An AnMBR-PN/A system was developed for mainstream sewage treatment.To verify the efficient methanation and subsequent chemolitrophic nitrogen removal,a long-term experiment and analysis of microbial activity were carr...An AnMBR-PN/A system was developed for mainstream sewage treatment.To verify the efficient methanation and subsequent chemolitrophic nitrogen removal,a long-term experiment and analysis of microbial activity were carried out.AnMBR performance was less affected by the change of hydraulic retention time(HRT),which could provide a stable influent for subsequent PN/A units.The COD removal efficiency of AnMBR was>93%during the experiment,85.5%of COD could be recovered in form of CH4.With the HRT of PN/A being shortened from 10 to 6 h,nitrogen removal efficiency(NRE)of PN/A increased from 60.5%to 80.4%,but decreased to 68.8%when the HRTPN/A further decreased to 4 h.Microbial analysis revealed that the highest specific ammonia oxidation activity(SAOA)and the ratio of SAOA to specific nitrate oxidation activity(SNOA)provide stable NO_(2)^(−)-N/NH_(4)^(+)-N for anammox,and anammox bacteria(mainly identified as Candidatus Brocadia)enriched at the bottom of Anammox-UASB might play an important role in nitrogen removal.In addition,the decrease of COD in Anammox-UASB indicated partial denitrification occurred,which jointly promoted nitrogen removal with anammox.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.52070148 and 52270049)the Shaanxi Provincial Key Program for Science and Technology Development(China)(No.2022KWZ-25)the Japan Society for the Promotion of Science(No.P20794).
文摘An AnMBR-PN/A system was developed for mainstream sewage treatment.To verify the efficient methanation and subsequent chemolitrophic nitrogen removal,a long-term experiment and analysis of microbial activity were carried out.AnMBR performance was less affected by the change of hydraulic retention time(HRT),which could provide a stable influent for subsequent PN/A units.The COD removal efficiency of AnMBR was>93%during the experiment,85.5%of COD could be recovered in form of CH4.With the HRT of PN/A being shortened from 10 to 6 h,nitrogen removal efficiency(NRE)of PN/A increased from 60.5%to 80.4%,but decreased to 68.8%when the HRTPN/A further decreased to 4 h.Microbial analysis revealed that the highest specific ammonia oxidation activity(SAOA)and the ratio of SAOA to specific nitrate oxidation activity(SNOA)provide stable NO_(2)^(−)-N/NH_(4)^(+)-N for anammox,and anammox bacteria(mainly identified as Candidatus Brocadia)enriched at the bottom of Anammox-UASB might play an important role in nitrogen removal.In addition,the decrease of COD in Anammox-UASB indicated partial denitrification occurred,which jointly promoted nitrogen removal with anammox.
