Microalgae cells are small (typically in the range of Ф2-70 pm) and the cell densities in culture broth are low (usually in the range of 0.3-5 gL-1). Harvesting microalgae from the culture broth and dewatering them are en­ergy intensive and therefore a major obstacle to commercial scale produc­tion and processing of microalgae. Many harvesting technologies, such as centrifugation, flocculation, filtration, gravity sedimentation, floatation, and electrophoresis techniques have been tested [45]. The choice of har­vesting technique depends on, in part, the characteristics of microalgae (such as their size and density) and the target products.