Themulti-soil-layering(MSL)systems is an emerging solution for environmentally-friendly and cost-effective treatment of decentralized rural domestic wastewater.However,the role of the seemingly simple permeable layer ...Themulti-soil-layering(MSL)systems is an emerging solution for environmentally-friendly and cost-effective treatment of decentralized rural domestic wastewater.However,the role of the seemingly simple permeable layer has been overlooked,potentially holding the breakthroughs or directions to addressing suboptimal nitrogen removal performance in MSL systems.In this paper,the mechanism among diverse substrates(zeolite,green zeolite and biological ceramsite)coupled microorganisms in different systems(activated bacterial powder and activated sludge)for rural domestic wastewater purification was investigated.The removal efficiencies performed by zeolite coupled with microorganisms within 3 days were 93.8%for COD,97.1%for TP,and 98.8%for NH_(4)^(+)-N.Notably,activated sludge showed better nitrification and comprehensive performance than specialized nitrifying bacteria powder.Zeolite attained an impressive 89.4%NH4+-N desorption efficiency,with a substantive fraction of NH_(4)^(+)-N manifesting as exchanged ammonium.High-throughput 16S rRNA gene sequencing revealed that aerobic and parthenogenetic anaerobic bacteria dominated the reactor,with anaerobic bacteria conspicuously absent.And the heterotrophic nitrificationaerobic denitrification(HN-AD)process was significant,with the presence of denitrifying phosphorus-accumulating organisms(DPAOs)for simultaneous nitrogen and phosphorus removal.This study not only raises awareness about the importance of the permeable layer and enhances comprehension of the HN-AD mechanism in MSL systems,but also provides valuable insights for optimizing MSL system construction,operation,and rural domestic wastewater treatment.展开更多
By combining with the actual situation in the rural area,the practical technology of domestic wastewater treatment which had the wide popularization value was developed in the rural area of Taihu Basin.Moreover,the mu...By combining with the actual situation in the rural area,the practical technology of domestic wastewater treatment which had the wide popularization value was developed in the rural area of Taihu Basin.Moreover,the multi-soil-layering system was used to treat the concentrated rural domestic wastewater,and the demonstration project was established in Fenshui Village,Yixing,Jiangsu.The result showed that the infrastructure and operating cost of system was low,and the treatment effect was good.The average removal ratios of COD,NH+4-N,TN,TP and SS were respectively 70%,83%,59%,76% and 94%.The quality of yielding water could reach Grade A standard of Pollutant Emission Standards in Urban Wastewater Treatment Plant.展开更多
Concentrated turtle aquaculture effluent poses an environmental threat to water bodies, and therefore needs to be treated prior to disposal. This study was conducted to assess the effect of multi-soil-layer（MSL） sys...Concentrated turtle aquaculture effluent poses an environmental threat to water bodies, and therefore needs to be treated prior to disposal. This study was conducted to assess the effect of multi-soil-layer（MSL） systems treating turtle aquaculture effluent with adding different amounts of sludge. Four MSL systems were constructed with dry weight ratios of sludge with 0%, 5%, 10%, and 20%（MSL 1, MSL 2, MSL 3, and MSL 4, respectively）. The turtle aquaculture effluent had an average chemical oxygen demand（COD）, ammonia nitrogen（NH4^＋-N） and total nitrogen（TN） concentration of 288.4, 213.4, and 252.0 mg/L, respectively. The COD/TN（C/N） ratio was 1.2. The results showed that the four MSL systems could effectively treat the COD, NH4^＋-N, and TN, and MSL 4 showed significantly improved NH4^＋-N removal efficiency, suggesting the potential of sludge addition to improve the turtle aquaculture effluent treatment. The average COD, TN, and NH4^＋-N removal efficiencies of MSL 4 were 70.3%, 66.5%, and 72.7%, respectively. To further interpret the contribution of microorganisms to the removal, the microbial community compositions and diversities of the four MSL systems were measured. Comparisons of the denaturing gradient gel electrophoresis（DGGE） profiles revealed that the amount of nitrifying bacteria and diversity in MSL 4 were higher than those in the other three systems. We concluded that adding 20% of sludge improved the NH4^＋-N removal and stability of the system for nitrification, due to the enrichment of the nitrifying bacteria in MSL 4.展开更多
基金supported by the National Natural Science Foundation of China(No.42077163).
文摘Themulti-soil-layering(MSL)systems is an emerging solution for environmentally-friendly and cost-effective treatment of decentralized rural domestic wastewater.However,the role of the seemingly simple permeable layer has been overlooked,potentially holding the breakthroughs or directions to addressing suboptimal nitrogen removal performance in MSL systems.In this paper,the mechanism among diverse substrates(zeolite,green zeolite and biological ceramsite)coupled microorganisms in different systems(activated bacterial powder and activated sludge)for rural domestic wastewater purification was investigated.The removal efficiencies performed by zeolite coupled with microorganisms within 3 days were 93.8%for COD,97.1%for TP,and 98.8%for NH_(4)^(+)-N.Notably,activated sludge showed better nitrification and comprehensive performance than specialized nitrifying bacteria powder.Zeolite attained an impressive 89.4%NH4+-N desorption efficiency,with a substantive fraction of NH_(4)^(+)-N manifesting as exchanged ammonium.High-throughput 16S rRNA gene sequencing revealed that aerobic and parthenogenetic anaerobic bacteria dominated the reactor,with anaerobic bacteria conspicuously absent.And the heterotrophic nitrificationaerobic denitrification(HN-AD)process was significant,with the presence of denitrifying phosphorus-accumulating organisms(DPAOs)for simultaneous nitrogen and phosphorus removal.This study not only raises awareness about the importance of the permeable layer and enhances comprehension of the HN-AD mechanism in MSL systems,but also provides valuable insights for optimizing MSL system construction,operation,and rural domestic wastewater treatment.
基金Supported by The Important Special Item of National Water Body Pollution Control and Treatment Science Technology(2009ZX07528005)~~
文摘By combining with the actual situation in the rural area,the practical technology of domestic wastewater treatment which had the wide popularization value was developed in the rural area of Taihu Basin.Moreover,the multi-soil-layering system was used to treat the concentrated rural domestic wastewater,and the demonstration project was established in Fenshui Village,Yixing,Jiangsu.The result showed that the infrastructure and operating cost of system was low,and the treatment effect was good.The average removal ratios of COD,NH+4-N,TN,TP and SS were respectively 70%,83%,59%,76% and 94%.The quality of yielding water could reach Grade A standard of Pollutant Emission Standards in Urban Wastewater Treatment Plant.
基金supported by the Ministry of Environmental Protection of China(No.2010467014)the Science and Technology Key Plan of Huzhou(No.2011GN19),China
文摘Concentrated turtle aquaculture effluent poses an environmental threat to water bodies, and therefore needs to be treated prior to disposal. This study was conducted to assess the effect of multi-soil-layer（MSL） systems treating turtle aquaculture effluent with adding different amounts of sludge. Four MSL systems were constructed with dry weight ratios of sludge with 0%, 5%, 10%, and 20%（MSL 1, MSL 2, MSL 3, and MSL 4, respectively）. The turtle aquaculture effluent had an average chemical oxygen demand（COD）, ammonia nitrogen（NH4^＋-N） and total nitrogen（TN） concentration of 288.4, 213.4, and 252.0 mg/L, respectively. The COD/TN（C/N） ratio was 1.2. The results showed that the four MSL systems could effectively treat the COD, NH4^＋-N, and TN, and MSL 4 showed significantly improved NH4^＋-N removal efficiency, suggesting the potential of sludge addition to improve the turtle aquaculture effluent treatment. The average COD, TN, and NH4^＋-N removal efficiencies of MSL 4 were 70.3%, 66.5%, and 72.7%, respectively. To further interpret the contribution of microorganisms to the removal, the microbial community compositions and diversities of the four MSL systems were measured. Comparisons of the denaturing gradient gel electrophoresis（DGGE） profiles revealed that the amount of nitrifying bacteria and diversity in MSL 4 were higher than those in the other three systems. We concluded that adding 20% of sludge improved the NH4^＋-N removal and stability of the system for nitrification, due to the enrichment of the nitrifying bacteria in MSL 4.
