American Chemical Science Journal, ISSN: 2249-0205,Vol.: 3, Issue.: 4 (October-December)
Solvent Extraction Studies of Uranium (VI) from Aqueous Media into Chloroform Solution of N,N´-ethylenebis(4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-oneimine)
U. J. Chukwu1* and J. Godwin2 1Department of Pure and Industrial Chemistry, University of Port Harcourt, PMB, 5323, Port Harcourt, Rivers State, Nigeria.
2Department of Chemical Sciences, Niger Delta University Wilberforce Island Bayelsa State, Nigeria.
U. J. Chukwu1* and J. Godwin2
1Department of Pure and Industrial Chemistry, University of Port Harcourt, PMB, 5323, Port Harcourt, Rivers State, Nigeria.
(1) Francisco Marquez-Linares, Full Professor of Chemistry, Nanomaterials Research Group, School of Science and Technology, University of Turabo, USA.
(1) Ana Paula Paiva, Faculty of Sciences of the University of Lisbon, Portugal.
(3) Ihesinachi A. Kalagbor, Nigeria.
Complete Peer review History: http://www.sciencedomain.org/review-history/1850
The extraction of Uranium (VI) from aqueous media of varying pH values (0.3 – 9.0) was studied using chloroform solution of 0.05M N,N`-ethylenebis(4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H- pyrazol-3-oneimine) (H2PrEtP) Schiff base. The effect of 4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (HPrP) as a mixed ligand in these extractions was also studied. The ligand H2PrEtP was shown to behave in solution as a very weak acid with potentiometrically determined acid dissociation constants pKa of 6.1±0.1 and 7.6±0.1. Colorimetric method was used to determine the Uranium(VI) concentrations in aqueous media after extraction processes. Slope analysis showed that the extracted uranyl complexes were UO2(HPrEtP).X in the absence of the mixed ligand (H2PrEtP/HPrP) and UO2(HPrEtP)HPrP.X in the presence of HPrP as a mixed ligand, with the excess anion X- coming from the buffers. The pH1/2 shifted from 6.9 ± 0.10 for H2PrEtP to 4.4 ± 0.10 for H2PrEtP/HPrP organic mixture. Though, log Kex values (-5.84 ± 0.18 log Kex H2PrEtP) > -8.71 ± 0.50 log Kex H2PrEtP/HPrP) indicated that the formation constant for UO2(HPrEtP).X was higher than that for UO2(HPrEtP)HPrP.X. Thus, the mixed ligand organic phase was shown to be a better extractant for Uranium(VI) with a wide extraction pH range of 4.0–6.5, a higher partition coefficient(KD) of 2.49 and quantitative extraction of 99.9% compared to extraction pH range of 7.75 – 8.75 and KD of 1.49 when H2PrEtP was used alone.
Aqueous media; buffered; extraction; N,N’-ethylenebis(4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-oneimine); mixed ligand; uranium (VI).
Full Article - PDF Page 479-488
DOI : 10.9734/ACSJ/2013/4155Review History Comments