Optimal control of physical backwash strategy - towards the enhancement of membrane filtration process performance

In this work, we show how optimal control theory can be used to optimize membrane filtration processes. The objective is to determine the optimal switching between filtration and backwash sequences in order to maximize the net water production per membrane area of microfiltration or ultrafiltration systems over a given period of time. The optimal solutions, whether the backwash flux is constant or variable, have been derived for a membrane filtration process operating at constant transmembrane pressure using a class of filtration models defined only by their qualitative behaviors. The optimal solution is applied in a simulation case study by considering a specific model validated on data recovered from the literature. The robustness of the approach has been evaluated for different disturbances.