"November 1971." Prepared for the Environmental Protection Agency. Includes bibliographical references.

Seventeen different reverse osmosis membranes were evaluated as to their ability to separate heavy metal ions, acids, bases, and cyanides from metal finishing wastewaters. Although no one membrane was found to be effective for all effluents, membranes of 5 different polymers showed considerable promise. Simulated acidic nickel, iron, zinc, and copper plating bath rinses were effectively treated by ultrathin membranes of cellulose acetate, cellulose methyl sulfonate, O-propyl sulfonic acid, or B-glucan acetate diaminoethyl ether. The investigations have demonstrated that ultrathin membrane separation performance can be modified by: Modifying the chemical composition; Optimizing the annealing conditions; Producing as thin a membrane as practical; and Using a polysulfone support film. Preliminary engineering considerations for reverse osmosis applications to treatment and recycle of acidic copper plating bath rinse waters are presented.