Amendment of chitosan biopolymer with graphite for augmented confiscation of reactive blue-19 and reactive orange-16 textile dyes

Abstract

In this work, we report the adsorption of reactive blue-19 (RB-19) and reactive orange-16 (RO-16) dyes from the aqueous solution onto chitosan-graphite composite (Chi-Gr). The adsorption of this textile dye has been tremendously improved after successfully immobilizing chitosan on graphite. The Chi–Gr has been characterized through Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and the pH point of zero charge for the physicochemical, structural and morphological analyses. The characterization of synthesized Chi-Gr indicates that the composite formation improves not only the surface chemistry but also its textural properties. Adsorption experiment reveals excellent adsorption capacity 123.21 mg of RB-19 dye and 62.16 mg per gram of Chi-Gr composite in accordance with Langmuir model with a coefficient of determination value of 0.9994 for RB-19 and 0.991 for RO-16 dyes. Furthermore, adsorption process follows pseudo-second order kinetics and thermodynamic equilibrium study revealed it’s spontaneous, endothermic and entropy driven nature. The overall study demonstrates the importance of the synthesized adsorbent as potential candidature towards removal of RB-19 and RO-16 dyes from the wastewater.