State and parameter estimation of an anaerobic digester model

Wastewater treatment is a current technological and scientific challenge due to the requirements of the high variety of wastewater coming from industries and municipal residuals. In particular, anaerobic digestion process is a useful approach for treatment of wastewater with high load of organic matter. The need of implementing treatment plants for anaerobic digestion has open many research opportunities about modeling and control of this complex biochemical process. In particular, this contribution deals with the lack of variable´s information from available sensors. We propose a state and parameter estimation of a nonlinear dynamical model of anaerobic digestion; specifically, the proposed approach is able to estimate the states: acidogenic and methanogenic bacteria concentrations, as well as the parameters: maximum bacterial growth rates for acidogenesis and methanization, and the hydrodynamic regimen. The estimation approach is based on adaptive observers, and it provides a reliable tool towards the control of anaerobic digesters.