SELECTIVE EXTRACTION USING PREFERENTIAL TRANSPORT THROUGH ADSORPTIVE MEMBRANES

Selective extraction of a protein from a mixture can be accomplished u sing an adsorptive membrane and low displacement recuperative parametr ic pumping. Low displacement recuperative parametric pumping can lead to the preferential transport of an adsorbing solute and the rejection of nonadsorbing solutes by the adsorptive membrane. Using a protein m ixture consisting of lysozyme and myoglobin, we have found the conditi ons under which lysozyme is preferentially transported through an ion- exchange membrane cartridge while myoglobin is rejected by the membran e. Trends observed when parameters such as the desorbent concentration , feed concentration, and flow rate are varied agree with the predicti ons of a mathematical model. Comparison with facilitated diffusion sho ws that preferential transport can lead to higher solute fluxes, albei t at lower selectivity. Additionally, preferential transport can be us ed to transport a solute up a concentration gradient and to selectivel y extract a solute from a feed that contains suspended solids. (C) 199 6 John Wiley & Sons, Inc.