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Solid-phase extraction of plutonium in various oxidation states from simulated groundwater using N-benzoylphenylhydroxylamine.

Perevalov SA, Malofeeva GI, Kuzovkina EV, Spivakov BY - J Radioanal Nucl Chem (2011)

Bottom Line: It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase.Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%.In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents.

View Article: PubMed Central - PubMed

Affiliation: V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences (GEOKHI RAS), Kosygina St. 19, 119991 Moscow, Russian Federation.

ABSTRACT

Solid-phase extraction of plutonium in different individual and mixed oxidation states from simulated groundwater (pH 8.5) was studied. The extraction of plutonium species was carried out in a dynamic mode using DIAPAK C16 cartridges modified by N-benzoylphenylhydroxylamine (BPHA). It was shown that the extent of recovery depends on the oxidation state of plutonium. The extraction of Pu(IV) was at the level of 98-99% regardless of the volume and flow-rate of the sample solution. Pu(V) was extracted by 90-95% and 75-80% from 10- and 100-mL aliquots of the samples, respectively, whereas the extraction of Pu(VI) did not exceed 45-50%. An equimolar mixture of Pu(IV), Pu(V), and Pu(VI) was extracted by 74%. The distribution coefficients (K d) and kinetic exchange capacities (S) of plutonium in various oxidation states were measured. It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase. Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%. In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents.

No MeSH data available.


The plutonium speciation during the sorption onto BPHA (100% corresponds to the total content of Pu in the respective eluent)
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Fig2: The plutonium speciation during the sorption onto BPHA (100% corresponds to the total content of Pu in the respective eluent)

Mentions: Figure 2 represents the plutonium oxidation states distribution after the sorption onto BPHA. During the desorption of Pu(IV), 86.2% of plutonium came out of the cartridge within passing the first 5 mL of 0.35 M HNO3 + 0.01 M HF eluent. An additional 5-mL portion almost completes the recovery of the residual Pu(IV). Pu(V) was fully eluted by 10 mL of 0.35 M HNO3 + 0.01 M HF solution. The absorption spectra have shown up to 80% of Pu to be present as Pu(IV) (the absorption band at 477 nm), and the rest exists as Pu(V) (the absorption band at 569 nm). These data are consistent with the suggestion that Pu(V) is reduced by BPHA during the sorption. Pu(VI) was also shown to be partially reduced in the cartridge: the effluent contained simultaneously Pu(IV), Pu(V), and Pu(VI). This explains the low efficiency of sorption of the hexavalent plutonium from SGW solutions. Mainly tetravalent plutonium is extracted during the sorption process. The eluate obtained by the desorption of mixed-valent plutonium consists of only Pu(IV) and Pu(V). Probably, Pu(VI) is reduced to Pu(V) or takes part in the following reaction:7\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {{\text{PuO}}_{2}}^{2+} + {\text{Pu}}^{4+} = 2{{\text{PuO}}_{2}}^{+} $$\end{document}Fig. 2


Solid-phase extraction of plutonium in various oxidation states from simulated groundwater using N-benzoylphenylhydroxylamine.

Perevalov SA, Malofeeva GI, Kuzovkina EV, Spivakov BY - J Radioanal Nucl Chem (2011)

The plutonium speciation during the sorption onto BPHA (100% corresponds to the total content of Pu in the respective eluent)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4514682&req=5

Fig2: The plutonium speciation during the sorption onto BPHA (100% corresponds to the total content of Pu in the respective eluent)
Mentions: Figure 2 represents the plutonium oxidation states distribution after the sorption onto BPHA. During the desorption of Pu(IV), 86.2% of plutonium came out of the cartridge within passing the first 5 mL of 0.35 M HNO3 + 0.01 M HF eluent. An additional 5-mL portion almost completes the recovery of the residual Pu(IV). Pu(V) was fully eluted by 10 mL of 0.35 M HNO3 + 0.01 M HF solution. The absorption spectra have shown up to 80% of Pu to be present as Pu(IV) (the absorption band at 477 nm), and the rest exists as Pu(V) (the absorption band at 569 nm). These data are consistent with the suggestion that Pu(V) is reduced by BPHA during the sorption. Pu(VI) was also shown to be partially reduced in the cartridge: the effluent contained simultaneously Pu(IV), Pu(V), and Pu(VI). This explains the low efficiency of sorption of the hexavalent plutonium from SGW solutions. Mainly tetravalent plutonium is extracted during the sorption process. The eluate obtained by the desorption of mixed-valent plutonium consists of only Pu(IV) and Pu(V). Probably, Pu(VI) is reduced to Pu(V) or takes part in the following reaction:7\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {{\text{PuO}}_{2}}^{2+} + {\text{Pu}}^{4+} = 2{{\text{PuO}}_{2}}^{+} $$\end{document}Fig. 2

Bottom Line: It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase.Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%.In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents.

View Article: PubMed Central - PubMed

Affiliation: V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences (GEOKHI RAS), Kosygina St. 19, 119991 Moscow, Russian Federation.

ABSTRACT

Solid-phase extraction of plutonium in different individual and mixed oxidation states from simulated groundwater (pH 8.5) was studied. The extraction of plutonium species was carried out in a dynamic mode using DIAPAK C16 cartridges modified by N-benzoylphenylhydroxylamine (BPHA). It was shown that the extent of recovery depends on the oxidation state of plutonium. The extraction of Pu(IV) was at the level of 98-99% regardless of the volume and flow-rate of the sample solution. Pu(V) was extracted by 90-95% and 75-80% from 10- and 100-mL aliquots of the samples, respectively, whereas the extraction of Pu(VI) did not exceed 45-50%. An equimolar mixture of Pu(IV), Pu(V), and Pu(VI) was extracted by 74%. The distribution coefficients (K d) and kinetic exchange capacities (S) of plutonium in various oxidation states were measured. It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase. Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%. In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents.

No MeSH data available.