Diagnosis And Rehabilitation Of Treatment Of Treatment Of Dominized Wastewater By Double - Flowed Biological Membrane

With the rapid advance of urbanization in recent years, the surface water pollution is becoming more serious. At present, the ammonia nitrogen(NH3-N) has become the leading indicator of affecting the quality of surface water environment. Our country make ammonia nitrogen into the “Twelfth Five-year” obligatory target for energy saving. Governments at all levels pay more attention about rural environmental protection. A lot of rural towns built sewage treatment facilities with different process. But the wastewater treatment process in towns were almost based on the process of cities. There were some problems, including mismatching process, high failure rate of equipment and the low level stability and quality of effluent. In this paper, a town sewage treatment plant with baffle submerged biofilm process as the research object in Chongqing banan district. The sewage treatment as an object was diagnosed and then tracked and monitored the situation of operation condition which investigated the effect of the upgrade and transform.The water quantity and quality of influent rule were detected and observed in long time before diagnosis. Then the baffled submerged biofilm process was inspected by monitoring the conventional water quality of every processing unit associated with date analysis method. At the diagnostic process, observed the baffled submerged removal effect for pollutants and find that the treatment system average removal rate only reach 49.9%, 46% and 68.4% for NH3-N, COD and total phosphorus(TP).Explored the high efficient nitrobacteria and temperature influence to wastewater treatment plant between observed the removal effect of system at the diagnostic process. The result showed that the wastewater treatment system’s removal efficient for NH3-N improved 43.15% by adding the high efficient nitrobacteria. Temperature also have the important influence to the system’s removal effect. This research object’s main part are underground and the lowest water temperature was 15.5℃. The system’s removal efficient for NH3-N reduced 14.4% at hypothermia.The diagnose result showed that there were some problems of the WWTP, including inadequate denitrification by virtue of lacking of refluxing mixture in the anoxic tank, short circuit situation from the anoxic tank to the aeration tank, some vulnerability of the baffle leading to inadequate hydraulic retention time(HRT), the low dissolved oxygen(DO) of the aeration tanks, the low C/N of influent and some process defaults which made NH3-N emission not meet the standard(on average of 15.99mg/L). Based on these problems, though add aerator device in the too long anaerobic zone and led refluxing mixture in the anoxic tank to the primary settling tank that mixing with influent which reconstructed into A/O Biofilm process. Through the upgrade the average value of NH3-N decreased to 7.31mg/L. The average emission concentration of NH3-N reduced by 54.3%, and the average removal rate of NH3-N increased by 23.7%.At last this paper compare the pollutants removal efficiency between the baffle submerged biofilm process and A/O Biofilm process. In low C/N rural domestic sewage, the long anaerobic consume more organics which influence the system’s nitrogen removal effect. Use A/O biofilm process and supplemented chemical phosphorus removal equipment which have nitrogen and phosphorus removal effect achieve the require of denitrification and organics is the best choose.