摘要详情
  1. 活动首页
  2. 摘要清单
  3. 摘要详情
127 / 2025-04-03 17:00:42
New Insight into the Natural Detoxification of Cr(VI) in Fe-Rich Surface Soil: Crucial Role of Photogenerated Silicate-Bound Fe(II)
Cr(VI) biogeochemistry,clay-iron (hydr)oxide associations,photogenerated Fe(II),surface soil,solar irradiation
Theme 2: Geobiology of Modern Habitable Earth > Session 2c: Geomicrobiology of Hazardous Elements Generated by Anthropogenic Activities
摘要待审
zehong zhang / Shanghai Jiao Tong University
Photoexcitation of natural semiconductor Fe(III) minerals has been proven to generate Fe(II), but the photogeneration of Fe(II) in Fe-rich surface soil as well as its role in the redox biogeochemistry of Cr(VI) remains poorly understood. In this work, we confirmed the generation of Fe(II) in soil by solar irradiation and proposed a new mechanism for the natural reductive detoxification of Cr(VI) to Cr(III) in surface soil. The kinetic results showed that solar irradiation promoted the reduction of Cr(VI) in Fe-rich soils, while a negligible Cr(VI) reduction was observed in the dark. Fe(II), mainly in the form of silicate-bound Fe(II), was generated under solar irradiation and responsible for the reduction of Cr(VI) in soils, which was evidenced by sequential extraction, transmission electron microscopy with electron energy loss spectroscopy, and electron transfer calculation. Photogenerated silicate-bound Fe(II) resulted from the massive clay–iron (hydr)oxide associations, consisting of iron (hydr)oxides (e.g., hematite and goethite) and kaolinite. These associations could generate Fe(II) under solar irradiation either via intrinsic excitation to produce photoelectrons or via the ligand-to-metal charge transfer process after the formation of clay–iron (hydr)oxide–organic matter complexes, which was proven by photoluminescence spectroscopy and X-ray photoelectron spectroscopy. These findings highlight the important role of photogenerated Fe(II) in Cr(VI) reduction in surface soil, which advances a fundamental understanding of the natural detoxification of Cr(VI) as well as the redox biogeochemistry of Cr(VI) in soil.
重要日期

  • 会议日期

    06月10日

    2025

    至

    06月13日

    2025

  • 04月15日 2025

    初稿截稿日期

主办单位
National Natural Science Foundation of China
Geobiology Society
National Committee of Stratigraphy of China
Ministry of Science and Technology
Geological Society of China
Paleontological Society of China
Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (CAS)
Institute of Vertebrate Paleontology and Paleoanthropology, CAS
International Commission on Stratigraphy
International Paleontological Association
承办单位
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (CUG, Wuhan)
联系方式
登录查看完整联系方式
历届会议
移动端
在手机上打开
小程序
打开微信小程序
客服
扫码或点此咨询