Highly efficient elimination of uranium from wastewater with facilely synthesized Mg-Fe layered double hydroxides: Optimum preparation conditions and adsorption kinetics

Mg-Fe layered double hydroxides (Mg-Fe LDHs) was synthesized via a facile, economical, and environmentally friendly procedure for the elimination of uranium from wastewater. The obtained absorbent was thoroughly investigated by FE-SEM, EDS, TEM, and XRD techniques as well as using bulk uranium adsorption tests, in order to identify optimal synthesis and adsorption conditions. A superior crystalline structure and high uranium adsorption capacity were observed, and the optimal adsorbent is detected as well-crystallized hierarchical amorphous sjogrenite LDHs with particle size appropriately 80 nm, its uranium adsorption capacity was 710.0 mg/g. Uranium was removed in form of UO22+ through the complexation reaction with the interlayer anions in the LDHs. The Mg-Fe LDHs showed considerable stability during cyclic uranium adsorption-desorption. Finally, uranium absorption selectivity was demonstrated with authentic uranium mining wastewater treatment. Compared with other reported nanomaterials, this Mg-Fe LDHs would be a promising material for the efficient elimination of uranium from polluted wastewater. (C) 2019 Elsevier Ltd. All rights reserved.