三级AO生物接触氧化工艺处理农村生活污水试验

Experimental Study on Degradation of Rural Domestic Sewage by Tertiary AO Biological Contact Oxidation Process

为降低农村污水处理的运行成本,探究最适宜农村污水处理的最佳运行条件,采用三级AO生物接触氧化工艺处理农村生活污水,利用自然跌水的方式来补充溶解氧,并对跌水的影响因子进行试验研究.结果表明:在试验环境温度为24~30℃,pH为7~8,溶解氧质量浓度为3.0~3.5 mg/L,辅助曝气量为500 L/h,最佳水力停留时间为6 h时,化学需氧量(COD)的平均去除率为88.98%,氨氮的平均去除率为83.56%,总磷的平均去除率为77.78%,达到河北省《农村生活污水排放标准》(DB13/2171—2020)一级标准,并结合Box-Behnken响应曲面模型原理,得出三级生物接触氧化工艺的COD去除率模型学方程.

In order to reduce the operating cost of rural wastewater treatment,the optimal operating conditions that are most suitable for rural wastewater treatment are investigated.The experiment uses three-stage AO contact oxidation process to treat rural domestic wastewater,and applies natural water fall to supplement dissolved oxygen,and the influence factors of water fall are studied experimentally.Results show that the average removal rate of COD is 88.98%,the average removal rate of ammonia nitrogen is 83.56%and the average removal rate of total phosphorus is 77.78%at the ambient temperature of 24~30℃,pH 7~8,dissolved oxygen is 3.0~3.5 mg/L,the auxiliary aeration is 500 L/h and the optimal hydraulic retention time is 6 h.The average COD removal rate of the three-stage biological contact oxidation process is derived by combining the Box-Behnken response surface model with the primary standard of the Hebei Province"Rural Village Domestic Sewage Discharge Standard"(DB13/2171-2020).