Efficient removal of Sb(III) from aqueous solution using recyclable magnetic metal-organic frameworks Fe3O4@MIL-100 and Fe3O4@MIL-101

Abstract Antimony (Sb) pollution is becoming increasingly serious. The pollution of water bodies containing antimony poses a great threat to the ecological environment and human health. In this study, two types of magnetic metal-organic frameworks(MOFs), namely Fe₃O₄@MIL-100(Fe) and Fe₃O₄@MIL-101(Fe), were prepared to investigate the removal effect on antimony (Sb). The influence of factors such as pH value and initial concentration on the adsorption effect was studied in detail. Compared to Fe₃O₄@MIL-100(Fe), the study found that the adsorption reaction rate of Fe₃O₄@MIL-101(Fe) was much higher than the former, reaching equilibrium after 10 minutes of addition. The fitting results conformed to the chemical adsorption behavior of the pseudo-second-order kinetic model. Mechanism characteristic analysis revealed that the Fe-O-Sb formed by Fe ions in the metal clusters and Sb (III) was the main adsorption mechanism. In addition, vibrating sample magnetometer (VSM) and adsorption tests showed that the material still possesses magnetism after adsorption, and the adsorption capacity remains basically unchanged after three cycles. These results indicated that the two magnetic Fe-based MOFs were effective and recyclable adsorbents, providing a new approach to the design of regenerative adsorbent materials.