Ammonia control of a wastewater treatment process using model predictive control

Activated sludge wastewater treatment processes are difficult to be controlled because of their complex and nonlinear behaviour. However, the control of the ammonia concentration is very important to achieve the effluent standard. In this paper, the ammonia model is developed which could be used for model predictive control (MPC) of ammonia concentration to a certain value in a wastewater treatment plant. The control strategy is investigated and evaluated based on the simulation benchmark-the ammonia concentration is controlled to maintain at different set-point ammonia concentration in an activated sludge process using MPC. The effect of parameters such as the predictive horizon, the control horizon, the weights of input and the sample time are also investigated. The simulation results show that MPC can be effectively used for ammonia control in wastewater treatment plants.