MEMBRANE PARTITION AND MASS-TRANSFER IN ULTRAFILTRATION

Through ultrafiltration experiments with a macromolecular solution of dextran and a suspension of bentonite, it is shown how the understanding of mass transfer phenomena involved in ultrafiltration can be improved if several limiting mechanisms working simultaneously over different parts of a same membrane are taken into account This partition is determined according to the operating conditions as well as the characteristics of the treated fluid. This approach is convenient to describe an entire range of experimental variations in solvent and solute transfer through hollow fiber membranes induced either by macromolecular concentration polarization or by particles fouling. It is shown that reversible fouling can have effects as dramatic as irreversible fouling (pore plugging) in some circumstances. © 1990, Taylor & Francis Group, LLC. All rights reserved.