A RISK MANAGEMENT CRITERION FOR AN UNSTABLE WASTEWATER TREATMENT PROCESS

In this paper we consider an unstable biological process used for wastewater treatment. This anaerobic digestion ecosystem can have 2 locally stable steady states and one unstable steady state. We first study the model and characterise the attraction basin associated to the normal operating mode. In a second step we estimate the size of this attraction basin by using a simplified criterion that turns out to be a good approximation. Finally we apply the approach on a real anaerobic digestion plant, and we show that the proposed criterion allows to rapidly detect the conditions of a destabilisation.