| dc.description.abstract | The modified A2O activated sludge treatment system removes carbon, nitrogen and phosphorus from water by microbial action to meet the flow standard. Generally, the A2O wastewater treatment system is a semi-open system, and changes in the external environment will affect the water quality characteristics of the sewage, thereby affecting the treatment efficiency. Failure to properly control the water quality in a timely manner may result in deterioration of the outflow water quality. This study uses the concept of system dynamics to analyze the reaction mechanism between various substances and microorganisms in the system, and based on this, develops and establishes the dynamic mode of the aerobic tank and membrane filter system of the modified A2O system. At the same time, the rate of microbial reaction in the model is estimated by using artificial neural network. Compare the simulation results with the actual outflow water quality data, the relative error between the simulation results of MLSS, ammonia nitrogen, nitrate nitrogen and orthophosphate is 3.57%~196.65%, and the absolute error is less than 8.1919mg/L, which is an allowable error range. This result indicates that the model can effectively estimate the concentration of the substance. The absolute error of the simulated concentration and actual concentration of SCOD is 24.07 mg/L, and the simulation results are not as good as other water quality project estimation results, which may be caused by the gradual accumulation of errors in the SCOD estimation results in a single tank. When the data of the second experiment is used for simulation, the error between the simulation result and the actual data increases. Comparing the two experimental data, although the influent water quality has changed, it is oscillated around the first batch of experimental data. Therefore, the judgment caused the error because the system phase changes. | en_US |