Removal of Cu2+ from wastewater by modified xanthan gum (XG) with ethylenediamine (EDA)

摘要

Herein, a new adsorbent was synthesized by modifying xanthan gum for the removal of Cu2+ fromwastewater. Xanthan gum was first successfully modified with thionyl chloride followed byethylenediamine. The modified xanthan gum was characterized via Fourier transform infraredspectrometry (FTIR), carbon nuclear magnetic resonance (13C NMR), scanning electron microscopy (SEM),energy dispersion spectroscopy (EDS) and thermogravimetry (TG) for a better understanding of its Cu2+removal efficiency. In addition, the effects of pH, contact time, adsorbent dosage, initial concentration ofCu2+ and coexisting ions on the adsorption of Cu2+ were investigated via batch adsorption studies.Results suggest that the adsorption process of Cu2+ follows a pseudo second order kinetics model withan equilibrium time of 120 min. The experimental data could be fitted with the Langmuir isotherm better than the Freundlich model. The adsorption capacity of Cu2+ by the modified xanthan gum reached up to46.95 (mg g_1). The adsorbent could be easily regenerated by only the addition of 0.1 M HCl. Also, the adsorption effect of other divalent cations by XG-NH2 was preliminarily investigated.