Adsorption of Ru, Ce and Eu radionuclides within naturally precipitated polycrystalline calcium carbonate under acidic environment

¹⁰⁶Ru, ¹⁴⁴Ce and ^152+154Eu radiotracers sorption experiments (pH: 1-6) have been carried out with polycrystalline columnar/microcrystalline calcite and aragonite obtained from a stalagmite of Dharamjali cave, India. The different domains of the sample were powdered and thoroughly studied using electron microscopic and X-ray spectroscopic techniques. Both ¹⁰⁶Ru and ¹⁴⁴Ce exhibited higher sorption within calcite varieties compared to aragonite and increased with rising pH, while it showed reverse relation in case of ^152+154Eu. Further, it is noted that aragonite offers the highest K_d values for ^152+154Eu, whereas ¹⁰⁶Ru and ¹⁴⁴Ce prefer calcite. (author)