中文摘要：

采用改良而成的OGO工艺技术，以试验配水模拟城市生活污水，研究了OGO系统的脱氮效果，通过分析反应器各反应区的脱氮效果，并结合OGO系统脱氮效果观察系统中活性污泥絮体特性，研究分析了OGO系统的脱氮机理。试验结果表明，在进水总氮（TN）和氨氮（NH4^＋ -N）分别为31．15—42．26mg／L和27．53—38．58mg／L的条件下，OGO系统对总氮和氨氮的平均去除率分别可达74．31％和83．75％。反应器外环脱氮方式为同时硝化反硝化（SND）脱氮，其脱氮量占反应器脱氮总量的80．48％，OGO工艺对氮素的生物去除绝大部分是通过同时硝化反硝化来实现的；同时硝化反硝化的宏观分区理论和微环境理论均适用于OGO系统。

英文摘要：

Nitrogen removal efficiency in the OGO reactor was studied based the improved OGO reactor, and the test water was simulated municipal wastewater, further study has been done to analyze the nitrogen removal mechanism of the OGO system through analyzing the nitrogen removal effect in each part of the OGO reactor and observing the activated sludge characteristic in the reactor. When influent total nitrogen（TN） and ammonia nitrogen（ NH4 ±N） are 31.15 - 42.26 mg/L and 27.53 - 38.58 mg/L respectively, the average removal efficiencies of TN, NH4 ± N achieve 74.31% and 83.75%. The nitrogen removal in the outer-loop of OGO reactor is achieved by Simultaneous Nitrification and Denitrification（SND）. In outer-loop, the nitrogen removal amount is 80.48% of that in the whole reactor. Thus, in OGO reactor, the nitrogen removal mostly depends on SND. Both bioreactor macro-environment and floc microe-environment for SND are existed in OGO system.