Modification of the relative concentration of ions in fluid media

Claim 1

A PROCESS FOR CHANGING THE RATIO OF A PLURALITY OF ANIONS IN AN AQUEOUS MEDIUM WHICH COMPRISES PASSING AN AQUEOUS FEED SOLUTION CONTAINING A PLURALITY OF ANIONS INCLUDING ANION A'' AND ANION A'''' THROUGH A BED OF SYNTHETIC RESINOUS ANION ACTIVE MATERIAL WHICH HAS BEEN SUBSTANTIALLY COMPLETELY SATURATED WITH ANION A BY TREATMENT WITH A COMPOUND OF THE FORMULA CA WHERE C IS THE CATION OF A STRONG BASE AND A IS AN ANION WHICH FORMS WITH HYDROGEN A DISSOCIABLE COMPOUND HAVING A DISSOCIATION CONSTANT NO GREATER THAN 1X10-4, SAID DISSOCIABLE COMPOUND BEING WEAKER THAN THE ACID CORRESPONDING TO ANION A'' WHICH, IN TURN, IS STRONGER THAN THE ACID CORRESPONDING TO ANION A'''', SAID SYNTHETIC RESINOUS ANION ACTIVE MATERIAL ACTING PREFERENTIALLY TO RETAIN A'' ANIONS OF THE AQUEOUS FEED SOLUTION, AND COLLECTING A PORTION OF THE EFFLUENT AFTER A'''' APPEARS THEREIN AND BEFORE THE EFFLUENT CONTAINS THE ORIGINAL PLURALITY OF ANIONS INCLUDING A'' AND A'''' IN SUBSTANTIALLY THE SAME RATIO AS ORIGINALLY IN THE FEED SOLUTION.