Study On The Performance Analysis And The Upgrading Project Of A Township Wastewater Treatment Plant In Jiangyin City

With the development of society,people's efforts to control environmental pollution are also growing.A township sewage treatment plant in Jiangyin mainly treats the domestic sewage in the town and the industrial wastewater in the industrial park.It adopts the A²/O process,and the designed treatment scale is 10000m³/d,and the discharge standard is Grade B.According to the requirements of the"Water Ten",the discharge standard of the sewage plant needs to implement the Class A standard before the end of 2017.Due to the process technology,equipment and operation management of the sewage treatment plant,the nitrogen removal effect of the system is poor.Especially under the influence of low temperature,with the decrease of biological activity,the water quality of NH₃-N and TN effluent deteriorates,and there is a phenomenon that it does not meet the standard.In this paper,the research on the phenomenon that the denitrification effect of the plant is poor and the effluent water quality is not up to standard is carried out.The factors affecting the denitrification are investigated one by one.The research finds that the function of the original process denitrification process is not normal.For the stable operation of the sewage plant,it is proposed to upgrade the denitrification process section of the sewage plant.Through analysis and comparison,the transformation plan is proposed and the transformation project is implemented.According to the results of the investigation,measures are taken to enhance the denitrification effect,such as strict managed from the sewage plant's influent,adjusting tank dredging,adding the flow ejector,and adding sludge detection equipment to the biochemical pool.The original denitrification tank was reformed to enhance the mixing effect and reduce the occurrence of short-flow,and the denitrification deep-bed filter process was added after the effluent from the secondary settling tank.Comparing the scheme,and considering the current situation of the wastewater treatment plant and the operating cost,the project was implemented with a scale of 8000m³ and a effluent standard of 5mg/L.Through the small test,the dosage and mode of carbon source were determined.After the installation,the filter was inoculated and the equipment was operated.After the completion of the denitrification reform,a series of optimized operations were carried out.Continually strict management from influent was implemented,and the influent water quality index was controlled within the take-over standard,COD219⁷47mg/L,TN 17.96⁵4.49mg/L,NH₃-N 10.6³0.1mg/L,SS 84²00mg/L,TP2.09⁸.49mg/L.The reflux ratio was reduced and energy was saved without affecting the emission index.Carbon source types for denitrification deep bed filter and dosage methods,and etc.had been optimized to achieve savings.The effect analysis of the reformed sewage treatment plant was carried out.The average value of tail water was COD 34.62mg/L,NH₃-N 0.70mg/L,TN 5.15mg/L,TP 0.15mg/L and SS 4.3mg/L,all of which were less than the limits specified in the A emission standard and had met the transformation objectives.A total investment of 10.279 million yuan was invested in the renovation project.After the operation,the operating cost increased,adding 0.01yuan/ton of water in the only filtration mode and 0.03 yuan/ton of water in the dephosphorization mode,and 0.49 yuan/ton of water in the denitrification mode,and0.51 yuan/ton of water in the dephosphorization and denitrification filtration mode.Compared with condition before transformation,the operation of the facility reduced the risk of exceeding the standard of the effluent water quality.Because the facilities were put into operation,the effluent quality was stable and the sewage treatment plant efficiently treated the sewage.It reduces the emission of pollutants to the environment and reflects good social effects.