Speciation of Radionuclides in Sediments and Soils. Part II. Studies with a Sequential Organic Extraction Procedure

摘要

A series of chemical extractions with a range of organic solvents has been performed to investigate the speciation of radionuclides in soil and sediment samples from the Mt. Brockman area in the Northern Territory. The major result is that of all the organic solvents used in the extractions, only acetic acid removes large proportions of the radionuclides sup 210 Pb (ca. 30-70%) and sup 226 Ra (10-55%) from the soil and sediment samples. The failure of the other organic solvents, and in particular dimethylformamide, to extract appreciable amounts of these radionuclides is taken to indicate that sup 210 Pb and sup 226 Ra are not present as discrete metal complexes of organic ligands. The overriding conclusion, that the acidic nature of the solvent is the most important property in releasing the bound radionuclides into solution, suggests that even under mildly acidic conditions encountered in the environment significant amounts of sup 210 Pb and sup 226 Ra may be released for transport. (Atomindex citation 15:024409)