Design And Construction Optimization Of Lifting And Renovation Project Of Chengbei Wastewater Treatment Plant In Changsha Economic And Technological Development Zone

This paper outlines the original construction and operation status of Chengbei Wastewater Treatment Plant in Changsha Economic and Technological Development Zone,and points out the shortcomings in the operation process.To protect the Xingsha water environment and the water environment of Laodaohe and Xiangjiang Rivers,ensure the safety of drinking water in cities and actively respond to national energy conservation.The call for emission reduction,the upgrading project of the plant and its design optimization are very necessary.In order to ensure the reduction of COD and NH₃-N in the“Twelfth Five-Year Plan”of Changsha City,the Chengbei Wastewater Treatment Plant of Changsha Economic and Technological Development Zone will improve the effluent quality of the first phase of 7.0×10⁴ m³/d,so that the effluent water quality will be implemented by the original“Urban Sewage Treatment”.The pollutant discharge standard of the factory（GB18918-2002）is upgraded to the first-class A standard.In view of the original construction and operation of th e Chengbei Wastewater Treatment Plant in Changsha Economic and Technological Development Zone,the problems in the operation of the sewage treatment plant at that time were pointed out and solved in the design of the upgrading project,including optimizati on of oxidation ditch’s volume.An agitator and a pusher are added to the inner return gate for hydraulic adjustment,a fine grid process is added in front of the turntable filter,and a sludge deep treatment system is newly buil,and compare the effluent water quality before and after the completion of the project.After the completion of the upgrading project,according to the treatment scale,the annual reduction of COD_cr emissions will be 11592t,BOD₅ emissions will be 7056t,SS emissions will be 10584t,NH₃-N emissions will be 856.8t,and TP emissions will be 126t,which will greatly reduce the sewage to the environment.The harm is conducive to the protection of the water environment quality and ecological environment quality of the Ladaohe River and the Xiangjiang River.After the completion of the upgrading,the effluent quality of the Chengbei WWTP in the Changsha Economic and Technological Development Zone has reached the“Emission Standard for Pollutants in Urban Sewage Treatment Plants”（GB18918-2002）Grade A standard,the main control indicators are as follows:BOD ₅≤10mg/L,COD≤50mg/L,SS≤10mg/L,TN≤15mg/L,TP≤0.5mg/L,NH₃-N≤5mg/L.The design optimization and construction optimization effects are more significant,and better optimization results have been obtained,which can provide reference for the design and prod uction management of sewage treatment plants,and reduce the construction cost and production operation cost as well as improve work efficiency.