Elevated Concentrations of U and Co-occurring Metals in Abandoned Mine Wastes in a Northeastern Arizona Native American Community

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• 作者：Johanna M. Blake ; Sumant Avasarala ; Kateryna Artyushkova ; Abdul-Mehdi S. Ali ; Adrian J. Brearley ; Christopher Shuey ; Wm. Paul Robinson ; Christopher Nez ; Sadie Bill ; Johnnye Lewis ; Chris Hirani ; Juan S. Lezama Pacheco ; Jos茅 M. Cerrato
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：July 21, 2015
• 年：2015
• 卷：49
• 期：14
• 页码：8506-8514
• 全文大小：504K
• ISSN：1520-5851

文摘

The chemical interactions of U and co-occurring metals in abandoned mine wastes in a Native American community in northeastern Arizona were investigated using spectroscopy, microscopy and aqueous chemistry. The concentrations of U (67鈥?69 渭g L^鈥?) in spring water samples exceed the EPA maximum contaminant limit of 30 渭g L^鈥?. Elevated U (6,614 mg kg^鈥?), V (15,814 mg kg^鈥?), and As (40 mg kg^鈥?) concentrations were detected in mine waste solids. Spectroscopy (XPS and XANES) solid analyses identified U (VI), As (-I and III) and Fe (II, III). Linear correlations for the release of U vs V and As vs Fe were observed for batch experiments when reacting mine waste solids with 10 mM ascorbic acid (鈭紁H 3.8) after 264 h. The release of U, V, As, and Fe was at least 4-fold lower after reaction with 10 mM bicarbonate (鈭紁H 8.3). These results suggest that U鈥揤 mineral phases similar to carnotite [K₂(UO₂)₂V₂O₈] and As鈥揊e-bearing phases control the availability of U and As in these abandoned mine wastes. Elevated concentrations of metals are of concern due to human exposure pathways and exposure of livestock currently ingesting water in the area. This study contributes to understanding the occurrence and mobility of metals in communities located close to abandoned mine waste sites.