Redistribution of Electron Equivalents between Magnetite and Aqueous Fe2+ Induced by a Model Quinone Compound AQDS
Redistribution of Electron Equivalents between Magnetite and Aqueous Fe2+ Induced by a Model Quinone Compound AQDS
复制标题
模型醌化合物 AQDS 诱导磁铁矿和 Fe2 水溶液之间电子当量的重新分布
DOI：
10.1021/acs.est.8b05098
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发表时间：
2019
影响因子：
11.4
通讯作者：
Liu Juan
中科院分区：
文献类型：
--
作者：
Peng Huan;Pearce Carolyn I.;N'Diaye Alpha T.;Zhu Zhenli;Ni Jinren;Rosso Kevin M.;Liu Juan
磁铁矿与Fe 2+水溶液（Fe 2+（aq））之间复杂的相互作用涉及缺氧地下环境中的许多生物地球化学氧化还原过程。在这些相同的环境中丰富的天然有机物对Fe 2+（aq）-磁铁矿相互作用的影响是一个额外的复杂的，仍然知之甚少。我们研究了模型醌分子蒽醌-2，6-二磺酸盐（AQDS）对Fe 2+（aq）-磁铁矿相互作用的影响，系统地研究了平衡Fe 2+（aq）浓度、AQDS还原速率和程度，以及在不同控制实验条件下磁铁矿中结构与表面局部Fe（II）/Fe（III）比。Fe 2+（aq）的平衡浓度的Fe 2+修正的磁铁矿悬浮液与AQDS成比例地改变溶液的pH值或初始AQDS浓度，但独立的磁铁矿负载通过固体浓度，在这里研究。AQDS还原Fe 2 +-修正磁铁矿的速率和程度成比例增加溶液pH值，磁铁矿负载，和初始Fe 2+（aq）浓度，这与相应的变化的Fe 2 +-磁铁矿系统的还原电位。AQDS减少表面相关的Fe（II）的Fe 2 +-磁铁矿悬浮液诱导固态迁移的电子等价物从颗粒内部的近表面区域和生产的铁（II）的含物种，这抑制了Fe 2+（aq）纳入或电子注入到磁铁矿结构。研究表明醌类化合物对Fe ~（2+）-磁铁矿体系的还原活性有显著影响。
The complex interactions between magnetite and aqueous Fe2+(Fe2+(aq)) pertain to many biogeochemical redox processes in anoxic subsurface environments. The effect of natural organic matter, abundant in these same environments, on Fe2+(aq)–magnetite interactions is an additional complex that remains poorly understood. We investigated the influence of a model quinone molecule anthraquinone-2,6-disulfonate (AQDS) on Fe2+(aq)–magnetite interactions by systematically studying equilibrium Fe2+(aq)concentrations, rates and extents of AQDS reduction, and structural versus surface-localized Fe(II)/Fe(III) ratios in magnetite under different controlled experimental conditions. The equilibrium concentration of Fe2+(aq)in Fe2+-amended magnetite suspensions with AQDS proportionally changes with solution pH or initial AQDS concentration, but independent of magnetite loadings through the solid concentrations that were studied here. The rates and extents of AQDS reduction by Fe2+-amended magnetite proportionally increased with solution pH, magnetite loading, and initial Fe2+(aq)concentration, which correlates with the corresponding change of reduction potentials for the Fe2+–magnetite system. AQDS reduction by surface-associated Fe(II) in the Fe2+–magnetite suspensions induces solid-state migration of electron equivalents from particle interiors to the near-surface region and the production of nonmagnetic Fe(II)-containing species, which inhibits Fe2+(aq)incorporation or electron injection into the magnetite structure. This study demonstrates the significant influence of quinones on reductive activity of the Fe2+–magnetite system.