Facile preparation of oxine functionalized magnetic Fe3O4 particles for enhanced uranium (VI) adsorption

• Magnetic oxine were prepared and well characterized.
• Magnetic oxine exhibited fast and efficient sorption for uranium (VI).
• The dominant adsorption mechanism for uranium (VI) was studied in detail.
• Magnetic oxine could be easily separated from aqueous solutions with a magnet.

We present a study of uranium (VI) adsorption in aqueous solutions by magnetic oxine (ferroferric oxide/oxine composite). Batch experiments of uranium (VI) adsorption were conducted, investigating the significance of solution pH, contact time, ionic strength, and temperature on uranium sorption efficiency. The results suggest that maximum adsorption capacity is 125 mg g−1 when the initial uranium (VI) concentration is 50 mg L−1 at 298 K, displaying a mass transport property of the magnetic oxine for the removal of uranium (VI). The sorption was strongly dependent on pH and independent of ionic strength, indicating that the sorption was mainly dominated by inner-sphere surface complexation. The experimental data are analyzed using sorption kinetic models, revealing that the process follows a pseudo-second-order kinetic model. The thermodynamic parameters show that the process is endothermic and spontaneous. We demonstrate a fast, efficient and convenient material for the removal of uranium (VI) from aqueous solutions.

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