Removal of phosphate from aqueous solution by magnetic Fe–Zr binary oxide

Phosphorus removal was a crucial aspect in controlling eutrophication problem of water pollution. Zirconium oxide was a suitable adsorbent for phosphate removal due to its good adsorption efficiency, but it suffered from the separation inconvenience. In this paper, magnetic Fe–Zr binary oxide was synthesized and used as adsorbent for removing phosphate from aqueous solution. The adsorbent was characterized by energy dispersive analysis system of X-ray, scanning electron microscopy (SEM), infrared spectrum (IR), X-ray powder diffraction (XRD) analysis and BET surface area measurements. The results showed that kinetic data followed a pseudo-second-order model and equilibrium data were well fitted by the Langmuir model. The maximum adsorption capacity was 13.65 mg P/g at pH 4. The adsorption mechanism was mainly derived from ion-exchange of zirconium species and partly originated from magnetite species of Fe–Zr binary oxide. The main advantages of magnetic Fe–Zr binary oxide adsorbent consisted in its separation convenience and highly efficient reusability compared to the other adsorbents.