Liquid-liquid extraction of Pu(IV), U(VI) and Am(III) using malonamide in room temperature ionic liquid as diluent

Solvent extraction of Th(IV) from aqueous solution with methylimidazole in ionic liquid

An extraction of Th(IV) was performed using 1- methylimidazole (1-MIM) or 2-methylimidazole (2-MIM) as the extractant in imidazolium type ionic liquids (ILs) or n-pentanol. The extractability for Th4+ in ILs was by far higher than that obtained in n-pentanol. The extraction mechanism was determined by slope analysis and ESI-MS. The transfer of Th4+ with MIM into ILs proceeded through both a cationic exchange and a neutral solvation mechanism, whereas the partitioning of Th4+ with MIM into n-pentanol only underwent a neutral solvation mechanism. The thermodynamic parameters values (ΔH, ΔS and ΔG) for extraction of Th4+ with 1-MIM in IL were calculated and the results indicated the extraction reaction was spontaneous and went through endothermic process. Separation of Th4+ from the solution of lanthanides (III) and uranium was also carried out by 1-MIM in ILs and n-pentanol.

Highly efficient extraction of actinides with pillar[5]arene-derived diglycolamides in ionic liquids via a unique mechanism involving competitive host–guest interactions

A novel extraction mechanism is described.

Ionic liquid-based uranium(vi) extraction with malonamide extractant: cation exchange vs. neutral extraction

The U(VI) extraction with DMDBMA is performed in the [C₄mim][Tf₂N] ionic liquid (IL) either as a cationic or a neutral species, without the help of IL ions. However, this does not prevent a noticeable pollution of the aqueous phase with the IL.

Zeta potential-assisted sorption of uranyl tricarbonate complex from aqueous solution by polyamidoxime-functionalized colloidal particles

A new method has been developed for effective uranium(vi) capture from an aqueous solution through zeta potential-assisted sorption.

Influence of the ionic liquid cation on the solvent extraction of trivalent rare-earth ions by mixtures of Cyanex 923 and ionic liquids

Trivalent rare-earth ions were extracted from nitric acid medium by the neutral phosphine oxide extractant Cyanex 923 into ionic liquid phases containing the bis(trifluoromethylsulfonyl)imide anion. Five different cations were considered: 1-butyl-3-methylimidazolium, 1-decyl-3-methylimidazolium, methyltributylammonium, methyltrioctylammonium and trihexyl(tetradecyl)phosphonium. The extraction behavior of neodymium(iii) was investigated as a function of various parameters: pH, extractant concentration, concentration of the neodymium(iii) ion in the aqueous feed and concentration of the salting-out agent. The loading capacity of the ionic liquid phase was studied. The extraction efficiency increased with increasing pH of the aqueous feed solution. The extraction occurred for all ionic liquids via an ion-exchange mechanism and the extraction efficiency could be related to the solubility of the ionic liquid cation in the aqueous phase: high distribution ratios for hydrophilic cations and low ones for hydrophobic cations. Addition of nitrate ions to the aqueous phase resulted in an increase in extraction efficiency for ionic liquids with hydrophobic cations due to extraction of neutral complexes. Neodymium(iii) could be stripped from the ionic liquid phase by 0.5-1.0 M nitric acid solutions and the extracting phase could be reused. The extractability of other rare earths present in the mixture was compared for the five ionic liquids.

Binary lanthanide(iii)/nitrate and ternary lanthanide(iii)/nitrate/chloride complexes in an ionic liquid containing water: optical absorption and luminescence studies

Thermodynamic and spectroscopic data indicate that nitrate and chloride are stronger ligands than water for lanthanides in water saturated BumimTf₂N.

Solvent extraction of lanthanides and yttrium from aqueous solution with methylimidazole in an ionic liquid

Methylimidazoles combined with ILs transfer lanthanides and yttrium from aqueous solution to ILs via a cation-exchange mechanism and a neutral solvation mechanism.

Solvent extraction of europium(iii) to a fluorine-free ionic liquid phase with a diglycolamic acid extractant

Bis(2-ethylhexyl)diglycolamic acid (DEHDGA) dissolved in the fluorine-free ionic liquid tetraoctylammonium dodecyl sulphate, [N₈₈₈₈][DS] is an efficient extractant for europium(iii).

Extraction mechanism and γ-radiation effect on the removal of Eu3+ by a novel BTPhen/[Cnmim][NTf2] system in the presence of nitric acid

The extraction mechanism of Eu³⁺ by using BTPhen/[C_nmim][NTf₂] (n = 2, 4, 8) was investigated in the presence of nitric acid, and the new extraction system shows high radiation stability.

Ionothermal effects on low-dimensionality uranyl compounds using task specific ionic liquids

Task specific ionic liquids are employed in the development of two new low-dimensionality uranyl compounds.

Bioreduction and precipitation of uranium in ionic liquid aqueous solution by Clostridium sp

The ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6], N-ethylpyridiniumtrifluoroacetate [EtPy][CF3COO] and N-ethylpyridiniumtetrafluoroborate [EtPy][BF4], affected the reduction and precipitation of uranium by Clostridium sp. to a varying degree. Characterization of uranium association with the ionic liquids showed that uranium formed a monodentate complex with the anion BF4(-) and PF6(-) of [EtPy][BF4] and [BMIM][PF6], respectively; and a bidentate complex with carboxylate of [EtPy][CF3COO]. Bioreduction of U(VI) was influenced by the type of complex formed: monodentate complexes were readily reduced whereas the bidentate complex of U(VI) with [CF3COO] was recalcitrant. [EtPy][BF4] affected the rate and extent of precipitation of the reduced uranium; at higher concentration the reduced U(IV) remained in the solution phase. The results suggest that by tuning the properties of ionic liquids they may be valuable candidates for uranium biotreatment.