中文摘要：

采用连续流气升环流生物反应器,考察水力停留时间（HRT）对同步硝化反硝化（SND）体系下污泥聚集状态与脱氮及N2O释放特性影响。对不同HRT下污泥的聚集状态及脱氮特性、N2O释放速率和来源等进行了分析。结果表明,HRT的调控对污泥聚集体的形成及状态有重要影响。HRT为14、7和4 h下,反应体系内形成了以粒径区间0.2～0.45 mm、0.6～0.9 mm和〈0.2 mm占优的3种的污泥聚集体体系。HRT为7 h的条件下,污泥在保持良好脱氮效果（氨氮平均去除率、总氮平均去除率及SND平均效率分别为96.7%、56.0%和60.0%）基础上,可实现N2O减量化释放11.1%（相较于HRT为14 h的条件）。3种条件下,N2O释放的主要来源存在差异。HRT为14 h时,N2O主要来源于AOB反硝化,其对N2O的贡献为异养菌反硝化的1.1倍;HRT为7 h和4 h时,N2O主要来源于异养菌反硝化,其对N2O的贡献分别为AOB反硝化的1.1和1.3倍。

英文摘要：

A continuous-flow airlift reactor was used to investigate the effects of hydraulic retention time（ HRT）on microbial aggregates and the relationship of nitrogen removal characteristics with the simultaneous nitrification and denitrification（ SND） process. According to the results,when the HRT gradually decreased from 14 hours to 7 hours to 4 hours,the predominant proportions of microbial aggregates in the reactor were 0. 2 to 0. 45 mm,0. 6 to 0. 9 mm,and 0. 2 mm,respectively. When the HRT was 7 hours,the microbial aggregates had excellent nitrogen removal characteristics（ the efficiencies of ammonia removal,TN removal,and SND were 96. 7%,56. 0%,and 60. 0%,respectively） and realized an N2 O reduction of about 11. 1% when compared to an HRT of 14 hours. Meanwhile,the main source of N2 O emissions was different under the three conditions. When the HRT was 14 hours,denitrification by nitrifiers was the main source of N2 O,and the N2 O yield of this process was 1. 1 times higher than that of denitrification by heterotrophs. Under the two other HRT conditions,denitrification by heterotrophs was the dominant source of N2 O,which was 1. 1 and 1. 3 times higher than it was from denitrification by nitrifiers.