Performances of Methyl Blue and Arsenic(V) Adsorption from Aqueous Solution onto Magnetic 0.8Ni0.5Zn0.5Fe2O4/0.2SiO2 Nanocomposites

Abstract

Magnetic 0.8Ni0.5Zn0.5Fe2O4/0.2SiO2 nanocomposites were prepared by the facile citrate-gel thermal decomposition process. Their microstructure and magnetic properties were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), and vibrating sample magnetometer (VSM). The as-prepared magnetic 0.8Ni0.5Zn0.5Fe2O4/0.2SiO2 nanocomposites were characterized with about 8-nm grains, specific surface area of 119.3 m2/g, and magnetization of 38.7 Am2/kg. The adsorption kinetics and adsorption isotherms of methyl blue (MB) and As(V) onto the magnetic 0.8Ni0.5Zn0.5Fe2O4/0.2SiO2 nanocomposites at room temperature were investigated. Adsorption kinetics of MB and As(V) onto the magnetic 0.8Ni0.5Zn0.5Fe2O4/0.2SiO2 nanocomposites have been researched using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, the statistic results show that the pseudo-second-order kinetic model is fitted well to describe the MB and As(V) adsorption process. The adsorption equilibrium data of MB and As(V) onto the magnetic 0.8Ni0.5Zn0.5Fe2O4/0.2SiO2 nanocomposites at room temperature were analyzed with Langmuir, Freundlich, and Temkin models, and the adsorption isotherms was more effectively described by the Freundlich model based on the values of the correlation coefficient.