Reaching Standard and Renovation Project Design of a Wastewater Treatment Plant with Carrousel Oxidation Ditch Process

The design capacity of a city wastewater treatment plant was 2¡Á10⁴ m³/d. Carrousel oxidation ditch was adopted in biological treatment process. In the reaching standard and renovation project, based on Carrousel oxidation ditch, anoxic zone and nitrifying liquid backª²flow system were added, carbon source was supplemented and high efficient sedimentation tank was built. This process had advantages of small modification extent, low influence on wastewater treatment process, less investment, strong adaptability to impaction of raw wastewater and easy management. The coagulating sedimentation and rotary disc filter and chlorine dioxide disinfection process was used for the advanced treatment. The effluent quality could meet the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002).