Speaker
Irena Špendlíková
(KJCH FJFI CVUT)
Description
This study deals with the effects of irradiation on the stability and extraction properties of thiacalixarenes1, the prospective liquid-liquid extractants for the extraction of actinides and lanthanides from aqueous solutions. Thiacalixarenes (T1, T2) dissolved in cyclohexanone and 1,2-dichloroethane were irradiated with 60Co gamma rays or accelerated electrons with energy of 4.5 MeV. The absorbed doses ranged from 0 to 100 kGy.
The extraction properties towards europium and americium, as lanthanide and actinide representatives, were studied in synergistic systems. The combinations of two thiacalixarene extracting agents, three COSAN molecules and three diluents (chlorobenzene, nitrobenzene and 1,2-dichloroethane) were evaluated.
For the determination of residual concentration, the HPLC method was used and compared with the assessment of the change of the D(Am) and D(Eu) values in solvent extraction experiments. The aqueous phase consisted of a solution of COSAN (chloro-protected bis(1,2-dicarbollide) cobaltic acid) in 0.1mol/l nitric acid; solutions of thiacalixarene T2 in 1,2-dichlorethane were used as the organic phase. Distribution ratios D for 152Eu and 241Am and their mutual separation factors were evaluated. The activity of aqueous and organic phase was measured via gamma spectrometer with HPGe detector.
The results obtained from both methods correspond to each other and the decline in the extraction behaviour can be derived from the residual concentration determination and otherwise. Both thiacalixarenes seem to be more stable in the irradiated cyclohexanone samples than in the 1,2-dichloroethane samples which is in good agreement with the state that during cyclohexanone radiolysis less aggressive intermediates are produced comparing with the latter case.
This work was performed under the auspices of Czech Science Foundation grant GACR 104-07-1242 and Ministry of the Interior of the Czech Republic grant VG20132015132.
REFERENCES
1. Lhoták P.: Eur. J. Org. Chem., 2004(8), 1675.
Primary author
Irena Špendlíková
(KJCH FJFI CVUT)
Co-authors
Jan John
(Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, 115 19 Prague, Czech Republic)
Pavel Lhoták
(Department of Inorganic Chemistry, ICT Prague, Technická 5, 166 28 Praha 6)
Václav Čuba
(Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, 115 19 Prague, Czech Republic)
