Internal Model Control for Wastewater pH Neutralization Process

This paper presents the results of testing an advanced control method, Internal Model Control (IMC) on wastewater pH neutralization process. Because the process has a strong nonlinearity it was modeled using different linear models for different operating ranges so that the IMC controller can use the adequate model parameter values according to the current operating range. The results obtained using the multi-model standard IMC algorithm are compared with the ones obtained using the conventional PID (Proportional-Integral-Derivative) algorithm tuned using the same model parameter values used for designing the IMC controller. The simulations showed that using the proposed multi-model standard IMC algorithm is a feasible alternative for controlling this kind of process with a high nonlinear behavior, obtaining good static and dynamic performance.