Arsenic-Bearing Calcite in Natural Travertines: Evidence from Sequential Extraction, 渭XAS, and 渭XRF

详细信息    查看全文

• 作者：Pilario Costagliola ; Fabrizio Bardelli ; Marco Benvenuti ; Francesco Di Benedetto ; Pierfranco Lattanzi ; Maurizio Romanelli ; Mario Paolieri ; Valentina Rimondi ; Gloria Vaggelli
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：June 18, 2013
• 年：2013
• 卷：47
• 期：12
• 页码：6231-6238
• 全文大小：395K
• 年卷期：v.47,no.12(June 18, 2013)
• ISSN：1520-5851

文摘

Recent studies demonstrated that synthetic calcite may host considerable amounts of arsenic (As). In this paper, the concentration of As in natural calcite was determined using two novel, specifically designed, sequential extraction procedures. In addition, the oxidation state of As and its distribution between calcite and coexisting Fe-oxyhydroxides was unravelled by 渭XRF elemental mapping and As K-edge 渭XAS spectroscopy. Our results conclusively demonstrate that arsenic can be found in natural calcite up to 2 orders of magnitude over the normal crustal As abundances. Because of the large diffusion of calcite in the environment, this phase may exert an important control on As geochemistry, mobility, and bioavailability.