The low removal efficiency of total nitrogen （TN） is one of the main disadvantages of traditional single stage subsurface infiltration system, which combines an anaerobic tank and a soil filter field. In this study,...The low removal efficiency of total nitrogen （TN） is one of the main disadvantages of traditional single stage subsurface infiltration system, which combines an anaerobic tank and a soil filter field. In this study, a full-scale, two-stage anaerobic tank and soil trench system was designed and operated to evaluate the feasibility and performances in treating sewage from a school campus for over a one-year monitoring period. The raw sewage was prepared and fed into the first anaerobic tank and second tank by 60% and 40%, respectively. This novel process could decrease chemical oxygen demand with the dichromate method by 89%-96%, suspended solids by 91%-97%, and total phosphorus by 91%-97%. The denitrification was satisfactory in the second stage soil trench, so the removals of TN as well as ammonia nitrogen （NH4^＋-N） reached 68%-75% and 96% 99%, respectively. It appeared that the removal efficiency of TN in this two-stage anaerobic tank and soil trench system was more effective than that in the single stage soil infiltration system. The effluent met the discharge standard for the sewage treatment plant （GB18918-2002） of China.展开更多
The significance and necessity of decentralized domestic sewage treatment were introduced firstly, and then three main decentralized technologies of domestic sewage such as constructed wetlands, subsurface infiltratio...The significance and necessity of decentralized domestic sewage treatment were introduced firstly, and then three main decentralized technologies of domestic sewage such as constructed wetlands, subsurface infiltration and purification tanks in China and abroad were discussed.展开更多
The concentration of total nitrogen(TN) is reported to vary between 20 and 35 mg/L in domestic wastewater. In raw wastewater, ammonia nitrogen eNHt4-NT is the main nitrogen form, accounting for 70%e82% of the TN conce...The concentration of total nitrogen(TN) is reported to vary between 20 and 35 mg/L in domestic wastewater. In raw wastewater, ammonia nitrogen eNHt4-NT is the main nitrogen form, accounting for 70%e82% of the TN concentration. Organic nitrogen, nitrite nitrogen eNOà2-NT,and nitrate nitrogen eNOà3-NT are present as well. For years, due to the lack of regulatory limits on nitrogen concentration in surface waters,nitrogen from secondary effluent has posed a significant threat to the health of aquatic ecosystems. Researchers have made substantial efforts to reduce the nitrogen concentration in secondary effluent. As a kind of advanced wastewater treatment technology, the subsurface infiltration(SI)system has been widely used, owing to its advantages, which include low operation cost, easy maintenance, and low energy consumption. This review discusses the fate of various forms of nitrogen in SI treatment, including organic nitrogen, NHt4-N, NOà2-N, and NOà3-N. Major biological processes involved in nitrogen removal and the main factors influencing its transformation are suggested. Finally, it is shown that ammonification followed by nitrification-denitrification plays a major role in nitrogen removal. Further research needs to focus on the emission characteristics of gaseous nitrogen(generated from the nitrification, denitrification, and completely autotrophic nitrogen-removal over nitrite(CANON) processes) with respect to their greenhouse effects.展开更多
基金the National High Technology Research and Development Program (863 Program) of China(No2002AA601012-01)
文摘The low removal efficiency of total nitrogen （TN） is one of the main disadvantages of traditional single stage subsurface infiltration system, which combines an anaerobic tank and a soil filter field. In this study, a full-scale, two-stage anaerobic tank and soil trench system was designed and operated to evaluate the feasibility and performances in treating sewage from a school campus for over a one-year monitoring period. The raw sewage was prepared and fed into the first anaerobic tank and second tank by 60% and 40%, respectively. This novel process could decrease chemical oxygen demand with the dichromate method by 89%-96%, suspended solids by 91%-97%, and total phosphorus by 91%-97%. The denitrification was satisfactory in the second stage soil trench, so the removals of TN as well as ammonia nitrogen （NH4^＋-N） reached 68%-75% and 96% 99%, respectively. It appeared that the removal efficiency of TN in this two-stage anaerobic tank and soil trench system was more effective than that in the single stage soil infiltration system. The effluent met the discharge standard for the sewage treatment plant （GB18918-2002） of China.
文摘The significance and necessity of decentralized domestic sewage treatment were introduced firstly, and then three main decentralized technologies of domestic sewage such as constructed wetlands, subsurface infiltration and purification tanks in China and abroad were discussed.
基金supported by the National Natural Science Foundation of China(Grants No.41571455 and 51578115)the Basic Science Research Fund of Northeastern University(Grant No.N160104004)
文摘The concentration of total nitrogen(TN) is reported to vary between 20 and 35 mg/L in domestic wastewater. In raw wastewater, ammonia nitrogen eNHt4-NT is the main nitrogen form, accounting for 70%e82% of the TN concentration. Organic nitrogen, nitrite nitrogen eNOà2-NT,and nitrate nitrogen eNOà3-NT are present as well. For years, due to the lack of regulatory limits on nitrogen concentration in surface waters,nitrogen from secondary effluent has posed a significant threat to the health of aquatic ecosystems. Researchers have made substantial efforts to reduce the nitrogen concentration in secondary effluent. As a kind of advanced wastewater treatment technology, the subsurface infiltration(SI)system has been widely used, owing to its advantages, which include low operation cost, easy maintenance, and low energy consumption. This review discusses the fate of various forms of nitrogen in SI treatment, including organic nitrogen, NHt4-N, NOà2-N, and NOà3-N. Major biological processes involved in nitrogen removal and the main factors influencing its transformation are suggested. Finally, it is shown that ammonification followed by nitrification-denitrification plays a major role in nitrogen removal. Further research needs to focus on the emission characteristics of gaseous nitrogen(generated from the nitrification, denitrification, and completely autotrophic nitrogen-removal over nitrite(CANON) processes) with respect to their greenhouse effects.
