Speciation Gamma-Spectrometry: the Fate of Environmental Radio-Nuclides in Hard-Water Lakes
2005 (English)In: Physica scripta. T, ISSN 0281-1847, Vol. T118, 35- p.Article in journal, Meeting abstract (Refereed) Published
A sequential fractionation method for simultaneous and absolute measurement of environmental radio-nuclides, 241Am, 210Pb, 226Ra, 137Cs, 40K and 234Th/238U, by gamma-spectrometry was tested and applied to hard-water lake-sediments. The carbonate, fulvic, humic and mineral insoluble fractions were extracted from the sediments. Correction of self-absorption and geometrical effects, arising from the conditioning of bulk and fractionated sediments, were done using Monte Carlo simulations. This "non-destructive" fractionation procedure allows further analysis of other chemical species in the same fractions thus creating possibilities to study the dynamics of self-cleaning mechanism in lakes. The results demonstrate that the procedure is quantitative and suitable for the determination of environmental key radio-tracers in different fractions. Unlike other fresh-water sediments the major part of the environmental radio-nuclides is associated with "mineral" fractions. This speciation gamma-spectrometry procedure was supplemented by isotope-dilution alpha-spectrometry 210Po (210Pb), for determining the acid-soluble organic fractions in fresh-water lakes. The overall speciation procedure demonstrated that carbonate fractions, extracted from hard-water lake sediments, could be separated either free from, or associated with, fulvic-compounds. This speciation procedure can be applied to other aquatic deposits, however supplementary steps can be added if other data are required.
Place, publisher, year, edition, pages
2005. Vol. T118, 35- p.
IdentifiersURN: urn:nbn:se:uu:diva-90008DOI: 10.1238/Physica.Topical.118a00035OAI: oai:DiVA.org:uu-90008DiVA: diva2:162012
FIRST INTERNATIONAL MEETING ON APPLIED PHYSICS (APHYS-2003)13–18 October 2003, Badajoz, Spain