Harvesting of Scenedesmus obliquus Cells by Chemical Flocculation: The Effects of Various Flocculants in Bio-recovery of Carotenoids
Hamisu Afiya *
Department of Biological Sciences, Yusuf Maitama Sule University, Kano, Nigeria.
K. M. Umar
Centre for Dryland Agriculture, Bayero University, Kano, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
One of the major challenges in the downstream processing of microalgae is harvesting cells from the culture medium, which account for 20-30% of the production cost. Several harvesting methods and their combinations are available efficiency of which depends on algal sp. and biomass concentration. However, the bio recovery of algal metabolites for quite a number of harvesting methods is rarely reported. In the present study, an experiment was carried out to determine the effects of different flocculants (AlCl2, FeCl3 and ZnSO4, MgSO4) in harvesting Scenedesmus obliquus and its bio recovery of carotenoids. From the result obtained FeCl3 was the best flocculant harvesting up to 99.69% algal cells at the first 30 minutes of reaction time. Similarly, in terms of carotenoid bio-recovery, the highest carotenoids content was recorded in cells harvested with ferric chloride (i.e., 2.81 mg/ml) as compared to other coagulants.
Keywords: Scenedesmus obliquus, chemical flocculation, carotenoids bio recovery