MBase: The Molecular Basis of Advanced Nuclear Fuel Separations
Lead Research Organisation:
University of Reading
Department Name: Chemistry
Abstract
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Organisations
Publications
A. Afsar
(2014)
Article
in Jordan Journal of Chemistry
Distler P
(2020)
Thermodynamic parameters of Am(III), Cm(III) and Eu(III) extraction by CyMe4-BTPhen in cyclohexanone from HNO3 solutions
in The Journal of Chemical Thermodynamics
Lewis F
(2018)
Separation of the Minor Actinides Americium(III) and Curium(III) by Hydrophobic and Hydrophilic BTPhen ligands: Exploiting Differences in their Rates of Extraction and Effective Separations at Equilibrium
in Solvent Extraction and Ion Exchange
M. Harwood L
(2014)
Immobilisation of Phenanthroline-Bis Triazine (C1-BTPhen) on Magnetic Nanoparticles for Co-Extraction of Americium(III) and Europium(III)
in HETEROCYCLES
M. Harwood L
(2012)
Tuning the Solubilities of Bis-triazinylphenanthroline Ligands (BTPhens) and Their Complexes
in HETEROCYCLES
| Description | Separation of the minor actinides from lanthanides and other fission products is a key step in the partitioning and transmutation scenario for reprocessing of used nuclear fuel, and has been achieved using nitrogen-bearing ligands; for instance the bis-triazinyl-phenanthroline (BTPhen) ligands. We have investigated the influence of subtle electronic effects of bromine substitution at the 5 and 5,6-positions of the 1,10-phenanthroline nucleus of BTPhen ligand on their extraction properties for Ln(III) and An(III) cations. Compared to C5-BTPhen, electronic modulation in BrC5-BTPhen and Br2C5-BTPhen enabled these ligands to be fine-tuned in order to enhance the selectivity of Am(III) from Eu(III). Magnetic iron oxide (Fe2O3) nanoparticles (MNPs) have attracted much interest over recent years because of their large surface area and magnetic properties, meaning they can be extracted from solution by the application of an external magnetic field. We have investigated the extraction of copper (II) at levels reflecting ground water contamination and have shown that we can extract up to 99% of the copper from such samples using a simple copper ligating agent covalently bound to magnetic maghemite nanoparticles. Such particles effectively provide a third phase, acting as if soluble in water but extractable by a magnetic and, as such, can be applied to soil decontamination. We have also investigated the separation of minor actinides from lanthanides using CyMe4-BTPhen-functionalized SiO2-coated MNPs. These MNPs exhibited quantitative selectivity for Am(III) over Eu(III) at 4 M HNO3 (with a separation factor in excess of 1300) and also showed a small but significant selectivity for Am(III) over Cm(III) with a separation factor of around 2 in 4 M HNO3. |
| Exploitation Route | Selective actinide complexation and extraction allows the partitioning of these elements, reducing environmental impact. As such it is an essential component of modern nuclear waste processing techniques. Actinide complexation and extraction also has potential uses in analysis, catalysis and low-level waste clean-up (e.g. from a "dirty bomb"). This separation is made all the more difficult, given the chemical similarities between the two groups of elements. The ligands developed at Reading, have been investigated for their ability to carry out this separation by solvent extraction. Tri- and quadridentate ligands have been developed that allow preferential extraction of the trivalent minor actinides Am(III) and Cm(III) from lanthanides in acidic solutions, making them potentially suitable for a continuous liquid-liquid separation process for nuclear waste processing. Attaching the ligands to solid supports via a covalent linker allows extraction of higly radioactive elements by solid-liquid extraction from very low concentrations solutions, making the solid-supported ligands ideal for soil remediation or waste water treatment. The use of magnetic nanoparticles further allows extremely simple removal of radioactive contaminants through cheap and efficient magnetic separation. Please see potential non-acedemic use. |
| Sectors | Chemicals Energy Environment |
| URL | http://pubs.rsc.org/en/results?searchtext=Author%3AAshfaq%20Afsar |
| Description | Remediation of contaminated soils and water with engineered nanoparticles |
| Amount | £63,588 (GBP) |
| Funding ID | F3368005 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 11/2011 |
| End | 09/2015 |