Harvesting effectiveness of Chlorella sp. biomass using different flocculation treatments of Moringa oleifera extract and pH conditions

Abstract

Chlorella sp. is microalgae species that is commonly found in seawater. Chlorella biomass have been produced worldwide and considered as sources for commercial high value bioproducts and biofuels for the last few decades. However, its microscopic size and negatively charged cell surface causes the difficulties of harvesting process or separation of its biomass from the culture medium. The common techniques for harvesting microalgae biomass are centrifugation, filtration, and flocculation. The determination of efficient harvesting methods was the background of this study to lower the cost of harvesting. In this study, the flocculation harvesting method was used by applying several flocculant doses of moringa seeds extract (Moringa oleifera) and adjusted pH. Moringa seed was used as a flocculant to reduce the use of synthetic flocculant materials, especially metals, in order to achieve an environmentally friendly, more efficient, and safe biomass harvesting method for uses as aquaculture feed. The results showed that the moringa seeds are considered efficient for use as flocculants of Chlorella biomass. This flocculant achieved the optimum performance in the treatment of pH 11 with a dose of 0.15 grams moringa seeds flocculant in 1 Liter of Chlorella sp. culture.