Influence of pH on the adsorption of uranium ions by oxidized activated carbon and chitosan

The adsorption characteristics of uranyl ions on surface-oxidized carbon we re com pared with those of powdered chitosan over a wide pH range. In parti cular, an extensive analysis was made on solution pH variation during the a dsorption process or after adsorption equilibrium. Uranium adsorption on th e two adsorbents was revealed to be strongly dependent on the initial pH of the solution. A quantitative comparison of the adsorption capacities of th e two adsorbents was made, based on the isotherm data obtained at initial p H 3, 4, and 5. In order to analyze the adsorption kinetics incorporated wit h pH effects, batch experiments at various initial pH values were carried o ut, and solution pH profiles with the adsorption lime were also evaluated. The breakthrough behavior in a column packed with oxidized carbon was also characterized with respect to the variation of effluent pH. Based on these experimental results, the practical applicability of oxidized carbon for ur anium removal from acidic radioactive liquid waste was suggested.