Reduction Pathway-Dependent Formation of Reactive Fe(II) Sites in Clay Minerals

Rothwell Katherine A.; Pentrak Martin P.; Pentrak Linda A.Stucki Joseph W.Neumann Anke

首页> 外文期刊>Environmental Science & Technology: ES&T >Reduction Pathway-Dependent Formation of Reactive Fe(II) Sites in Clay Minerals

【24h】

Reduction Pathway-Dependent Formation of Reactive Fe(II) Sites in Clay Minerals

机译：Reduction Pathway-Dependent Formation of Reactive Fe(II) Sites in Clay Minerals

获取原文

获取原文并翻译 | 示例

掌桥外文数据库（机构版） >>

开具论文收录证明 >>

文献代查 >>

页面导航

摘要
著录项
相关主题

摘要

Structural Fe in clay minerals is an important, potentially renewable source of electron equivalents for contaminant reduction, yet our knowledge of how clay mineral Fe reduction pathways and Fe reduction extent affect clay mineral Fe-(II) reactivity is limited. Here, we used a nitroaromatic compound (NAC) as a reactive probe molecule to assess the reactivity of chemically reduced (dithionite) and Fe-(II)-reduced nontronite across a range of reduction extents. We observed biphasic transformation kinetics for all nontronite reduction extents of ≥5% Fe-(II)/Fe-(total) regardless of the reduction pathway, indicating that two Fe-(II) sites of different reactivities form in nontronite at environmentally relevant reduction extents. At even lower reduction extents, Fe-(II)-reduced nontronite completely reduced the NAC whereas dithionite-reduced nontronite could not. Our 57Fe Mo?ssbauer spectroscopy, ultraviolet–visible spectroscopy, and kinetic modeling results suggest that the highly reactive Fe-(II) entities likely comprise di/trioctahedral Fe-(II) domains in the nontronite structure regardless of the reduction mechanism. However, the second Fe-(II) species, of lower reactivity, varies and for Fe-(II)-reacted NAu-1 likely comprises Fe-(II) associated with an Fe-bearing precipitate formed during electron transfer from aqueous to nontronite Fe. Both our observation of biphasic reduction kinetics and the nonlinear relationship of rate constant and clay mineral reduction potential E H have major implications for contaminant fate and remediation.

著录项

来源
《Environmental Science & Technology: ES&T》 |2023年第28期|10231-10241|共11页
作者
Rothwell Katherine A.; Pentrak Martin P.; Pentrak Linda A.Stucki Joseph W.Neumann Anke;
展开▼
作者单位

Newcastle University;

University of Illinois at Urbana-Champaign;

展开▼
收录信息美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
原文格式 PDF
正文语种英语
中图分类环境科学、安全科学;
关键词
iron; redox; nontronite; contaminant reduction; kinetics; reactive precipitates; nitroaromatic compounds; Mössbauer spectroscopy;

Reduction Pathway-Dependent Formation of Reactive Fe(II) Sites in Clay Minerals

摘要

著录项

相关主题

期刊订阅