In this study, the decolorization and sedimentation of strong colored solutions containing a reactive textile dye, Remazol Red RB, were investigated. Aluminum hydroxides from dissolution of metallic aluminum were used as flocculant. Experiments were performed according to "2(4) full factorial experimental design." By using MINITAB software, analysis of variance was carried out. The parameters investigated were aluminum dissolution temperature, initial pH, aluminum dissolution time, and effect of surfactant. Aluminum dissolution temperature and dissolution pH were found to be statistically significant parameters in the decolorization process. From the variance analysis of settling rate, the amount of dissolved aluminum and the mean distribution of floc size, it was found that pH was a significant parameter common in all of these processes. These results suggest that decolorization by flocculation with direct dissolution of metallic aluminum may be practically used for the removal of reactive dyes from aqueous solutions.