Membrane technology for the continuous separation microalgae/culture medium: compared performances of cross-flow microfiltration and ultra-filtration

Cross-Bow microfiltration and ultrafiltration techniques have become a suit able process for the separation of micro-organisms in a variety of biotechn ical applications. In this paper, eight commercial membranes (IRIS, Orelis, Miribel, France) were evaluated for the harvesting of two marine microalga e: Haslea ostrearia and Skeletonema costatum, both widely cultivated in wes tern France (Region des Pays de Loire). The effects of cross-flow velocity, transmembrane pressure, concentration and the characteristics of suspensio ns are discussed. The ultrafiltration membrane (polyacrylonitrile, 40 kDa) proves to be the most efficient in the peculiar conditions of low pressure and low tangential velocity for a long-term operation. (C) 1999 Elsevier Sc ience B.V. All rights reserved.