Dynamic modelling of a single-stage high-rate anaerobic reactor—I. Model derivation

Abstract

A mathematical model of a high-rate anaerobic treatment system was developed by defining the biological make-up of the anaerobic ecosystem, the physico-chemical system, and the reactor process. The biological model was extended from current theory to include the accumulation of lactic acid under specific process conditions. Product inhibition and pH inhibition of each group of bacteria were represented in the model so as to utilize all the available information about the anaerobic process. A rigorous approach was applied to the development of the physico-chemical model which was used in the determination of the reactor pH and ionic species concentrations. The overall reactor equations were based on continuous well-mixed processes, with no effective solids residence time parameter introduced to account for bacterial retention in the process. Parameters were taken from models developed by previous researchers, and from mixed and pure culture studies of the anaerobic bacteria.