The Research Of Dissolved Oxygen Mechanism Based On ASM2D

Aerobic activated sludge process is the main use of sewage treatment plant biotechnology,Aeration system occuppies the largest energy consumption when operating,and it is the focus of energy saving in sewage treatment plant.The improvement and rationality of the dissolved oxygen mechanism model is very important for the control of dissolved oxygen and aerobic activated sludge.At present,the model of dissolved oxygen is mainly based on oxygen mass transfer,and we consider little of the water quality and other factors involved in its specific impact.Therefore,this paper addresses this situation,combined with ASM2 D model research basis,establish a SBR process in laboratory.Investigate the relationship between the COD components and DO under different water quality conditions.In order to explore the DO mechanism under the influence of water quality components.This paper mainly studies from the following parts:(1)Based on ASM2 D model,puts forward a new method to control of dissolved oxygen optimally.At present,sewage treatment plants are main use vulgar control and automatic control of the control of dissolved oxygen.Combined with activated sludge mathematical model,puts forward a new method to control of dissolved oxygen optimally.(2)Preliminary study on the characteristics of water quality model.Explores the change rule of water quality and COD components(S_A,S_F,S_I,X_S,X_I)of urban mixed sewage and urban sewage water,and compares the measured values of the COD components with the typical values which reported by the international water association(IWA).Results found that the actual COD compositions range values which measured from sewage treatment plants are different from the typical values reported by IWA.This is mainly due to the regional difference(diet differences and industrial wastewater compositions differences)of sewage treatment plant water.(3)Explores the aeration rates on the influence of dissolved oxygen.By compared the biomass and the removal rates of wate quality(COD?NH4+-N?TP)under different aeration rates(1.0 ?1.5 ?2.0?3.0 L/min),and the stability of different monitoring sites.As the experiment result shows that,the biomass and the removal rates of wate quality are improved with the aeration rates increased,and will be best at 2 L/min.(4)Researched the influence of the simulation wasterwater components(S_A,S_F,S_I,X_S,X_I)on the biomass,removal rate and the DO,analyzes the impact strength of this components on DO.Through the material and oxygen balance under the process of biochemical reaction,establish a mathematical model with the COD components and DO preliminary.And it had been proved to a good correlation through other wasterwater.This model is as follows:On the basis of the ASM2 D model,combined with oxygen?biomass(MLSS)and the COD components on the influence of DO,establish a dynamic model is as follows:The model is verified through additional water quality data,the accuracy and relevance of the model is examined,and points out the shortages of this model and the direction where can be optimized,propose suggestions for future research work.