Environmental application of amine functionalised magnetite nanoparticles grafted graphene oxide chelants

This study proposed a two-step method involving hydrothermal and electrostatic self-assembly processes for synthesising an amine-functionalised magnetic ligand graphene oxide-based nanocomposite (EDTA@Fe₃O₄@GO). The amine groups were successfully attached to the surface of iron (II, III) oxide (Fe₃O₄), which were embedded on the surface of graphene oxide (GO) (Fe₃O₄@GO). This EDTA@ Fe₃O₄@GO nanocomposite was used as a chelating agent to bind the toxic heavy metal ions. EDTA@Fe₃O₄@GO demonstrated the synergistic effect between the large surface area and magnetic behaviour of Fe₃O₄@GO and the chelating effect of EDTA, and it showed higher efficiency than the individual GO and Fe₃O₄. The possible structural and compositional characteristics were proposed based on Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) and Raman spectroscopy analysis. The outcomes revealed the mechanism behind the excellent As(V) adsorption onto EDTA@Fe₃O₄@GO. The adsorption process was studied by fitting the experimental data obtained into various kinetic and isotherm models. The pseudo-second-order (PSO) kinetic model and the Freundlich isotherm model (FIM) were found to be the best fit models for the removal of As(V) by EDTA@Fe₃O₄@GO. EDTA@Fe₃O₄@GO has the utmost adsorption capacity of 178.4 mg/g. Furthermore, the EDTA@Fe₃O₄@GO nanocomposite is reusable, and it showed excellent adsorption capacity up to 5 cycles. This study has provided insight into the potential of EDTA@Fe₃O₄@GO and its applications in large-scale wastewater treatment.