Harvesting methods of microalgae

The field studies of microalgae have increased in the last ten years due to the wide range of applications related to these aquatic microorganisms in the industry. Microalgae are an important source of oils and other biomolecules that can be used in the production of biofuels and high-valued products such as biodiesel, bioethanol, biogas and bio hydrogen, fish feed, animal feed, human food supplements and cosmetic products. However, the use of microalgae in these green processes is still not economically viable. One of the main costs associated to microalgal production is related to the harvesting process, as it usually accounts for about 20–30% of total cost. Harvesting microalgae basically is a process of removing the microscopic plants from the medium they grow and concentrate them into a paste. Therefore, this study highlighted on three harvesting method applied to microalgae which are bioflocculation, centrifugation and filtration, and identified the most effective method of harvesting by comparing the mean value of dry cell weight (DCW) determined from the separation of microalgal biomass from the culture medium. Among the three method of harvesting, filtration obtained the highest value of DCW which indicated as the most effective method for harvesting microalgae in this research. Even though, the weight of biomass obtained through the both processes of filtration and centrifugation were high, harvesting by filtration was considered as most effective in term of low energy consumption and cost.