中文摘要：

采用SBR反应器研究了在生活污水的生物脱氮过程中pH、DO和投加碳源对N2O释放的影响，并对各条件下N2O的产生特点进行了分析。结果表明，当控制初始pH值为6～9时，N2O释放的峰值均出现在曝气前期、对氨氮的去除率为30%～40%的阶段，当对氨氮的去除率达70%时，N2O的释放量显著下降；初始pH值为8时N2O的产生量最小，且N2O的释放量与硝化强度呈负相关。随DO浓度的增大，硝化过程中N2O的释放量逐渐降低。在硝化过程中将体系的DO控制在不同水平时，N2O的释放会呈现不同的特点：当DO为1.2～1.5 mg/L时，N2O主要产生于硝化阶段，释放量明显大于反硝化阶段的；当DO为1.8～2.3 mg/L时，硝化和反硝化阶段的N2O产生量相当；当DO为2.6～3 mg/L时，N2O主要产生于反硝化前期。在反硝化开始时补充碳源（葡萄糖）可有效提高对总氮和硝酸盐氮的去除率，但同时会引起N2O释放量的显著上升。

英文摘要：

The influence of pH, dissolved oxygen （DO） and external carbon source on N2O emis- sion was studied in SBR system, and the characteristics of N2O production were analyzed. The results show that at initial pH between 6 and 9, N2O emission peaks appear in the earlier aeration stage with am- monia nitrogen removal rate of 30% to 40%. When the removal rate of ammonia nitrogen reaches 70%, N2O emission decreases significantly. The lowest NzO production occurs at initial pH 8, and a negative correlation exists between the emission amount of N2O and the nitrification capacity. N2O emission during nitrification decreases as DO increases. N2O emission during biological nitrogen removal shows different characteristics under different DO levels in nitrification. When DO concentration is controlled at 1.2 to 1.5 mg/L, N2O is mainly produced by nitrification, which is more than that by denitrification. When DO concentration is controlled at 1.8 to 2.3 mg/L, N2O productions during the two stages are equivalent. When DO concentration is controlled at 2.6 to 3 mg/L, N2O is mainly produced in the early stage of denitrifieation. Adding external carbon source （glucose） at the beginning of denitrification can effectively improve the removal rates of total nitrogen and nitrate nitrogen and result in a significant increase in N2O emission.