In this study, we used advanced oxidation process (AOP)for the removal of a cationic and anionic blue dyes, namely Basic Blue 3 (BB3) and Acid blue 62(AB62), from aqueous solutions. Fenton reactions are mixture of H2 O2 and Fe2+. However this paper investigates the application of twelve different catalysts such as: FeCl2 , FeSO4, (NH4 )Fe(SO4 )2 , FeCl3 , Nano iron (Fe0 ), Fe(NO3 )3 , K2FeO4 , ...