In this research, the adsorptive removal of diclofenac sodium, one of the representative pharmaceuticals and personal care products, from aqueous solution using Fe3O4@MOF-100(Fe) magnetic microspheres was studied for the first time. The Fe3O4@MOF-100(Fe) microspheres exhibit strong magnetism and stability, which were observed as a core-shell structure. The maximum adsorption capacity of Fe3O4@MOF-100(Fe) for diclofenac sodium can reach 377.36 mg L-1, which was higher than most of the adsorbents reported. The adsorption kinetics follows the pseudo-second-order kinetic equation. And the adsorption equilibrium of DCF can be described with Langmuir isotherm. In the cycle experiment, Fe3O4@MOF-100(Fe) material performed high adsorption efficiency for low-concentration diclofenac sodium solution, and the removal rate can still reach 80% after 5 cycles of adsorption without desorption. The mechanisms including electrostatic interaction, H-bond interaction, and π-π interaction that coexisted in the adsorption processes would be of benefit to enhance the adsorption capacity. The Fe3O4@MOF-100(Fe) magnetic microspheres offer exciting opportunities for further application.
Keywords: Adsorption; Core-shell structure; Diclofenac sodium; Fe3O4; MOF-100(Fe).