Hybrid adaptive observer design for the Alternating Activated Sludge Process

A hybrid adaptive observer is proposed for a hybrid model of the alternating activated sludge process. Our objective is to reconstruct both the the ammonia concentration state and the parameter of performance of heterotrophic biomass. Numerical simulations are devoted to emphasize the efficiency of the designed estimation scheme in the aerobic (nitrification) and the anoxic (denitrification) phases.