HYDRAULIC PERMEABILITY, MASS-TRANSFER, AND RETENTION OF PEGS IN CROSS-FLOW ULTRAFILTRATION THROUGH A SYMMETRICAL MICROPOROUS MEMBRANE

The flow and retention of 0.1 % w/w aqueous solutions of several polyethylene glycols with molecular weights ranging from 3,000 to 35,000 dalton are studied when they are tangentially filtered through a nuclear track-etched symmetric microporous membrane made from polycarbonate with transmembrane pressure differences going up to 200 kPa. The work was done within the framework of the film layer theory for the concentration polarization phenomenon which allows one to obtain the mass transfer coefficient for the cell used as a function of the feed circulation speed and the molecular weight of the solute. The retention curves obtained lead to a sieve radius smaller than the nominal one.