Performance evaluation of the anaerobic fluidised bed system: III. Process kinetics

The anaerobic fluidised bed system for methane recovery from liquid wastes is modelled as a continuous‐flow, completely‐mixed homogeneous microbial system, with the feed COD as the limiting substrate concentration. The average microbial residence time in the reactor is defined in terms of conventional sludge retention time. The experimental data obtained indicate that the Michaelis‐Menten expression is applicable for description of substrate utilisation (i.e. COD removal) in the anaerobic fluidised bed system. The observed biomass yield in the reactor decreases with increasing sludge retention time which is consistent with the prediction of the biokinetic theory developed for suspended‐growth systems. The specific methane production rate observed is a linear function of the specific substrate utilisation rate.