Facile synthesis of chitosan/gelatin filled with graphene bead adsorbent for orange II removal

In this work, the bead adsorbent derived from chitosan and gelatin, filled with graphene for orange II (ORII) removal was prepared facilely. The synthesized samples were analyzed by means of Fourier transform infrared spectroscopy, X-ray powder diffraction, Zetasizer Nano, field emission scanning electron microscopy and thermogravimetric analysis. The analysis of adsorption behavior of the as-prepared composite toward ORII was conducted, where the effects of the contact time, pH, the initial ORII concentration, swelling behavior and recyclability were studied. The highest removal efficiency of 84.3% at the optimum conditions (0.03 g beads, 10 mL 50 mg L-1 ORII, original pH (7.14), 120 min) was obtained. In addition, the effects of salts and surfactants on the adsorption performance were also investigated. Subsequently, the adsorption kinetics and isotherms were performed and analyzed in order to achieve a thorough comprehension of dyes adsorption mechanism. The results revealed that electrostatic interactions and hydrogen bonding played an important role in the dye adsorption process. Based on these analyses, it can be concluded that the as-prepared chitosan-gelatin-graphene trinary composite should be acted as a promising adsorbent for high-efficiency dye removal to deal with water pollution. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.