Mechanism Modeling And Predictive Control For Wastewater Treatment

In order to solve the problem that denitrification process is easy to be influenced by inlet water composition and unsatisfactory conventional control effect in sewage treatment processes,a nonlinear predictive control algorithm based on least square support vector is presented.Effective of this control method was validated by simulation.The main research work and innovation of this paper are as follows:Firstly,on the basis of deep analysis of the technological process of wastewater treatment,the mathematical model of activated sludge and the mathematical model of settler,BSM1 simulation platform were established in SIMULINK.The open loop simulation result in initial value and inlet water data provided by International Water Association is same as dynamic test data by provided by International Water Association.It shows that BSM1 simulation platform is established success,and the next research can be accessed.Secondly,the concentration of nitrate nitrogen in the second pool and the concentration of dissolved oxygen in the fifth pool were used as controlled variable according to mechanism of denitrification process.The closed loop simulation with PI controlling was conducted.According to analysis of the closed loop simulation with PI controlling,the concentration of nitrate nitrogen is easy to influence by inlet water.And the controlling effect of denitrification process is bad.A better control strategy should be presented to control denitrification process in wastewater treatment.At last,the simulation of generalized predictive control was conduct.The simulation result shows that wastewater treatment process can't be controlled stability by generalized predictive control because of strongly nonlinear process of wastewater treatment.After the principle of predictive control is deeply studied in this paper,a nonlinear predictive control algorithm based on least square support vector is presented.In this nonlinear predictive control algorithm,nonlinear model of denitrification process in wastewater treatment was established in leastsquare support vector.The current optimal values to control the denitrification processes were found by drosophila optimization algorithm.