ANALYSIS OF REVERSE-OSMOSIS DATA FOR THE SYSTEM POLYETHYLENE GLYCOL WATER CELLULOSE ACETATE MEMBRANE AT LOW OPERATING PRESSURES

Reverse osmosis separations of polyethylene glycol (PEG) solutes PEG-6000, PEG-9000, PEG-15000, and PEG-20000 in aqueous solutions in the concentration range 50 to 5000 ppm of solute have been studied using porous cellulose acetate membranes in the operating pressure range 25 to 100 psig. While the feed solution systems involving PEG-6000, PEG-9000, or PEG-15000 behaved normally, the system involving PEG-20000 showed the characteristics of pre-gel polarization and retarded flow of pre-gel through membrane pores during reverse osmosis. On the basis of analysis of all experimental results, the necessary physicochemical data and practical techniques have been generated for predicting membrane performance (both solute separation and product rate) for reverse osmosis separations of different PEG solutes in aqueous solutions from only a single set of experimental data for a reference feed solution system such as one involving a dilute solution of PEG-6000. © 1979, American Chemical Society. All rights reserved.