Study On Control Strategy Of Urban Wastewater Treatment Process

With the continuous development of market economy and the improvement of people's living standards,pollution has become an increasingly serious issue.In the meanwhile,water pollution has triggered wide concerns among experts and scholars because human cannot live without water resources.Due to the acceleration of industrial development,the amount of domestic sewage and industrial wastewater has been mounting year by year,making the process of sewage treatment more challenging.In order to further promote the sustainable development of urbanization and economy in China and ease the shortage of water resources,the construction of wastewater treatment project seems valuable.The project makes it possible to use urban water resources sustainably,strengthen urban sewage treatment,as well as eliminate water pollution.Therefore,it is of far-reaching significance to study the control strategy of urban sewage treatment process.First of all,on the base of the analysis of the sewage treatment process,we determined the activated sludge process and main control parameters of the sewage treatment.According to the control requirements of the sewage treatment aeration stage,the controlling scheme of dissolved oxygen concentration and the PH neutralization process were designed.And a mathematical model of dissolved oxygen concentration and PH neutralization process was also established.Secondly,research on the control strategy of dissolved oxygen concentrations in aeration tanks was conducted.As non-linearity,instability and other factors may affect the control of dissolved oxygen concentration,we design a fuzzy self-tuning PID controller and according to actual conditions,we adjust the PID parameters online to achieve optimal control of dissolved oxygen concentration.The simulation experimental results show that the algorithm of fuzzy self-tuning PID parameter control allows we find the index of sewage treatment during the control process of dissolved oxygen concentration.Thirdly,we studied the control strategy of PH neutralization process within the aeration tank.The premise of controlling the dissolved oxygen concentration in aeration tank is that the PH of the aeration tank should be kept within a constant range of 6-8.As randomness,lag and other factors may affect the PH neutralization process,wedesigned expert PID controller to realize the optimal control of the PH neutralization process in the aeration tank.The simulative results show that the expert PID control algorithm is of great validity during the process of PH value neutralization in the aeration tank.Finally,we designed a monitoring system for sewage treatment in the aeration tank.The system adopts DCS system structure,using PLC as the controller and employing Configuration King to design a configuration interface for the aeration monitoring system.Therefore,it is realizable to the monitor the dissolved oxygen concentration and PH neutralization process in the aeration tank during the wastewater treatment in real time.