UPTAKE OF Cd2+ FROM AQUEOUS SOLUTIONS USING PROTONATED DRY ALGINATE BEADS

The use of protonated dry alginate beads for the uptake of cadmium ions from aqueous solutions was studied at 25 deg C. The uptake of Cd2+ produced a release of protons, for which a molar ratio d[H-1/d[Cd2+] of 2.0 was established. This ion exchange was the mechanism of cadmium uptake which followed...

Full description

Saved in:
Bibliographic Details
Published in:Canadian metallurgical quarterly 2008-01, Vol.47 (1), p.45-50
Main Authors: IBÁÑEZ, J.P., UMETSU, Y.
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The use of protonated dry alginate beads for the uptake of cadmium ions from aqueous solutions was studied at 25 deg C. The uptake of Cd2+ produced a release of protons, for which a molar ratio d[H-1/d[Cd2+] of 2.0 was established. This ion exchange was the mechanism of cadmium uptake which followed a pseudo-second order kinetic model. The uptake was strongly dependent on the solution pH up to a value of 4.5 after which it remained constant. The maximum Cd-uptake was computed in 285.7 mg per gram of alginate beads (dry wt.) at pH 4.5 by the Langmuir adsorption model. A residual concentration of around 0.09 mg/L of Cd2+ which allowed safety discharge of some types of effluents having this heavy metal ion, was reached with a solution initially having 25 mg/L of Cd2+. EPMA-EDX of Cd-loaded beads showed a uniform distribution of the metal ions throughout the structure of the alginate bead, regardless the solution pH.
ISSN:0008-4433
DOI:10.1179/000844308794408542