Study On The Seasonal Operation Plan Of A Reversed A~2O WWTP Based On WEST

This paper focuses on the quarterly operation plans of a Chongqing WWTP based on the WEST software,and three models of winter,spring and summer have been constructed based on the ASM2 D model.In order to find the reasonable levels of the key factors which affect the effluent,the single factor analysis method is adopted.Then,to obtain the optimal methods,the response surface method is adopted.Finally,According to the optimal methods,the proposals of the operation can be offered.(1)The different quarterly models for the Chongqing WWTP are constructed based on the WEST software.Firstly,to study the effects of stoichiometric parameters and kinetic parameters on the effluent results,the global sensitivity analysis method has been adopted.Then,the author use the method of parameter estimation to find the optimized parameters,and inputs the adjusted parameters into each model,to obtain the optimized model.And the author find that the model can be used for subsequent simulation studies.In addition,a model of a Kunming WWTP is established,and compared with a Chongqing WWTP,the results show that WEST software could be used to build a sewage treatment plant for A2 O process.(2)The levels of factors in different quarters are as follows by single factor simulation experiments:1)For winter : DO(1.5mg/L、1.75mg/L、2mg/L)、sludge recycle ratio(85%、90%、95%)、The mixed liquor reflux ratio(20%、50%、80%)、amount of the emission sludge(1900 m3/d、1950 m3/d、2000 m3/d);2)For spring: DO(1.5mg/L、2mg/L、2.5mg/L)、sludge recycle ratio(70%、80%、90%)、The mixed liquor reflux ratio(20%、50%、80%)、amount of the emission sludge(2050 m3/d、2100m3/d、2150 m3/d);3)For summer: DO(1.5mg/L、1.75mg/L、2mg/L)、sludge recycle ratio(80%、85%、90%)、amount of the emission sludge(2050 m3/d、2100m3/d、2150 m3/d).(3)By using the response surface method,the quarterly optimization plans are obtained.The optimization plan for winter: DO=1.5mg/L、sludge recycle ratio =0.86、The mixed liquor reflux ratio =0.59、The amount of the emission sludge =1998.29m3/d.The optimization plan for spring: DO=1.5mg/L、sludge recycle ratio =0.70、The mixed liquor reflux ratio =0.69、The amount of the emission sludge =2050.01m3/d.The optimization plan for summer: DO=1.87mg/L、sludge recycle ratio =0.80、The mixed liquor reflux ratio =0、The amount of the emission sludge =2149.36m3/d.(4)In order to make the effluent reaching Grade A,Two optimization methods,which are carbon source dosing and chemical phosphorus removal,have been taken.1)Denitrification: to cast the carbon source into the anoxic tank;The autor choose the landfill leachate to be carbon source,and acetic acid will be used if necessary.2)Chemical phosphorus removal: add the phosphorus removal agent to the aerobic tank,and FeCl3 is the main phosphorus removal agent,and PAM is the Coagulant.