Research Of Activated Sludge Wastewater Treatment Process Based On Fuzzy ADRC

With the rapid development of human society,water resources are increasingly scarce and water pollution is becoming more and more serious.Wastewater treatment can make the secondary utilization,and help protect the environment and achieve the rational utilization of water resources.Activated sludge process is the main method of wastewater treatment.It uses the microorganisms in activated sludge to adsorb and degrade the organic matter in sewage,so that the wastewater can meet the emission requirements.However,the activated sludge procee is a large scale nonlinear time varying system for the biochemical reactions are complex.Therefore,the focus of this paper is to realize effective control of activated sludge system.The wastewater treatment process of activated sludge process is first introduced in the paper,and the workings of aeration system is explained.Dissolved oxygen concentration can influence biochemical reactions in the aeration tank,then it has an effect on the water quality.Therefore,the dissolved oxygen concentration is used as the controlled variable by controlling the intake valve of the blower to adjust the air volume in the aeration tank.It can keep the concentration of dissolved oxygen in the appropriate range.Mathematical model of activated sludge system is established in the next step.Benchmark simulation model no.1(BSM1)can reflect the basic principle and dynamic process of activated sludge process,which is mainly composed of the activated sludge model no.1(ASM1)and the secondary sedimentation tank model.ASM1 model is incarnated the biochemical reaction process in the aeration tank,which contains 8 biochemical processes,13 components,5 stoichiometric parameters and 14 kinetic parameters.Matrix form is adopted to express the relationship between the components.The secondary sedimentation tank model uses double exponential settlement equation to describe the sedimentation process after the sewage enters tank.Finally,fuzzy active disturbance rejection control(ADRC)is designed to control the blower inlet valve.In three different kinds of weather conditions,the effectiveness of the proposed fuzzy ADRC is analyzed through the changes of dissolved oxygen concentration and COD concentration.Compared with conventional control fuzzy PID control,the fuzzy ADRC has good control performance and strong robustness.Dissolved oxygen concentration can be controlled within the scope of the small change,it can ensure the quality of water,reduce energy waste,improve production efficiency.