为探究低温条件下溶解氧（DO）质量浓度对微氧生物脱氮反应器启动和运行的影响，采用外曝气回流上升流式微氧污泥处理系统，将低C/N比模拟城市污水泵入反应器进行处理，实验各阶段微调DO浓度并测定主要出水水质指标。结果表明，反应器对TOC、IC、NH₄⁺-N和TN去除率分别为62.32%、60.02%、91.56%、64.09%，在低温、低DO、低C/N比的条件下处理效果良好。菌群结构分析表明，驯化污泥存在促进颗粒化菌，好氧氨氧化、厌氧氨氧化、自养反硝化、异养反硝化和好氧反硝化可协同脱氮，在低温、低C/N比下富集节能高效脱氮菌群。

In order to explore the influence of dissolved oxygen (DO) concentration on the start-up and operation of the microaerobic biological nitrogen-removing reactor under low temperature (15℃) conditions, the simulated municipal sewage with a low C/N ratio is pumped into the reactor with an external aeration-reflux upflow microaerobic sludge treatment system.The concentration of DO is adjusted slightly at each stage of the experiment, meanwhile main effluent water quality indicators are determined accordingly.It is shown that the removal efficiencies of TOC, IC, NH₄⁺-N and TN by the reactor are 62.32%, 60.02%, 91.56%, 64.09%, respectively, showing that the treatment effect by the reactor is good under the conditions of low temperature, low DO and low C/N ratio.The results from analyzing the structure characteristics of bacterial flora show that domesticated sludge can promote granular bacteria, aerobic oxidation of ammonia, anaerobic oxidation of ammonia, autotrophic denitrification, heterotrophic denitrification and aerobic denitrification to coordinate with removal of nitrogen, and enrich bacterial flora with energy-saving and high-efficiency nitrogen-removing performances at low temperature and low C/N ratio.

李慧(1995-),女,硕士研究生,研究方向为水污染控制与水质安全保障,601602906@qq.com