Biodegradation of substitutable substrates in a continuous bioreactor with cell recycle: A study of static bifurcation

The static bifurcation of an unstructured model of a continuous bioreactor with cell recycle involving the biodegradation of mixed wastes is analyzed using the singularity theory. The biodegradation of the dissimilar substrates follows Andrew's inhibitory kinetic models. It is shown that the steady state locus of the model can be described by a polynomial of seven order. The stability analysis shows that the model exhibits a number of singularities, including hysteresis and pitchfork that occurs at clean feed conditions. It is also shown that the model cannot predict isola, mushroom, or winged cusp singularities. The effect of the model kinetic and operating parameters on its stability characteristics are also discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.