A STRUCTURED MODEL FOR SIMULATION OF CULTURES OF THE CYANOBACTERIUM SPIRULINA-PLATENSIS IN PHOTOBIOREACTORS .1. COUPLING BETWEEN LIGHT TRANSFER AND GROWTH-KINETICS

The study of the interactions between physical limitation by light and biological limitations in photobioreactors leads to very complex partial differential equations. Modeling of light transfer and kinetics and the assessment of radiant energy absorbed in photoreactors require an equation including two parameters for light absorption and scattering in the culture medium. In this article, a simple model based on the simplified, monodimensional equation of Schuster for radiative transfer is discussed. This approach provides a simple way to determine a working illuminated volume in which growth occurs, therefore allowing identification of kinetic parameters. These parameters might then be extended to the analysis of more complex geometries such as cylindrical reactors. Moreover, this model allows the behavior of batch or continuous cultures of cyanobacteria under light and mineral limitations to be predicted.