Benyahia, B.Sari, T.Cherki, B.Harmand, J.2013-04-152013-04-152012-07https://dspace.univ-tlemcen.dz/handle/112/1766Journal of Process Control, Volume 22, Issue 6, July 2012, Pages 1008–1019.This paper deals with the equilibria and stability analysis of the two step anaerobic model initially proposed by[12] to describe the dynamical behavior of an anaerobic fixed-bed wastewater treatment process. In a first part, the model is analyzed: its equilibria and their stability are established considering qualitative properties of the kinetics. In a second part, it is shown that the overloading tolerance (denoted herein OT), a parameter proposed in [9] to monitor anaerobic processes on-line, may not be suitable for monitoring the system and even causes serious problems under certain functioning conditions. Based on the analysis results established in the first part, a modified OT is proposed and evaluated in simulation.enAnaerobic digestionBiotechnologySteady state analysisEquilibriumModel approximationRisk analysisArticle