Effect of activated carbon surface chemistry on the activity of ZVI/AC catalysts for Fenton-like oxidation of phenol

Abstract

Activated carbons with different amounts of surface oxygenated groups were used as adsorbents or supports for zero-valent iron (ZVI) catalyst and tested in phenol adsorption and catalytic wet peroxide oxidation, respectively. The results revealed that the surface chemistry of the support plays an important role in phenol adsorption and in the catalytic performance of the respective iron-supported catalysts. ZVI is active when the support has only a limited amount of oxygenated groups on the surface. The presence of acidic oxygenated surface groups is not favorable for the catalytic activity of ZVI in phenol oxidation as well as for phenol adsorption. ZVI supported on activated carbon heat-treated at 900 degrees C yields the best phenol removal, reaching over 85% after 3 h, under the conditions tested: 150 mg L-1 of initial phenol concentration, initial pH set at 3, 30 degrees C, and the stoichiometric amount of hydrogen peroxide for achieving complete mineralization.