Interactions of Aqueous Selenium (-II) and (IV) with Metallic Sulfide Surfaces

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• 作者：Aude Naveau ; Fanny Monteil-Rivera ; Emmanuel Guillon ; Jacques Dumonceau
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：August 1, 2007
• 年：2007
• 卷：41
• 期：15
• 页码：5376 - 5382
• 全文大小：175K
• 年卷期：v.41,no.15(August 1, 2007)
• ISSN：1520-5851

文摘

The present study was initiated to determine the capacityof sulfide minerals (pyrite FeS₂ and chalcopyrite CuFeS₂)to delay the migration of inorganic selenium speciesin geological formations. Interactions between Se^IV andSe^-II and synthetic and natural sulfide minerals wereinvestigated under anoxic conditions using the batch method.Significant sorption of selenium occurred under acidicconditions. Analysis of the solids after Se sorption usingX-ray photoelectron spectroscopy (XPS) and X-ray absorptionnear edge structure (XANES) demonstrated the presenceof reduced selenium species on the metallic sulfidesurfaces, thus suggesting an oxido-reduction processcoupled with sorption. Selenium reduction occurredconcomitantly with the oxidation of pyritic sulfur, whereasmetallic species (Fe, Cu) were not involved in the redoxprocess. Formation of ferroselite (FeSe₂) was postulated totake place on the synthetic solid while surface complexationor ionic exchange processes were more likely on thenatural solids.