三峡库区Carrousel氧化沟工艺提标升级改造设计

Design of Upgrading and Reconstruction of Carrousel Oxidation Ditch Process in Three Gorges Reservoir Area

三峡库区某污水处理厂设计规模为3×10^4m^3/d,采用Carrousel氧化沟工艺,原设计出水标准为《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级B标准。升级改造工程中,针对Carrousel氧化沟脱氮除磷效果不佳、难以满足新的排放标准的问题,通过采取新增前置缺氧池、改变硝化液及污泥回流方式、新增多点进水等改造措施,提高了生化系统的脱氮除磷效率。实际运行结果表明,升级改造后生化系统对TN、TP、NH3-N的平均去除率均提高,出水水质稳定达到一级A标准。

The design scale of a WWTP in Three Gorges Reservoir Area was 30 000 m^3/d,the main treatment process of this WWTP was Carrousel oxidation ditch,the effluent was adapted to the first level B standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant( GB18918—2002). During the upgrading and reconstruction project, the efficiency of nitrogen and phosphorus removal in the biochemical system was improved in order to meet the new emission standards.Aiming at the problems that the effect of nitrogen and phosphorus removal in Carrousel oxidation ditch was not good,and it was difficult to meet the new discharge standard,the process was reconstructed by adding a new pre-anoxic tank,changing the nitrification and sludge return method,and adding multipoint water inflow. The actual operation results showed the average removal efficiency of TN,TP and ammonia nitrogen were improved. The effluent quality could meet the first level A standard of GB18918-2002 stably.