小型污水厂A/O+硅藻精土工艺优化设计

Optimization Design of A/O + Diatomite Process for Small Wastewater Treatment Plant

湖北省利川市凉雾乡小型污水处理厂一期工程设计规模为1 000 m3/d,采用A/O+硅藻精土工艺。在设计时对水力流程、生物池水力停留时间、混合液及污泥回流方式、硅藻精土混合方式、消毒方式等进行了优化。当调节池停留时间为6 h,生物池缺氧区水力停留时间为2. 5 h、好氧区为7 h,硅藻精土采用机械混合方式,紫外线消毒调整为二氧化氯消毒后,工艺对SS、氨氮、总磷、动植物油和粪大肠菌群的去除率均达90%以上。该厂试运行4个月后,出水水质达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。

The A/O ＋ diatomite process was optimal designed, and used in Liangwu wastewater treatment plant with capacity as 1000 m3/d in Lichuan City, Hubei Province. The hydraulic process, the retention time of biological treatment tank, the reflux of mixed liquid and sludge, the mixing mode of diatom fine soil and the way of disinfection were optimized. When HRT of regulating tank and AO tank was respectively 6 h and 9.5 h （ anoxic 2.5 h, aerobic 7 h）, the diatomite was mixed via mechanical stirring, and ultraviolet radiation disinfection was replaced by chlorine dioxide disinfection, the removal efficiency of SS, NH3 - N, TP, animal and vegetable oil and Fecal Coliform were more than 90%. After operation for 4 months, the effluent reached the first level A criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （ GB 18918 - 2002）.