Adsorption of phosphate from solution by iron modified macroporous chelating resin

In this study, D751 resin (macroporous styrene chelated ion exchange resin, sodium form) was modified by FeCl3 to enhance the adsorption performance of phosphate from solution. The modified resin (D751-Fe) was characterized by FTIR and XPS, and its adsorption property toward phosphate was presented. The results showed that it was favorable of phosphate adsorption with the increase in the temperature and acidity. The effect of coexisting ions (chloride and sulfate) was insignificant. When the solid–liquid ratio was 1.5 g L–1, the unit adsorption amount of D751-Fe toward phosphate was to 14.1 mg g–1 (according to P element) with solution pH 3. The adsorption isotherms were well fitted by Langmuir model, Freundlich model, and Koble–Corrigan model while the kinetic curves were well described by pseudo-first-order kinetic model, double constant model, and intraparticle model. There were both physical adsorption and chemical adsorption between D751-Fe and phosphate. It was effective for 0.1 mol·L–1 sodium hydroxide solution as desorbent to regenerate phosphate-loaded adsorbent. It is concluded that that D751-Fe can be used well for the removal of phosphate from solution.