A^2O-BAF中试系统处理城镇污水的脱氮除磷性能

Nitrogen and Phosphorus Removal Performance of Pilot-scale A^2O- BAF System in Treating Municipal Wastewater

针对目前城镇污水处理厂升级改造的技术需求,研发了"厌氧/缺氧/短时好氧—曝气生物滤池(A2O-BAF)"工艺,并建立一套20 m3/d的中试系统。A2O段的HRT为4.0 h,厌氧、缺氧、好氧体积比为1∶2∶1;BAF的HRT为1.2 h,硝化液回流比为100%。研究表明,在进水COD、NH3-N、TN、TP、SS分别为249、28.77、40.37、1.04、108 mg/L条件下,出水值分别为28.44、2.63、9.51、0.42及9.21 mg/L,出水水质达到城镇污水处理厂一级A排放标准。同时,该工艺还具有占地面积小、运行成本低、污泥产率低等特点,是一种有较好应用前景的污水处理组合工艺。

An anaerobic/anoxic/short-time aerobic process coupled with biological aerated filter （ A2O - BAF） was developed, and a pilot-scale 20 m3/d system was set up to meet the technical require- ment of upgrading and retrofitting for municipal wastewater treatment. The HRT of the A2O reactor was 4 h with the anaerobic/anoxic/aerobic volume ratio of 1 ： 2 ： 1, and the HRT of the BAF was 1.2 h with nitrification liquid reflux ratio of 100%. The average concentrations of COD, ammonium nitrogen, total nitrogen, total phosphorus and suspended solids were reduced from 249 mg/L, 28.77 mg/L, 40.37 rag/ L, 1.04 mg/L and 108 mg/L to 28.44 mg/L, 2.63 mg/L, 9.51 rag/L, 0.42 mg/L and 9.21 rag/L, respectively. The effluent quality could meet the national discharge standard （the first class-A） for mu- nicipal wastewater treatment plant. The combined process has the advantages of small footprint, low operation cost and low excess sludge, and its application prospect is wide.