| Autor: |
Bejaoui, Jaloul, Samaali, Mohamed, Baccouche, Souad, Regugui, Nafaa, Hamouda, Mohamed, Azzouz, Zohra, Trabelsi, Adel, Bouhlel, Salah, Salim, Boulamia |
| Zdroj: |
Arabian Journal of Geosciences; Jul2013, Vol. 6 Issue 7, p2685-2689, 5p |
| Abstrakt: |
In this study we investigate the radiological hazard of naturally occurring radioactive material in Tunisian and Algerian phosphorite deposits. Eight samples of phosphorite were collected from the phosphorite mines. The Tunisian and Algerian phosphorites occur in the Late Paleocene and Lower Eocene (Ypresian-Lutetian) in age (Béji Sassi and Zaïer ). Activity concentrations in all the samples were measured by alpha spectrometry and gamma spectrometry. Alpha spectrometry analyses show that the specific activity values of U, U and U in the samples of Tunisian phosphorite were 327 ± 7 (321-327), 326 ± 6 (325-331) and 14.50 ± 0.72 (13.90-15.57) Bq kg, respectively. Specific activity measured by gamma spectrometry in the samples of the Tunisian and Algerian phosphorite shows a small difference. Specific activity levels of K, Ra, Th, U and U in the phosphorite samples from Tunisia were, respectively, 71.10 ± 3.80, 391.54 ± 9.39, 60.38 ± 3.74, 12.72 ± 0.54 and 527.42 ± 49.57 Bq kg and Algeria were 15.72 ± 1.73, 989.65 ± 12.52, 12.08 ± 1.20, 47.50 ± 1.52 and 1,148.78 ± 7.30 Bq kg, respectively. The measured value of specific activity of Th and K in the Tunisian phosphorite samples is relatively higher than that found in the samples of Algerian phosphorite. The measured activity of uranium (U) in the Tunisian phosphorite (527 ± 49) Bq kg is lower than in Algerian phosphorite. The measured activity of U in the Tunisian phosphorite samples was (527-1,315 ± 65) U Bq kg which is higher than its maximum background value of 110 Bq kg in soils of the various countries of the world (). Different geological origins of phosphorites deposits are the main reason for the large spread in worldwide specific activities. The obtained results of uranium concentrations in phosphorites of different types (Algerian and Tunisian) demonstrate that the uranium concentrations are mainly governed by the phosphatic material. The present study reveals that phosphorite deposits contain natural radioactivity higher than background level. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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