Study On A_mO_n Integrative Process For Domestic Wastewater Treatment

As domestic wastewater is the main component of township sewage,in view ofthis characteristic,the outlet from the primary settling tank in Dong Qu wastewatertreatment plant of Shanghai is selected as the target which is similar to the quality oftownship wastewater．And the wastewater is treated by the integrated A_mO_n processin this paper．This paper is mainly composed of the following three parts:1．The study on continuous aeration integrated A_mO_n process uses the pilotreactor,which is 2．3 meters deep and has the diameter of 1．4 meters．The effect onthe reactor treatment rate is studied by the dissolve oxygen concentration in aerobiczone in the reactor,the perforated pipe sparger operating depth,and reactor HRT．The experiment results shows that:(1)The DO value in the aerobic zone is the key parameter of the processoperation and control,which not only influences kinds of microbe activities,but alsothe valid volume of anaerobic／anoxic zone．The test shows that maintaining the DOvalue in the aerobic zone in the range 0．5～1．0 mg／L is the suitable choice in order toattain better removal rate of nitrogen and phosphorus and maintain the existence ofanaerobic／anoxic zone．(2)Increasing the operating depth of perforated pipe sparger,and it canincrease the volume of aerobic zone correspondingly．Comprehensively consideringthe removal efficient of ammonia,total nitrogen and total phosphorus,the optimaloperating depth of perforated pipe sparger is 1．5 meters．(3)The integrated reactor has good removal efficient of organics,nitrogen andphosphorus when the reaction zone HRT is 8 h．When the HRT of reaction zone isabove 8 h,there is no obvious increace of removal effect on the reactor pollutants．2,The primary test study of intermittent aerobic A_mO_n process uses the A_mO_nreactor which is 1 meters high and has the diameter of 0．4 meters．The effect ofworking condition that is time period with 2 h aeration and 2 h non-aeration on thepollutants removal efficient is studied．The test shows that the ideal removal rate ofnitrogen and phosphorus is not attained．The average removal rate of COD_Cr,NH₃-N,TN and TP are respetively 75．7ï¼…,14．9ï¼…,12．4ï¼…and 39．2％．The further test isnecessary for the optimal working parameters．3,On the base of summarizing predecessors'study results,a new type of jet flow aeration integrated A_mO_n reactor is designed．It has the diameter of 2．6 meters,and6．6 meters high．The CFD technology is used to numerically simulate the flow state inthe reactor．The results show that CFD technology can be used to guide the optimaldesign of reactor．...