中文摘要：

采用气升环流生物反应器建立全程同步硝化反硝化（SND）体系,在此基础上,通过提高进水pH值从而增加反应器中的游离氨（FA）浓度,可以实现全程SND向短程SND的转变.以全程SND过程为参照,分析了短程SND过程的脱氮及N2O释放特性.结果表明,短程SND过程的总氮平均去除率及SND平均效率分别为71.9%和80.9%,比全程SND过程分别提高了18.0和16.8个百分点,短程SND过程的平均总氮去除速率为0.11 mg.（L.min）^-1,是全程SND过程的1.4倍.虽然短程SND较全程SND具有更高的脱氮效率,但该过程的N2O平均转化率为57.1%,N2O平均累积释放量约为全程SND过程的5倍.研究还发现,N2O的释放量急剧上升与体系中NO2--N的积累浓度升高密切相关.

英文摘要：

Complete simultaneous nitrification and denitrification（SND） was achieved in an air lift circulation bioreactor.Based on this condition,the system could be switched to shortcut SND as the free ammonia（FA） concentration was increased with higher influent pH.The nitrogen removal and N2O emission characteristics of the shortcut SND process were investigated and those of the complete SND process were also observed as control.In the shortcut SND process,the average total nitrogen removal and average SND efficiency reached 71.9% and 80.9%,which was 18.0 and 16.8 percents higher than those in the complete SND process,respectively.In addition,the total nitrogen removal rate in the shortcut SND process was 0.11 mg·（L·min）-1,1.4 times as high as that in the complete SND process.Although higher nitrogen removal efficiency was obtained in the shortcut SND process,the mean N2O conversion rate reached 57.1% and the average N2O accumulated emission amount was approximately 4 times higher than that in the complete SND process.The results also indicated that the increase of NO-2-N concentration in the reactor should be responsible for the remarkable enhancement of N2O emission.