Fate of inert cod fractions in two‐stage biological treatment of a strong wastewater

Abstract

Abstract In this study, the effluent of an alcohol distillery after passing through a chemical treatment is characterized in terms of its inert COD Suctions and the changes likely to be induced by two‐stage biological treatment on the magnitude of these fractions are observed. The experimentally obtained results indicated that the anaerobic treatment gives lower soluble inert COD fractions than a corresponding aerobic treatment for the investigated wastewater. Therefore, the preference of anaerobic treatment instead of an aerobic one as the first stage is ascertained. The anaerobic first stage has a COD removal efficiency of 96 %, whereas with a subsequent aerobic treatment 79 % removal can be achieved on the basis of the stoichiometry of the inert COD. The anaerobic full‐scale plant performance of 80 % can be improved up to 96 %.