A review on solid phase extraction of actinides and lanthanides with amide based extractants.

Recently, phenanthroline-based ligands have received increasing attention due to their excellent separation capabilities for trivalent actinides over lanthanide. In this work, we designed a soft-hard donor combined tetradentate phenanthroline-based extractant, tetraethyl (1,10-phenanthrolin-2,9-diyl)phosphonate (C2-POPhen), for the selective separation of trivalent Am(III) over Ln(III) from HNO3 media. The solvent extraction and complexation behaviors of Am(III) and Ln(III) by C2-POPhen were investigated both experimentally and theoretically. C2-POPhen could selectively extract Am(III) over Eu(III) with an extremely fast extraction kinetics. NMR titration studies suggest that only 1:1 complexes of Ln(III) with C2-POPhen formed in CH3OH in the presence of a significant amount of nitrate, while both 1:1 and 2:1 complexes species could form between C2-POPhen and Ln(III) perchlorate in CH3OH without nitrate ions. The stability constants for the complexation of Am(III) and Ln(III) with C2-POPhen in CH3OH were determined by spectrophotometric titrations and the Am(III) complexes are approximately 1 order of magnitude stronger than those of Ln(III), which is consistent with the extraction results. Theoretical calculations indicate that the Am-N bonds in Am/C2-POPhen complexes possess more covalent characters than the Eu-N bonds in Eu/C2-POPhen complexes, shedding light on the underlying chemical force responsible for the Am/Eu selectivity by C2-POPhen. This work represents the first report utilizing phenanthroline-based phosphonate ligands for selective separation of actinides from highly acidic solutions.

Selective Separation and Complexation of Trivalent Actinide and Lanthanide by a Tetradentate Soft-Hard Donor Ligand: Solvent Extraction, Spectroscopy, and DFT Calculations.

Extraction and separation of palladium(II), platinum(IV), gold(III) and rhodium(III) using piperidine-based extractants

Tailoring pillararene-based receptors for specific metal ion binding: From recognition to supramolecular assembly

Low-cost biosorbents (ginkgo leaf, osmanthus leaf, banyan leaf, magnolia leaf, holly leaf, walnut shell, and grapefruit peel) were evaluated in the simultaneous removal of La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Yb3+, Lu3+, UO22+, Th4+, Y3+, Co2+, Zn2+, Ni2+, and Sr2+ from aqueous solutions. In single metal systems, all adsorbents exhibited good to excellent adsorption capacities toward lanthanides and actinides. In a simulated multicomponent mixed solution study, higher selectivity and efficiency were observed for Th4+ over other metal cations, with ginkgo leaves providing the highest adsorptivity (81.2%) among the seven biosorbents. Through optimization studies, the selectivity of Th4+ biosorption on ginkgo leaf was found to be highly pH-dependent, with optimum Th4+ removal observed at pH 4. Th4+ adsorption was found to proceed rapidly with an equilibrium time of 120 min and conform to pseudo-second-order kinetics. The Langmuir isotherm model best described Th4+ biosorption, with a maximum monolayer adsorption capacity of 103.8 mg g-1. Thermodynamic calculations indicated that Th4+ biosorption was spontaneous and endothermic. Furthermore, the physical and chemical properties of the adsorbent were determined by scanning electron microscopy, Brunauer-Emmett-Teller, X-ray powder diffraction, and Fourier transform infrared analysis. The biosorption of Th from a real sample (monazite mineral) was studied and an efficiency of 90.4% was achieved from nitric acid at pH 4 using ginkgo leaves.

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Selective biosorption of thorium (IV) from aqueous solutions by ginkgo leaf

Extraction of trivalent americium and europium from nitric acid solution with a calixarene-based diglycolamide

Extraction of palladium(II) from nitric acid solutions with diglycolthioamide

The invention discloses a method for synthesizing diamide podand extraction agent, wherein chloro-carbonic ester and diglycolic anhydride react to generate mixed anhydride under the action of tertiary amine, and then the reaction is performed with amine to generate the diamide podand extraction agent. The method has mild reaction condition, can be performed at a low temperature, and has high reaction speed and short consumed time; the product purification operation is simple and easy; the obtained diamide podand extraction agent can meet the extraction purity requirement, and is beneficial to establishing flow that the diamide podand is used for treating high-level liquid waste in spent fuel reprocessing plant; the used chloro-carbonic ester is easy to prepare and has a low price, therefore, the cost for preparation of a great amount of extraction agent is greatly reduced; and besides, the yield of the extraction agent is high, so that the method is very suitable for industrial production and application.

Yuxuan Wu

Papers

Extraction of trivalent americium and europium from nitric acid solution with a calixarene-based diglycolamide

Extraction of palladium(II) from nitric acid solutions with diglycolthioamide

Method for synthesizing diamide podand extraction agent