FeOOH-loaded MnO₂ nano-composite: An efficient emergency material for thallium pollution incident

A FeOOH-loaded MnO₂ nano-composite was developed as an emergency material for Tl(I) pollution incident. Structural characterizations showed that FeOOH successfully loaded onto MnO₂, the nanosheet-flower structure and high surface area (191 m² g^-1) of material contributed to the excellent performance for Tl(I) removal. FeOOH-loaded MnO₂ with a Fe/Mn molar ratio of 1:2 exhibited a noticeable enhanced capacity for Tl(I) removal compared to that of pure MnO₂. The outstanding performance for Tl(I) removal involves in extremely high efficiency (achieved equilibrium and drinking water standard within 4 min) and the large maximum adsorption capacity (450 mg g^-1). Both the control-experiment and XPS characterization proved that the removal mechanism of Tl(I) on FeOOH-loaded MnO₂ included adsorption and oxidation: the oxidation of MnO₂ played an important role for Tl(I) removal, and the adsorption of FeOOH loaded on MnO₂ enhanced Tl(I) purification at the same time. In-depth purification of Tl(I) had reach drinking water standards (0.1 μg L^-1) at pH above 7, and there wasn't security risk produced from the dissolution of Mn²⁺ and Fe²⁺. Moreover, the as-prepared material could be utilized as a recyclable adsorbent regenerated by using NaOH-NaClO binary solution. Therefore, the synthesized FeOOH-loaded MnO₂ in this study has the potential to be applied as an emergency material for thallium pollution incident.