城镇污水处理厂以液位为核心的跌水复氧工程改造

Waterfall Reoxygenation Engineering Reconstruction with Liquid Level as the Core in a Municipal WWTP

我国城镇污水处理厂普遍存在跌水复氧现象,导致碳源无效损耗,造成脱氮成本居高不下,因此减少和消除跌水复氧备受关注。针对四川省岷江流域某城镇污水处理厂高效脱氮与节省运行成本的综合需求,在调研二沉池、中间提升泵房和高效沉淀池跌水复氧特征的基础上,开展了以液位控制为核心的跌水复氧控制工程改造。运行结果表明,反硝化深床滤池进水DO降低约4.4 mg/L,外加碳源利用率提升26%,碳源投加成本降低0.078元/m^(3),全年节约28万余元,对同类城镇污水处理厂降本增效、高效经济脱氮具有一定的参考价值。

The phenomenon of waterfall reoxygenation is common in Chinese wastewater treatment plants(WWTPs),which leads to ineffective loss of carbon source and high nitrogen removal cost.Thus reducing and eliminating waterfall reoxygenation is concerned.According to the needs of efficient nitrogen removal and operation cost saving in a WWTP of Minjiang River basin in Sichuan Province,the waterfall reoxygenation control project with liquid-level as the core was carried out based on the investigating the characteristics of the secondary sedimentation tank,the intermediate pump station and the high-efficiency sedimentation tank.The results showed that the influent DO concentration of the deep denitrification bed filter process was decreased by about 4.4 mg/L,the utilization rate of added carbon source was decreased by 26%,the cost of carbon was reduced by about 0.078 yuan/m^(3),and the annual saving was over 280000 yuan.The renovation can provide guiding significance for the similar municipal WWTPs in reducing cost as well as efficient and economic nitrogen removal.