ADVANCED DYNAMICAL RISK ANALYSIS FOR MONITORING ANAEROBIC DIGESTION PROCESS

In this paper we study an unstable biological process used for waste water treatment. This ecosystem can have two locally stable equilibria and an unstable one. We first introduce the model and recall its main properties. We then study the phase plane and split it into fifteen zones according to the sign of the derivatives of the state vector. Then we propose a methodology to monitor in real-time the trajectory of the system across these zones and determine its position in the plane. We finally define a dynamical risk index based on the transitions from one zone to another and classify the zones according to their dangerousness. It is worth noting that the proposed approach do not rely on the value of the parameters and is thus very robust.