Akademik Veri Yönetim Sistemi
JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY, cilt.32, sa.10, ss.1008-1017, 1995 (SCI-Expanded)
Bauxite wastes of alumina manufacture, i.e., red muds, have been tested for radiocesium and strontium removal from water. The red muds were water-washed, acid-, and heat-treated before usage to produce hydrous oxide like sorbents. Surface treatment of the sorbent was benefical for Cs-137 uptake, while heat-treatment was detrimental to the -SOH surface sites responsible for high Sr-90 affinity. Fractionation of the sorbent with respect to apparent grain size did not produce significant differences in the sorption efficiency. The distribution coefficients vs. equilibrium activity in solution showed a maximum with Cs, and a gradual decrease trend with Sr. The solution activity vs. adsorption data were fitted to B.E.T. (essentially types IV-V) isotherms for Cs and B. E. T.-Langmuir isotherms for Sr. Desorption, temperature, pH-, and ionic strength-dependence tests revealed that the primary mode of sorption for both cations is specific adsorption while the secondary mode is ion exchange. A rise in pH favours the ion-exchange sorption of Sr while the specific adsorption of Cs is negatively affected. Competitive adsorption of an inert electrolyte, i.e., NaCl, severely hinders Cs sorption, while Sr sorption on water-washed red mud is not significantly affected.