Problems treating sewage in rural areas in China have attracted increasing attention in recent years. However, only 6% of rural areas had spray drainage and wastewater treatment systems by the end of 2010. It is neces...Problems treating sewage in rural areas in China have attracted increasing attention in recent years. However, only 6% of rural areas had spray drainage and wastewater treatment systems by the end of 2010. It is necessary to assess the technologies currently used so that sewage treatment in rural areas can be developed appropriately, to provide reliable and affordable waste- water treatment, in these areas. We evaluated the sewage treatment technologies currently used in rural areas by conducting case studies on 62 facilities that had each been operating for at least one year. Our study was carried out between 2009 and 2011, and the aim was to assess the situation during that period and assess any problems involved in decentralized sewage treatment in villages. We found that decentralized sewage treatment is the most popular wastewater treatment method in villages, and that the most common primary treatment technology used in rural areas is the septic tank. Our investigation highlights the need to establish standards for assessing effluent quality, including a range of target pollutants. Our results also show that effluents should be reused to meet the local environmental requirements in different areas, especially in ecologically sensitive areas.展开更多
In order to control water pollution in the rapidly urbanizing South China area,biological contact oxidation(BCO)process and biological aerated filter(BAF)process were applied in a pilot-scale experiment for decentrali...In order to control water pollution in the rapidly urbanizing South China area,biological contact oxidation(BCO)process and biological aerated filter(BAF)process were applied in a pilot-scale experiment for decentralized wastewater treatment.An investigation to find the optimal parameters of the two biofilm systems was conducted on hydraulic loading,organic loading,and aeration rate.The results indicated that the water reuse criteria required a maximum hydraulic and organic loading of 30.0 m^(3)/(m^(2)·d)and 4.0 kg COD/(m^(3)·d),respectively,as well as a minimum effluent DO of 4.0 mg/L.The utilization of a new media allowed BAF to perform better than BCO.The kinetic description of the COD removal process for BAF and BCO are Se=S0e^(-0.639t)/(1+1.035t),and S_(e)=S_(0)/[(1+0.947t)(1+1.242t)],respectively.The correlativity analysis showed that the two models could predict the effluent water quality based on the hydraulic retention time.Thus,the appropriate hydraulic loading for certain effluent water quality demands could be determined.The two models could be applied to wastewater treatment practice.展开更多
The distribution of antibiotic resistance genes(ARGs)has been intensively studied in large-scale wastewater treatment plants and livestock sources.However,small-scale decentralized sewage treatment facilities must als...The distribution of antibiotic resistance genes(ARGs)has been intensively studied in large-scale wastewater treatment plants and livestock sources.However,small-scale decentralized sewage treatment facilities must also be explored due to their possible direct exposure to residents.In this study,six wastewater treatment facilities in developed rural areas in eastern China were investigated to understand their risks of spreading ARGs.Using metagenomics and network analysis tools,ARGs and bacterial and viral communities were identified in the influent(INF)and effluent(EFF)samples.The dominant ARGs belonged to the bacitracin class,which are different from most of municipal wastewater treatment plants(WWTPs).The dominant hosts of ARGs are Acidovorax in bacterial communities and Prymnesiovirus in viral communities.Furthermore,a positive relationship was found between ARGs and phages.The ARGs significantly correlated with phages were all hosted by specific genera of bacteria,indicating that phages had contributed to the ARG’s proliferation in sewage treatment facilities.Paying significant concern on the possible enhanced risks caused by bacteria,viruses and their related ARGs in decentralized sewage treatment facilities is necessary.展开更多
The development of self-powered water purification technologies for decentralized applications is crucial for ensuring the provision of drinking water in resource-limited regions. The elimination of the dependence on ...The development of self-powered water purification technologies for decentralized applications is crucial for ensuring the provision of drinking water in resource-limited regions. The elimination of the dependence on external energy inputs and the attainment of self-powered status significantly expands the applicability of the treatment system in real-world scenarios. Hybrid energy harvesters, which convert multiple ambient energies simultaneously, show the potential to drive self-powered water purification facilities under fluctuating actual conditions. Here, we propose recent advancements in hybrid energy systems that simultaneously harvest various ambient energies (e.g., photo irradiation, flow kinetic, thermal, and vibration) to drive water purification processes. The mechanisms of various energy harvesters and point-of-use water purification treatments are first outlined. Then we summarize the hybrid energy harvesters that can drive water purification treatment. These hybrid energy harvesters are based on the mechanisms of mechanical and photovoltaic, mechanical and thermal, and thermal and photovoltaic effects. This review provides a comprehensive understanding of the potential for advancing beyond the current state-of-the-art of hybrid energy harvester-driven water treatment processes. Future endeavors should focus on improving catalyst efficiency and developing sustainable hybrid energy harvesters to drive self-powered treatments under unstable conditions (e.g., fluctuating temperatures and humidity).展开更多
Sustainable water management is essential to guaranteeing access to safe water and addressing the challenges posed by climate change,urbanization,and population growth.In a typical household,greywater,which includes e...Sustainable water management is essential to guaranteeing access to safe water and addressing the challenges posed by climate change,urbanization,and population growth.In a typical household,greywater,which includes everything but toilet waste,constitutes 50e80%of daily wastewater generation and is characterized by low organic strength and high volume.This can be an issue for large urban wastewater treatment plants designed for high-strength operations.Segregation of greywater at the source for decentralized wastewater treatment is therefore necessary for its proper management using separate treatment strategies.Greywater reuse may thus lead to increased resilience and adaptability of local water systems,reduction in transport costs,and achievement of fit-for-purpose reuse.After covering greywater characteristics,we present an overview of existing and upcoming technologies for greywater treatment.Biological treatment technologies,such as nature-based technologies,biofilm technologies,and membrane bioreactors(MBR),conjugate with physicochemical treatment methods,such as membrane filtration,sorption and ion exchange technologies,and ultraviolet(UV)disinfection,may be able to produce treated water within the allowable parameters for reuse.We also provide a novel way to tackle challenges like the demographic variance of greywater quality,lack of a legal framework for greywater management,monitoring and control systems,and the consumer perspective on greywater reuse.Finally,benefits,such as the potential water and energy savings and sustainable future of greywater reuse in an urban context,are discussed.展开更多
基金Acknowledgements This research was financial supported by the National Natural Science Foundation of China (Grant No. 20077085), Key Project of the National Natural Science Foundation of China (Grant No. 51138009), and Key Project of the Chinese Academy of Science (No. KZZD-EW-09).
文摘Problems treating sewage in rural areas in China have attracted increasing attention in recent years. However, only 6% of rural areas had spray drainage and wastewater treatment systems by the end of 2010. It is necessary to assess the technologies currently used so that sewage treatment in rural areas can be developed appropriately, to provide reliable and affordable waste- water treatment, in these areas. We evaluated the sewage treatment technologies currently used in rural areas by conducting case studies on 62 facilities that had each been operating for at least one year. Our study was carried out between 2009 and 2011, and the aim was to assess the situation during that period and assess any problems involved in decentralized sewage treatment in villages. We found that decentralized sewage treatment is the most popular wastewater treatment method in villages, and that the most common primary treatment technology used in rural areas is the septic tank. Our investigation highlights the need to establish standards for assessing effluent quality, including a range of target pollutants. Our results also show that effluents should be reused to meet the local environmental requirements in different areas, especially in ecologically sensitive areas.
基金the National High Technology Research and Development Program(863 Program)of China(No.2003AA601040)the Program for the High-Level Returned Overseas Chinese Scholars(No.2005-118).
文摘In order to control water pollution in the rapidly urbanizing South China area,biological contact oxidation(BCO)process and biological aerated filter(BAF)process were applied in a pilot-scale experiment for decentralized wastewater treatment.An investigation to find the optimal parameters of the two biofilm systems was conducted on hydraulic loading,organic loading,and aeration rate.The results indicated that the water reuse criteria required a maximum hydraulic and organic loading of 30.0 m^(3)/(m^(2)·d)and 4.0 kg COD/(m^(3)·d),respectively,as well as a minimum effluent DO of 4.0 mg/L.The utilization of a new media allowed BAF to perform better than BCO.The kinetic description of the COD removal process for BAF and BCO are Se=S0e^(-0.639t)/(1+1.035t),and S_(e)=S_(0)/[(1+0.947t)(1+1.242t)],respectively.The correlativity analysis showed that the two models could predict the effluent water quality based on the hydraulic retention time.Thus,the appropriate hydraulic loading for certain effluent water quality demands could be determined.The two models could be applied to wastewater treatment practice.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(2017ZX07202-003)National Natural Science Foundation of China(51778325)+1 种基金the Fundamental Research Fund for the Central Universities(FRF-TP-20-011A)the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology(2020B 1212060022).
文摘The distribution of antibiotic resistance genes(ARGs)has been intensively studied in large-scale wastewater treatment plants and livestock sources.However,small-scale decentralized sewage treatment facilities must also be explored due to their possible direct exposure to residents.In this study,six wastewater treatment facilities in developed rural areas in eastern China were investigated to understand their risks of spreading ARGs.Using metagenomics and network analysis tools,ARGs and bacterial and viral communities were identified in the influent(INF)and effluent(EFF)samples.The dominant ARGs belonged to the bacitracin class,which are different from most of municipal wastewater treatment plants(WWTPs).The dominant hosts of ARGs are Acidovorax in bacterial communities and Prymnesiovirus in viral communities.Furthermore,a positive relationship was found between ARGs and phages.The ARGs significantly correlated with phages were all hosted by specific genera of bacteria,indicating that phages had contributed to the ARG’s proliferation in sewage treatment facilities.Paying significant concern on the possible enhanced risks caused by bacteria,viruses and their related ARGs in decentralized sewage treatment facilities is necessary.
基金supported by the National Key R&D Program of China(No.2022YFC3205400)the National Natural Science Foundation of China(Grant No.52200079).
文摘The development of self-powered water purification technologies for decentralized applications is crucial for ensuring the provision of drinking water in resource-limited regions. The elimination of the dependence on external energy inputs and the attainment of self-powered status significantly expands the applicability of the treatment system in real-world scenarios. Hybrid energy harvesters, which convert multiple ambient energies simultaneously, show the potential to drive self-powered water purification facilities under fluctuating actual conditions. Here, we propose recent advancements in hybrid energy systems that simultaneously harvest various ambient energies (e.g., photo irradiation, flow kinetic, thermal, and vibration) to drive water purification processes. The mechanisms of various energy harvesters and point-of-use water purification treatments are first outlined. Then we summarize the hybrid energy harvesters that can drive water purification treatment. These hybrid energy harvesters are based on the mechanisms of mechanical and photovoltaic, mechanical and thermal, and thermal and photovoltaic effects. This review provides a comprehensive understanding of the potential for advancing beyond the current state-of-the-art of hybrid energy harvester-driven water treatment processes. Future endeavors should focus on improving catalyst efficiency and developing sustainable hybrid energy harvesters to drive self-powered treatments under unstable conditions (e.g., fluctuating temperatures and humidity).
基金KR and AVDWare supported by De Watergroep.This work was conducted within the framework of the CAPTURE(Centre for Advanced Process Technology for Urban Resource recovery)initiative.XW is supported by the Special Research Fund from Ghent University,BOF.PDO.2021.0036.01This work was also supported under the framework of the international cooperation program managed by the National Research Foundation of Korea(2020K2A9A1A06103416)by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(2022R1A4A3029607).We would like to thank Tim Lacoere for his contributions to the figures.
文摘Sustainable water management is essential to guaranteeing access to safe water and addressing the challenges posed by climate change,urbanization,and population growth.In a typical household,greywater,which includes everything but toilet waste,constitutes 50e80%of daily wastewater generation and is characterized by low organic strength and high volume.This can be an issue for large urban wastewater treatment plants designed for high-strength operations.Segregation of greywater at the source for decentralized wastewater treatment is therefore necessary for its proper management using separate treatment strategies.Greywater reuse may thus lead to increased resilience and adaptability of local water systems,reduction in transport costs,and achievement of fit-for-purpose reuse.After covering greywater characteristics,we present an overview of existing and upcoming technologies for greywater treatment.Biological treatment technologies,such as nature-based technologies,biofilm technologies,and membrane bioreactors(MBR),conjugate with physicochemical treatment methods,such as membrane filtration,sorption and ion exchange technologies,and ultraviolet(UV)disinfection,may be able to produce treated water within the allowable parameters for reuse.We also provide a novel way to tackle challenges like the demographic variance of greywater quality,lack of a legal framework for greywater management,monitoring and control systems,and the consumer perspective on greywater reuse.Finally,benefits,such as the potential water and energy savings and sustainable future of greywater reuse in an urban context,are discussed.