Filtration separation of Chlorella vulgaris, a species with excellent potential for CO2 capture and lipid production, was studied using a surface-modified hydrophilic polytetrafluoroethylene (PTFE) membrane. Coagulation using chitosan effectively removed turbidity at >100 mg l(-1) chitosan. The membrane filtration flux at 1 bar was increased with chitosan dose. The filtered cake at the end of filtration tests peaked in solid content at 100 mg l(-1) chitosan, reaching 30.5% w/w, about 50% higher than that of the original suspension. Coagulation using 100 mg l(-1) chitosan followed by PTFE membrane filtration at 1 bar is a feasible process to harvest C. vulgaris from the algal froth. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.