Effects of dissolved oxygen on formation of corrosion products and concomitant oxygen and nitrate reduction in zero-valent iron systems with or without aqueous Fe2+
Effects of dissolved oxygen on formation of corrosion products and concomitant oxygen and nitrate reduction in zero-valent iron systems with or without aqueous Fe2+
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DOI：
10.1016/j.watres.2005.03.002
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发表时间：
2005-05-01
期刊：
影响因子：
12.8
通讯作者：
Zhang, TC
中科院分区：
文献类型：
--
作者：
Huang, YH;Zhang, TC
在零价铁（ZVI 或 Fe-0）系统中进行了批量测试，以研究耗氧量和溶解氧 (DO) 对铁腐蚀产物形成、硝酸盐还原、Fe 的反应性、Fe2+ (aq) 所起的作用以及 Fe2+ 的归宿的影响。研究表明，在不增加 Fe2+ (aq) 的情况下，Fe-0 无法有效去除硝酸盐和 DO。在存在 Fe2+ (aq) 的情况下，硝酸盐和 DO 可以同时被还原，且彼此之间的干扰有限。与硝酸盐还原不同，Fe-0 去除 DO 不会消耗 Fe2+ (aq)。在 DO 存在下，可以形成两层结构，内层为磁铁矿，外层为纤铁矿。当 DO 耗尽时，外部纤铁矿层转变为磁铁矿。磁铁矿内层，即使厚度很大，也可能不会像氧化物涂层和液体之间的薄界面层那样阻碍 Fe-0 反应性。表面结合的Fe2+可以大大增强从Fe-0核到固液界面的电子转移，从而提高Fe-0工艺的性能。 (c) 2005 Elsevier Ltd. 保留所有权利。
Batch tests were conducted in zero-valent iron (ZVI or Fe-0) systems to investigate oxygen consumption and the effect of dissolved oxygen (DO) on formation of iron corrosion products, nitrate reduction, the reactivity of Fe, the role Fe2+ (aq) played, and the fate of Fe2+. The study indicates that without augmenting Fe2+ (aq), neither nitrate nor DO could be removed efficiently by Fe-0. In the presence of Fe2+ (aq), nitrate and DO could be reduced concomitantly with limited interference with each other. Unlike nitrate reduction, DO removal by Fe-0 did not consume Fe2+ (aq). A two-layer structure, with an inner layer of magnetite and an outer layer of lepidocrocite, may be formed in the presence of DO. When DO depleted, the outer lepidocrocite layer was transformed to magnetite. The inner layer of magnetite, even in a substantial thickness, might not impede the Fe-0 reactivity as much as the thin interfacial layer between the oxide coating and liquid. Surface-bound Fe2+ may greatly enhance the electron transfer from the Fe-0 core to the solid-liquid interface, and thus improve the performance of the Fe-0 process. (c) 2005 Elsevier Ltd. All rights reserved.