Enhanced adsorption of arsenate by spinel zinc ferrite nano particles: Effect of zinc content and site occupation

摘要

In this work, zinc ferrite spinel with different zinc contents(ZnxFe_3-xO_4) was synthesized by a hydrothermal method and used for removing As(V) in aqueous solution. X-ray diffraction(XRD) results indicated that in the crystal structure of ZnxFe_3-xO_4, the zinc atoms tended to occupy the octahedral sites for x 0.6. The size of ZnxFe_3-xO_4 crystallites increased with the increasing zinc content. Batch adsorption experiments showed that the adsorption isotherms could be well described by the Langmuir model, while the adsorption kinetics followed the pseudo-second-order kinetic model. Zinc ferrite exhibited the highest adsorption capacity towards As(V) when x = 0.6. Study of the mechanism indicated that doping with zinc increased the number of surface hydroxyl groups on ferrite spinel, and thus enhanced the adsorption capacity when x = 0.6. This work revealed the effects of doping site and content of metal atoms on the adsorption ability of ferrite spinel towards As(V).