Abstract
Bifunctional starch composites were prepared by γ-induced grafting of acrylamide (Aam) and acrylic acid (AA) onto maize starch. The prepared composites were characterized by FTIR spectroscopy and scanning electron microscope (SEM). The feasibility of these composites to remove anionic dyes, direct blue 21 (D. Blue 21) and direct brown 2 (D. Brown 2) and a cationic dye, methylene blue (MB) were examined. Factors affecting adsorption of anionic and cationic dyes onto these starch composites were studied. These factors were radiation dose, agitation time, adsorbent and adsorbate concentrations. Prepared composites were effectively used in adsorption of D. Blue 2, D. Brown 2 and MB from aqueous solutions. The Adsorption data of both D. Blue 21 and D. Brown 2 complied with the Langmuir and Freundlich isotherms.