亚硝氮停供及恢复供给对Anammox反应器中氮去除的影响

在Anammox-UASB反应器中研究了亚硝氮停供及恢复供给后不同进水亚硝氮/氨氮比(R_I)对Anammox系统脱氮的影响,对Anammox系统停供亚硝氮培养后的污泥微生物群落进行了分析.结果表明,Anammox反应器在长期停供亚硝氮培养后,微生物多样性增加,氨氧化菌(Nitrosomonas)和Anammox菌都大量增殖,这两种微生物通过协同作用使得部分氨氮得以去除,NH_4~+-N最大去除速率可达68.77 mg·L~(-1)·d~(-1),出水p H低于进水.反应器恢复亚硝氮供给后,脱氮效果快速恢复.Anammox反应器中存在的氨氮"超量去除"现象是由氨氧化菌作用引起的,氨氧化菌活性易受亚硝氮浓度抑制.氨氮"超量去除"量占氨氮总去除量的百分比与R_I呈负相关关系.当R_I为0.17时,氨氮"超量去除"量占氨氮总去除量的百分比高达68.83%;当R_I增加到1.30∶1后,氨氮"超量去除"现象基本消失.

Effect of stop feeding and resupplying of nitrite on nitrogen removal in an Anammox-UASB

The effects of no feeding of nitrite and its resupplying on ammonium and nitrogen removal in an Anammox-UASB reactor were investigated. The microbial community structure in the system of no feeding of nitrite was analysed. The results indicated that the microbial diversity increased and the ammonia oxidizing bacteria and Anammox bacteria in the reactor proliferated without any nitrite supply. Two groups of microorganism removed ammonium in anaerobic condition collaboratively with a maximum removal rate of 68.77 mg·L^-1·d^-1, meanwhile, the pH of the effluent from the reactor was higher than that of the influent. The nitrogen removal performance restored when nitrite was resupplied to the reactor. It was considered the excessive removal of ammonium in the system was contributed by the ammonia oxidizing bacteria, and the activity of the bacteria was liable to be inhibited by nitrite. There was a negative correlation between the percentage of excessive removal of ammonium in total ammonium and the ratio of nitrite to ammonium(R_I) in the influent. When R_I was 0.17, the percentage of excessive removal of ammonium was 68.83%, and when the R_I increased to 1.30, there was no excessive removal of ammonium.