Sorption study of u+6 in brazilian soils

Resumo

This study has highlighted important sorption characteristics of the studied Brazilian soils. The fit of the kinetic model to the experimental data, evaluated based on the determination coefficient (R2); found that, though empirical, both the kinetic model Freundlich as Langmuir satisfactorily describe the  experimental  data,  with  R2   values higher than  0.9,  while  the constant partition of the model is not adequate description of sorption data. Already multi model assessment undertaken in AICC function, showed that the Langmuir model was the best fit to the U sorption curve in Rhodic, while the model Freundlich adjusted better to Nitosol.

The Kd values reported in this study differ from those recommended by the United States Environmental Protection Agency (20 mL / g for soils with pH <5), so should be considered as benchmarks for highly weathered soils because they relate to the conditions Brazilian pedoenvironmental.

The low Kd values obtained in this study allowed us to evaluate the high vulnerability of soils studied contamination of uranium. Therefore, it is evident the need to generate regional parameter values to subsidize environmental radiation protection in mining and tailings that result in contamination of highly weathered soils with uranium.