Abstract

J. Godwin¹, L. S. Tella¹, J. I. Consul², A. N. Ebelegi¹ and N. Ayawei¹

DOI : http://dx.doi.org/10.13005/ojc/350611

The effect of some acids, anions and auxiliary complexing agents on the extraction of Cadmium (II) from aqueous solutions buffered to pH 7.5 using a chloroform solution of the Schiff base ligand 4,4´-(1E,1E´)-1,1´-(ethane-1,2-diylbis(azan-1-yl-1ylidene))bis(5-methyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-ol) (H2BuEtP) alone and in the presence of 1-(3-hydroxy-5-methyl-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) butan-1-one (HBuP) after an equilibration time of sixty minutes was investigated. Working concentration of Cd(II) was 50mgL-1, while a range from 0.001M-3.0M was used for acid and 0.001M-1.0M for anions and auxiliary complexing agents. Extraction raffinates were analysed for Cd(II) using Flame Atomic Absorption spectrophotometry and Distribution Ratios. Percentage Extractions (%E) were calculated by difference of Cd(II) concentrations before and after equilibration. The mixed ligands H2BuEtP/HBuP organic phase was a better extractant for Cadmium than H2BuEtP alone but the difference was not significant for all acids, Cl-, Oxalate and Tartrate. The results indicated that at lower concentrations of the acids, anions and auxiliary complexing agents, a releasing effect occurred with improved extraction of Cadmium > 90% in most cases and at high concentrations there was reduced percentage extraction due to masking of Cadmium from formation of stable salts of Cadmium. Comparing results with other those of other metals studied under same conditions showed that multi-metal extraction with the ligand (H2BuEtP) is possible. H3PO4, H2SO4, HCl, PO43-, EDTA and Oxalate all showed theoretical potentials for separating Cadmium from other studied metals with Separation Factors βxy = Dx/Dy close to and above 104.

Cadmium; Acids; Anions; Auxiliary Complexing Agents; 4;4´-(1E;1E´)-1;1´-(ethane-1;2-diylbis(azan-1-yl-1ylidene))bis(5-methyl-2-phenyl-2;3-dihydro-1H-pyrazol-3-ol); Extraction and Theoretical Separation

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