Efficient removal of Chromium(VI) from aqueous solution using chitosan grafted graphene oxide (CS-GO) nanocomposite

Abstract

The present study involves the adsorption of hexavalent Chromium(Cr(VI)) using chitosan grafted graphene oxide (CS-GO) nanocomposite in batch mode. The CS-GO nanocomposite material was prepared by ultrasonic irradiation technique. The CS-GO adsorbent was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Tunnelling electron microscopy (TEM), followed by Cr(VI) adsorption studies. The adsorption capacity of 104.16 mg/g was achieved at pH 2.0, in the contact time of 420 min. The adsorption process was described by the pseudo second order kinetic and Langmuir isotherm model. The nano-microstructural investigation validates the successful adsorption of Cr(VI) on CS-GO nanocomposite. The CS-GO material is recyclable up to 10 cycles with the minimum loss in adsorption capacity.

Keywords: Chitosan-graphene oxide; Chromium(VI); Isotherms; Kinetics; Thermodynamics; Ultrasonic irradiation.