摘要： 利用SBR反应器，以NO₃^-为电子受体，分别投加乙酸钠、乙醇、甲醇作为电子供体，控制初始C/N为5，考察不同负荷条件下反硝化过程中NO₂^-和N₂O的积累过程。结果表明，不同进水NO₃^-浓度下，3种碳源均有NO₂^-积累且持续至反硝化结束，而且均会出现N₂O的积累和还原过程。与乙酸钠相比，高浓度甲醇具有生物毒性，提供电子速率较低，无法满足亚硝态氮还原酶和氧化亚氮还原酶对电子的需求。以易生物降解有机物作为电子供体，提高其提供电子速率，能有效降低系统N₂O积累并防止其在后续好氧阶段的释放。

关键词: 反硝化, 碳源, 亚硝酸, N₂O

Abstract: Using NO₃^- as electron acceptor,the effect of carbon sources(ethanol,sodium acetate and methanol) on the NO₂^- and N₂O accumulation was investigated in a lab-scale sequencing batch reactor(SBR),with the controlled initial C/N ratio of 5. The results showed that at different NO₃^- concentrations,NO₂^- accumulation for all three carbon sources occurred till the end of the denitrification process,as well as the accumulation and reduction of N₂O occurred. Compared with sodium acetate,the methanol oxidation rate decreased due to the biotoxicity of higher methanol. The electron supply rate of methanol was relatively low,which was unable to meet the electron demands of nitrite reductase and nitrous oxide reductase. The biodegradable organic matter was used as electronic donor,and its electron providing rate was improved to effectively reduce the accumulation of N₂O in the system and prevent its release in the subsequent aerobic stage.

Key words: denitrification, carbon source, nitrite, N₂O

中图分类号: 

• X703.1