Development of Aspartame Functionalized Magnetic Polymer Nanocomposites for the Zinc (Ⅱ) Removal from Aqueous Solution

摘要

This work aimed to provide a continuous method for the synthesis of aspartame magnetic dialdehyde starch (Aspa-MDAS) nano-composite that can be applied for removal of Zn(II) ions from aqueous media. Successful formation, structure, morphology and magnetic properties of the adsorbent were characterized by X-ray diffraction (XRD), fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The excellent monodispersity and uniform morphology of nanocomposite demonstrate the removal ability for zinc. The effects of solution pH, adsorbent dosage, contact time and Zn(II) initial concentration on the adsorption process were discussed. Results indicated that with an enhancement in contact time, the removal rate of Zn (II) ions was increased rapidly and reached equilibrium at 50 min with 96.6% of Zn (II) being adsorbed. When the initial concentration of metal ion was 120 mg L-1, the maximum adsorption capacity of Zn (II) adsorbed onto Aspa-MDAS at natural pH was 334.715 mg g(-1). Based on the kinetic data obtained, it can be concluded that the experimental data were fitted to the pseudo-second-order model, and the equilibrium data were consistent with the Langmuir isotherm model. The results provided a potential method for continuously preparing novel adsorbent with low cost and nontoxic materials, excellent monodispersibility, high adsorption capacity and easy separation.