A Novel Ailift Photobioreactor With Flashing Light Effect for Microalgae Cultivation

Microalgae can be used as a food for both human and animals, pharmaceuticals and health product, it also can be used to fix atmospheric CO₂ and produce biofuel. Among the photobioreactors used for microalgae cultivation, the airlift photobioreactors were widely reported. However, there is still much space to enhance the biomass production in these photobioreactors. It is well known that the flashing light effect (FLE) could have a considerable influence on the efficiency of light utilization and photosynthesis.  In this work, a novel airlift photobioreactor with flashing light effect was developed. When the cells move in the airlift photobioreactor, they will pass through light region and dark region alternatively, so the FLE of microalgae is produced. The effect of light intensity, light fraction and the gas rate on biomass production of Scenedesmus were investigated. The results showed that the biomass production of Scenedesmus increased with an increase of the light intensity. And the higher the light intensity, the lower of the light fraction is needed to get a great enhancement of the biomass production. With increasing the gas rate, the biomass production of Scenedesmus firstly increased and then decreased.