Study On The Characters Of Treating Urban Sewage To Remove Pollutants With MBBR Process

At present, a large number of small and medium-sized urban wastewater treatment plants are being constructed in China. Moving Bed Biofilm Reactor process(MBBR), which is characteristic of low-cast, high efficiency, simple operation and management, has a broad prospect in application. However, both domestic and foreign scholars focus their research of Moving Biofilm Bed Reactor (MBBR) on the aerobic process and pay little attention to the anaerobic process. This research studies on urban domestic sewage in South tropical and subtropical with MBBR. The studies are carried out to study the effects of hydraulic retention time, pH, filling rate of suspended carrier and impact load on the treatment results of the reactor both under aerobic and anaerobic conditions. It also explores the reation kinetics of treating domestic sewage with MBBR.During the experimentation of biofilm culturing load, the activated sludge from the wastewater treatment plant and the rapid biofilm culturing load are used to shorten the time required. Using the rapid biofilm culturing load doesn't need too much activated sludge. Beside, it doesn't need circulating pool and recycle pump. This method of biofilm culturing load can not only been used under the conditions of aerobic, but also the conditions of hypoxia and anaerobic.The results show that the aerobic MBBR had good effect on reducing the organic matter and nitrogen. When HRT is 6h, the COD_Cr concentration of influent is 300mg/L, the filling rate of suspended carrier is 30%, the NH₃-N concentration of influent is 15mg/L, the pH is around 7, the removal efficiency of COD_Cr can reach 84%, the removal efficiency of NH₃-Nis 78.7% and the removal efficiency of TN-N is 50%. The anaerobic MBBR had less effect on reducing the organic matter and nitrogen, the removal efficiency of COD_Cr can reach 55.7%, the removal efficiency of NH₃-N is 44.5% and the removal efficiency of TN-N is 35.6% when HRT is 12h, the COD_Cr concentration of influent is 300mg/L, the filling rate of suspended carrier is 30%, the NH₃-N concentration of influent is 15mg/L, the pH is around 7.At last, based on the formulary on the specific substrate degradation efficiency and the substrate concentration brought by Monod and the formulary on the net microbial growth efficiency and substrate utilization rate brought by Heukelekian, etc., a study of the reation kinetics of COD_Cr and NH₃-N removel in the domestic sewage with MBBR is discussed.