Growth Kinetic Model for Chlorella Vulgaris Under Limiting Light Conditions

Light is an essential source for the autotrophic growth of microalgae.  However, the distribution of light in the reactor decreases when microalgae grow.  Thus light intensity decreases with the growth as a result of the shading effect.  In this respect, a light distribution model should be coupled with a microalgal growth model.  Previously, a light distribution model in terms of biomass concentration was suggested, but an interactive growth and light distribution model has not been developed.  In this study, the growth of Chlorella vulgaris was investigated under different light intensities (0, 30, 55, 80, 197, 476, and 848 µmol/(m²∙s)) on the surface of the cylindrical reactor and was expressed with a modified Monod model.  Then, a growth kinetic expression for Chlorella vulgaris was combined with the light distribution model.  This model can be used to predict interactive microalgal growth and light intensity for the design and operation of various photobioreactors.