Study On Advanced Treatment Of Municipal Wastewater By High Efficiency Reaction Sedimentation And Fiber Filter

In 2007,cyanobacteria broke out in Taihu Lake.In order to improve the water quality,the standard raising and reconstruction work of the urban sewage treatment plant in Taihu Lake Basin began.Based on the practical case of the second phase project of Suzhou Wuzhong Chengnan sewage treatment plant,this paper mainly studies how to determine the advanced treatment process scheme of the sewage treatment plant,the treatment effect and energy consumption of the advanced treatment system under different operation modes.Through the summary of the design parameters and actual operation of each process section of the first phase of Chengnan Wastewater Treatment Plant,th e first phase of the project exists these problems: the COD,SS and TP in the influent are basically in line with the original design inflow index,but the BOD is lower than the original design index.Ammonia nitrogen and TN are higher than the original de sign index.For the impact of the carbon source utilization of denitrification in biological treatment system,the total nitrogen in the effluent may exceeding the standard;the existing process of secondary sedimentation tank is discharged after precipita tion,and the effluent SS is difficult to meet the first-level A discharge standard;the existing process of adding chemical phosphorus removal agents at the outlet end of the biochemical pool has unstable effect of phosphorus removal,occasionally exceeding the standard,and the reaction precipitates follow the activated sludge back to the biochemical system,which is not conducive to the operation of the biochemical system.After fully demonstrating the water quality of the sewage treatment plant,the removal rate and water quality characteristics of each pollutant were analyzed in detail,the overall process flow and the direction of the process route were determined,and the high-density sedimentation tank was combined with the V-type fiber filter technique.The comprehensive technical and economic comparison of the three advanced treatment processes of fiber filter process,elimi-NITE denitrification deep bed filter process and reaction sedimentation tank combined microfiltration machine process determined that the deep treatment process of this project is most suitable for high-density sedimentation.The pool incorporates a V-fiber filter process.After the process route is determined,the technical parameters of each process section are optimized.In the operation stage,the operation effect of the advanced treatment system is verified.At the same time,in order to optimize the operation effect and achieve the goal of energy saving and consumption reduction,the removal rate and energy consumption of COD,ammonia nitrogen,total phosphorus and SS of the advanced treatment system under different operation modes are compared.When Fe Cl3 agent is only added,COD removal rate,TP removal rate,SS removal rate are 25%,40%,66%and filter backwash interval is 20.5 hours,which is the optimal operation mode of the advanced treatment system.