倒置A^2/O+A/O工艺用于某城市污水厂二期扩建工程

Application of Reversed A^2/O + A/O Process in the Second-phase Extension Project of a Municipal Wastewater Treatment Plant

某城市污水处理厂一期设计规模为2×10~4m^3/d,采用传统A^2/O工艺,出水水质很难达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。二期扩建工程设计规模为3×10~4m^3/d,在总结一期工程运行经验基础上,提出倒置A^2/O+A/O工艺,并辅以化学除磷及接触过滤等深度净化处理工艺,确保出水稳定达标排放。二期扩建工程投入运营后,出水COD、SS、氨氮、TP平均浓度分别为34. 5、7. 8、3. 8、0. 34 mg/L,稳定达到一级A排放标准。

The first-phase design capacity of a wastewater treatment plant was 2 × 10 4 m3/d. With the traditional A2/O process, the effluent quality was very difficult to meet the first class A criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918 - 2002）. The design capacity of second-phase extension project was 3 × 10 4 m3/d, on the basis of operation experience of the first-phase project, the combination process of reversed A2/O ＋ AO followed by the advanced treatment process of chemical phosphorous removal and contact filtration were adopted in ensure the stable effluent quality. After second-phase extension project was put into operation, the effluent concentrations of COD, SS, ammonia nitrogen, TP were 34.5 mg/L, 7.8 mg/L, 3.8 mg/L, 0.34 mg/L, respectively, and all effluent indexes could meet the first level A criteria.