Method for improving the separating action in the ultrafiltration of aqueous solutions

Abstract

A method for improving the separating action in the ultrafiltration of aqueous solutions containing high-molecular-weight organic compounds including water-soluble anionic and/or non-ionic surface-active compounds consisting essentially of subjecting an aqueous solution containing high-molecular-weight organic compounds including water-soluble anionic and/or non-ionic surface-active compounds to an ultrafiltration through a porous membrane in the presence of olefinically-unsaturated C.sub.16-22 fatty acids or water-soluble salts thereof, in a weight ratio of surface-active compound to fatty acid or salt of from 20:1 to 1:1 and recovering said aqueous solution substantially separated from said high-molecular-weight organic compounds. The retention power for water-soluble tensides can be 0.9 or more with this measure (without the addition, .ltoreq.0.1 to 0.5). Furthermore oil can be removed to a mineral oil content of 20 mg/l, whereas without the addition of the invention, values of more than 100 mg/l in the permeate are obtained.

Dependencies are inferred from the claim text.