Stability analysis of the biodegradation of mixed wastes in a continuous bioreactor with cell recycle

The stability characteristics of a continuous bioreactor with cell recycle for biodegradation of mixed wastes are investigated. The system involves a pure culture of Pseudomonas putida and media containing phenol and glucose as carbon and energy sources. The model growth kinetics for the two substit utable substrates were experimentally validated in a previous study. The st ability analysis carried out using elementary principles of bifurcation the ory shows rich dynamics characteristics of the reactor model, including ste ady-state multiplicity and hysteresis. The effect of the bioreactor operati ng parameters on the stability behavior of the model is discussed. Practica l criteria are also derived for the safe operation of the unit and to preve nt the occurrence of wash-out conditions. (C) 2001 Elsevier Science Ltd. Al l rights reserved.