AN EVALUATION OF A DYNAMIC-MODEL OF THE SECONDARY CLARIFIER

The main objective of the paper is to support and illustrate recent th eoretical results on the mathematical modelling of the secondary clari fier. A new settler model is compared with a traditional layer model b y means of numerical simulations. Emphasis is put on the numerical sol ution's ability to approximate the analytical solution of the conserva tion law written as a non-linear partial differential equation. The ne w settler model is consistent in this respect. Another important concl usion is that a layer model dividing the settler into only ten layers (normally used in settler models) is too crude an approximation to cap ture the detailed dynamic behaviour of the settler. All simulations pr esented are performed with the settler models coupled to the IAWQ Acti vated Sludge Model No. 1. Copyright (C) 1996 IAWQ.