Fractionation and extractability of sulfur, iron and trace elements in sulfidic sediments
Fractionation and extractability of sulfur, iron and trace elements in sulfidic sediments
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DOI：
10.1016/j.chemosphere.2005.12.003
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发表时间：
2006-08-01
期刊：
影响因子：
8.8
通讯作者：
Sullivan, Leigh A.
中科院分区：
文献类型：
--
作者：
Burton, Edward D.;Bush, Richard T.;Sullivan, Leigh A.
本研究描述了河口沉积物中铁和硫的分馏，以及选定的微量元素（As，Cd，Cr，Cu，Ni，Pb和Zn）的相关提取性。沉积物是硫化物，具有中等高浓度的孔隙水硫化物（200-600 μ mol l（-1））和酸挥发性硫化物（AVS; 9.9-129 μ mol g（-1））。黄铁矿硫浓度随深度增加，W1点为63-251 μ mol g（-1），W2点为312-669 μ mol g（-1）。硫化程度一般较高（> 80%），表明Fe可能限制黄铁矿的积累。AVS黄铁矿-S的比例随沉积深度的增加，如预期的固相AVS的黄铁矿化。镉、铅和锌在1 M盐酸中的可提取性表明，这些元素在黄铁矿化过程中并未显着被封存，而封存对于As、Cu和可能的Ni可能很重要。铬的可提取性趋势表明，在硫化物沉积物中的成岩作用可能会提高铬的反应性。总体而言，在成岩作用期间，黄铁矿对AVS的取代可能会增强Cd、Cr、Pb和Zn的反应性，而As、Cu和可能的Ni的反应性可能会降低。(c)2005爱思唯尔有限公司保留所有权利。
This study describes iron and sulfur fractionation, and the related extractability of selected trace elements (As, Cd, Cr, Cu, Ni, Pb and Zn) in estuarine sediments. The sediments were sulfidic, with moderately high concentrations of pore-water sulfide (200-600 mu mol l(-1)) and acid-volatile sulfide (AVS; 9.9-129 mu mol g(-1)). Pyrite-S concentrations increased with depth, with 63-251 mu mol g(-1) at site W1 and 312-669 mu mol g(-1) at site W2. The degree of sulfidisation was generally high (> 80%), indicating that Fe may be limiting pyrite accumulation. The ratios of AVS to pyrite-S increased with sediment depth, as expected for the pyritisation of solid-phase AVS. Cadmium, Pb and Zn extractability in 1 M HCl indicated that these elements are not significantly sequestered during pyritisation, whereas sequestration may be important for As, Cu and possibly Ni. Extractability trends for Cr suggest that diagenesis in sulfidic sediments may enhance Cr reactivity. Overall, replacement of AVS by pyrite during diagenesis may enhance the reactivity of Cd, Cr, Pb and Zn, whereas As, Cu and possibly Ni may be rendered less reactive. (c) 2005 Elsevier Ltd. All rights reserved.