Ship-in-a-bottle CMPO in MIL-101(Cr) for selective uranium recovery from aqueous streams through adsorption

Jeroen De Decker; Karel Folens; Jeriffa De Clercq; Maria Meledina; Gustaaf Van Tendeloo; Gijs Du Laing; Pascal Van Der Voort

doi:10.1016/j.jhazmat.2017.04.029

Ship-in-a-bottle CMPO in MIL-101(Cr) for selective uranium recovery from aqueous streams through adsorption

J Hazard Mater. 2017 Aug 5:335:1-9. doi: 10.1016/j.jhazmat.2017.04.029. Epub 2017 Apr 9.

Authors

Jeroen De Decker¹, Karel Folens², Jeriffa De Clercq³, Maria Meledina⁴, Gustaaf Van Tendeloo⁴, Gijs Du Laing², Pascal Van Der Voort⁵

Affiliations

¹ Department of Inorganic and Physical Chemistry, Center for Ordered Materials, Organometallics, and Catalysis (COMOC), Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium.
² Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
³ Department of Materials, Textiles, and Chemical Engineering, Industrial Catalysis and Adsorption Technology (INCAT), Ghent University, Valentin, Vaerwyckweg 1, 9000 Ghent, Belgium.
⁴ EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
⁵ Department of Inorganic and Physical Chemistry, Center for Ordered Materials, Organometallics, and Catalysis (COMOC), Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium. Electronic address: pascal.vandervoort@ugent.be.

PMID: 28414943
DOI: 10.1016/j.jhazmat.2017.04.029

Abstract

Mesoporous MIL-101(Cr) is used as host for a ship-in-a-bottle type adsorbent for selective U(VI) recovery from aqueous environments. The acid-resistant cage-type MOF is built in-situ around N,N-Diisobutyl-2-(octylphenylphosphoryl)acetamide (CMPO), a sterically demanding ligand with high U(VI) affinity. This one-step procedure yields an adsorbent which is an ideal compromise between homogeneous and heterogeneous systems, where the ligand can act freely within the pores of MIL-101, without leaching, while the adsorbent is easy separable and reusable. The adsorbent was characterized by XRD, FTIR spectroscopy, nitrogen adsorption, XRF, ADF-STEM and EDX, to confirm and quantify the successful encapsulation of the CMPO in MIL-101, and the preservation of the host. Adsorption experiments with a central focus on U(VI) recovery were performed. Very high selectivity for U(VI) was observed, while competitive metal adsorption (rare earths, transition metals...) was almost negligible. The adsorption capacity was calculated at 5.32mg U/g (pH 3) and 27.99mg U/g (pH 4), by fitting equilibrium data to the Langmuir model. Adsorption kinetics correlated to the pseudo-second-order model, where more than 95% of maximum uptake is achieved within 375min. The adsorbed U(VI) is easily recovered by desorption in 0.1M HNO₃. Three adsorption/desorption cycles were performed.

Keywords: Adsorption; Environmental chemistry; Metal-organic frameworks; Uranium.