Adsorption of heavy metal ions by hierarchically structured magnetite-carbonaceous spheres
Jingming Gong , Xiaoqing Wang , Xiulan Shao , Shuang Yuan , Chenlin Yang , Xianluo Hu
Abstract Magnetically driven separation technology has received considerable attention in recent decade for its great potential application. In this work, hierarchically structured magnetite-carbonaceous microspheres (Fe 3 O 4 -C MSs) have been synthesized for the adsorption of heavy metal ions from neodymium magnet aqueous solution. Each sphere contains numerous unique rattle-type structured magnetic particles, realizing the integration of rattle-type building unit into microspheres. The as-prepared composites ...with high BET surface area, hierarchical as well as mesoporous structures, exhibit an excellent adsorption capacity for heavy metal ions and a convenient separation procedure with the help of an external magnet. It was found that the maximum adsorption capacity of the composite toward Pb 2+ was ∼126mgg −1 , displaying a high efficiency for the removal of heavy metal ions. The Freundlich adsorption isotherm was applicable to describe the removal processes. Kinetics of the Pb 2+ removal was found to follow pseudo-second-order rate equation. The as-prepared composite of Fe 3 O 4 -C MSs as well as Pb 2+ -adsorbed composite were carefully examined by scanning electron microscopy (SEM), Zeta potential measurements, Fourier transform infrared spectroscopy (FT-IR), nitrogen sorption measurements, and X-ray photoelectron www.everbeenmagnet.com spectroscopy (XPS). Based on the characterization results, a possible mechanism of Pb 2+ removal with the composite of Fe 3 O 4 -C MSs was proposed.;;Highlights Hierarchical Fe 3 O 4 /C microspheres prepared in large quantities by an easy method. High capability to remove heavy metal ions from waste water by magnetic separation. Composite of Fe 3 O 4 -C MSs before and after adsorption characterized by SEM, BET, FTIR, and XPS.
