Design And Efficiency Analysis Of Upgrading And Reconstruction Project Of A Sewage Treatment Plant In Wuhu City

With the development of urbanization,people pay more and more attention to water pollution.Government’s improvement of water quality standards of surface receiving water also causes the main sewage source of surface runoff —— sewage treatment plants to face the problem of upgrading standards.A large number of sewage treatment plants across the country are required to implement the Class A effluent discharge requirements of the Municipal Sewage Treatment Plant Pollutant Discharge Standard(GB18918-2002).In order to ensure that the effluent quality meets the higher watershade discharge requirements and reduce pollution discharge,a sewage treatment plant in Wuhu City has designed the effluent water quality analysis,sewage advanced treatment process screening analysis,coagulant dosage ratio and advanced treatment process unit monomer design.It strives to select upgrading process with advanced and mature technology,stable and reliable treatment effect,and economy and rationality to ensure the effluent quality requirements while reducing the operation cost of the sewage treatment plant.(1)Through the preliminary field surveys and investigations,the present treatment scale of a sewage treatment plant in Wuhu is 100000 m3/d and "multi-mode A/A/O sewage treatment process " is adopted,and the effluent index carries out in accordance with the Class B standard,which cannot meet the designed effluent quality standard.Therefore,the standard should be upgraded and the further treatment units should be increased to ensure that the effluent reaches the designed effluent quality;(2)After comparing the rationality,economy and applicability,and studying the different advanced treatment processes,the "coagulation sedimentation filtration" process route was selected,and the two processes were further optimized and compared to determine that the high-efficiency sedimentation tank."Denitrification deep bed filter" process is close to the ideal process for advanced treatment of nitrogen and phosphorus removal in sewage treatment plants;(3)The advanced treatment process was designed with a design scale of 100,000 m3/d,including one new sewage lift pump tank,two new high-efficiency sedimentation tanks and one new filter room,including denitrification deep bed filter and ultraviolet disinfection;(4)The results show that the effluent quality of the system has little fluctuation and is better than that of the first-class A discharge.The SS、TP is removed by chemical coagulation and precipitation through high efficiency sedimentation tank plus flocculant,and the TN can be treated well by denitrifying with external carbon source.