Upgrading & Reconstruction Research Of One Sewage Treatment Plant In Taizhou

The raw water quality of the mentioned plant is complex with big water fluctuation, substandard biological treatment index and lower removal biochemical process. The discharged water cannot meet the A standard of "urban sewage treatment plant emission standards" GB 18918- 2002 and needs nitrogen and phosphorus removal and advanced physical and chemical treatment.To achieve an A discharge standard, this paper optimize the process of nitrogen and phosphorus removal and advanced treatment, determine the sedimentation tanks+ carbon+efficient denitrification+sterile nitrogen and phosphorus removal and advanced treatment process. Using AN956 model PACL with net amount of around 15 mg/1. When the CODcr is higher than 65mg/l, adding the activated carbon powder according to the consentration of the CODcr. Usually, it needs about 3-4mg/l activated carbon powder in order to remove lmg/l CODcrThrough the reconstruction of the first idle regulation pool, blower room, aeration tank for the first period of processing, sedimentation tanks, sludge transformation of the reflow process unit pump tank for first period of processing, return sludge aeration tank and pump tank for the second period of processing, to achieve the upgrading and reconstruction of the first stage of the project. Through the construction of the following upgrading process like the new chemical wastewater grid stations, grit chamber, two stage pump tank, efficient sedimentation tanks, deep bed denitrification filters, activated carbon dosing etc, and through the reconstruction of the processing of chemical wastewater regulation pool, mixed reaction sedimentation tank, pool acid hydrolysis, biochemical pool and sedimentation tank etc. to achieve the upgrading and reconstruction of the second stage project.According to the evaluation of the environmental benefits of this project, the reduction rate of odor is up to 75% to 85%, and the wastewater pollutant is around 50～83%; Regarding the evaluation of the regional environmental benefit, the discharge water quality of Taizhou Water Development Co., Ltd. sewage treatment plant is improved from the current second grade to A grade with the reduction of CODcr 1825 t/a, Ammonia 365 t/a, Total Bitrogen 1460 t/a, Total Phosphorus 91.25 t/a. This upgrading the reconstruction process help to improve the overall water environment in Taizhou and leads to good environmental and social benefits.