Y-Type Zeolites for the Catalytic Oxidative Degradation of Organic Azo Dyes in Wastewater

Cobalt- and iron-containing catalysts active in the oxidation of organic dyes with hydrogen peroxide have been prepared from granular synthetic NaY and HY zeolites without a binder by ion exchange followed by heat treatment at 350-500 degrees C. It has been demonstrated by X-ray photoelectron spectroscopy that cobalt and iron in these catalysts are in the form of Co2+ and Fe3+ ions on the support surface. The FeHY and CoNaY catalysts are most effective and stable in the oxidation of the anionic dye carmoisine in weakly acidic and alkaline media.