A fully predictive model for one‐dimensional light attenuation by Chlamydomonas reinhardtii in a torus photobioreactor

The light attenuation in a photobioreactor is determined using a fully predictive model. The optical properties were first calculated, using a data bank of the literature, from only the knowledge of pigments content, shape, and size distributions of cultivated cells which are a function of the physiology of the current species. The radiative properties of the biological turbid medium were then deduced using the exact Lorenz‐Mie theory. This method is experimentally validated using a large‐size integrating sphere photometer. The radiative properties are then used in a rectangular, one‐dimensional two‐flux model to predict radiant light attenuation in a photobioreactor, considering a quasi‐collimated field of irradiance. Combination of this radiative model with the predictive determination of optical properties is finally validated by in situ measurement of attenuation profiles in a torus photobioreactor cultivating the microalgae Chlamydomonas reinhardtii, after a complete and proper characterization of the incident light flux provided by the experimental set‐up. © 2005 Wiley Periodicals, Inc.