SORPTION OF RADIOIODINE ON ORGANIC-RICH SOIL, CLAY-MINERALS AND ALUMINA

Batch method was used in investigate the sorption behavior of radioiod ine on organic rich soil alumina, chlorite-illite clay mixture and ben tonite. I-131 was used as tracer. The grain sizes of the samples used were all below 38 mum. A rather slow kinetics was observed for the ads orption of radioiodine on organic rich soil. The distribution ratio in creased with increasing solution/solid (V/m) ratio, and the contact ti me. The pH of the synthetic groundwater did not change the distributio n ratio appreciably. The soil biomass however, showed a striking effec t on the adsorption of radioiodine. Among the clay minerals, the highe st distribution ratio value was found for chlorite-illite clay mixture . All the values were however well below those of the organic rich soi l. The sorption data were fined to Freundlich and Dubinin-Radushkevich type isotherms. Mean energies of adsorption, as well as the affinity ratios of the sorption sites to iodine and chlorine were calculated.