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This work aims at the application of chitosan-based materials in the treatment of oil incrustations containing Ra-226 and Ra-228 after an initial extraction process. Acid digestion in ultrasound and microwave of oil resulted in radium extraction. In this way, adsorption assay with chitosan powder (without modification) and chitosan bead (chemical modification) were performed using high-resolution gamma-ray spectrometry. The adsorption test revealed that chitosan beads were more efficient in the capture of Ra-226 and Ra-228 than chitosan control. Thus, the chitosan beads as a biomaterial may be utilized as a green alternative in the management of oil incrustation. [ABSTRACT FROM AUTHOR]

Mangroves are essential for protecting coastal environments and biodiversity; however few studies encompass the distribution of radionuclides in soils from these ecosystems. By applying high resolution gamma-ray spectrometry, natural radionuclides were quantified in soils from the Chico Science Mangrove and Rio Formoso Mangrove (RFM), areas subjected to different human impacts. The activity concentrations of Ra and Ra were quite similar for the mangroves despite the differences found for K. Moreover, no correlation with the environmental impacts on the mangroves was observed, although RFM soil was K-enriched compared to deep sediments from other estuaries in the world. [ABSTRACT FROM AUTHOR]

Considerable amounts of biological material contaminated with artificial radionuclides were generated to obtain the efficiency curves for low-activity radionuclide analyses of large environmental samples. Likewise, improving detection geometry is also an important task, mainly for studies involving conservation units with a high level of biodiversity preservation. This study aimed to evaluate the Monte Carlo efficiency curves without generating contaminated material with artificial radionuclides for water and vegetation measurements. An in-house adapted Marinelli geometry was applied to reduce the sampled amount of biological material in the ecosystem, which was combined with the Monte Carlo assisted efficiency curve for a more sustainable radiometric analysis. [ABSTRACT FROM AUTHOR]

The purpose of this work was to determine concentrations of Ra, Ra and K in scales generated inside industrial boilers. Radionuclide activities were determined by high resolution gamma-ray spectrometry. Activity concentrations of Ra were in the range of 3.0 (22) to 1300 (6) Bq kg and Ra activity concentrations varied from <2.0 Bq kg (Minimum detectable activity concentration) to 266 (3) Bq kg. Activity concentrations of K were in the range of <15 Bq kg (Minimum detectable activity concentration) to 290 (5) Bq kg. Activity concentrations were lower than the limits established by the Brazilian Commission of Nuclear Energy. [ABSTRACT FROM AUTHOR]