Fractional Order Predictive Proportional Integral Control of pH in Effluents of Industrial Plants

A robust and advanced controller for pH monitoring and control is necessary in industrial processes inorder to treat the effluents to protect the flora and fauna in the environment. Advanced controllers such as fractional controllers could be used for effective control with increased accuracy and reliability. This study includes a comparison of conventional controllers with advanced fractional order controllers to improve the performance of pH control in effluents from the industrial plants. A fractional order predictive proportional integral (FOPPI) controller for effective control of pH was designed and simulated. This controller includes the advantages of a smith predictor for dead time compensation and the robustness of a fractional order controller. The presented method shows an improvement in control performance in terms of rise time (32 s), settling time (140 s), lesser oscillations (2%), and lesser integral of the absolute error of 171. FOPPI provides efficient control of pH in all regions of the titration curve and can be used for the control of pH in industrial waste water.