Radiotracer technique in adsorption study. Pt. 11. Adsorption of barium and strontium ions on hydrous ceric oxide

Adsorption behaviour of Ba and Sr ions on hydrous ceric oxide in aqueous solution has been studied as a function of concentration (10-2-10-7M), temperature (303-333 K) and pH (7.24-11.42) of the adsorptive solution applying radiotracer technique. The kinetics of adsorption for both ions follows first-order rate law and agrees well with the classical Freundlich isotherm in the entire range of adsorptive concentration. The effect of temperature on the equilibrium adsorption values has been utilized to evaluate the change in standard thermodynamic quantities (viz. ΔH0, ΔG0 and ΔS0). Pre-irradiation of adsorbent with neutrons (3.85 x 106n cm-2 s-1) and γ-radiations (ca 172 rad h-1) has practically no effect on the extent of adsorption for both the ions. The uptake process for both ions is found to be endothermic and irreversible in nature. (author)