A fundamental analysis of continuous flow bioreactor and membrane reactor models with death and maintenance included

• Published in: Asia-Pacific journal of chemical engineering 2008-01, Vol.3 (1), p.70-80
• Main Authors: Nelson, Mark Ian, Kerr, Tara Bridget, Chen, Xiao Dong
• Format: Article
• Language: English
• Subjects: activated sludge; modelling; recycling; stirred tank; wastewater; water treatment
• ISSN: 1932-2135; 1932-2143
• DOI: 10.1002/apj.106

In this research we analyse the steady‐state operation of a continuous flow bioreactor, with or without recycle, and an idealised, or non‐idealised, continuous flow membrane reactor. The reaction is assumed to be governed by the well‐known Monod growth kinetics. We show that a flow reactor with idealised recycle has the same performance as an idealised membrane reactor and that the performance of a non‐idealised membrane reactor is identical to an appropriately defined continuous flow bioreactor with non‐idealised recycle. The performance of all three reactor types can therefore be obtained by analysing a flow reactor with recycle. The steady‐states of the recycle model are found and their stability determined as a function of the residence time. The performance of the reactor at large residence times is obtained. In the limit, as the residence time becomes very large, all three reactor configurations have identical performances. Thus the main advantage of using a membrane reactor, or a flow reactor with recycle, for the treatment of industrial wastewaters and slurries is to improve the performance at low residence times. This is quantified for the case of an ideal membrane reactor. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.