关键词:

N₂O产量;生活污水;全程硝化反硝化, 短程硝化反硝化;同步硝化反硝化

Abstract:

The formation and emission of N₂O in various nitrogen removal processes for treatment of domestic sewage were investigated using oxic-anoxic SBR systems and a continuum aerobic submerged biofilm reactor system SBBR, from which complete, shortcut and simultaneous nitrification and denitrification(SND) processes were realized, respectively.Meanwhile, the effect of DO on the SND efficiency and N₂O yield in SBBR was also studied.The results showed that for both complete and shortcut N removal processes the formation of N₂O was in nitrification process, while denitrification one was favorable for decrease of N₂O emission.N₂O yield was 4.67 mg·L^-1，6.48 mg·L^-1 and 0.35 mg·L^-1 for complete, shortcut and simultaneous nitrification-denitrification processes, respectively.The main reason for the formation of N₂O was the accumulation of NO₂^--N during N removal process.A part of AOB could be denitrified between NH₄⁺-N as electron donor and NO₂^--N as electron acceptor under low DO level,which led to the formation of N₂O finally.The formation of N₂O in simultaneous nitrification and denitrification process at various DO conditions showed that in SBBR system, the minimun N₂O yield could be achieved by the control of DO concentration and the efficiency balance of nitrogen removal in both nitrification and denitrification processes.

Key words:

N₂O产量;生活污水;全程硝化反硝化, 短程硝化反硝化;同步硝化反硝化