Purification of hydrogen peroxide solution

Claim 1

A process for purifying a hydrogen peroxide solution which comprises treating a 10 to 60% by weight hydrogen peroxide solution having a pH between 1.5 and 5.0 and containing anionic impurities with a hydrogencarbonate form or carbonate form anion exchange resin to remove the anionic impurities while adding an acid or a salt thereof having an acid dissociation constant pKa in water of not more than 5 to the hydrogen peroxide solution to be treated continuously or semi-continuously in an amount of from 0.1 to 5.0 milliequivalents per liter of hydrogen peroxide solution; wherein said acid or salt thereof is at least one compound selected from the group consisting of hydrochloric acid, chlorous acid, hydrofluoric acid, nitric acid, sulfuric acid, phosphinic acid, phosphonic acid, phosphoric acid, diphosphoric acid, tripolyphosphoric acid, formic acid, acetic acid, chloroacetic acid, cyanoacetic acid, dichloroacetic acid, trichloroacetic acid, fluoroacetic acid, bromoacetic acid, iodoacetic acid, lactic acid, 2-chloropropionic acid, citric acid, tartaric acid, aminobenzoic acid, clorobenzoic acid, dichlorobenzoic acid, nitrobenzoic acid, dinitrobenzoic acid, salicylic acid, p-hydroxybenzoic acid, o-fluorobenzoic acid, difluorobenzoic acid, o-bromobenzoic acid, o-iodobenzoic acid, phenoxyacetic acid, benzenedicarboxylic acid, aminotris(methylenephosphonic acid), nitrilotri(methylenephosphonic acid), hydroxyethylidenediphosphonic acid, ethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), cyclohexanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, glycol ether diaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, and nitrilotriacetic acid, and salts thereof.