Organic Matter Counteracts the Enhancement of Cr(III) Extractability during the Fe(II)-Catalyzed Ferrihydrite Transformation: A Nanoscale- and Molecular-Level Investigation

文献类型： 外文期刊

第一作者： Xia, Xing

作者： Xia, Xing;Xia, Xing;Jin, Lin;Darma, Aminu Inuwa;He, Chao;Liu, Jin;Wang, Jian;Shakouri, Mohsen;Hu, Yongfeng;Yang, Jianjun

作者机构：

关键词： iron (oxyhydr)oxides; organic matter; chromium; coprecipitation; XANES

期刊名称：ENVIRONMENTAL SCIENCE & TECHNOLOGY （ 影响因子：11.4； 五年影响因子：12.0 ）

ISSN： 0013-936X

年卷期： 2023 年 57 卷 36 期

页码：

收录情况： SCI

摘要： Phase transformation of ferrihydrite to more stable Fe (oxyhydr)oxides, catalyzed by iron(II) [Fe(II)], significantly influences the mobility of heavy metals [e.g., chromium (Cr)] associated with ferrihydrite. However, the impact of organic matter (OM) on the behavior of Cr(III) in the Fe(II)-catalyzed transformation of ferrihydrite and the underlying mechanisms are unclear. Here, the Fe(II)-catalyzed transformation of the coprecipitates of Fe(III), Cr(III), or rice straw-derived OM was studied at the nanoscale and molecular levels using Fe and Cr K-edge X-ray absorption spectroscopy and spherical aberration corrected scanning transmission electron microscopy (Cs-STEM). Batch extraction results suggested that the OM counteracted the enhancement of Cr(III) extractability during the Fe(II)-catalyzed transformation. Cs-STEM and XAS analysis suggested that Cr(III) could be incorporated into the goethite formed by Fe(II)-catalyzed ferrihydrite transformation, which, however, was inhibited by the OM. Furthermore, Cs-STEM analysis also provided direct nanoscale level evidence that residual ferrihydrite could re-immobilize the released Cr(III) during the Fe(II)-catalyzed transformation process. These results highlighted that the decreased extractability of Cr(III) mainly resulted from the inhibition of OM on the Fe(II)-catalyzed transformation of ferrihydrite to secondary Fe (oxyhydr)oxides, which facilitates insightful understanding and prediction of the geochemical cycling of Cr in soils with active redox dynamics.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序