Aquifer-Scale Observations of Iron Redox Transformations in Arsenic-Impacted Environments to Predict Future Contamination.
Aquifer-Scale Observations of Iron Redox Transformations in Arsenic-Impacted Environments to Predict Future Contamination.
复制标题
DOI：
10.1021/acs.estlett.0c00672
复制
发表时间：
2020-12-08
影响因子：
10.9
通讯作者：
Bostick BC
中科院分区：
文献类型：
--
作者：
Nghiem AA;Shen Y;Stahl M;Sun J;Haque E;DeYoung B;Nguyen KN;Mai TT;Trang PTK;Pham HV;Mailloux B;Harvey CF;van Geen A;Bostick BC
氧化铁控制着含水层系统中大量污染物的流动性，地下铁氧化物的微生物还原与地下水中高含量的砷有关，影响到全球1.5亿多人。地下水和固相含水层组成的配对观测对于了解污染的时空趋势和有效管理不断变化的水资源至关重要，但在与砷污染相关的氧化还原梯度中，现场代表性矿物学数据很少。我们使用X射线吸收光谱在越南地下水砷污染的自然梯度的铁矿物学特征。分层聚类分析将沉积物分为有意义的组，描绘风化和氧化还原变化，沉积历史的诊断，在这第一次直接表征氧化还原转换领域。值得注意的是，这些分组揭示了铁矿物在地下水中砷污染开始之前经历主动还原的特征。更新世沉积物经历沉积后减少可能比以前认识到的更广泛，由于以前的错误分类。通过放大到南亚和东南亚的类似环境中，通过多项式逻辑回归模型，我们发现，活跃的铁还原，因此对未来砷污染的敏感性，是更广泛地分布在可能的原始含水层比预期的。
Iron oxides control the mobility of a host of contaminants in aquifer systems, and the microbial reduction of iron oxides in the subsurface is linked to high levels of arsenic in groundwater that affects greater than 150 million people globally. Paired observations of groundwater and solid-phase aquifer composition are critical to understand spatial and temporal trends in contamination and effectively manage changing water resources, yet field-representative mineralogical data are sparse across redox gradients relevant to arsenic contamination. We characterize iron mineralogy using X-ray absorption spectroscopy across a natural gradient of groundwater arsenic contamination in Vietnam. Hierarchical cluster analysis classifies sediments into meaningful groups delineating weathering and redox changes, diagnostic of depositional history, in this first direct characterization of redox transformations in the field. Notably, these groupings reveal a signature of iron minerals undergoing active reduction before the onset of arsenic contamination in groundwater. Pleistocene sediments undergoing postdepositional reduction may be more extensive than previously recognized due to previous misclassification. By upscaling to similar environments in South and Southeast Asia via multinomial logistic regression modeling, we show that active iron reduction, and therefore susceptibility to future arsenic contamination, is more widely distributed in presumably pristine aquifers than anticipated.
登录
查看更多内容
影响因子：
3.1
作者：
Hawthorne, Frank C.;Oberti, Roberta;Welch, Mark D.
通讯作者：
Welch, Mark D.
影响因子：
5
作者：
Kocar, Benjamin D.;Borch, Thomas;Fendorf, Scott
通讯作者：
Fendorf, Scott
影响因子：
5.4
作者：
Mozumder, M. R. H.;Michael, H. A.;van Geen, A.
通讯作者：
van Geen, A.
影响因子：
5
作者：
Gillispie, Elizabeth C.;Matteson, Audrey R.;Polizzotto, Matthew L.
通讯作者：
Polizzotto, Matthew L.
DOI：
10.1073/pnas.0710477105
发表时间：
2008-06-24
影响因子：
11.1
作者：
Michael, Holly A.;Voss, Clifford I.
通讯作者：
Voss, Clifford I.