Interaction of U(VI) with MnAl and MnFeAl layered double hydroxides: batch and spectroscopy study

Herein, the binary and ternary layered double hydroxides (MnAl-LDHs and MnFeAl-LDHs) were synthesized using a one-pot hydrothermal method for efficient adsorption of U(VI), and characterized by SEM, FTIR, XRD and XPS technologies in detail. The removal mechanism of U(VI) on LDHs was investigated by batch experiments and collective spectroscopy characterizations. The results showed that MnAl-LDHs and MnFeAl-LDHs exhibited rapidly binding U(VI) within 60 min and large adsorption capacity (70.72 mg/g for MnAl-LDHs and 157.73 mg/g for MnFeAl-LDHs) at pH=5.0, which were superior to those LDHs-based adsorbents in previous literatures. In addition, the great uptake performance could be maintained with various relevant interferences. The adsorption of U(VI) on LDHs was controlled by inner-sphere surface complexation or ions substitution, which was confirmed by spectroscopic analysis. This article revealed the great potential of manganese-containing LDHs in the remediation of real nuclear wastewater.