Maghemite nanoparticles bearing di(amidoxime) groups for the extraction of uranium from wastewaters

Eva Mazarío (1) , Ahmed Helal (1, 2) , Jérémy Stemper (3) , Alvaro Mayoral (4) , Philippe Decorse (1) , Alexandre Chevillot-Biraud , Sophie Novak , Christian Perruchot , Claude Lion , Rémi Losno (5) , Thierry Le Gall (6) , Souad Ammar (1) , Jean-Michel El Hage Chahine (1) , Miryana Hemadi

1 ITODYS (UMR_7086) - Interfaces, Traitements, Organisation et Dynamique des Systèmes
2 Nuclear Materials Authority [Le Caire]
3 ICSN - Institut de Chimie des Substances Naturelles
4 LMA - Laboratorio de microscopias avanzadas
5 IPGP (UMR_7154) - Institut de Physique du Globe de Paris
6 SC - Département Signal et Communications

Polyamidoximes (pAMD) are known to have strong affinities for uranyl cations. Grafting pAMD onto the surface of functionalized maghemite nanoparticles (MNP) leads to a nanomaterial with high capacities in the extraction of uranium from wastewaters by magnetic sedimentation. A diamidoxime (dAMD) specifically synthesized for this purpose showed a strong affinity for uranyl: Ka = 105 M-1 as determined by Isothermal Titration Calorimetry (nano-ITC). The dAMD was grafted onto the surface of MNP and the obtained sorbent (MNP-dAMD) was characterized. The nanohybrids were afterward incubated with different concentrations of uranyl and the solid phase recovered by magnetic separation. This latter was characterized by zeta-potential measurements, X-Ray Photoelectron Spectroscopy (XPS) and X-Ray Fluorescence spectroscopy (XRF), whereas the supernatant was analyzed by Inductively Coupled Plasma coupled to Mass Spectrometry (ICP-MS). All the data fitted the models of Langmuir, Freundlich and Temkin isotherms very well. These isotherms allowed us to evaluate the efficiency of the adsorption of uranium by MNP-dAMD. The saturation sorption capacity (qmax) was determined. It indicates that MNP-dAMD is able to extract up to 120 mg of uranium per gram of sorbent. Spherical aberration (Cs)- corrected High-Resolution Scanning Transmission Electron Microscopy (HRSTEM) confirmed these results and clearly showed that uranium is confined at the surface of the sorbent. Thus, MNP-dAMD presents a strong potential for the extraction of uranium from wastewaters

Domaines: Planète et Univers [physics]; Interfaces continentales, environnement

Eva Mazarío, Ahmed Helal, Jérémy Stemper, Alvaro Mayoral, Philippe Decorse, et al.. Maghemite nanoparticles bearing di(amidoxime) groups for the extraction of uranium from wastewaters. AIP Advances, 2017, 7 (5), pp.056702. ⟨10.1063/1.4973436⟩. ⟨insu-02526266⟩