Synthesis of magnetic S-nZVI nanoparticle and its application for the effective removal of radioactive uranium from seawater

Herein, S-nZVI was synthesized to remove U(VI) from seawater. At a S/Fe ratio of 0.18 and pH of 5, adsorption of U(VI) reached equilibrium after 20 min with the removal rate of 97.93%. And the maximum adsorption capacity obtained by Langmuir isothermal model was 1177.09 mg/g. Moreover, S-nZVI exhibited selectivity in the presence of interfering ions, regeneration performance in 5 reuse cycles, and high removal efficiency in actual seawater. Mechanism investigations showed that UO 2 2+ uniformly adsorbed on S-nZVI surface was irreversibly reduced and generated UO 2 precipitates due to the electrons provided by S 2− , S 2 2− and Fe(II).