On the dynamics of biodegradation of wastewater in aerated continuous bioreactors

The paper investigates the static and dynamic behavior of a continuous flow bioreactor for the aerobic biodegradation of municipal and industrial waste. The unstructured kinetic model for the bioreactor accounts for oxygen limitation in the bioreactor model while the growth rate is described by the biomass-dependent Contois model. This kinetic model is known to explain the aerobic biodegradation of solid municipal organic waste well. The yield coefficient is assumed to depend linearly on the substrate. The analysis of the unsteady-state model is carried out both analytically and through numerical simulations. The results show the ability of the model to predict a wide range of behavior, including oscillations for some range of kinetic and operating parameters. The analysis also showed that a variability of the yield coefficient is necessary for the existence of Hopf points in the model. The effects of the model parameters on the performance of the bioreactor are also investigated. © 2011 Elsevier Ltd. All rights reserved.