Study On Shortened Simultaneous Nitrification And Denitrifying Phosphorus Removal In SBR

Water eutrophication problem caused by nitrogen and phosphorus discharged excessivlyhas become a environmental issue most concerned by human. It results of the requirementson emission of nitrogen and phosphorus increasing strictly in Sewage disposal standards.Thus, developing energy-efficient wastewater biological nitrogen and phosphorus removalprocess will be a new research focus in the field of water pollution controlling.The test researches the training process, removal efficiency, process of NO2--N aselectron acceptor for denitrifying phosphorus removal and main factors of combiningshortened simultaneous nitrification and denitrification and denitrifying phosphorus removalin sequencing batch reactor (SBR), with treatment object being simulated the urban sewage.It determines the best operating conditions to achieve the process of combining shortenedsimultaneous nitrification and denitrification and denitrifying phosphorus removal. In addition,it is use of denaturing gradient gel electrophoresis (DGGE) technique to explore microbialcommunity structure of combining shortened simultaneous nitrification and denitrificationand denitrifying phosphorus removal system.The results show that it achieves the process of combining shortened simultaneousnitrification and denitrification and denitrifying phosphorus removal by controlling theanaerobic and aeration time, DO concentration and drainage ways. In the stable operationperiod,when the conditions of influent COD is 178.85~253.76mg/L, NH4+-N is25.65~30.1mg/L,TN is 26.81~32.37 mg/L,TP is 5.62~7.18 mg/L, the best controlling rangeof factors in combining shortened simultaneous nitrification and denitrification anddenitrifying phosphorus removal are : DO about 0.5~1.0mg/L, sludge age about 9 ~ 13d,temperature about 17~25℃. In the parameters of this process, the average effluentconcentration of COD,NH4+-N,TN and TP are 17mg/L,0.9mg/L,3 mg/L and 0.6 mg/L, theaverage removal rates are 92%,96%,89% and 90%. While denitrifying phosphorus removalbacreria uses NO2--N as electron acceptor for denitrifying phosphorus removal, it putsNO2--N into N2. Thus it achieves shortened simultaneous nitrification and denitrifyingphosphorus removal successfully and the effect of nitrogen and phosphorus removalefficiently. Using molecular biology techniques in microbial community structure, the testshowed that it can extract completed DNA of activated sludge by traditional SDS and enzyme from the system. In order to identify and analyze the microbiological species in sewagetreatment, it has PCR extension PCR and denaturing gradient gel electrophoresis. Thus, it canoptimize operated conditions and improve the efficiency of sewage treatment.