Analysis of Some Properties of an Activated Sludge Wastewater Treatment Model

Abstract

The aim of the paper is to study some properties of a model describing the wastewater treatment process with activated sludge. The process configuration consists of an aeration tank and of a secondary settler. The mathematical model is described by three nonlinear ordinary differential equations. The paper presents important results on existence and uniqueness of positive model solutions. Numerical computations establish the stability properties of the equilibrium points with respect to two important control model parameters and present the corresponding input-output static characteristics. The dynamic behaviour of the model solutions is illustrated through computer experiments carried out in the computer algebra system Maple. The results can be useful in designing real control strategies of the wastewater treatment processes with activated sludge.