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Title: Time Evolution of Activity Concentration of Natural Emitters in a Scenario Affected By Previous Phosphogypsum Contamination

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.2991229· OSTI ID:21152461
;  [1]; ; ;  [2]; ;  [3]
  1. Centro de Investigation, Tecnologia e Innovation. CUIUS. Universidad de Sevilla. Av. Reina Mercedes 4B. 41012-Sevilla (Spain)
  2. E. T. S. Arquitectura. Dpto. de Fisica Aplicada II. Universidad de Sevilla. Av. Reina Mercedes, 2. 41012-Sevilla (Spain)
  3. Dpto. de Fisica Aplicada. Facultad de Ciencias Experimentales. Universidad de Huelva. Campus de El Carmen. 21007-Huelva (Spain)

The estuary formed by the confluence of Tinto and Odiel river-mouths is located in the South of Spain, close to Huelva town. This estuary has been deeply studied through the years because it has a double particularity. On one hand, since the beginning of the 1960s, the estuary has been affected by direct and indirect phosphogypsum (pg.) releases from two phosphoric acid and fertilizers factories that are working in the area. On the other hand, the pyrite mining operations upstream the Odiel and Tinto rivers has caused historically the formation of H{sub 2}SO{sub 4}, through oxidation of the natural sulphur deposits, the acidification of the waters and the consequent mobilisation of heavy metals from the mining area to the Huelva estuary. As a consequence, enhancement contamination levels in natural emitters from the {sup 238}U series were found in the surroundings of the factories in the previous years to 1998. However, in 1998 the management policy of waste releases drastically changed in the area, and direct discharges to Tinto and Odiel River had to be ceased.A thorough study of the affected zone is being carried out. Riverbed sediments and water samples have been analyzed from four different sampling campaigns in the estuary during the years 1999, 2001, 2002 and 2005. Different radioanalytical techniques have been employed to obtain the activity concentrations of U-isotopes, Th-isotopes, {sup 226}Ra, {sup 210}Pb and {sup 210}Po. Furthermore, the results for the rates of de-contamination of the area are presented. This data will be discussed in order to establish the present status of the contamination in the area, and moreover, to predict the time-evolution of the self-cleaning.

OSTI ID:
21152461
Journal Information:
AIP Conference Proceedings, Vol. 1034, Issue 1; Conference: NRE-VIII: 8. International symposium on the natural radiation environment, Buzios, RJ (Brazil), 7-12 Oct 2007; Other Information: DOI: 10.1063/1.2991229; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English