the solvent extraction of rare earth metal ions from nitrate solutions by 5.11.17.23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-dihydroxycalix[4]arene (l) in 1,2-dichloroethane has been investigated. the alalysis of the extraction equilibrium obtained from a mixture of la3+, eu3+, er3+ and y3+ revealed that the extracted species have a 1:1 metal/ligand ratio. the intra-group sepa...

efforts to increase the mass transfer coefficient, enhance the contact area, and decrease the power input of contractors have given risen to the development of the pre-dispersed solvent extraction (pdse) contactor and the devise of the new dissolved nitrogen pdse (dnpdse) contactors. the studies conducted after the design of the new contactor to determine the working conditions for its suitable...

There has been increasing environmental concerns on the metallic pollution in recent decades. The conventional technologies used for metal extraction are ion-exchange resins, polymer ultrafiltration and microemulsion. The whole extraction mechanism can be divided into 4 steps: 1) The binding of dissolved metal to active sites, 2) Separation of the metal load extractant from the lean phase, 3) R...

oxime extractants 3-tert-butyl-2-hydroxy-5-methyl benzaldehyde oxime (hl1) and 3-tert-butyl-2-hydroxy-5-methoxy benzaldehyde oxime (hl2) were synthesized and characterized by conventional spectroscopic methods. suitable lipophilic nature of the prepared extractants allowed examining the ability of these molecules for extraction-separation of copper from its mixture with normally associated meta...

Chemical extractants used to measure labile soil metal must ideally select for and solubilise the labile fraction, with minimal solubilisation of non-labile metal. We assessed four extractants (0.43 M HNO3, 0.43 M CH3COOH, 0.05 M Na2H2EDTA and 1 M CaCl2) against these requirements. For soils contaminated by contrasting sources, we compared isotopically exchangeable Ni, Cu, Zn, Cd and Pb (EValue...

This paper reports on solvent-extraction studies of Ni(II) from sulfate solutions with LIX 84I (2-hydroxy-5-nonylacetophenoneoxime) as the extractant. The extraction of metal depends on the equilibrium pH of the aqueous phase and the extractant concentration. The transfer of metal follows a cation exchange-type mechanism: Ni2+ + 2HA --> NiA2 + 2H+. Extraction varies with the nature of the dilue...

in this article cloud-point extraction (cpe) was used with chelating agent to extract uranium from aqueous solutions. the methodology used is based on the formation of metal complexes soluble in a micellar phase of surfactant. the metal ions complexes are then extracted into the surfactant-rich phase at a temperature above the cloud-point temperature. the effect of type of surfactants and ligan...

The extraction efficiency of heavy metals from soils using three forms of gamma poly-glutamic acid (γ-PGA) as the washing agents was investigated. Controlling factors including agent concentrations, extraction time, pH, and liquid to soil ratio were evaluated to determine the optimum operational conditions. The distribution of heavy metal species in soils before and after extraction processes w...

4,4'-Bis(dihexylaminocarbonyl)-2,2'-bipyridine (BDC-Bipy) was synthesized and studied systematically as a chelating reagent for metal ions extraction in supercritical CO(2). The compound showed high extraction efficiency for Co(2+) (100%), Cu(2+) (100%), Cd(2+) (98.2%), and Zn(2+) (100%) ions and good extraction efficiency for Sr(2+) (79.4%) and Pb(2+) (89.8%) when the extraction was performed ...