Coupling biological and radiative models to describe microalgal growth in a photobioreactor

International audienceA new dynamical model has been developped to describe microalgal growth in a photobioreactor under light and nitrogen limitations. The strong interactions between irradiance and chlorophyll encouraged us to couple biological and radiative models. We assume that biomass growth is a function of light and nitrogen quota and we relate the chlorophyll content to the nitrogen quota, for a given photoadaptation light. The biomass and chlorophyll contents are used to compute the radiative properties for the medium from which we can deduce an irradiance distribution inside the photobioreactor. The resulting model is used to simulate Isochrysis affinis galbana growth under light/dark cycles and to study the dependence of biomass production on the dilution rate and the influent substrate concentration