Fabrication of chitosan/graphene oxide-gadolinium nanorods as a novel nanocomposite for arsenic removal from aqueous solutions

Abstract

Chitosan-graphene oxide-gadolinium oxide (CGO-Gd) nanocomposite was prepared to adsorption removal of arsenic(V) from water. The CGO-Gd nanocomposite were characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption/desorption isotherms, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Thermal gravimetric analysis (TGA), and Raman spectroscopy analyses. The 50 nm long rods were found to possess a crystalline morphology with highly active oxygenated functional groups (OH−, COO−, C–O–C, and Gd2O3), which aid in the adsorptive removal of arsenic. Batch experiments, including pH, adsorption kinetics, and equilibrium isotherms studies were performed to evaluate arsenic adsorptive removal using prepared CGO-Gd. The efficacy of CGO-Gd for arsenic removal was found to be high in the range of pH 3 to 7, and then decline above pH >7. However, the removal capacity for As(V) was 252.12, and 128.20 mg/g for 0.1 and 0.3 g/L of CGO-Gd, respectively, obtained at pH 6.0. Moreover, the CGO-Gd can be reused up to five times for As(V) removal that demonstrates the feasibility and cost-effectiveness of the material. Further evaluated the applicability of developed method for real water samples treatment that results demonstrates that the CGO-Gd can reduce the quantity of As(V) in water to the regulatory standards required for drinking water (10 μg/L) stipulated by environmental protection agencies. Moreover, the loaded Gd2O3 not only enhanced the adsorption ability of CGO but also improve the separation and stability of the CGO-Gd. Thus, the prepared CGO-Gd has a latent for As(V) removal from various real water effluents.