Study On The Design Of The Upgrading Project About Sewage Treatment Plant Of Liuhe District In Nanjing

The basic principles of commonly used processes in domestic sewage treatment plants and the original construction operation of Liuhe Sewage Treatment Plant in Nanjing were summarized in this paper which points out the problems found in the operation of the sewage treatment plant.It illustrates that the implementation of upgrading and the deep dewatering of the sludge of the Liuhe Sewage Treatment Plant has been imminent.It is a necessary measure to accomplish energy conservation and emission reduction and improve the surrounding environment further.In order to improve the overall effluent quality of the 40,000 tons/day sewage treatment plant at the first state,the Liuhe Sewage Treatment Plant has raised the effluent quality from the previous execution Level 1 B Index to A index in Table "the Urban Sewage Treatment Plant Pollutant Discharge Standard"(GB18918-2002),and the sludge was dehydrated at the same time.Therefore,the equipment of sand removal pool,intermediate lift pumping station,post denitrifying filter pool,fiber turntable filter,ultraviolet disinfection pool,and the integrated biological filter deodorizing system had been added in the sewage treatment system for upgrading the standard.The system will enable the emission of exhaust gas to meet the secondary standards of the“the Urban Sewage Treatment Plant Pollutant Discharge Standard"(GB18918-2002).The deep dewatering of sludge adopts a new generation of double-diaphragm sludge pressure filtration technology,so that the moisture content of the dewatered cake is 60-55%.After the completion of the upgrade,the effluent quality concentration and efficiency were compared before and after the upgrading.The upgrading project is located in Liuhe Sewage Treatment Plant in Nanjing.The total scale of this sewage upgrading project will be 40 thousand m3/d,and the depth of sludge dehydration will be 5 tons dry mud/d.There are environmental protection measures adopted during the construction and operation period of the project which will not have adverse effects on the surrounding environment.At the same time,the social,economic and environmental benefits of this project will be analyzed.The effluent quality of the Liuhe Sewage Treatment Plant in Nanjing has reached the first grade A standard in "the Urban Sewage Treatment Plant Pollutant Discharge Standard"(GB18918-2002)after the accomplish of upgrading project.The main control indexes are as follows:BODS?10mg/L,COD?50mg/L,SS?10mg/L,TN?15mg/L,NH3-N?5(8)mg/L,TP?0.5mg/L.