DEVELOPMENT OF EFFECTIVE SEDIMENTATION OF MICROALGAL CELLS BY MORINGA POWDER

Microalgae find multiple applications as a source of a great variety of biologically active compounds as well as biofuels. The most common methods of microalgae separation from cultivation media are filtration and centrifugation. However, these are not optimal because of small cell size, high gravitational forces and shear stresses applied for separation that can damage the cell structure, and high energy consumption. Flocculation of microalgal cells can be a good alternative to these methods since it avoids the above mentioned disadvantages. Flocculants are used worldwide for water treatment. Aluminum salts flocculate microalgae efficiently, although they are unsuitable for use for microalgal biomass due to their adverse health effects on animals and humans. Moringa seeds, on the other hand, do not pose the same health risks as aluminum salts yet maintain a high flocculation potential. Moringa peregrina seeds, which offer high flocculation potential, low cost and low toxicity, are tested in the present study for flocculating Chlorella, a microalgae with high biodiesel production potential, and Phaeodactylum tricornutum, a microalgae which grows in sea water. The powder of Moringa peregrina and Moringa oleiferaseeds are by-products of the oil extraction process. Previously Moringa oleifera powder had been shown to be effective in flocculation of microalgae. In this study Moringa peregrina powder exhibited flocculating capacity similar to the Moringa oleifera powder in the case of both algae species - Chlorella sp. and Phaeodactylum tricornutum. This study aims to develop an effective and low energy technique for microalgae separation without damaging their structure, thereby reducing the cost of biofuel production and other industrial applications of microalgae.