城市生活污水短程硝化系统的恢复与启动

Biological activity recovery and start-up of mainstream shortcut nitrafication system

为了实现主流的短程硝化反硝化和厌氧氨氧化,设计了基于pH-DO和阀ON-OFF间歇曝气的在线控制系统,搭建了中试级别的短程硝化SBR,在高DO条件下基于城市生活污水恢复种泥活性后,加入反硝化稳定短程,最后接入厌氧氨氧化滤池实现全过程自养脱氮。将脱氮率、NO-2-N积累率等作为考察指标,研究了系统的启动过程和稳定性。结果表明:控制SBR(sequencing batch reactor)中DO=2~2.5 mg·L^(-1)、HRT=8~10 h、SRT=4~5 d、T=25℃,启动恢复3个月后,系统能保持90%以上的NO-2-N积累率、NO-2-N/NH+4-N=0.96±0.18;短程硝化反硝化能达到50%左右的NH+4-N去除率,60%左右的TIN去除率;短程硝化接厌氧氧氨氧化能保证90%左右的NH+4-N去除率和TIN去除率,出水达一级A标准。由实验结果分析,系统在高DO条件下能恢复短程硝化污泥的活性,基于pH-DO和阀ON-OFF间歇曝气的在线控制系统稳定性高,能保证短程硝化系统的稳定运行;恢复活性后,后接厌氧氨氧化滤池能实现中试级别的全过程自养脱氮。

In order to achieve the mainstream shortcut nitrification-denitrification and nitritation-ANAMMOX,an online pH-DO control mainstream nitritation system was built,which in a pilot SBR. After recovering the activity of seed sludge under high DO and municipal wastewater,denitrification was added to stabilize shortcut nitrification. At last,ANAMMOX was connected with SBR to realize auto trophic nitrogen removal. The nitrogen removal rate,nitrite accumulation rate during start-up process was investigated to characterize the stabilization of system. The results showed that when control the DO of SBR reactor at 2 to 2. 5 mg·L^-1,HRT from 8 to 10 h,SRT from 4 to 5 d,and T = 25 ℃,the nitrite accumulation rate can keep 90%,and NO2^--N/NH4^＋-N = 0. 96 ±0. 18. The nitrogen removal rate of shortcut nitrification-denitrification can reach 50% and TIN removal rate can reach 60% after 3 months. The nitrogen removal rate and TIN removal rate of nitritation-ANAMMOX can achieve90%,and the effluent can reach primary discharging standard A.Our study shows that shortcut nitrification system can be start-up under high DO successfully,and the online pH-DO control system play an important role in the stability of nitritation. Nitritation-ANAMMOX can realize autotrophic nitrogen removal.