The first biological treatments of air, and in particular odours, were implemented industrially in France in the 1980s. Today, there are some 300 industrial installations, mainly biofilters, but bioscrubbers are also gaining in popularity . These biological air treatment systems are well suited to the treatment of high air flows with low levels of odorous molecules or volatile organic compounds to . Sizing data and operating conditions have been established experimentally on laboratory pilot units and on industrial sites. However, in order to better design, dimension and manage bioprocesses, through a detailed understanding of the processes involved, it is necessary to be able to model and numerically simulate all the phenomena involved. Several approaches are possible, using either stochastic models (correlations of experimental data) or deterministic models (balance, transfer, flow equations, etc.) . Coupling the two approaches provides a better understanding of system complexity. This is achieved by equating physical, chemical and...