Research On Shenyang LZ Sewage Treatment Plant Upgrading Process And Analysis Of Operation Effect

In order to prevent the deterioration of the water environment and protect the water resources,the requirements for the effluent quality of urban sewage treatment plants have been increasing year by year."Discharge standards of pollutants from urban sewage treatment plants"?gb18918-2002?clearly points out that the effluent quality of urban sewage treatment plants above the county level must meet the first-grade A standard.In China,the effluent of many municipal sewage treatment plants that were built earlier cannot reach this standard,and many municipal sewage treatment plants need to be upgraded.Shenyang LZ Sewage Treatment Plant project is the national"tenth five-year plan"Liao River basin water pollution control and the key project supported by national debt.The design effluent of phase I and phase II is first-grade B standard,which fails to reach first-grade A standard.Therefore,it needs to bid transformation.The purpose of this study is to study the upgrading plan of Shenyang LZ Sewage Treatment Plant and to design the process.In this study,Shenyang LZ Sewage Treatment Plant bid upgrading project is taken as the research object,according to the operation status of the sewage treatment plant and the current status of the effluent data analysis,through comparison and discussion to select the bid upgrading program suitable for the sewage treatment plant,optimize the design parameters,analysis of the operation effect.According to the water inflow analysis of Shenyang LZ Sewage Treatment Plant in 2016,the design scale of the project for the bid upgrading is determined to be 5×10⁴m³/d.According to the analysis results of annual inlet water quality of Shenyang LZ Sewage Treatment Plant in 2016,and referring to the water quality of similar sewage treatment plants at home and abroad,the designed inlet water quality of Shenyang LZ Sewage Treatment Plant is determined to be COD_cr=300mg/L,BOD₅=150mg/L,SS=180mg/L,NH₃-N=28mg/L,TN=35mg/L,and TP=4mg/L.The designed effluent quality is subject to the first-grade A discharge standard of discharge standards for pollutants in urban sewage treatment plants?gb18918-2002?.COD_cr?50mg/L,BOD₅?10mg/L,SS?10mg/L,NH₃-N?5mg/L,TN?15mg/L,TP?0.5mg/L.BOD₅/COD_crof Shenyang LZ Sewage Treatment Plant was greater than 0.45 all year round,which was biodegradable.BOD₅/TN is greater than 3.0 all year round,and the carbon source in sewage is sufficient,so biological denitrification should be adopted.Through the analysis of the treatment effect of the present situation of Shenyang LZ Sewage Treatment Plant,and the comparison of various phosphorus and nitrogen removal processes,combined with the existing processes,the"Moing Bed Biofilm Reactor?MBBR?process+deep treatment combination"process was finally selected.The transformation of the first stage biochemical tank into MBBR process was carried out,and the advanced treatment was carried out by the tubular static mixer?coagulation?+grid flocculation tank?flocculation?+inclined plate sedimentation tank?precipitation?+continuous sand filter?filtration?.The operation results show that the upgrade and transformation of Shenyang LZ Sewage Treatment Plant has achieved the expected effect,effectively solved the problem of TN,SS and TP not up to the standard,and all the effluent indexes have reached the first-grade A standard.After the implementation of the upgrading and upgrading project of Shenyang LZ Sewage Treatment Plant,the effluent quality has been improved,and the pollution caused by pollutants to Pu River has been reduced.