Robust resonant controllers for wastewater treatment systems

An important issue in analyzing a Wastewater Treatment Plant (WWTP) is modelling the disturbances acting on the control loops of the plant, especially in case of urban WWTPs. Although in the literature periodic variations are systematically adopted for the influent description, the control solutions to reject these disturbances are not taken into consideration. This paper aims to establish a WWTP control solution based on PI + Resonant controller (PI+R), which are suitable for the rejection of the periodical disturbances. The control strategy was validated on a Activated Sludge Model No. 1 (ASM1) based WWTP implemented in SIMBA®.