Adsorptive Removal of Cu~(2+) in Aqueous Solutions Using Silica Grafted with Bayberry Tannin

Aminated silica beads(NH2-SiO2) were prepared using microemulsion method,and then grafted with bayberry tannin through the Mannich reaction to prepare a novel adsorbent,namely silica grafted with bayberry tannin(SiO2-BT).The obtained adsorbent was characterized by Fourier Transform Infrared spectrometry(FTIR) and X-ray Photoelectron Spectroscopy(XPS).Furthermore,the adsorption behaviors of Cu2+ on SiO2-BT were systematically investigated,including pH effect,kinetics,isothermals,co-existing ions effect and desorption characteristics.The experimental results indicated that SiO2-BT was effective for the adsorptive removal of Cu2+ from aqueous solutions,and its adsorption capacity to Cu2+ was 28.1 mg/g at 30 ℃ and increased with the increasing of temperature.The adsorption kinetics of Cu2+ on SiO2-BT can be well described by the pseudo-first-order model,and the adsorption isotherms can be well fitted by the Langmuir equation.In addition,the adsorption of SiO2-BT to Cu2+ has the advantages of fast adsorption rate,high adsorption capacity and easy desorption.Therefore,SiO2-BT can be used for the adsorptive removal of Cu2+ from aqueous solutions.