曝气生物滤池与地下渗滤系统工艺脱氮除磷

以生活污水为研究对象，考查了曝气生物滤池和地下渗滤系统组合工艺脱氮除磷的性能。工艺运行过程中，曝气生物滤池只考虑COD和氨氮的去除，把总氮和总磷的去除分离到地下渗滤系统中。实验结果表明，曝气生物滤池和地下渗滤系统组合工艺有良好的脱氮除磷能力。滤速为0.6 m·h-1，气水比为5：1，反冲洗周期为7 d时，曝气生物滤池达到最佳运行状态，对COD、氨氮、TN、TP的去除率分别达到85.3%、83.5%、30%、56%。为了提高TN、TP的去除率，地下渗滤系统采用间歇的方式运行，每个周期连续进水12 h，放空12 h，进水为曝气生物滤池出水，水力负荷为5 cm·h-1，对COD、氨氮、TN、TP的去除率分别达到41.3%、62.8%、81.3%、82%。

Phosphorus and nitrogen removal by a combined process of BAF and subsurface wastewater infiltration system

With the treatment of domestic wastewater as the objective,the pattern of phosphorus (P)and nitrogen (N)removal were investigated in a lab-scale combined technology system,based on the biological aerated filter (BAF)and the subsurface wastewater infiltration system (SWIS). In this system,the BAF reactor was mainly used for the removal of COD and NH4+-N,while the SWIS system was used for the removal of TN and TP. The experimental results clearly showed that optimum treatment efficiency can be achieved when the upflow velocity was 0.6 m·h-1,the ratio of gas to water was 5:1 and the backwash period was 7 days. Under the proposed optimal operating conditions,the removal efficiencies of COD,NH4+-N,TN and TP were up to 85.3%,83.5%,30% and 56%,respectively. In order to improve the removal efficiencies of TN and TP,the SWIS was operated in an intermittent pattern,with a flooding period of 12 h and a drying period of 12 h. At a hydraulic loading of 5 cm·h-1,the removal of COD,NH4+-N,TN and TP was achieved at average rates of 41.3%,62.8%,81.3% and 82%,respectively.