Evaluation of 55Fe as a tracer of Fe(III) reduction in aquatic sediments
Evaluation of 55Fe as a tracer of Fe(III) reduction in aquatic sediments
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DOI：
10.1080/01490459309377931
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发表时间：
1993
影响因子：
2.3
通讯作者：
E. Roden;D. Lovley
中科院分区：
文献类型：
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作者：
E. Roden;D. Lovley
摘要利用美国马里兰州波托马克河的淡水沉积物评价了55 Fe作为Fe（III）还原示踪剂的潜在效用，其中Fe（III）还原是主要的末端电子接受过程。在用结晶不良的55 Fe（III）氧化物修饰的沉积物的实验室孵育中，随着时间的推移，55 Fe在Fe（II）中的积累与Fe（II）的产生平行。然而，在1小时内添加的55 Fe（III）氧化物，大量的55 Fe中回收的可提取物（1 M醋酸钠，pH 5）和可溶性Fe（II）池。Fe（II）浓度越高，沉积物中55 Fe（II）活性越高。这些结果表明，有快速的同位素交换之间的55 Fe在不良结晶的Fe（III）氧化物和Fe（II）池。由于这种交换，55 Fe不能像35 SO4 2−那样用于追踪硫酸盐还原，而用于追踪沉积物中的Fe（III）还原。虽然55Fe在Fe（II）池中的积累并不明显。
Abstract The potential utility of 55Fe as a tracer for Fe(III) reduction in aquatic sediments was evaluated using freshwater sediments from the Potomac River, Md, in which Fe(III) reduction was the predominant terminal electron accepting process. In laboratory incubations of sediments amended with poorly crystalline 55Fe(III) oxide, the accumulation of 55Fe in Fe(II) over time paralleled Fe(II) production. However, within 1 h of addition of 55Fe(III) oxide, significant quantities of 55Fe were recovered in extractable (1 M sodium acetate, pH 5) and soluble Fe(II) pools. There was proportionately more 55Fe(II) activity in sediments with higher Fe(II) concentrations. These results suggest that there was rapid isotopic exchange between 55Fe in poorly crystalline Fe(III) oxide and the Fe(II) pools. Because of this exchange, 55Fe could not be used to trace Fe(III) reduction in sediments in the manner that 35SO4 2− is used to trace sulfate reduction. Although accumulation of 55Fe in Fe(II) pools paralleled unla‐...