A different approach for steady-state activated sludge modelling

Abstract

The complexity of the Activated Sludge Model no. 1 (ASM1) is one of the main obstacles hindering its use, particularly among wastewater treatment plant (WWTP) professionals. In this paper, a simplification procedure, based on steady-state mass balances, is proposed for the basic activated sludge process (ASP) configuration, consisting of an aerated bioreactor and a settler. Only organic carbon removal and nitrification were investigated. The proposed approach was applied to ASM1. It allowed having simple analytical expressions of the state variables. Expressions were then validated by comparison to simulation results given by the software GPS-X. As a result, they may be useful for different applications such as optimization, control or design.