Conclusions

The sorption and desorption characteristics of two significant radionuclides Sr-85 and Cs-137 in selected soil samples from around of NPP Bohunice and NPP Mochovce and other localities of the Slovakia were examined. The experiments shows that radiocesium is most sorbed with soils in relation to radiostrontium. For both radionuclides a main process which is responsible for retention is ion exchange (for Sr-85 it is almost reversible, for Cs-137 it is only partially reversible. The influence of concurrent ions significantly influences binding on soil. Increasing of contain of followed salts and their mixtures in soils, which may be presents as a fertilizers, has a consequence decreasing of sorption of the radiostrontium. Lowermost sorption of Sr-85 in the presence of 0.15 M Ca(NO3)2 was recorded. The present concurrent ions in the soil solutions decreases the sorption of Cs-137 in soils, too. With the multi-parametric regression analysis the dependencies between the values obtained from sorption and migration experiments and selected agriculture characteristics of followed soils were determined. The correlation between the sorption of the Sr-85 or Cs-137 and contain of organic matter in soil was obtained. The binding of the Cs-137 on soil is more intensively as Sr-85. The sorption is in reverse relation with vertical motion of radionuclides in soils. Strong fixation of radionuclide has a consequence that does not proceed a significant motion into depth of soil. The physical-chemical forms of radionuclides in soils and their bioavailability significantly influence on their migration. The results of Tessiere's sequential extraction analysis show on gross variability in binding of radionuclides on soils. The values of velocity coefficients of followed radionuclides were obtained by multi-parametric regression analysis. The application of the zeolite into these soils increases their sorption capability and decreases mobility of the radionuclides. In the case of radiostrontium the application of the zeolite is more effective as in the case of radiocesium