کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1739739 1016890 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Partitioning of radionuclides and trace elements in phosphogypsum and its source materials based on sequential extraction methods
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی انرژی هسته ای و مهندسی
پیش نمایش صفحه اول مقاله
Partitioning of radionuclides and trace elements in phosphogypsum and its source materials based on sequential extraction methods
چکیده انگلیسی

Phosphogypsum is a waste produced by the phosphate fertilizer industry. Although phosphogypsum is mainly calcium sulphate dihydrate, it contains elevated levels of impurities, which originate from the source phosphate rock used in the phosphoric acid production. Among these impurities, radionuclides from 238U and 232Th decay series are of most concern due to their radiotoxicity. Other elements, such as rare earth elements (REE) and Ba are also enriched in the phosphogypsum. The bioavailability of radionuclides (226Ra, 210Pb and 232Th), rare earth elements and Ba to the surrounding aquatic system was evaluated by the application of sequential leaching of the phosphogypsum samples from the Brazilian phosphoric acid producers. The sequential extraction results show that most of the radium and lead are located in the “iron oxide” (non-CaSO4) fraction, and that only 13–18% of these radionuclides are distributed in the most labile fraction. Th, REE and Ba were found predominantly in the residual phase, which corresponds to a small fraction of the phosphate rock or monazite that did not react and to insoluble compounds such as sulphates, phosphates and silicates. It can be concluded that although all these elements are enriched in the phosphogypsum samples they are not associated with CaSO4 itself and therefore do not represent a threat to the surrounding aquatic environment.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Environmental Radioactivity - Volume 87, Issue 1, 2006, Pages 52–61
نویسندگان
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