Degradation of acid orange II (AOII), a dye present in textile industry wastewater, by the heterogeneous Fenton process (HFP) was performed. In order to select ail adequate support, heterogeneous Fenton catalysts were prepared using several materials Such its carbon nanotubes, carbon nanofibers, activated carbon, hydrotalcite-like materials, mesoporous silica (MCM41), silica, silica xerogel, sepiolite, and zeolite USY, that were tested in the degradation of AOII as the model compound. Color, total organic carbon, chemical oxygen demand removal, and toxicity were studied in the process. The best catalyst was iron supported on sepiolite. The best performing catalytic material was used to investigate the influence of the presence of carbonate ions, pH, and reuse of catalyst. Also, a real textile wastewater was Successfully treated with this catalyst.