改良型氧化沟扩容改造AAO-MBR工艺工程设计

针对四川省某县城市污水处理厂存在的处理能力不足、厂区用地紧张、出水水质亟需提标等问题,扩容改造工程中将现状改良型氧化沟改造为AAO生化池,现状二沉池改造为MBR膜池,并同时新建一座MBR膜综合车间与之配套,形成新的AAO-MBR深度处理工艺。工程完成后,污水处理能力由3. 0×10~4m^3/d提升至3. 5×10~4m^3/d,实际运行出水COD≤25. 0 mg/L、NH_3-N≤1. 5 mg/L、TN≤8. 0 mg/L,出水水质满足《四川省岷江、沱江流域水污染物排放标准》(DB 51/2311—2016)相关标准。工程总投资为3 589. 2万元,MBR膜系统运行成本为0. 439元/m^3,结合整体厂区运行工况,总处理成本稳定在1. 15~1. 30元/m^3之间。

Design of AAO-MBR Process for Modified Oxidation Ditch Expansion

In view of the problems of insufficient treatment capacity,the shortage of land use in the plant area,and urgent need to enhance the quality of the effluent water in a county wastewater treatment plant in Sichuan Province,the modified oxidation ditch was transformed into AAO tank,and the present secondary sedimentation tank was transformed into MBR tank.At the same time,a new MBR membrane comprehensive workshop was built to support it so as to form a new AAO-MBR advanced treatment process.After the completion of the project,the wastewater treatment capacity increased from3.0×104 m3/d to 3.5×104 m3/d.The COD,NH3-N,TN concentrations in the effluent were respectively≤25.0 mg/L,≤1.5 mg/L and≤8.0 mg/L.The effluent quality was implemented in accordance with the Discharge Standards of Water Pollutants in Minjiang and Tuojiang River Basins of Sichuan Province(DB 51/2311-2016).The total investment of the project was 35.892 million yuan,the water operating cost of MBR membrane system was 0.439 yuan/m3.Combined with overall plant operating conditions,the treatment cost stabilized between 1.15-1.30 yuan/m3.