Enhanced adsorption of synthetic dyes from aqueous solution by a semi-interpenetrating network hydrogel based on starch

Several semi-interpenetrating network (Semi-IPN) hydrogels were synthesized by free radical copolymerization of acrylamide, hydroxyethyl methacrylate and N′N′-methylene bis acrylamide crosslinker (MBA) in presence of starch. These hydrogels were characterized by FTIR, DTA-TGA, XRD and SEM. The hydrogel showing the highest swelling% in water was used for removal of low (2.5–40 mg/L) and high (200–500 mg/L) concentration range of malachite green and methyl violet dyes from water. The hydrogel showed high adsorption for both of these dyes. Isotherms, kinetics, mass transfer coefficients and thermodynamics of dye adsorption were also studied.