MULTITRACER STUDY ON ADSORPTION OF METAL-IONS ON ALPHA-FE2O3

pK dependence of the adsorption of Na, Sc, Ga, As, Se, Rb, Sr, Y, Zr, Nh, Mo, Tc, Ru, Rh, and Pd on alpha-Fe2O3 from a 0.1 mol dm(-3) NaCl s olution was studied by using a multitracer technique. Desorption of th e metal ions from the alpha-Fe2O3 with the adsorbed metal ions at pH 1 1 was also studied by lowering the pH of the suspensions. The desorpti on curve of each element was in good agreement with the adsorption cur ve except for Ru and Rh under conditions studied. Adsorption kinetics showed that the adsorption of most metal ions increases with shaking t ime before an adsorption equilibrium is attained. An increase in the a dsorption was also observed with an elevation in temperature for the e lements, suggesting that the adsorption is involved in chemisorption.