ADSORPTION OF METAL-IONS ON POLYAMINATED HIGHLY POROUS CHITOSAN CHELATING RESIN

Highly porous chelating resin was fabricated from the natural polysaccharide chitosan. The adsorption capacity was increased by polyamination with poly(ethylene imine) (MW = 10000). The capacity was about 1-2-times larger than that of commercial chelate resins. The selectivity for adsorption of metal ions on the resin, which was determined for a single solute at pH congruent-to 7, was Hg(II) > UO2(II) > Cd(II) > Zn(II) > Cu(II) > Ni(II). Mg(II), Ca(II), Ga(III), As(III), and Sr(II) were not adsorbed on the resin at all. The selectivity depended on the pH of each mental solution. The equilibrium isotherms for adsorption of HgCl2 were correlated by the Langmuir equation. The saturation capacities were close to the concentration of amino group fixed on the resin. When HCl or NaCl coexisted in HgCl2 solution and their concentrations were lower than 100 mol/m3, the saturation capacity of HgCl2 was little affected by them. When 500 mol/m3 H2SO4 coexisted in HgCl2 solution, extremely low pH inhibited the adsorption of Hg(II) at all.