Extração liquido-liquido por fase unica : estudo no sistema agua-etanol-cloroformio com 8-hidroxiquinolina e Al,Fe,Cu e Zn

AUTOR(ES)
DATA DE PUBLICAÇÃO

1981

RESUMO

In this work, the extraction behavior of the water-ethanol-chloroform system, which had not yet been investigated by the Single Phase Extraction tecnique, was studied with respect to the extractions of Al, Cu, Fe, and Zn with 8-hydroxyquinoline (Oxine) as the chelating agent. Al, Fe and Cu are little extracted at low acidity (low pH fu values) but are quantitatively extracted by increasing pH fu. Zn is not extracted at low pH fu values and presents an anomalous behavior at high pH fu: as the Oxine concentration decreases (from 0,05 M to 0,01 M), the quantity of Zn extracted gradualIy increases, possibilly due to adduct formation of the chelate with an ionized form of chelant. EDTA addition largely reduces the extraction of all ions studied and no extraction occurs at low pH fu values. Variation in the temperature of the separation water system does not give any appreciable effect on the extraction efficiency. The effect of varying the volume (as well as the height) of the liquid column of the separation water is negligible as related to the extraction efficiency. This study indicates that the use of an organic extraction solvent which is denser than water (chloroform) gives the same high extraction coefficients as do the less dense organic solvents.

ASSUNTO(S)

extração (quimica) extração por solventes equilibrio liquido-liquido

ACESSO AO ARTIGO

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