Removal of zinc and mercury ions from aqueous solution by hydrous ceric oxide

Uptake behavior of zinc and mercury ions by hydrous ceric oxide applying a radiotracer technique is studied. The influence of various parameters such as concentration, temperature and pH have been examined. It was observed that the amount of zinc and mercury ions absorbed at equilibrium increases with increase of adsorptive concentration (1.0 x 10-7 to 1.0 x 10-2M), temperature (303-333 K) and pH (ca. 3-10). Concentration dependence data agree well with the classical Freundlich isotherm. The radiation stability of hydrous ceric oxide was also investigated by exposing it to a 11.1 GBq (Ra-Be) source associated with γ-dose of 1.72 Gy x h-1 and also using a 60Co source (4.66 kGy x h-1). Adsorption of these metal ions in the presence of some monovalent and divalent cations and complexing agents has also been included in the study. (author)