Mobility of arsenic and trace element inventories in sediment cores from Masuda City, southwestern Japan
Mobility of arsenic and trace element inventories in sediment cores from Masuda City, southwestern Japan
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DOI：
10.1007/s00254-007-0863-y
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发表时间：
2008-04
期刊：
影响因子：
--
通讯作者：
M. Hawa Bibi;F. Ahmed;H. Ishiga
中科院分区：
文献类型：
--
作者：
M. Hawa Bibi;F. Ahmed;H. Ishiga
对日本西南部岛根县增田市、长岛和奥凯特的四个沉积物岩心中砷和其他微量元素和常量元素的垂直分布进行了研究。沉积物岩心也进行了浸出技术和 14 C 测年。岩心中的地层序列由顶部的粉砂和砂质粉砂组成，向下进入灰色至黑色粘土。几个层位中的 As、Pb、Zn、Cu、Ni、Cr 和 V 含量较高，而这些元素的丰度在黑色和灰色粘土中往往较高，可能是由于粘土沉积物的吸附所致。黑粘土中铁和总硫 (TS) 的浓度较高。痕量金属与铁的相关性表明它们吸附在氢氧化铁上，而某些岩心中与硫的相关性表明它们以铁硫化物的形式沉淀。年龄测定表明，约 5 m 深的粘土层是在距今 5,000 和 6,000 年（14C 年龄）左右海平面变化的海侵阶段沉积的。岩心样品浸出技术的结果表明，用去离子水提取了更高含量的砷。即使在中性pH值下，砷也可以从沉积物中释放到地下水中，因此地下水污染是增田市及周边地区的一个问题。
The vertical distribution of arsenic and other trace and major elements has been studied in four sediment cores from Masuda City, Nagashima and Okite in the Shimane Prefecture of southwestern Japan. The sediment cores were also subjected to leaching techniques and14C dating. The stratigraphic sequences in the cores consist of silt and sandy silt at top, passing downward into gray to black clays. Elevated values of As, Pb, Zn, Cu, Ni, Cr, and V are present in several horizons while abundances of these elements tend to be higher in the black and gray clays, probably due to adsorption onto clay sediments. Higher concentrations of Fe and total sulfur (TS) occur in black clays. The correlations of the trace metals with iron suggest their adsorption onto Fe (oxy)hydroxides, whereas correlations with sulfur in some cores indicate that they were precipitated as Fe-sulfides. Age determinations suggest that clay horizons at ∼5 m depth were deposited at around 5,000 and 6,000 years BP (14C ages) during the transgressive phase of sea level change. The results of the leaching techniques in the core samples show that higher amounts of As were extracted with deionized water. Even at neutral pH, As can be released from sediments to groundwater, and therefore groundwater pollution is a concern in Masuda City and the surrounding area.