Design Scheme And Aeration Control Optimization Of Municipal Wastewater Treatment Process

In recent years,the issue of environmental protection has been paid more and more attention.Sewage is one of the important factors causing environmental pollution.Therefore,it is imperative to develop sewage treatment.Today,there are more and more sewage treatment plants,but most of their automation are in low level,resulting in a lot of waste of manpower and material resources.Water quality is not stable.To enhance its automation level is imminent.In this paper,the research is on a project for Dabancheng Sewage Treatment Plant.A distributed control system with supervisory control level,control level,field level and management level is designed for the scene.Control method selecte IPC+PLC,which use Siemens S7-400 PLC,based on the factory process,realized the control program with STEP 7 development;IPC configuration software took Kingview software,By analyzing its advantages and disadvantages and combining with the actual situation,the communication method selects "PROFIBUS field bus + industrial Ethernet".After running the system,the effluent quality has reached th e national standard.The aeration control of the oxidation ditch is one of the difficulties in the control system,mainly because the aeration process is a large lag and nonlinear process.Therefore,the aeration control is optimized.First,the control parameters of the aeration system was selected.The dissolved oxygen concentration(DO)was selected as the control parameters.Then designed the simplified mathematical model of the aeration process based on DO,and compared the modeling on SIMULINK,addingPID,fuzzy PID and Smith-fuzzy PID three control programs respectively.The simulation results of the three programs are compared.The control effect of the Smith-fuzzy PID fuzzy scheme is the best.And the optimization of the aeration system is realized.The software design of the control system is also divided into the upper computer and the lower computer,the lower computer through the software design to achieve the control requirements of sewage treatment plants,especially the aeration control part,the use of-fuzzy control strategy,so that the water effect is better,the The host computer through which to monitor and control the sewage treatment process.It includes the sewage pretreatment stage,the three-ditch oxidation ditch biological treatment stage,the sludge treatment stage and the real-time data report,the alarm list and so on.The monitoring and control of the sewage treatment process is realized by using the configuration king.There are many kinds of network and bus used in sewage treatment.The design of the sewage treatment plant achieved the automatic control and monitoring to improve the level of automation of sewage treatment.It is of great practical significance to the similar environmental pollution problem.