The following chemicals were used in this study. Sodium borohydride (NaBH4) and ferric chloride (FeCl3.6H2O) were purchased from Merck. MB (C.I. 52015) was obtained from Alvan Sabet Co. and was used without further purification. All other reagents were analytical reagent grade. Deionized water was used throughout this study. Adjustment of pH of the dye solution prior to adsorption was carried out with NaOH or HCl from Merck.