The extraction of Zn(II), Cu(II) and Cd(II) from nitrate solutions at 0.1 ionic strength by impregnatedresinscontainingdi-(2,4,4-trimethylpentyl)phosphonic acid (HL) has been studied at 25°C. The distribution coefficient of the metal ion was determined as a function of both pH and extractant concentration in the resin phase, and the data were analyzed graphically using the slope analysis method and numerically using the program LETAGROP-DISTR. Analysis of the results showed that the extraction of these metal ions can be explained by the formation of metal complexes in the resin phase with a general composition ML2(HL)q where the value of q depends on the metal. Extractions reactions are proposed and the extraction constants of these reactions are presented. Finally, a comparison between the extraction of Zn(II), Cu(II) and Cd(II) with di-(2,4,4-trimethylpentyl)phosphinic acid sorbed into Amberlite XAD-2 and the extraction using an organic solvent as Isopar H has been made.
Solvent Impregnated Resins Containing di-(2,4,4-Trimethylpentyl)Phosphinic Acid. II. Study of the Distribution Equilibria of Zn(II), Cu(II) and Cd(II).
PROFUMO, ANTONELLA;PESAVENTO, MARIA
1993-01-01
Abstract
The extraction of Zn(II), Cu(II) and Cd(II) from nitrate solutions at 0.1 ionic strength by impregnatedresinscontainingdi-(2,4,4-trimethylpentyl)phosphonic acid (HL) has been studied at 25°C. The distribution coefficient of the metal ion was determined as a function of both pH and extractant concentration in the resin phase, and the data were analyzed graphically using the slope analysis method and numerically using the program LETAGROP-DISTR. Analysis of the results showed that the extraction of these metal ions can be explained by the formation of metal complexes in the resin phase with a general composition ML2(HL)q where the value of q depends on the metal. Extractions reactions are proposed and the extraction constants of these reactions are presented. Finally, a comparison between the extraction of Zn(II), Cu(II) and Cd(II) with di-(2,4,4-trimethylpentyl)phosphinic acid sorbed into Amberlite XAD-2 and the extraction using an organic solvent as Isopar H has been made.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
