Simple control equations using F:M ratio for operation of activated sludge aeration basins

Abstract

A simple control equation is developed for the operation of activated-sludge aeration basins. The equation takes into account the following parameters: the chemical oxygen demand and rate of flow of the feed; the concentration and rate of flow of the recycled sludge; the volume of the aeration basin and of the thickened sludge in the clarifier; the desired F:M ratio; the proportion of feed COD converted into biomass for disposal and the ratio of COD to solids of that biomass. Two worked examples are given.