In this work the decolorization of Acid Red 1 (AR1) dye was conducted using Fe(III) oxide immobilized on Montmorillonite K10 (Fe-MK10) catalyst in the presence of hydrogen peroxide (H2O2) in batch process The effects of different parameters such as Iron loading (Fe3+) on Montmonllonite K10 (MK10) catalyst dosage solution pH initial concentration of H2O2 and AR1 and reaction temperature on the decolorization efficiency of the process were studied The results indicated that by using 5 0 g L-1 catalyst dosage of 0 14 wt % Fe-MK10 at pH 2 5 and 16 mM of H2O2 99% of the 50 mg L-1 of AR1 was decolorized within 150 min Leaching test indicated that the leached iron from the catalyst was less than 5 mg L-1 (C) 2010 Elsevier B V All rights reserved