Selective Electrochemical Separation and Recovery of Uranium from Mixture of Uranium(VI) and Lanthanide(III) Ions in Aqueous Medium

Abstract

Separation of uranium (U) from interfering lanthanide ions (Ln) in aqueous medium is important in view of sustainable nuclear power production and remediation of radioactive waste. Separation of U in aqueous medium by electrochemical means is still unexplored. Herein, we report electrochemical separation of U from interfering lanthanides ions in 0.1 M KCl on poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) modified platinum (PEDOT:PSS/Pt) electrode. U in solution commonly exists as uranyl (UO). U separation is achieved in a two step process: (i) UO reduction to insoluble urania (UO) which gets deposited on PEDOT:PSS/Pt in the presence of Ln (La, Ce, and Sm) ions and (ii) oxidation of electrodeposited UO to UO in fresh 0.1 M KCl (pH = 2) solution. Electrodeposition of UO is confirmed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Although, the presence of Ln ions in UOsolution hinders electrodeposition of UO, but application of more negative reduction potential (-0.6 V vs Ag/AgCl) for longer duration (8 h) results in quantitative electrodeposition of UO. Inductively coupled plasma mass spectrometry (ICP-MS) shows that 94% (±10%) recovery of UO is possible from mixed solution of UOand Ln ions on PEDOT:PSS/Pt electrode.

Hydrophobic core formation and secondary structure elements in uranyl(vi)-binding peptides

“…This is presumably because the synthesized peptides are very expensive materials and cannot compete with bulk chemical substances employed in conventional separation processes. 4 The market price of uranium is too low to consider peptides as potential materials for uranium recovery, even though such a possibility exists. 5 A more promising application of uraniumpeptide interaction would be to use it in uranium-detecting sensors.…”

Graphene Oxide-based Nanomaterials for Uranium Adsorptive Uptake

“…[21][22][23] Thus, it is greatly important to remove and recycle uranium from aqueous solutions for environmental conservation, human health, and sustainable development of nuclear energy. [24,25] In the last few decades, various treatment techniques including biological treatments, [26] membrane treatment, [27,28] adsorption, [29][30][31][32] advance oxidation processes, [33] chemical precipitation processes, [34] ion exchange, [35][36][37] and electrochemical method [38][39][40] have been developed to uptake uranium from aqueous solutions. However, most of these methods have various drawbacks.…”

Electrochemical Ce(III)/Ce(IV) Redox Behavior and Ce Oxide Nanostructure Recovery over Thio-Terpyridine-Functionalized Au/Carbon Paper Electrodes

“…Furthermore, because actinide (An) elements fill the 5f subshell, the physicochemical properties and redox behaviors of Ln and An ions are observed to be very similar . Because of their similarities and diverse oxidation states, efficient detection, separation, and recovery of an Ln (or An) element from mixed ions have been a challenging project without any interferences among them. − …”

“…The electrochemical redox behaviors of metal ions are also known to be highly dependent on concentration, pH, and temperature. Furthermore, the nature of an electrode is another important factor, and the redox potentials and their corresponding current densities are reported to be tailored by the modification of an electrode. ,− Agarwal and Sharma developed a platinum (Pt) electrode modified by poly­(3,4-ethylenedioxythiophene)-poly­(styrenesulfonate) and showed that the newly developed electrode could efficiently electrodeposit UO 2 without any interferences of La 3+ , Ce 3+ , and Sm 3+ ions in solution . Surface functionalization of an electrode has also been employed using Lewis basic N-containing ligands such as terpyridines. − Dares et al developed a terpyridine-functionalized ITO electrode and controlled electrochemical oxidation of Am­(III) in a nitric acid solution for the selective separation of Am from Ln elements in nuclear wastes .…”