US EPA

4697648 

Journal Article 

Sono-assisted preparation of Fe(II)-Al(III) layered double hydroxides and their application for removing uranium (VI) 

Xie, L; Zhong, Yu; Xiang, R; Fu, G; Xu, Y; Cheng, Y; Liu, Z; Wen, Tao; Zhao, Y; Liu, X 

2017 

Yes 

Chemical Engineering Journal
ISSN: 1385-8947 

328 

574-584 

10.1016/j.cej.2017.07.051 

WOS:000411118300056 

Fe(II)-Al(III) layered double hydroxides (Fe-Al LDHs) were prepared by the sono-assisted precipitation method and used for the removal of uranium (VI) from aqueous solutions. The application of ultrasound in the Fe-Al LDHs preparation promoted the formation of the hydrotalcite-like phase and improved the adsorption capacity of U(VI). Batch experiments were carried out to investigate the influence of solid-to-solution ratio, initial U(VI) concentration, initial pH, contact time and temperature on the U(VI) removal process. The experimental results indicated that the removal process of U(VI) could be well described by the pseudo-second-order kinetic model. The equilibrium isotherm for U(VI) removal was fitted by the Langmuir model and the maximum adsorption capacity of Fe-Al LDHs was 113.64 mg/g at a temperature of 308 K. The thermodynamic parameters implied that the removal of U(VI) was essentially an endothermic process. The FT-IR, EDX and XPS results suggested that the removal mechanism involves combined adsorption-reduction processes. When the U(VI) ions absorbed onto the Fe-Al LDHs through physical adsorption, the Fe(II) in the structure of Fe-Al LDHs reduces U(VI) to U(IV) while Fe(II) was oxidized to Fe(III). (C) 2017 Elsevier B.V. All rights reserved. 

Uranium; Fe(II)-Al(III) layered double hydroxides; Ultrasound irradiation; Adsorption; Reaction mechanisms