RECYCLABLE REGENERANT FOR WEAK ACID ION EXCHANGE RESINS

摘要

A composition for regenerating spent weak cation exchange resin and a method of utilization including salts of alpha -hydroxy carboxylic acids or o-hydroxy benzoic acids. The following steps are employed in cyclically regenerating polycarboxylic acid cation exchange resins: (a) utilizing a charged or alkali metal salt of polycarboxylate acid cation resin to soften water; (b) regenerating the spent resin in one step with an active regenerant of the alpha -hydroxy carboxylic acids or o-hydroxy benzoic acids to produce spent regenerant; (c) precipitating the polyvalent hard ions in the spent regenerant with sodium or potassium carbonate to reform the active regenerant; (d) separating the precipitate; and (e) concentrating the dilute active regenerate solution to its approximate initial concentration and recovering of water for process rinses.