چكيده به لاتين
In this study new Nitrogen and Sulfur Co-doped Graphene/Chitosan Magnetic Nanocomposite (NS-MGC), for the uptake of cadmium (II), lead (II) and Zn (II) toxic ions from aqueous solutions. evaluating their morphologic and magnetic properties and assessing their performance the Fourier Transform Infrared Spectroscopy Analysis, Raman Spectroscopy Analysis, Scanning Electron Microscopy Analysis, Transmission Electron Microscopy Analysis, Energy-dispersive X-Ray Spectroscopy Analysis and X-Ray Diffraction Analysis results reveal that a synthesized nano particle complex with uniform spherical homogenous distribution of NPs and agglomeration over the graphene nanosheet. The effect of operating parameters including contact time, pH, initial metal ions concentration of cadmium (II), lead (II) and Zn (II) were studied. The effects of different parameters such as pH, contact time and initial concentration on the removal process of the three metals were examined at ambient temperature and a constant mass of sorbent. The best removal results were obtained for these ions at contact times of 15 to 60 min and pH values of 5.0 to 7.0. The maximum adsorption capacities up to 421.78, 318.44 and 169.58 mg.g-1 were achieved with NS-MGC structure for Zn2+, Cd2+ and Pb2+ ions, respectively. Freundlich isotherm model clarified the experimental adsorption data at equilibrium and the pseudo-second order model was suitable for describing the kinetic data from the adsorption experiments. The results showed that, at high concentration levels of metal ions, the basicity of the N-donor parts in the NS-MGC along with the acidity and ion exchange ability of –COOH+ groups determine the adsorption efficiency of the NS-MGC for the metal ions.
