Influence of Soil Type and Physical-Chemical Properties on Uranium Sorption and Bioavailability

This work was undertaken to study the influence of soil type and its physical and chemical properties on uranium sorption and bioavailability, in order to reduce the uncertainty associated with this parameter in risk assessment models and safe food production. The tests were conducted on three types of Serbian soils: alluvium, chernozem, and gajnjaca, from which 67 samples were taken. Dominant factors of uranium mobilisation: the specific content of total/available form of uranium and phosphorus, the degree of acidity (pH(KCl)), and humus content and their correlation, were analysed. Content of available uranium form, according to the type of soil decreases in the following order: gajnjaca > alluvium > chernozem. It was found the medium correlation between pH values and available content of uranium in chernozem and gajnjaca, statistically significant at the level of significance of 99% and the alluvium at the level of significance of 95%. Correlation coefficients in all cases were negative, indicating that the reduction in pH increases the mobility of uranium and thus its availability for the adoption of the plants. Soil pH was the only dominant factor that significantly controlled the uranium value with no further significant contribution of other soil parameters.