Dissolved oxygen control of the activated sludge wastewater treatment process using model predictive control

Activated sludge wastewater treatment processes are difficult to be controlled because of their complex and nonlinear behavior, however, he control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason a new pproach is studied in this paper using simulated case-study approach: model predictive control (MPC) has been applied to control the disolved oxygen concentration in an aerobic reactor of a wastewater treatment plant. The control strategy is investigated and evaluated on wo examples using systematic evaluation criteria: in a simulation benchmark – developed for the evaluation of different control strategies – he oxygen concentration has to be maintained at a given level in an aerobic basin; and a changing oxygen concentration in an alternating ctivated sludge process is controlled using MPC technique. The effect of some MPC tuning parameters (prediction horizon, input weight, ampling time) are also investigated. The results show that MPC can be effectively used for dissolved oxygen control in wastewater treatment lants. 2007 Elsevier Ltd. All rights reserved.