Research Of Nitrogen And Phosphorous Strengthen Removal Technology Of Town Sewage By MBBR

Based on the research of urban sewage in nitrogen and phosphorus strengthen removal technology, this paper innovatively selected with the filler which had appropriate Hydraulic characteristics and efficient nitrogen and phosphorus removal by forming biofilm in the moving biofilm bed reacter (MBBR), in-depth studide the factors which affecting the running performance of MBBR, and designed to provide reference and theoretical basis in developing new enhanced nutrient removal technology of MBBR and upgrading of wastewater treatment plant.The filler (YR-1, and BC250) aeration tests found that, filler YR-1 had better streaming performance. while filler BC250 had poor performance which had suspended and accumulated, there was stagnant water areas and stagnant water areas becauses of poor contact. As to the biofilm forming, pollutant removal efficiency and economic investment, filler YR-1 was suitable for biofilm domestication and Otimization of process conditions experiments. By controlling inflow quality and adjusting aeration, nitrifying bacteria enrichment had achieved (doubling time was 9.32h). COD and ammonia removal rates were significantly increased to 88.1% and 66.3% and remained stable on the fiftieth day. Scanning electron microscopy showed that quantity and variety bacteria in biofilm and mature biofilm had obtained.Packing rate (PR) and hydraulic retention time (HRT) dissolved oxygen (DO) and carbon sources affect the efficiency of nitrogen and phosphorus removal in MBBR process. Conditions test results showed:ammonia and TN removal rate was 87.8% and 31.5% when PR=30%,while HRT=6 h,BST=BSS(1164.3 mg/L)+BSM (2885.3 mg/L) COD, ammonia nitrogen and TN removal rate was 96.7%,95.8% and 45.7%. DO=3.0±0.25 mg/L, the reactor system attached to the highest biomass and the lowest concentration of suspended sludge, whith the highest total nitrogen removal efficiency(70.4%). with the C/N and C/P ratio increases, TN and TP removal rates were on the rise, the increase of carbon sources will certainly help with nitrogen and phosphorus removal. Under the conditions of PR=30%, HRT=6 h, DO= 3.0±0.25 mg/L, the Urban Simulation domesticated water treated by MBBR had achieved simultaneous nitrification and denitrification and carbon cutting down, The average COD removal of 92.4%, the average ammonia removal of 85.8%, TN average removal of 70.4%.In dealing with the actual sewage with a pilot MBBR coupling process, the total hydraulic retention time was 16.3 h, dissolved oxygen of MBBR was 1.5-2.5 mg/L, during four-month operation, the purification efficiency showed that the average COD concentration was lower than 81.5 mg/L.The average BOD5 concentration of effluent was lower than 15 mg/L. The average ammonia concentration of effluent was lower than 2 mg/L. the average TN concentration of effluent was lower than 25 mg/L.The average TP concentration of effluent was 1.78 mg/L, which meeted with the Town Sewage Discharge Standard (GB18918-2002).