Steady‐State Analysis for Biological Treatment of Inhibitory Substrates

Abstract

A steady‐state approach for designing biological wastewater treatment systems is developed for inhibitory substrates using the Haldane rate expression. Steady‐state solutions are derived for a continuous‐flow completely mixed reactor with recycle of the biomass. It is determined that two steady‐state operating regions exist at any one mean cell residence time; an unstable region, where the substrate concentration increases and the biomass concentration decreases as the mean cell residence time increases, and a stable region, where the substrate concentration decreases and the biomass concentration increases with mean cell residence time. A critical mean cell residence time,