Abstract
| - Composite gels of calcium alginate containing iminodiacetictype resin were prepared as a chemical analogue ofbiological tissues and membrane such as the cell wall.This chemical model was applied in copper biosorption fromsynthetic aqueous solutions. Experimental data on thecomposite were compared to those obtained for thebiopolymer and the iminodiacetic-type resin separatelyand fitted into the ion exchange equilibrium model proposedin this work, which basically assumes that metal retentionis the sum of the metal loaded onto the biopolymer andonto the resin. This model is tested with experimental dataon copper biosorption on composite gels, including theequilibrium expressions of all the ionic species that arepresent in the system, the fraction of metal enclosed in thegel fluid, the gel volume variation, and the Donnanequilibrium theory. Another simplified model that onlyrequires one equilibrium constant for each metal in theresin is shown to fit the results of the experiment fairly well,but it proves necessary to include an empirical parametern into the equilibrium equation of copper in the resin toobtain the best fit of experimental data.
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