Microalgae growth kinetic model based on the PSII quantum yield and its utilization in the operational curves construction

Abstract

In this study, a microalgae growth kinetic model based on its PSII quantum yield was built. It was used to simulate the following operational curves: microalgae concentration – dilution rate (X-D) and volumetric cell productivity – dilution rate (Q-D) in a continuous culture. The model considers 8 parameters particular for the microalgae species and its condition and 2 operational parameters (irradiance and flat plate photo-bioreactor (FPB) light path). The model was tested in a Scenedesmus obliquus continuous culture in FPB at a constant irradiance of 300μmol·m−2s−1 and a dilution rate range of (0.16 to 2.7d−1), with CO2-enriched air at 2%. The microalgae kinetic parameters were determined independently by means of simple methodologies, which were used to simulate the X-D and Qx-D operational curves. A very good correlation with the experimental results was found (correlation coefficient of 0.993 for the X-D curve). The optimal operating point to maximize the experimentally determined cell volumetric productivity was D=0.84d−1, while the model determined a value of D=1d−1.