中文摘要：

对于碳源不足的城市污水厂二沉池出水，通过外加碳源提高对其TN的去除率是一种直接而有效的方法。采用生物滤池（滤速为2m／h）深度处理二沉池出水，并投加乙酸钠碳源，发现当进水混合液的COD〉95．0mg／L时，对TN的去除率可达到98％；部分外加碳源可被DO消耗，只有当进水混合液COD增至57．7mg／L时，出水DO降到0．8m／L左右，反硝化现象才逐渐明显；当碳源投加不足时，会出现亚硝态氮的积累，当进水混合液的COD平均为81．1mg／L时，亚硝态氮积累量高达6mg／L。

英文摘要：

Additional carbon source is a direct and effective way to improve TN removal from the secondary effluent with carbon source shortage. The biological filter with a rate of 2 m/h is adopted for advanced treatment, and sodium acetate is used as carbon source. When the COD concentration in the influent mixture is more than 95.0 mg/L, the TN removal rate is 98%. The partial carbon source is consumed by DO. When the COD concentration in the influent mixture is 57.7 mg/L, the effluent DO is decreased to 0.8 rag/L, and the denitrification is obvious gradually. The carbon source shortage can result in nitrite accumulation, and the nitrite concentration is 6 mg/L when the COD concentration in the influent mixture is 81.1 mg/L.