Patent ID: 6054109
Filing Date: 2000-04-25
Classification: B01D,B01J,C01B

Abstract:
A method of purifying an aqueous solution of hydrogen peroxide for washing solutions used in the electronic industries by using an ion exchange resin and an adsorbent to obtain a highly pure aqueous solution of hydrogen peroxide with a metal concentration of not more than 0.1 ppb and a total organic carbon concentration of not more than 10 ppm, which comprises, in the order of purificatory passage of the solution:(A) a step of removing dissociable impurities by means of a mixed bed ion exchange resin,(B) a step of removing undissociable impurities by means of a hydrophilic porous adsorbent having a specific surface of not less than 1,000 m.sup.2 /g, and(C) a step of removing dissociable impurities by means of a mixed bed ion exchange resin.