Linear control of electrochemical tubular reactor system-Removal of Cr(VI) from wastewaters

An electrochemical tubular reactor system, which is used to remove the hexavalent chromium Cr(VI) from wastewaters, is presented. Under specific modeling and operating constraints, the axial dispersion reactor is described by the coupled nonlinear partial differential equations (PDEs) under Danckwerts boundary conditions. Through the composite finite difference combination, the lumped differential-algebraic equations (DAEs) turn out to be a two-input/two-output system. The overall system stability analysis is investigated via the Lyapunov's first method. According to the prescribed control configuration, the closed-loop simulation shows that a multi-loop PID control scheme can ensure the outlet concentration of Cr(VI) less than 0.5 mg/L in wastewaters.