Chemical Influences on Trace Metal-Sulphide Interactions in Anoxic Sediments
Chemical Influences on Trace Metal-Sulphide Interactions in Anoxic Sediments
复制标题
缺氧沉积物中痕量金属-硫化物相互作用的化学影响
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
G. Luther
中科院分区：
文献类型：
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作者：
G. Luther
含氧水和缺氧沉积物之间氧化还原条件发生的主要变化会对许多痕量金属的形态和生物利用度产生深远的影响。沉积物中的缺氧条件通常充分降低，导致海洋和河口环境中微生物介导的大量硫化氢的产生。尽管大部分 H2S 通常会被再氧化，但很大一部分通常会反应形成金属硫化物，其中黄铁矿 (FeS2) 是迄今为止最丰富的反应产物。然而，也有可能形成其他金属硫化物矿物，以及微量金属和痕量金属共沉淀并吸附在硫化铁上。尽管多年来人们对痕量金属和硫化物沉积物之间的相关性进行了观察，但直到不到十年前，缺氧沉积物中痕量金属与硫化物相互作用的主要直接证据才开始出现。 Huerta-Diaz 和 Morse (1990) 使用对 Lord (1982) 黄铁矿铁提取方法的改进，能够测定与黄铁矿铁共浸出的痕量金属。自从这项技术的发展以来，已经对来自多个地点的沉积物进行了数千次分析（例如 Huerta Diaz 和 Morse，1992；Morse，1994；Cooper 和 Morse，1996），并且已经出现了不同痕量金属的清晰行为模式。
The major changes that occur in redox conditions between oxic waters and anoxic sediments can have profound influences on the speciation and bioavailability of many trace metals. Anoxic conditions in sediments are commonly sufficiently reducing to result in the microbially-mediated production of major amounts of hydrogen sulphide in marine and estuarine environments. Although most of the H2S is usually reoxidized, a significant fraction generally reacts to form metal sulphides with pyrite (FeS2) being by far the most abundant reaction product. However, there is also the potential for other metal sulphide minerals to form, and for minor and trace metals to coprecipitate and adsorb on iron sulphides. Although for many years observations were made on correlations between trace metals and sulphidic sediments, it was not until less than a decade ago that major direct evidence for the interactions of trace metals with sulphides in anoxic sediments began to become available. Using a modification of the pyriteFe extraction method of Lord (1982), Huerta-Diaz and Morse (1990) were able to determine trace metals that were co-leached with pyrite-Fe. Since the development of this technique thousands of analyses have been performed on sediments from numerous locations (e.g. Huerta Diaz and Morse, 1992; Morse, 1994, Cooper and Morse, 1996) and clear patterns of behaviour for different trace metals have emerged.