Reverse osmosis separation of polar organic compounds in aqueous solution

Abstract

The reverse osmosis separation of polar organic compounds from water was examined. A total of 12 different reverse osmosis membranes were tested with 13 polar low-molecular-weight organic compounds consisting of various functional groups. Experimental data indicated that the separations of these compounds were not as effective as those of inorganic salts for all the membranes tested. The aromatic-polyamide-(AP)- and NS-type membranes gave respectively an overall of 50 and 75% separation of polar organic compounds, whereas the cellulose acetate base showed an overall separation ranging from 13-27%. The separation of a given organic compound with a given membrane depends on the chemical nature of the molecule as well as the characteristics of the membrane. In addition, the separation of compounds having the same functional group increases with the increase in the size and branching of the molecules.