The effects of increasing COD/N on nitrogen removal performance and microbial structure were investigated in a SBR adopting a completely autotrophic nitrogen removal over nitrite process with a continuous aeration mod...The effects of increasing COD/N on nitrogen removal performance and microbial structure were investigated in a SBR adopting a completely autotrophic nitrogen removal over nitrite process with a continuous aeration mode (DO at approximately 0.15-0.2 mg/L). As the COD/N increased from 0.1 to W0.59, the nitrogen removal efficiency QMRE) increased from 88.7% to 95.5%;while at COD/N ratios of 0.59-0.82, the NRE remained at 90.7%-95.5%. As the COD/N increased from 0.82 to 1.07, the NRE decreased continuously until reaching 60.1%. Nitrosomonas sp.(AOB) and Candidatus Jet tenia (anammox bacteria) were the main functional genera in the SBR. As the COD/N increased from 0.10 to 1.07, the relative abundance of Nitrosomonas decreased from 13.4% to 2.0%, while that of Candidatus Jettenia decreased from 35% to 9.9% with COD/N < 0.82 then increased to 45.4% at a COD/N of 1.07. Aerobic heterotrophic bacteria outcompeted AOB at high COD loadings (650 mg/L) because of oxygen competition, which ultimately led to deteriorated nitrogen removal pertormance.展开更多
基金the National Natural Science Foundation of China (Grant Nos. 51522809 and 51378370)the State Key Laboratory of Pollution Control and Resource Reuse (Tongji University), China (Grant No. PCRRT16005).
文摘The effects of increasing COD/N on nitrogen removal performance and microbial structure were investigated in a SBR adopting a completely autotrophic nitrogen removal over nitrite process with a continuous aeration mode (DO at approximately 0.15-0.2 mg/L). As the COD/N increased from 0.1 to W0.59, the nitrogen removal efficiency QMRE) increased from 88.7% to 95.5%;while at COD/N ratios of 0.59-0.82, the NRE remained at 90.7%-95.5%. As the COD/N increased from 0.82 to 1.07, the NRE decreased continuously until reaching 60.1%. Nitrosomonas sp.(AOB) and Candidatus Jet tenia (anammox bacteria) were the main functional genera in the SBR. As the COD/N increased from 0.10 to 1.07, the relative abundance of Nitrosomonas decreased from 13.4% to 2.0%, while that of Candidatus Jettenia decreased from 35% to 9.9% with COD/N < 0.82 then increased to 45.4% at a COD/N of 1.07. Aerobic heterotrophic bacteria outcompeted AOB at high COD loadings (650 mg/L) because of oxygen competition, which ultimately led to deteriorated nitrogen removal pertormance.
