改良A^(2)O工艺在两级生物滤池改造中的应用

Application of Improved A^(2)O Process in the Renovation of Two-Stage Biological Filter

厌氧生物滤池(AF)和曝气生物滤池(BAF)均属于生物膜法污水处理工艺,可以实现脱氮除磷。改造前,某城镇污水处理厂采用两级生物滤池(AF+BAF)组合工艺处理生活污水,冬季水温低至10℃左右,进水氨氮浓度超过60 mg/L,原工艺出水总氮浓度在20 mg/L以上,不满足《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级A标准要求。本次改造采用改良厌氧缺氧好氧池(A^(2)O)+竖流式沉淀池+高效沉淀池+反硝化滤池的组合工艺强化脱氮除磷,出水水质能够稳定达标。

Both anaerobic biofilter(AF)and biological aerated filter(BAF)belong to the biofilm sewage treatment process,which can achieve nitrogen and phosphorus removal.Before the renovation,a certain urban sewage treatment plant used a two-stage biological filter(AF+BAF)combination process to treat domestic sewage,in winter,the water temperature drops to around 10℃,and the ammonia nitrogen concentration in the influent exceeds 60 mg/L,and the total nitrogen concentration of the original process effluent is above 20 mg/L,which does not meet the first class A standard requirements of the“Pollutant Discharge Standard for Urban Sewage Treatment Plants”(GB 18918-2002).This renovation adopts a combination process of improved anaerobic-anoxic-oxic tank(A^(2)O)+vertical flow sedimentation tank+high-efficiency sedimentation tank+denitrification filter to enhance nitrogen and phosphorus removal,and the effluent quality can stably meet the standard.