LAUSR

Abstract In this study, Fe-Mg type hydrotalcite at different molar ratios (Mg/Fe = 3.0 and 5.0, Fe-HT3.0 and Fe-HT5.0) was prepared, and its physicochemical properties were investigated. The adsorption isotherms were measured, and the effects of contact time, temperature, and pH on the adsorption of phosphate ions, and the ad-desorption capability were evaluated. Elemental analysis and binding energy values of the Fe-HT adsorbent surface before and after adsorption of phosphate ions indicated that the adsorption mechanism of phosphate ions was related to the physicochemical properties of adsorbent surface. Adsorption mechanism of phosphate ion relates to ion exchange, electrostatic attraction, and surface inner sphere complex formation in this study. Moreover, the phosphate ions adsorbed onto Fe-HT were easily desorbed using sodium hydroxide solution; thus, five cycles of ad-desorption were carried out. Collectively, these results suggest that Fe-HT is promising for the adsorption and recovery of phosphate ions using sodium hydroxide solution.