Nanoporous Magnetic Cellulose-Chitosan Composite Microspheres: Preparation, Characterization, and Application for Cu(II) Adsorption

Novel nanoporous magnetic cellulose-chitosan composite microspheres (NMCMs) were prepared by sol-gel transition method using ionic liquids as solvent for the sorption of Cu(11). The composite microspheres were studied by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). Subsequelty, the adsorption of Cu(11) to NMCMs was investigated systematically with varried parameters such as pH, contact time, and initial concentration. Results revealed that the composite microspheres exhibited efficient adsorption capacity of Cu(11) from aqueous solution, due to their favorable chelating groups in structure. The adsorption process was best described by a pseudo-second-order kinetic model, while isotherm modeling revealed that the Langmuir equation better describe the adsorption of Cu(11) on NMCMs as compared to Freundlich model. Moreover, the loaded NMCMs can be easily regenerated with HCl and reused repeatedly for Cu(II) adsorption up to five cycles. The environmental friendly microspheres were expected to be a promising candidate for future practical use in heavy metal ions removal.