Speciation of protactinium(V) at tracer scale

2009 ◽  
Vol 97 (7) ◽  
Author(s):  
Claire Le Naour ◽  
M. V. Di Giandomenico ◽  
Y. Zhao ◽  
M. Mendes
Keyword(s):  
Ionic Strength ◽  
Solvent Extraction ◽  
Distribution Coefficient ◽  
Systematic Study ◽  
Chelating Agent ◽  
Constant Ionic Strength ◽  
Diethylene Triamine ◽  
Sulphate Chloride

AbstractSolvent extraction in the conditions of tracer scale chemistry was used to study protactinium(V) complexation with sulphate, chloride, oxalate and diethylene-triamine-pentaacetate. Extraction experiments were conducted using the chelating agent thenoyltrifluoroacetone (TTA) in toluene at constant ionic strength and temperature. Information on the species involved in partition equilibria relative to protactinium(V) complexation were deduced from a systematic study of the variations of distribution coefficient of Pa(V) as function of ligands, protons and TTA concentration.

Synergistic extraction of Ce(III), Tb(III) and Lu(III) with a mixture of hexafluoroacetylacetone and triphenylphosphineoxide in benzene

2007 ◽  
Vol 95 (12) ◽  
Author(s):  
Moazzaz Ali Rizvi ◽  
Akbar Ali ◽  
Mohammad Saeed Iqbal
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Solvent Extraction ◽  
Chelating Agent ◽  
Triphenylphosphine Oxide ◽  
Synergistic Extraction ◽  
Neutral Ligand ◽  
Trivalent Lanthanides ◽  
Synergistic Solvent Extraction

SummaryThe synergistic solvent extraction of trivalent lanthanides such as Ce(III), Tb(III) and Lu(III) has been studied with a mixture of hexafluoroacetylacetone (HHFA) acting as an acidic chelating agent and triphenylphosphine oxide (TPPO) as a neutral ligand in benzene from aqueous solution of pH 2.5 having ionic strength 0.01 mol dm

scholarly journals Solvent Extraction of Thorium(IV) by Didodecylphoric Acid

2003 ◽  
Vol 8 (2) ◽  
pp. 107
Author(s):  
Fawwaz I. Khalili ◽  
Khaled M. Mousa ◽  
Ehsan I. Soudani
Keyword(s):  
Free Energy ◽  
Ionic Strength ◽  
Solvent Extraction ◽  
Hydrochloric Acid ◽  
Distribution Coefficient ◽  
Acid Concentration ◽  
Supporting Electrolyte ◽  
Hydrochloric Acid Concentration ◽  
Different Temperatures ◽  
Extraction Processes

Solvent extraction of Thorium (VI) ion from perchlorate solution using didodecylphosphoric acid, DDPA, in chloroform diluent was studied. The effects of stripping hydrochloric acid concentration, stripping time, extraction time, DDPA concentration, pH, ionic strength, supporting electrolyte and temperature on the extraction processes have been studied. From the distribution coefficient values at different temperatures,the enthalpy, the free energy and the entropy changes associated with the extraction processes were determined. The composition of the complex formed was established to be Th(ClO4)4-nRn(HR)5-n where, n=1 or 2 and (HR)2 represents the dimer of DDPA.  

scholarly journals Solvent Extraction of Uranium (VI) by Didodecylphosphoric Acid

1999 ◽  
Vol 4 ◽  
pp. 15 ◽  
Author(s):  
Khaled Mousa ◽  
Fawwaz Khalili
Keyword(s):  
Free Energy ◽  
Nitric Acid ◽  
Ionic Strength ◽  
Solvent Extraction ◽  
Distribution Coefficient ◽  
Acid Concentration ◽  
Supporting Electrolyte ◽  
Nitric Acid Concentration ◽  
Different Temperatures ◽  
Extraction Processes

Solvent extraction of uranium(Vl) ion from perchlorate solution using didodecylphosphorie acid, DDPA, in toluene diluent was studied. The effects of stripping nitric acid concentration, stripping time, extraction time, DDPA concentration, pH, ionic strength, supporting electrolyte and temperature on the extraction processes have been studied. From the distribution coefficient values at different temperatures, the enthalpy, the free energy and the entropy changes associated with the extraction processes were determined. The composition of the complex formed was established to be UO2(CLO4)(HR2)(HR)2 where, (HR)2 represents the dimer of DDPA.

Adsorption of chlorate and bromate ions on mercury electrodes from constant ionic strength solutions

1988 ◽  
Vol 85 ◽  
pp. 523-527
Author(s):  
M.M. Zuleika ◽  
Palhares SILVA ◽  
Ernesto Rafael GONZALEZ ◽  
Luis Alberto AVACA ◽  
Artur de Jesus MOTHEO
Keyword(s):  
Ionic Strength ◽  
Constant Ionic Strength ◽  
Mercury Electrodes

Kinetics and Mechanism of Hexachloroiridate(IV) Oxidation of Arsenic(III) in Acidic Perchlorate Solutions

1992 ◽  
Vol 57 (7) ◽  
pp. 1451-1458 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Ionic Strength ◽  
Fractional Order ◽  
Activation Parameters ◽  
Order Reaction ◽  
First Order Reaction ◽  
Intermediate Complex ◽  
Constant Ionic Strength ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Kinetics Of

The kinetics of oxidation of arsenic(III) by hexachloroiridate(IV) at lower acid concentrations and at constant ionic strength of 1.0 mol dm-3 have been investigated spectrophotometrically. A first-order reaction in [IrCl62-] and fractional order with respect to arsenic(III) have been observed. A kinetic evidence for the formation of an intermediate complex between the hydrolyzed arsenic(III) species and the oxidant was presented. The results showed that decreasing the [H+] is accompanied by an appreciable acceleration of the rate of oxidation. The activation parameters have been evaluated and a mechanism consistent with the kinetic results was suggested.

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