کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10110799 | 1619993 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Mechanisms of arsenic attenuation in acid mine drainage from Mount Bischoff, western Tasmania
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم محیط زیست
شیمی زیست محیطی
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چکیده انگلیسی
There is a dearth of research concerning the geochemistry of arsenic in acid mine drainage (AMD) in western Tasmania. To help address this, the controls on the mobility and fate of arsenic in AMD and its associated sediment at the Mount Bischoff mine site in western Tasmania were investigated. AMD issuing from the adit mouth contained dissolved arsenic and iron concentrations of 2.5 and 800 mg Lâ1, respectively. The aqueous concentration of both arsenic and iron decreased markedly over a 150-m stretch from the adit mouth due to precipitation of hydrous ferric oxides (HFO) and jarosite, both of which are effective scavengers of arsenic. Microwave-assisted digestion of the sediment collected at the adit mouth revealed that the arsenic concentration exceeded 1%. Sequential extraction of this sediment showed that the bulk of arsenic was associated with amorphous and crystalline hydrous oxides of Al and/or Fe. Extended X-ray absorption fine structure (EXAFS) analysis indicated that the solid phase arsenic exists as As(V). EXAFS data were consistent with arsenate tetrahedra substituting for sulphate in jarosite and with corner-sharing complexes adsorbed on ferric oxyhydroxide octahedra. Erosional transport of AMD sediment downstream to higher pH waters may increase the mobility (and hence bioavailablity) of arsenic through dissolution of As-rich jarosite.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Science of The Total Environment - Volume 345, Issues 1â3, 1 June 2005, Pages 219-228
Journal: Science of The Total Environment - Volume 345, Issues 1â3, 1 June 2005, Pages 219-228
نویسندگان
Andrew G. Gault, David R. Cooke, Ashley T. Townsend, John M. Charnock, David A. Polya,