Simulation Research On ASM2D Model Of Activated Sludge Process Based On SIMULINK Platform

With city rapid development of city,the establishment of city sewage treatment plant is an important part of the city water pollution treatment,city water circulation and water environment construction.The research of sewage treatment technology has become very important.As one of the better way in sewage treatment,activated sludge wastewater treatment process has been widely used with the advantages of high processing efficiency and low operation cost.Nowadays,the improvement of computer technology makes the simulation of sewage treatment dynamic model more closely combined with computer calculation tools,but due to the late start of research,the study of sewage treatment model in China still needs a large number of related experiments and research?This paper starts with the mechanism of activated sludge process,introduces the steps of biological activated sludge in biological nitrogen and phosphorus removal,and the related information of oxidation ditch of sewage treatment plant structure?In the introduction of activated sludge process,a detailed introduction is given from the early traditional activated sludge sewage treatment model to the present activated sludge dynamic model.After understanding the dynamic model of activated sludge,ASMs model was selected according to the characteristics of activated sludge model.In the subsequent comparison,the ASM1,ASM2,ASM2 D and ASM3 models were analyzed and compared,and the ASM2 d model was selected as the model of activated sludge for simulation.After a series of model simplification of the model,the original data of the wastewater treatment plant is input into the model to obtain the relevant water discharge data.After comparing the actual data,test and verify the fit of the model to the actual wastewater treatment description process.The simulated data obtained by the ASM2 D model are calculated by the processed field wastewater treatment data.Through the relative error analysis of the data,the mean TN errors in March,June,September and December were 8.39%,1.02%,10.22% and – 3.37% in terms of the average error of the simulated data.The average TP errors were 3.45%,-8.74%,-3.47%,-4.65%,respectively.From the average error,it basically meets the requirements of the model.However,from the daily error analysis,TN in March and December the average and daily simulation data gap between the larger and larger TP deviation in December.From the simulation of the overall results of the analysis,TP simulation results better than TN simulation results.In the ASM2 d model setting,multiple settings are made for the wastewater treatment plant.There are many factors that affect the stability of the model and the reliability of the results.In this model,the setting of stoichiometric number is mainly based on the temperature,but for the analysis of water temperature and ambient temperature,the temperatures in spring and summer are more suitable,and the nitrifying bacteria and phosphorus accumulating bacteria are active at this time,and the sewage treatment result is relatively easy up to standard.In the fall and winter seasons,the activity of microorganisms in the activated sludge decreases as the temperature decreases.At this time,we can realize the water concentration becomes higher from the sewage plant inlet data.From four months of water temperature analysis,the temperature difference is nearly 10 degrees,which will lead to the number of stoichiometric factors and the choice of the puzzle.The correlation coefficient of the model selected according to the expert law will cause the data to be fixed and unable to cope with the data fluctuations caused by other factors as well as the data changes.This is the reason for this part of the model data fluctuations and stability changes.In future simulations,consideration may be given to adding hydraulic retention times and chemical inputs to the model's influencing factors,starting from a variety of factors to increase the stability and reliability of the model.At present,the application process of oxidation ditch in municipal wastewater treatment has been continuously improved.This model shows that using SIMULINK as the simulation platform with ASM2 D model and settlement model of secondary sedimentation tank,with the application of significance to predict other conditions water quality of a certain reference value.Future studies should take into account a variety of factors in the adjustment of the relevant parameters,making the sewage treatment model more in line with the operation of sewage through the simulation of wastewater treatment plant effluent effect and water plant operations and cost planning.