Stability of immobilized biosorbent and its influence on biosorption of copper

Biomass immobilization in a polymeric matrix may improve biosorption capacity and facilitate the separation of biomass from metal-bearing solutions. Many polymers are studied as immobilizing agents for biosorption including biopolymers such as sodium alginate. In the article swelling behaviour of gel and dry beads has been studied in aqueous solutions with different acid-base character. Swelling of gel or dry calcium alginate beads was found in all acidic and basic solutions except of the gel beads in strong acidic solutions, which exhibited the tendency to shrink. Dry beads in diluted acidic solutions had the greatest stability because they exhibited minimum swelling. Dry and gel beads were completely dissolved in concentrated solutions of sodium and potassium hydroxides. The potential use of immobilized algal biomass in Ca-alginate beads for removal of copper ions from aqueous solution was also investigated. The results of the kinetic studies showed that the sorption of copper ions on gel immobilized beads are the most suitable.