TRANSPORT CHARACTERISTICS IN THE REVERSE-OSMOSIS SYSTEM PARA-CHLOROPHENOL-WATER-CELLULOSE ACETATE MEMBRANE

Reverse osmosis separations of p-chlorophenol in the concentration range 26 to 482 ppm in aqueous solutions have been studied using porous cellulose acetate membranes in the operating pressure range 100 to 1500 psig. Solute separations varied in the range 6 to -30% depending on operating pressure, feed concentration, feed flow rate, and average pore size on the membrane surface. The PR/PWP ratio was significantly less than unity in all experiments in spite of the negligible osmotic pressures involved. The above ratio decreased with increase in feed concentration as well as decrease in average pore size on the membrane surface. The results are discussed on the basis of preferential sorption of solute at the membrane-solution interface, and the basic transport equations applicable for the above reverse osmosis system are derived. © 1979, American Chemical Society. All rights reserved.