Predictive control of an intermittently aerated activated sludge process

This paper presents model-based optimal control and predictive control of a biological wastewater treatment process with intermittent aeration. The objective of the control is to design an aeration strategy which minimizes the energy consumption induced by the aeration system, with adherence to the EU effluent standards and the operating constraints. The developed optimization problem is used with a receding horizon in nonlinear MPC based on the complete ASM3 model. The MPC aeration profile guarantees that the plant fulfills the effluent requirements at any time over long time periods. Significant energy saving is also obtained when comparing MPC to three traditional rule-based control strategies.