부산대학교 도서관

Microalgae harvesting includes conventional methods like centrifugation, sedimentation, and filtration, as well as advanced methods like flocculation, magnetic nanoparticle, and flotation. Biomass recovery using centrifugation is high but high gravitational force can alter the cell structure. Sedimentation is one of the most useful methods in wastewater microalgae harvesting, though it is applicable to large-cell microalgae (>70 μm). Filtration is a low-cost method and easy to process; however, fouling and clogging can result in low yield. Among several techniques, flocculation is one of the most effective and economical approaches for biomass harvesting. Nanomaterial-based flocculants are considered due to their efficiency and reusability. Nanoparticle-based flocculants have gained attention in recent years due to their unique properties, such as high surface area, small size, and enhanced reactivity. These nanoparticles can be engineered to interact with microalgal cells, causing agglomeration and facilitating the separation of biomass from the culture medium. Studies have demonstrated that using nanoparticle-based flocculants can significantly improve the efficiency of microalgae harvesting compared to traditional flocculation methods. This review emphasizes the mechanism of flocculation, types of flocculation, the dosages of flocculants, and the flocculation recovery efficiencies. The role of green routes in synthesizing nanoparticles for the advancement of flocculation technique is especially highlighted in this article for the sustainable biodiesel production from microalgae. Thorough evaluations, encompassing techno-economic and life cycle assessments, play a crucial role in appraising the economic feasibility and environmental ramifications of biofuels derived from microalgae. This article provides an overview of flocculation methods suitable for microalgal harvesting, their mechanisms, advantages, and drawbacks.