Synthesis of carboxymethyl beta-cyclodextrin bonded Fe3O4@SiO2-NH2 core-shell magnetic nanocomposite adsorbent for effective removal of Pb(II) from wastewater

摘要

In this work, a novel functionalized magnetic Fe3O4@SiO2 core-shell nanoparticles grafted with carboxymethyl beta-cyclodextrin (CM-beta-CD) is utilized for adsorption of Pb(II) ions from aqueous solutions. The grafting reaction was performed via carbodimide method by using 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The as-prepared nanoadsorbents were characterized by FTIR, SEM, TEM, XRD, TGA, and VSM. The grafting CM-beta-CD on the Fe3O4@SiO2 core-shell nanoparticles enhances the ion adsorption capacity due to the strong abilities of the enormous -OH and -COOH functional groups in CM-beta-CD to adsorb Pb(II) ions. The effects of factors such as the concentration of beta-CD, contact time, initial ion concentration, adsorbent dosage, adsorption kinetics, and isotherms on the adsorption behavior were studied properly. The results depicted that the nanoadsorbents had good adsorption with the maximum adsorption capacity of 170 mg g(-1) at 25 degrees C and pH 6.0. All the equilibrium adsorption kinetics of Pb(II) are fitted well to the pseudo-second-order model. The adsorption data were also found to follow the Langmuir adsorption isotherm model. In summary, the experimental Pb(II) ion adsorption data showed the prepared nanocomposites would be as promising adsorbents to remove various heavy metals from wastewater.