采用A^2O工艺处理低ρ（C）/ρ（N）实际生活污水，研究其脱氮除磷性能和反硝化除磷特性．试验结果表明：处理低ρ（C）/ρ（N）实际生活污水时，在不设置预缺氧区、无外加碳源的情况下，A^2O工艺的脱氮除磷能力受到严重影响，出水ρ（NO3^--N）高达35mg／L，TN平均去除率仅为47．1％；此时A^2O工艺除磷能力较差，缺氧段有释磷现象的发生．当设置预缺氧区后，A^2O工艺的脱氮除磷能力明显提高，TN平均去除率可达60．7％，PO4^3--P平均去除率为55．9％；此时系统存在反硝化除磷现象，缺氧段除磷率为31．4％～46．9％．在设置预缺氧区的基础上，通过外加碳源，提高进水ρ（C）/ρ（N），可进一步提高系统的脱氮除磷能力，TN平均去除率可达74．4％，出水ρ（PO4^3--P）小于0．5mg／L，缺氧段除磷率高达66．2％-90．9％．同时研究了外加碳源情况下污泥内PHA成分、含量及糖原含量在A^2O系统内的沿程变化趋势．经过驯化、富集，反硝化聚磷菌相对于全部聚磷菌的代谢活性从31．1％提高到74．7％．A^2O工艺反硝化除磷能力的增强，提高了碳源的利用效率．%A lab-scale A^2O process was operated to investigate the performance of biological nutrients removal and denitrifying phosphorus removal from low ρ（ C ）/ρ（N） ratio domestic wastewater. The results showed that only about 47.1% of TN could be removed with effluent ρ（ NO3^--N） above 35 mg/L when the A^2O process was operated without the pre-anoxic zone and additional carbon source. Under this condition, both conventional and denitrifying phosphate removal was not observed in the anoxic zone. When the A^2O process was operated with the pre-anoxic zone, about 60.7% of TN and 55.9% of PO4^3--P could be removed. Moreover, denitrifying phosphate removal occurred with a removal efficiency of 31.4% -46.9% in the anoxic zone. After the ρ（C）/ ρ（N） ratios were increased by adding the carbon sources, biological nutrients removal was enhanced with the TN removal of 74.4% and the ρ（PO4^3- -P） in the effluent below 0.5 mg/L, and the denitrifying phosphate removal efficiency was up to 66.2% - 90.9%. Furthermore, the variations of PHA and glycogen were investigated. The relative metabolic activity of the DNPAO （denitrifying phosphate accumulating organism） increased from 31.1% in the seed sludge to 74.7% in the acclimated sludge. The carbon sources utilization efficiency is upgraded with the achievement in denitrifying phosphate removal in the A^2O process.
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