Redox Measurements in Marine Sediments
Redox Measurements in Marine Sediments
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DOI：
10.1007/978-3-662-04080-5_19
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发表时间：
2000
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影响因子：
--
通讯作者：
H. Schulz
中科院分区：
文献类型：
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作者：
H. Schulz
几乎所有的（生物）地球化学过程中的一个年轻的海洋沉积物直接，或至少间接地，绑定到有机质的分解。有机物是在水柱的透光层合成的，只要阳光能够渗透。只有一小部分初级生产被埋在沉积物中（SUESS等人，1985年），在那里，它作为能量载体，构成了早期成岩过程的发动机（BERNER，1980年）。有机物的分解在一系列氧化还原反应中进行，氧化有机物以产生二氧化碳和水。第一电子受体是溶解在孔隙水中的自由氧，其次是存在于沉积物固相中的锰硒，然后是溶解的硝酸盐，然后是固相的铁氧化物，最后是溶解在孔隙水中的硫酸盐。最后，发生发酵反应，其中结合在有机物质中的零价碳的一半转化为甲烷的（-4）价碳，而另一半转化为二氧化碳的（+4）价碳。FROELICH等.（1979）发表的反应方案包括有机物质中氮和磷的结合量（图19.1）。的
Almost all (bio) geochemical processes in a young marine sediment are directly, or at least indirectly, bound to the decomposition of organic matter. Organic matter is synthesised in the euphotic zone ofthe water column as far as the sunlight is able to pervade. Only a small part of the primary production is buried in the sediment (SUESS et al., 1985) where it, functioning as an energy carrier, constitutes the motor of early diagenetic processes (BERNER, 1980). The decomposition of organic matter proceeds in a succession of redox reactions oxidising the organic substance to yield carbon dioxide and water. The first electron acceptor is free oxygen dissolved in pore water, followed by mangane se present in the sedimentary solid phase, then dissolved nitrate, then iron oxides of the solid phase, and finally sulfate dissolved in the pore water fraction. In the end, a fermentation reaction occurs in which one half of the zero-valent carbon bound in the organic substance is converted into the (-4)-valent carbon ofmethane, while the other half is converted into the (+ 4)-valent carbon of carbon dioxide. FROELICH et al.(1979) published areaction scheme that includes the amounts of nitrogen and phosphorus bound in the organic substance (Figure 19.1). The