Research On Design And Operation For Upgrading Project Of A Sewage Treatment Plant

The project,concerning the key technical issue in upgrading the effluent quality of municipal sewage treatment plant to achieve the type III standard of surface water,is carried out to cooperate with the East Route of South-to-North Water Transfer Project and improve the water quality of the Daqing River Basin in Hebei Province.We design the advanced treatment processes,test the operation parameters and check the operation effects.The main conclusions are as follows:1)Based on the pilot scale(1 m³·h^-1)results,the process“Denitrifying filter+Coagulation sedimentation+O₃+Biological aerated filter+Filter”is used to treat effluent from the secondary sedimentation tank at MSTP and the effluent from this process can meet the class?standards of“Surface Water Environment Quality Standards”?GB3838-2002?.The optimized operation conditions are that the hydraulic retention time?HRT?is 40 min and 45min for denitrifying filter tank and biological aerated filter tank,respectively,and the ozone dosage is 30-40 mg·L^-1.2)According to the pilot-scale experiment results and the idiographic instance of the MSTP,the final advanced treatment process should be arranged as“Denitrifying filter+Coagulation sedimentation+O3+Biological aerated filter+Rotary Fibre Disk Filtration”,The design of the upgrading reconstruction project of the MSTP is based on the pilot-scale experiment,the existing structures and plane arrangement of the sewage treatment plant,including the design and calculation of denitrifying filter tank,Ozone contact pool and Biological Aerated Filte,as well as the drawing of process flow chart and plane arrangement of the sewage treatment plant are drafted.3)Based on the commissioning and operation of the upgrading reconstruction project,when the concentration of COD,TN,NH₄⁺-N,TP and SS in the second effluent is57⁷4 mg·L^-1,11¹5 mg·L^-1,3.1⁵ mg·L^-1,0.5⁰.8 mg·L^-11 and 54⁶8 mg·L^-1,respectively,the corresponding final effluent is 9¹5 mg·L^-1,3.1⁶.8 mg·L^-1,0.6⁰.9mg·L^-1,0.08⁰19 mg·L^-11 and 3.1⁵ mg·L^-1.The COD?NH₄⁺-N and TP can meet the target of class?of“Surface Water Environment Quality Standards”?GB3838-2002?.The TN and SS can meet Grade A standards of“Integrated Discharge Standard of Water Pollutants in Beijing”?DB307-2013?.