中文摘要：

为了解决A2/O型氧化沟工艺生物除磷不稳定、出水磷难以达标的问题,在A2/O型氧化沟工艺生物脱氮除磷的基础上,增加厌氧段旁侧化学除磷,以提高其除磷效率,使之满足水质排放标准.结果表明：增加化学除磷能够提高系统的除磷效果,使系统出水TP＜1.0 mg/L,达到了国家排放标准（GB 18918-2002）;化学除磷前厌氧池出水的TP含量为20～39 mg/L,远大于原水中的TP平均值（5.88 mg/L）,在处理水量较少且化学除磷率为70%的情况下,便能够取得较好的总体除磷效果;回流污泥中携带的NO-x对生物除磷有较大的影响,其浓度和出水TP值有着较好的相关性,但旁侧化学除磷能够减弱回流污泥中的NO-x对生物除磷的影响;化学除磷剂的投配率为1：1（与TP物质的量之比）,低于传统化学除磷的1.5：1.基于氧化沟工艺的旁侧化学除磷能够弥补氧化沟工艺的除磷不稳定,使该工艺得以进一步完善.

英文摘要：

In order to give a solution to the instable biological phosphorus removal in A^2/O oxidation ditch process and the difficult achievement of the standard for effluent phosphorus, chemical phosphorus removal based on the A^2/O oxidation ditch process was added in the anaerobic zone to increase phosphorus removal efficiency. The result indicates that the effluent TP of the system is below 1.0 mg/L with up to the national discharge standard （GB 18918 -2002）. Before chemical phosphorus removal, the effluent TP of the anaerobic zone is 20 -39 rag/L, which is more than the average of 5.88 mg/L in raw wastewater. In the case of less treatment water and chemical phosphorus removal rate of 70%, the total phosphorus removal effect is better. NOx^- in the returned activated sludge of A^2/O oxidation ditch process has a great influence on the biological phosphorus removal, and its concentration has a linear correlation with effluent TP. However, chemical phosphorus removal process can trail off the influence of NOx^-. Chemical flocculant can be saved, the mole rate is 1 ： 1 which is less than 1.5 ： 1 in the traditional chemical phosphorus removal process.