On-line parameter and state estimation in membrane bioreactor systems

Membrane bioreactor (MBR) systems need to be controlled in order to extend the period of effective performance. The local critical flux (LCF) concept is a good starting point for a modelbased control strategy. Use of a novel linearly reparametrized recursive parameter estimation technique illustrated that, instead of a constant, the transmembrane pressure parameter is timevarying and obeying a hyperbolic relationship with respect to time. The hyperbolic relationship, which allows a physical interpretation, was substituted in the original LCF model. The modified LCF model was subsequently used in a linearly reparametrized recursive state estimator for the estimation of mass of deposited solutes and the number of open pores.