Study of nitrate complex formation with trivalent Pm, Eu, Am and Cm using a solvent extraction technique

2004 ◽  
Vol 92 (12) ◽  
Author(s):  
Sofie Andersson ◽  
C. Ekberg ◽  
J-O. Liljenzin ◽  
M. Nilsson ◽  
G. Skarnemark
Keyword(s):  
Solvent Extraction ◽  
Complex Formation ◽  
Nuclear Fuel ◽  
Stability Constants ◽  
Spent Nuclear Fuel ◽  
Aqueous Media ◽  
Separation Process ◽  
Nitrate Complex ◽  
The Stability ◽  
Solvent Extraction Technique

SummaryThe separation of actinides and lanthanides is an important question in the treatment of spent nuclear fuel in the transmutation concept. To find an efficient and well functioning separation process it is necessary to study the chemistry of the elements in the two groups in different aqueous media. The stability constants of the nitrate complex formation with Pm, Eu, Am and Cm were determined using solvent extraction. The extraction was studied using the synergistic system of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine and 2-bromodecanoic acid in

Berkelium nitrate complex formation using a solvent extraction technique

2006 ◽  
Vol 94 (1) ◽  
Author(s):  
Sofie Andersson ◽  
Heino Nitsche ◽  
Ralf Sudowe
Keyword(s):  
Complex Formation ◽  
Stability Constants ◽  
Aqueous Phase ◽  
Ion Concentration ◽  
Nitrate Complex ◽  
Nitrate Ion ◽  
Data Points ◽  
The Stability ◽  
Butyl Benzene ◽  
Solvent Extraction Technique

SummaryThe extraction of Bk(III) into an organic phase consisting of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine, 2-bromodecanoic acid and tert-butyl benzene as a function of nitrate ion concentration in the aqueous phase was studied in order to determine the stability constants of the formation of Bk nitrate complexes. Increasing the nitrate ion concentration in the aqueous phase will increase the nitrate complex formation and thus the extraction of metal ions will decrease. Measuring this decrease in distribution ratio and fitting the data points with an appropriate model gives the stability constants of the Bk nitrate complex formation.

Determination of stability constants of lanthanide nitrate complex formation using a solvent extraction technique

2006 ◽  
Vol 94 (8) ◽  
Author(s):  
Sofie Andersson ◽  
Klaus Eberhardt ◽  
Christian Ekberg ◽  
Jan-Olov Liljenzin ◽  
Mikael Nilsson ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Complex Formation ◽  
Stability Constants ◽  
Lanthanide Ions ◽  
Radioactive Isotopes ◽  
Ion Concentration ◽  
Extraction Technique ◽  
Nitrate Complex ◽  
Experimental Conditions ◽  
Solvent Extraction Technique

SummaryFor lanthanides and actinides, nitrate complex formation is an important factor with respect to the reprocessing of nuclear fuels and in studies that treat partitioning and transmutation/conditioning. Different techniques, including microcalorimetry, various kinds of spectroscopy, ion-exchange and solvent extraction, can be used to determine stability constants of nitrate complex formation. However, it is uncommon that all lanthanides are studied at the same time, using the same experimental conditions and technique. The strengths of the complexes are different for lanthanides and actinides, a feature that may assist in the separation of the two groups. This paper deals with nitrate complex formation of lanthanides using a solvent extraction technique. Trace amounts of radioactive isotopes of lanthanides were produced at the TRIGA Mainz research reactor and at the Institutt for Energiteknikk in Kjeller, Norway (JEEP II reactor).The extraction of lanthanide ions into an organic phase consisting of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine, 2-bromodecanoic acid andExtraction curves for La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Dy, Ho and Er were obtained and stability constants for their nitrate complex formation were estimated. Tb, Tm, Yb and Lu were also investigated, but no stability constants could be determined. The distribution ratios for the metal ions at low nitrate ion concentration were obtained at the same time, showing the effect of lanthanide contraction resulting in decreasing extraction along the series. A clear tetrad effect in the lanthanide group was also found.

Hafnium(IV) complexation with oxalate at variable temperatures

2017 ◽  
Vol 105 (5) ◽  
Author(s):  
Mitchell T. Friend ◽  
Nathalie A. Wall
Keyword(s):  
Solvent Extraction ◽  
Fission Product ◽  
Nuclear Fuel ◽  
Aqueous Phase ◽  
Spent Nuclear Fuel ◽  
Fission Products ◽  
Extraction Technique ◽  
Complexing Agents ◽  
Solvent Extraction Technique

AbstractAppropriate management of fission products in the reprocessing of spent nuclear fuel (SNF) is crucial in developing advanced reprocessing schemes. The addition of aqueous phase complexing agents can prevent the co-extraction of these fission products. A solvent extraction technique was used to study the complexation of Hf(IV) – an analog to fission product Zr(IV) – with oxalate at 15, 25, and 35°C in 1 M HClO

Equilibrium Studies of Alkyltin(IV) Complexes with D-Glucosamine

1997 ◽  
Vol 62 (7) ◽  
pp. 1023-1028 ◽  
Author(s):  
Mohamed M. Shoukry ◽  
Samir M. El-Medani
Keyword(s):  
Complex Formation ◽  
Stability Constants ◽  
Acid Base ◽  
Complex Formation Equilibria ◽  
Equilibrium Studies ◽  
Formation Equilibria ◽  
Effects Of Temperature ◽  
The Stability

The acid-base and complex-formation equilibria involving glucosamine and its complexes with alkyltin(IV) chlorides have been studied by potentiometric technique. The results prove to a formation of 1 : 1 complex with trialkyltin(IV) and both 1 : 1 and 1 : 2 complexes with dialkyltin(IV) species. The stability constants in water were determined, the effects of temperature (from 15 to 35 °C) and ethanol (up to 88 vol.%) was studied and the speciation of the complexes was resolved.

The affinity of aldehydic compounds to complex formation. Nickel(II) and cobalt(II) complexes with 2-pyridinecarboxaldehyde

1977 ◽  
Vol 55 (14) ◽  
pp. 2613-2619 ◽  
Author(s):  
M. S. El-Ezaby ◽  
M. A. El-Dessouky ◽  
N. M. Shuaib
Keyword(s):  
Complex Formation ◽  
Aqueous Solutions ◽  
Stability Constants ◽  
Metal Ion ◽  
Experimental Conditions ◽  
Complex Species ◽  
Spectrophotometric Methods ◽  
Complex Equilibria ◽  
The Stability ◽  
Hydroxy Groups

The interactions of Ni(II) and Co(II) with 2-pyridinecarboxaldehyde have been investigated in aqueous solutions at μ = 0.10 M (KNO3) at 30 °C. The stability constants of different complex equilibria have been determined using potentiometric methods. Spectrophotometric methods were also used in the case of the nickel(II) – 2-pyridinecarboxaldehyde system. It was concluded that nickel(II) and cobalt(II), analogous to copper(II), enhance hyrdation of 2-pyridinecarboxaldehyde prior to deprotonation of one of the geminal hydroxy groups. Complex species of 1:1 as well as 1:2 metal ion to ligand composition exist under the experimental conditions used.

Discontinuous spectrocolorimetric titration method for determining stability constants of fulvic acid - iron complexes

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1279 ◽  
Author(s):  
S. B. Pandeya ◽  
A. K. Singh
Keyword(s):  
Stability Constant ◽  
Stability Constants ◽  
Aqueous Media ◽  
Poultry Manure ◽  
Fulvic Acids ◽  
Titration Method ◽  
Binding Ability ◽  
Press Mud ◽  
Determining Factors ◽  
The Stability

The stability constants for the complexes formed between iron species existing in ambient soil environment and fulvic acids (FA) extracted from organic wastes like sewage sludge, farm yard manure (FYM), poultry manure, and press mud were determined in aqueous media of pH 5·0 and 8·5 by discontinuous spectrocolorimetric titration method. The values of stability constant (log K) of Fe–FA complexes estimated at pH 5·0 were 6·026, 6·212, 6·270, and 6·342 for FYM, sludge, poultry manure, and press mud, respectively. The respective values at pH 8·5 were 6·145, 6·276, 6·350, and 6·940. The order of the values of log K for different preparations of fulvic acids was press mud > poultry manure > sludge > FYM. The functional group contents, their pH of neutralisation, and electrostatic properties of the FA such as pKINT, pKm, and 0·868 nW, were found to be the determining factors for maximum binding ability of FA for metal cations and the stability constant of Fe–FA for different FA preparations. The basic assumptions and the limitations of the discontinuous spectrocolorimetric estimation of stability constants for Fe–FA are discussed.

Determination of Co(II) and Ni(II)-humate stability constants at high ionic strength NaCl solutions

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
D.N. Kurk ◽  
Gregory R. Choppin
Keyword(s):  
Humic Acid ◽  
Ionic Strength ◽  
Solvent Extraction ◽  
Potentiometric Titration ◽  
Stability Constants ◽  
Dissociation Constants ◽  
High Ionic Strength ◽  
Extraction Technique ◽  
Solvent Extraction Technique

Complexation of Ni(II) and Co(II) by unfractionated humic acid (HA) was measured in 0.3 to 5.0 m NaCl solutions at pH 6 and 20 °C, using a solvent extraction technique. The dissociation constants and capacities of the humic acid were investigated in 0.1 to 5.0 m NaCl solutions at 25 °C using potentiometric titration methods.

Die Komplexbildung von Tris(dihydroxy-phosphonylmethyl)phosphinoxid* mit einigen zweiwertigen Kationen / Complex Formation of Some Divalent Cations with Tris(dihydroxy-phosphonylmethyl)phosphine Oxide

1977 ◽  
Vol 32 (5) ◽  
pp. 547-550 ◽  
Author(s):  
G. Anderegg
Keyword(s):  
Complex Formation ◽  
Stability Constants ◽  
Phosphine Oxide ◽  
Divalent Cations ◽  
Ph Measurements ◽  
The Stability

The formation of the 1:1 complexes of Mg2+, Ca2+, Ni2+, Cu2+ and Zn2+ with tris-(dihydroxy-phosphonylmethyl)phosphine oxide has been studied by pH measurements. The values of the stability constants and their trend is similar to that found for the complexes of tripolyphosphate.

Sign in / Sign up

Export Citation Format

Share Document