Fenton-like oxidation of Reactive Black 5 dye was carried out using iron(III) impregnated on rice husk ash as heterogeneous catalyst. The catalyst was prepared by wet impregnation method and characterized. The effectiveness of this catalyst in degradation and decolorization of the dye, as well as the influence of reaction parameters on the catalytic activity was discussed. The effects of pH, the initial hydrogen peroxide concentration, the catalyst loading, and the temperature on the oxidative degradation and decolorization of Reactive Black 5 have been assessed. The best degradation efficiency (59.71%) and decolorization efficiency (89.18%) was obtained at temperature = 30 degrees C, pH =3, [H2O2](0)= 4 mM, catalyst loading = 0.5 g/L for initial dye concentration of 100 mg/L. (C) 2013 Elsevier B.V. All rights reserved.