Integrating wind-driven agitating blade into a floating photobioreactor to enhance fluid mixing and microalgae growth. (March 2023) - Fu, Jingwei
Graphical abstract: Highlights: An innovative floating PBR with wind-driven agitating blade (WDAB-FPBR) was proposed. The wind and wave energy could both be used for liquid mixing in the WDAB-FPBR. The WDAB module optimized mass transfer efficiency, cell distribution, and light utilization. The electron transport rate and photosynthesis efficiency increased by 38.1% and 140%. An improvement of 88.9% and 133% in algal biomass and lipid yield was achieved. Abstract: Aiming at optimizing the poor fluid mixing state in the traditional horizontal floating photobioreactors and reducing the high energy consumption and operational cost induced by electric-driven mixing, a novel floating photobioreactor with an embedded wind-driven agitating blade (WDAB-FPBR) was proposed in this study, which can effectively utilize both wind and wave energy for fluid mixing. The results show that the selected wind-driven agitating blade contributed to a decrement of 75.3% in mixing time and an increment of 87.5% in mass transfer coefficient, and meanwhile strengthened the fluid velocity along the light gradient. Owing to the enhanced fluid flow and mixing properties, an even distribution of algae cells was achieved in the WDAB floating photobioreactor, which resulted in an improvement of 140% in the photosynthesis efficiency of microalgae. From this, the biomass yield and carbon removal ratio showed an increment of 88.9% and 73.9%, respectively.