Nonlinear Control of a Wastewater Treatment Process inside a Biological Sequencing Batch Reactor

This paper deals with the problem of on-line estimation and nonlinear control of a wastewater treatment process, which takes place inside a biological Sequencing Batch Reactor. This bioprocess is highly nonlinear, the on-line measurements are lack and the reaction kinetics is not perfectly known. The unknown kinetic parameters are estimated by using nonlinear observers, based on high-gain approach. Also, the unavailable states are reconstructed by using an asymptotic state observer. The control objective is to maintain a low level of pollutant concentration. This goal is achieved by using a linearizing control law combined with the proposed nonlinear observers, which results in an adaptive control law. Simulations are included in order to test the behavior of the proposed estimation and control algorithms.