Design And Realization Of Dissolved Oxygen Control System In Wastewater Treatment

Wastewater is one of the sources that result in environmental pollution. The issue of its treatment has been placed on the agenda of World Environmental Organizations. In our country, the cost of wastewater treatment system comes to be high when the system runs, which restricts the development of wastewater treatment technology. Urban industrial sewage discharges are gradually increased, therefore, wastewater treatment technology with lower energy consumption and good effect turns into current trend. In the wastewater treatment system, the percentage of Dissolved Oxygen (DO) in water is an important parameter, which can reflect the operations of the entire system intuitively and quickly. The control of DO can directly affect the discharge process and energy consumption of the system. At present, PID control is widely used in control system, and dynamic performance of the system mainly relies on reasonable choices of the coefficient of controller. With the process changing, the performance of the system will be worse if the parameters of PID are not adjusted properly. To solve the problem existed in DO control, related literature and research are studied, and this work presents as follows:Firstly, the source and background of the subject is introduced in this paper and significance of the subject is discussed.Secondly, the wastewater treatment technics is introduced in this paper, and the stability and controllability of established mathematical models for aeration process objects are analyzed theoretically. In order to overcome the existing problems such as existing over-oxidation or anoxic situation, a suitable control scheme is presented.Thirdly, the conventional PID algorithm and its characteristics are discussed. Combined with BP network control theory, an adaptive PID controller and an identification implement based on BP network are analyzed. Simulation results are presented, related conclusions are summarized.Fourthly, configuration of monitor management software on PC is finished and the PLC system is designed. Automation control and digital management in wastewater treatment process are realized.