Research Of Modeling And Control Technology To SBR Wastewater Treatment Process

With economic development and accelerated urbanization,the pollution of water resources are becoming increasingly serious. To increase the water resources protection, a large number of sewage treatment plants under construction. Activated sludge process is a kind of effective method, which consumes the substrates and phosphate release and denitrification in wastewater by microorganism's metabolism. In the new sewage treatment plant, it also has been widely used. However, due to the sewage treatment process with the characteristics of nonlinear, multivariable, and large time delay, it is difficult to establish a precisely model for the sewage treatment process. To a certain extent, it restricts the control level of the sewage treatment process. Therefore, to enhance wastewater treatment process modeling and control algorithm, will be conducive to the rapid development of the water treatment industryIn this paper, from the analytical model of the ASM1 to understand the internal mechanism of the sewage treatment. On the basis of modeling experience in sewage treatment industry, has established two prediction models to predict COD. It was simulated by Matlab software, and analyzed the effects of the number of hidden layer neurons and different hidden layer activation function to the model prediction accuracy. Simulation results show that: both models can better predict the content of the effluent COD, and the relative error of BP network model is less than 3%, while the maximum relative error of the RBF network model achieves 9%, however, the RBF network training time is far less than the BP network.In addition, the dissolved oxygen (DO) is an important parameter of sewage treatment, it's control result determines the water quality. Therefore, the control of the DO is the control focus of the sewage treatment process. But the components of urban sewage is Volatile at different time, so,it is difficult to control the DO very well. as the traditional PID control method does not work very well in sewage treatment process, the author introduces the fuzzy controller based on self- adjustment factor and established a control system for the DO concentration. The ordinary fuzzy control and with self-adjusting factor fuzzy control is simulated by Matlab software.The simulation results show that: with self-modifying factor fuzzy controller can achieve good control requirements. It has better stability, real-time and robustness than ordinary fuzzy control system.