Removal of basic dyes from aqueous solutions using starch‐ graft ‐acrylic acid copolymers

Graft copolymerization of acrylic acid (AA) onto starch was carried out with ceric ammonium nitrate as initiator under nitrogen atmosphere. The grafting percentages (GP%) of starch‐ graft ‐AA (St‐ gr ‐AA) copolymers were determined. When the AA molar concentrations were 0.3 and 0.5 mol/L, GP% of St‐ gr ‐AA copolymers were 10.5% (St‐ gr ‐AA‐1) and 14% (St‐ gr ‐AA‐2), respectively. St‐ gr ‐AA copolymers have been used for the adsorption of basic dye (Safranine T) from aqueous solutions. Effects of various parameters such as treatment time, initial pH of the solution (pH = 2–6), initial dye concentration (50– 500 mg/L), and GP% of starch graft copolymers were investigated.Basic dye removal capacities of the copolymers increase along with the augment of initial concentration of the adsorbate, GP% of the copolymers, and pH. The adsorption capacities for St‐ gr ‐AA‐1 and St‐ gr ‐AA‐2 reach 116.5 and 204 mg/g, respectively. Equilibrium adsorption data were obtained and fitted very well to Freundlich model. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007