.2022YFB3305800-5,2024YFE0212400)+2 种基金the Youth Beijing Scholars Program (Grant No.037)the Beijing Nova Program (Grant Nos.20240484694,20250484938)the Beijing Natural Science Foundation (Grant No.L253010)。
文摘Active fault-tolerant control utilizes information obtained from fault diagnosis to reconfigure the control law to compensate for faults in the wastewater treatment process. However, since the similarity of fault characteristic in the incipient stage can result in misdiagnosis, it is a challenge for fault-tolerant control to ensure system safety and reliability. Therefore, to address this issue, a fault diagnosis and fault-tolerant control with a knowledge transfer strategy(KT-FDFTC) is proposed in this paper. First, a knowledge reasoning diagnosis strategy using multi-source transfer learning is designed to distinguish the similar characteristic of incipient faults. Then, the multi-source knowledge can assist in the diagnosis strategy to strengthen the fault information for fault-tolerant control. Second, a knowledge adaptive compensation mechanism, which makes knowledge and data coupled into the output trajectory regarded as an objective function, is employed to dynamically compute the control law. Then, KT-FDFTC can ensure the stable operation to adapt to various fault conditions. Third, the Lyapunov function is established to demonstrate the stability of KT-FDFTC. Then, the theoretical basis can offer the successful application of KTFDFTC. Finally, the proposed method is validated through a real WWTP and a simulation platform. The experimental results confirm that KT-FDFTC can provide good diagnosis performance and fault tolerance ability.
基金funded by the National Natural Science Foundation of China(42477406,51878617)the horizontal scientific research project(KYY-HX-20220803)the Engineering Research Center of Ministry of Education for Renewable Energy Infrastructure Construction Technology。
文摘The abundance of microplastics(MPs)in wastewater from three wastewater treatment plants(WWTPs)were determined in Hangzhou,Zhejiang Province,China.The MPs abundance was 140-350 particles per litre in the influent and 10-30 particles per litre in the effluent.Four shapes of MPs in the influent were observed,while mainly only debris was left in the effluent.The percentage of small(<100μm),medium(100-500μm),and large-sized(≥500μm)plastics in the raw leachate of the three WWTPs were 54.3%,8.6%,and 37.1%,28.6%,64.3%,and 7.1%,and 41.4%,24.1%,and 34.5%,respectively.Mainly only the size of≤100μm was left in the effluent of all.The removal efficiencies of MPs in a range of 78.6%to 96.6%were achieved.Polypropylene,polystyrene,polyethylene,polyethylene terephthalate and polyvinyl chloride were the main types and detected in all wastewater samples,accounting for over 75%of all types.The plastic components contained in different industrial wastewater were more complex.The distribution of MPs was significantly positively correlated with most conventional indicators such as chemical oxygen demead,ammonia nitrogen,and total phosphorus,but not with heavy metals.Similar wastewater,different treatment processes,or similar processes but different wastewater(industrial wastewater proportion varied)could all lead to differences in MPs removal.The MPs abundance measured in this experiment was similar to some previous studies,but relatively high.The three WWTPs can discharge up to 6.0×10^(-8)-1.8×10^(-9) plastics of MPs per day,which poses potential ecological risks.This study indicates that the source control of MPs and optimizing the process design of existing WWTPs are crucial for preventing and controlling MPs pollution.
文摘The uptake of biochar from sewage sludge has developed into a critical avenue for resource reclamation whilst solving waste disposal concerns.However,despite the latter side in environmental palliative,the use of this biochar for remediation,recovery of nutrients,or adsorption of pollutants is often suboptimal due to poor surface area,high percentage of ash and functional group scarcity.Sewage sludge-derived biochar(SSB)has emerged as a promising material for resource recovery,environmental remediation,and sustainable waste management.This review paper scopes out the recent developments in the field of sludge derived biochar and focuses on the advances in hydrothermal carbonization biochar and its modified forms.Pretreatment methods such as hydrothermal carbonization,enzymatic treatment,ultrasonic,and acid/base wash are looked into in order to improve the purity and the characteristics of the feedstock.Post the structural adjustments some of the molecular modification methods are implemented using KOH,ZnCl2 and H3PO4 for chemical activation,doping with Fe/Mn or Mg,and thermal and microwave processes which are aimed at increasing porosity,adsorption and catalytic activity.The review also evaluates the combination of various methods to fabricate multifunctional biochar for applications such as phosphate recycling,heavy metals and carbon absorption and utilization,as well as the application of biochar as catalysts in advanced oxidation processes.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.U2241232,U2341253 and 52375317)the National Key R&D Program of China(No.2022YFB3404204).
文摘In this study,the efects of diferent heat treatment process parameters on the microstructure and mechanical properties of Al-12Si-5Cu-1.1Mg-2.3Ni-0.3La alloy were explored.Research showed that eutectic Si underwent three stages during solution treatment:difusing,spheroidization and coarsening.As the solution temperature and time increased,the size of eutectic Si showed a trend of frst decreasing and then increasing.Compared with the heat treatment time,the heat treatment temperature had a more signifcant efect on the mechanical properties.The coarsening of microstructure was the main reason for the deterioration of mechanical properties.The Al_(3)Ti and Al_(3)CuNiLa in the microstructure after aging can signifcantly improve the mechanical properties of the alloy.The Al_(11)La_(3) with secondary precipitation occurred in the La-rich phase.The addition of La inhibited the growth of coherent/semi-coherentθandβphases,which was very benefcial for the improvement of high-temperature strength.Under the optimal heat treatment process parameters of 500℃×4 h+190℃×4 h,the ultimate tensile strength(UTS)of the alloy reached 366.65 MPa.The high-temperature strength and elongation of the alloy reached 101.98 MPa and 13.77%at 350℃,respectively.
基金supported by the National Science and Technology Major Projects for Water Pollution Control and Treatment(No.2017ZX07201-003)the Science and Technology Program of Zhejiang Province(No.LQ19E080023)the Zhejiang Public welfare technology research program(No.GG21E080021)。
文摘Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are critical to manage the risks posed by ARGs.This study summarizes the prevalence of ARGs in raw water sources and treated drinking water worldwide.In addition,the removal efficiency of ARGs and related mechanisms by different DWTPs are reviewed.Abiotic and biotic factors that affect ARGs elimination are also discussed.The data on presence of ARGs in drinking water help come to the conclusion that ARGs pollution is prevalent and deserves a high priority.Generally,DWTPs indeed achieve ARGs removal,but some biological treatment processes such as biological activated carbon filtration may promote antibiotic resistance due to the enrichment of ARGs in the biofilm.The finding that disinfection and membrane filtration are superior to other DWTPs adds weight to the advice that DWTPs should adopt multiple disinfection barriers,as well as keep sufficient chlorine residuals to inhibit re-growth of ARGs during subsequent distribution.Mechanistically,DWTPs obtain direct and inderect ARGs reduction through DNA damage and interception of host bacterias of ARGs.Thus,escaping of intracellular ARGs to extracellular environment,induced by DWTPs,should be advoided.This review provides the theoretical support for developping efficient reduction technologies of ARGs.Future study should focus on ARGs controlling in terms of transmissibility or persistence through DWTPs due to their biological related nature and ubiquitous presence of biofilm in the treatment unit.
基金Supported by the National Natural Science Foundation of China(61622301,61533002)Beijing Natural Science Foundation(4172005)Major National Science and Technology Project(2017ZX07104)
文摘In wastewater treatment process(WWTP), the accurate and real-time monitoring values of key variables are crucial for the operational strategies. However, most of the existing methods have difficulty in obtaining the real-time values of some key variables in the process. In order to handle this issue, a data-driven intelligent monitoring system, using the soft sensor technique and data distribution service, is developed to monitor the concentrations of effluent total phosphorous(TP) and ammonia nitrogen(NH_4-N). In this intelligent monitoring system, a fuzzy neural network(FNN) is applied for designing the soft sensor model, and a principal component analysis(PCA) method is used to select the input variables of the soft sensor model. Moreover, data transfer software is exploited to insert the soft sensor technique to the supervisory control and data acquisition(SCADA) system. Finally, this proposed intelligent monitoring system is tested in several real plants to demonstrate the reliability and effectiveness of the monitoring performance.
基金supported by National Natural Science Foundation of China(Nos.61203102 and 60874057)Postdoctoral Science Foundation of China(No.20100471464)
文摘Real-time and reliable measurements of the effluent quality are essential to improve operating efficiency and reduce energy consumption for the wastewater treatment process.Due to the low accuracy and unstable performance of the traditional effluent quality measurements,we propose a selective ensemble extreme learning machine modeling method to enhance the effluent quality predictions.Extreme learning machine algorithm is inserted into a selective ensemble frame as the component model since it runs much faster and provides better generalization performance than other popular learning algorithms.Ensemble extreme learning machine models overcome variations in different trials of simulations for single model.Selective ensemble based on genetic algorithm is used to further exclude some bad components from all the available ensembles in order to reduce the computation complexity and improve the generalization performance.The proposed method is verified with the data from an industrial wastewater treatment plant,located in Shenyang,China.Experimental results show that the proposed method has relatively stronger generalization and higher accuracy than partial least square,neural network partial least square,single extreme learning machine and ensemble extreme learning machine model.
基金Item Sponsored by National Nature Science Foundation of China(51071078)
文摘Dry sliding wear tests of a Cr-Mo-V cast hot-forging die steel was carried out within a load range of 50--300 N at 400℃ by a pin-on-disc high temperature wear machine. The effect of heat treatment process on wear resistance was systematically studied in order to select heat treatment processes of the steel with high wear resistance. The morphology, structure and composition were analyzed using scanning electron microscopy （SEM）, X-ray diffraction （XRD） and energy dispersive spectroscopy （EDS） ; wear mechanism was also discussed. Tribo-oxide layer was found to form on worn surfaces to reduce wear under low loads, but appear inside the matrix to increase wear under high loads. The tribo-oxides were mainly consisted of Fe3O4 and Fe2O3, FeO only appeared under a high load. Oxidative mild wear, transition of mild-severe wear in oxidative wear and extrusive wear took turns to operate with increasing the load. The wear resistance strongly depended on the selection of heat treatment processes or microstructures. It was found that bainite presented a better wear resistance than martensite plus bainite duplex structure, martensite structure was of the poorest wear resistance. The wear resistance increased with increasing austenizing temperature in the range of 920 to 1 120 ℃, then decreased at up to 1 220 ℃. As for tempering temperature and microstructure, the wear resistance increased in following order： 700℃ （tempered sorbite）, 200 ℃ （tempered martensite）, 440 to 650 ℃ （tempered troostite）. An appropriate combination of hardness, toughness, microstructural thermal stability was re- quired for a good wear resistance in high-temperature wear. The optimized heat treatment process was suggested for the cast hot-forging steel to be austenized at 1020 to 1 120 ℃, quenched in oil, then tempered at 440 to 650℃ for 2 h.
基金the National Natural Science Foundation of China (Nos.52075362 and 51975399)the Central Government Guides Local Foundation for Science and Technology Development,China (Nos.YDZJSX2022A020 and YDZJSX2022B004).
文摘Thermal Barrier Coatings(TBCs)technology is key to improving the service temperature and the productivity of aircraft engines.The performance and failure life of TBCs are strongly influenced by surface integrity and microstructure.Therefore,recognizing failure mechanisms and developing effective surface treatment processes are crucial for further improving the reliability and durability of TBCs.This paper explains the primary reasons for TBC failure,emphasizing on how integrity of surface and interface influences interfacial oxidation,high-temperature erosion,and Calcium-Magnesium-Alumina-Silicate(CMAS)corrosion.Furthermore,this paper completely and rigorously evaluates the research status of TBCs surface treatment processes,including the characteristics and effects of various processes,and describes the requirements and goals of pretreatment and post-treatment.In addition,a potential direction for the development and application of TBCs surface treatment is suggested.
基金supported by the Key program of Beijing Municipal Education Commission(KZ201810011012)National Natural Science Foundation of China(61873005)Support Project of High-level Teachers in Beijing Municipal Universities in the Period of 13th Fiveyear Plan(CIT&TCD201704044)。
文摘Waste water treatment process(WWTP)control has been attracting more and more attention.However,various undesired factors,such as disturbance,uncertainties,and strong nonlinear couplings,propose big challenges to the control of a WWTP.In order to improve the control performance of the closed-loop system and guarantee the discharge requirements of the effluent quality,rather than take the model dependent control approaches,an active disturbance rejection control(ADRC)is utilized.Based on the control signal and system output,a phase optimized ADRC(POADRC)is designed to control the dissolved oxygen and nitrate concentration in a WWTP.The phase advantage of the phase optimized extended state observer(POESO),convergence of the POESO,and stability of the closed-loop system are analyzed from the theoretical point of view.Finally,a commonly accepted benchmark simulation model no.1.(BSM1)is utilized to test the POESO and POADRC.Linear active disturbance rejection control(LADRC)and the suggested proportion-integration(PI)control are taken to make a comparative research.Both system responses and performance index values confirm the advantage of the POADRC over the LADRC and the suggested PI control.Numerical results show that,as a result of the leading phase of the total disturbance estimation,the POESO based POADRC is an effective and promising way to control the dissolved oxygen and nitrate concentration so as to ensure the effluent quality of a WWTP.
基金supported by the Natural Science Foundation of Shandong Province,China(No.ZR2021QE227)the Natural Science Foundation of Shandong Province,China(No.ZR2021QE272)+1 种基金the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.ES202120)the Taishan Scholars Program of Shandong Province,China(No.tsqn201812091)。
文摘It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotoxicity reduction of industrial wastewater are still limited.In this study,the toxic organics removal and biotoxicity reduction of coal chemical wastewater(CCW)along a novel full-scale treatment process based on the pretreatment process-anaerobic process-biological enhanced(BE)process-anoxic/oxic(A/O)process-advanced treatment process was evaluated.This process performed great removal efficiency of COD,total phenol,NH_(4)^(+)-N and total nitrogen.And the biotoxicity variation along the treatment units was analyzed from the perspective of acute biotoxicity,genotixicity and oxidative damage.The results indicated that the effluent of pretreatment process presented relatively high acute biotoxicity to Tetrahymena thermophila.But the acute biotoxicity was significantly reduced in BE-A/O process.And the genotoxicity and oxidative damage to Tetrahymena thermophila were significantly decreased after advanced treatment.The polar organics in CCW were identified as the main biotoxicity contributors.Phenols were positively correlated with acute biotoxicity,while the nitrogenous heterocyclic compounds and polycyclic aromatic hydrocarbons were positively correlated with genotoxicity.Although the biotoxicity was effectively reduced in the novel full-scale treatment process,the effluent still performed potential biotoxicity,which need to be further explored in order to reduce environmental risk.
基金supported by the National Natural Science Foundation of China (No. 51138009)
文摘In order to explore the biodegradation behavior of nonylphenolic compounds during wastewater treatment processing, two full-scale wastewater treatment plants were investigated and batch biodegradation experiments were conducted. The biodegradation pathways under the various operational conditions were identified from batch experiments： shortening of ethoxy-chains dominated under the anaerobic condition, whereas oxidizing of the terminal alcoholic group prevailed over the other routes under the aerobic condition. Results showed that the anoxic condition could accelerate the biodegradation rates of nonylphenolic compounds, but had no influence on the biodegradation pathway. The biodegradation rates of nonylphenol （NP） and short-chain nonylphenol polyethoxylates （NPnEOs, n： number of ethoxy units） increased from the anaerobic condition, then the anoxic, finally to the aerobic condition, while those of long-chain NPnEOs and nonylphenoxy carboxylates （NPECs） seemed similar under the various conditions. Under every operational condition, long-chain NPnEOs showed the highest biodegradation activity, followed by NPECs and short-chain NPnEOs, whereas NP showed relatively recalcitrant characteristics especially under the anaerobic condition. In addition, introducing sulfate and nitrate to the anaerobic condition could enhance the biodegradation of NP and short-chain NPnEOs by supplying more positive redox potentials.
文摘The process characteristics of heat treatment of aluminum alloy auto body sheet and the working principle of air cushion furnace were introduced.The process position and irreplaceable role of air cushion furnace in the aluminum alloy auto body sheet production was pointed out after the difficulty and key points in the whole production process of auto body sheet were studied.Then the development process of air cushion furnace line of aluminum alloy sheet was reviewed,summarized and divided to two stages.Based on the research of air cushion furnace,the key technology of it was analyzed,then the key points on process,equipment and control models of air cushion furnace for aluminum alloy auto body sheet in future were put forward.With the rapid development of automotive industry,there will be certainly a new upsurge of research and application of air cushion furnace for heat treatment of aluminum alloy auto body sheet.
基金supported by Heilongjiang Natural Science Fund for Distinguished Young Scientists(No.JC200909)
文摘In this study, we investigated the occurrence and fate of nonylphenol（NP）, nonylphenol monoethoxylate（NP1EO） and nonylphenol diethoxylate（NP2EO） in a full scale sewage treatment plant, which applied an Anaerobic/Oxic process. Concentrations of NP, NP1 EO and NP2 EO in the wastewater were measured during the period spanning a whole year.The results showed remarkable seasonal variation in the concentrations of the compounds.The NPn EO compounds were most abundant in winter, with the total concentrations of influent NP, NP1 EO and NP2 EO ranging from 3900 to 7000 ng/L, 4000 to 4800 ng/L and 5200 to 7200 ng/L, respectively. Regarding the total removal efficiencies of the three types of short-chain NPn EO compounds, different trends were exhibited according to different seasons. The average removal efficiency of NP for the different seasons ranked as follows：winter 〉 summer 〉 autumn 〉 spring; NP2 EO concentrations decreased as follows： summer 〉autumn 〉 winter 〉 spring, while NP1 EO concentrations reduced according to： spring 〉summer 〉 autumn 〉 winter. We also investigated the contribution ratio of individual treatment units in the A/O process, with the findings suggesting that the anaerobic treatment unit plays an important role in the elimination of short-chain NPn EOs from the wastewater.
文摘An as-cast Al-Zn-Mg-Sc alloy was friction stir processed varying tool related parameters, yielding microstructures with different grain sizes （0.68, 1.8 and 5.5 μm）. Significant increases in room temperature ductility were obtained in these materials with reasonable enhancement in strength. It is demonstrated that the type of microstructure produced by friction stir processing （FSP） has a significant influence on the choice of post-FSP heat treatment design for achieving improved tensile properties. It is also found that the ultrafine grained FSP material could not achieve the desired high strength during the post-FSP heat treatment without grain coarsening, whereas the micro-grained FSP materials could reach such strength levels （〉560 MPa） under conventional age hardening heat treatment conditions.
基金the National Key Research and Development Program of China(2022YFB3305800-5)the National Natural Science Foundation of China(62125301,62021003)+2 种基金the Beijing Outstanding Young Scientist Program(BJJWZYJH01201910005020)the Natural Science Foundation of Beijing Municipality(KZ202110005009)Youth Beijing Scholar(037).
文摘In wastewater treatment systems,extracting meaningful features from process data is essential for effective monitoring and control.However,the multi-time scale data generated by different sampling frequencies pose a challenge to accurately extract features.To solve this issue,a multi-timescale feature extraction method based on adaptive entropy is proposed.Firstly,the expert knowledge graph is constructed by analyzing the characteristics of wastewater components and water quality data,which can illustrate various water quality parameters and the network of relationships among them.Secondly,multiscale entropy analysis is used to investigate the inherent multi-timescale patterns of water quality data in depth,which enables us to minimize information loss while uniformly optimizing the timescale.Thirdly,we harness partial least squares for feature extraction,resulting in an enhanced representation of sample data and the iterative enhancement of our expert knowledge graph.The experimental results show that the multi-timescale feature extraction algorithm can enhance the representation of water quality data and improve monitoring capabilities.
文摘According to different mechanism of microbial degradation of organics, this article divided the treatment processes of garbage landfill into four kinds, analyzed each kind of the treatment leachate process and presented a better improved process. (Author abstract) 4 Refs.
文摘The characteristics and harm of high concentrations of organic wastewater were introducecl firstly, and then several treatment processes and effects of high concentrations of organic wastewater were summarized, which can provide theoretical references for the choice of wastewater treatment process.
基金Supported by General Colleges and Universities Youth Innovative Talents Project of Guangdong Province(2019GKQNCX134)Guangdong Doctoral Workstation Funds。
文摘[Objectives]To detect the protective effects of six protopanaxatriols(PPTs)on hypoxia/reoxygenation(H/R)induced cardiomyocyte injury by different treatments.[Methods]The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide(MTT)assay was used for detecting the protective effects of six PPTs including ginsenoside Rg1,Re,Rf,Rg2,(R)Rh1 and(S)Rh1 on cell viability reduced by H/R in different treatments.And the adenosine triphosphate(ATP)content and mitochondrial membrane potential(MMP)were used for detecting the mitochondrial function change during PPTs treatment.[Results]Among six PPTs,ginsenoside Rg1,Re,Rf,Rg2 and(R)Rh1 at the concentration of 12.5μM significantly increased the cell survival when treated before and during H/R.These five PPTs also significantly increased the ATP content and MMP reduced by H/R in the same manner.In comparison,only Rg1 significantly increased the cell viability compared with H/R group by pretreating and treating the cells during hypoxia process.[Conclusions]Different treatments affect the protective effects of PPTs.When treated before and during H/R,ginsenoside Rg1,Re,Rf,Rg2 and(R)Rh1 protect the cardiomyocyte against H/R injury mitochondrial function,and only ginsenoside Rg1 has protective effects when treated before and during hypoxia process.
文摘The sour gas sweetening is one of the main processes in gas industries. Gas sweetening is done through chemical processes. Therefore, it requires high cost and energy. The results show that increasing the operating temperature increases the mass transfer coefficient and increases the mass transfer rate. Theoretical and experimental data show that sulfur removal in 4.5 W magnetic field is desirable. The increase in sulfur removal percentage in the magnetic field of 4.5 W and 6.75 W is about 16.4% and 15.2%, respectively. According to the obtained results, the effect of temperature increase from 18.8°C to 23.4°C is more evident than the effect of temperature change from 23.4°C to 32.2°C. Because more thermal energy is needed to provide higher temperatures. Therefore, the temperature of 23.4°C is reported as the optimal temperature. The results of this research show that the percentage of sulfur removal is also high at this temperature.
