radiation synthesis of novel hydrogel based on wheat flour for dyes removal

Abstract

A novel hydrogel based on wheat flour (F) and acrylic acid (AAc) was performed by gamma irradiation. The parameters that controlled the preparation conditions were studied including irradiation dose and hydrogel composition. Characterization of the produced hydrogel (F/AAc) was done by infrared spectroscopy to confirm the structure and the change in morphology was investigated by the scanning electron microscope. The thermal stability was also investigated using thermogravimetric analysis (TGA). The swelling properties were investigated in relation to time and irradiation dose. The developed hydrogel was used for the removal of Congo Red dye (CR) from aqueous solution. Effects of different operating parameters such as effect of pH, contact time, concentration of the dye and temperature on the adsorption capacity of the dye have been studied. It was found that marvelous adsorption capacities were obtained at pH 3. The adsorption capacity at pH 3 is 19.5 mg/g for (F/AAc) hydrogel contains (15wt% AAc) at 2.5 kGy, 17.3mg/g for (F/AAc) hydrogel contains (15wt% AAc) at 20 kGy, and 13.4 mg/g for (F/AAc) hydrogel contains (20 wt% AAc) at 20 kGy. The pseudo-second-order model and the Freundlich model describe well the adsorption kinetic and isotherm, respectively.