Adsorption of low level 51Cr(VI) from aqueous solution by bismuth trioxide

Radiotracer technique has been used for the investigation of adsorption of chromium(VI) traces on bismuth trioxide from aqueous solution. The effect of pH (2-10), concentration of chromate solution (10-6-10-2M) and temperature (303-323 K) has been thoroughly investigated. The influence of certain foreign ions has also been studied. The calculated kinetic and thermodynamic parameters indicate the first order rate law, spontaneity and exothermic nature of the adsorption process. Further, IR studies have established the chemical interaction between the sorbate and sorbent and a possible mechanism of the sorption process based on ligand exchange has been proposed. (author) 23 refs.; 5 figs.; 2 tabs