Removal of F− from water by magnetic floriform magnesium zirconium hydrotalcite-like material doped with Fe2O3 and ZrO2

It is urgent to synthesize a kind of fluoride adsorbent with excellent fluorine removal performance in the field of treating fluorine-containing water. In this study, a magnetic floriform magnesium zirconium hydrotalcite-like material doped with Fe2O3 and ZrO2 was synthesized by urea hydrothermal method. Fe2O3 and ZrO2 particles and hexagonal laminae of hydrotalcite in the adsorption materials are uniformly stacked with each other. This structure allows the adsorbent to possess a large specific surface area (48.76 m2·g−1). The results of adsorption experiments indicate that the adsorption capacity of the adsorbent for fluoride can reach 113.38 mg·g−1. In addition, the adsorbent can be applied in a wide pH range (3–10) and has strong resistance to the effect of coexisting anions. After 5 cycles of adsorption, the fluorine removal performance of the adsorbent still maintained 80.93 % of the fresh adsorbent. Finally, DFT calculation of fluoride adsorption on the adsorbent was also carried out, and combined with the results of characterization and adsorption experiments, it is found that electrostatic attraction, hydrogen bond interaction, ion exchange and chemical adsorption are the main mechanisms of adsorption. Therefore, the material may be a potential fluoride adsorbent with good application prospect due to its various excellent properties.