Influence of Spatial Heterogeneity and Hydrological Perturbations on Redox Dynamics: A Column Study

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• 作者：Bhavna Arora^a ; ^b ; ^{barora@lbl.gov} ; Binayak P. Mohanty^a
• 关键词：Subsurface heterogeneity ; macropore ; reactive transport ; sulfate reduction
• 刊名：Procedia Earth and Planetary Science
• 出版年：2017
• 出版时间：2017
• 年：2017
• 卷：17
• 期：Complete
• 页码：869-872
• 全文大小：445 K
• 卷排序：17

文摘

This study focuses on understanding the complex interactions between hydrological and biogeochemical processes and specifically how these interactions are affected by spatial heterogeneity at the column scale. The hypothesis of this study is that “regions with higher water flux will have higher redox potential”. To test this hypothesis, flow experiments were conducted on experimental soil columns with different spatial architecture of soil collected from the Norman Landfill site. The Norman Landfill is a closed municipal facility with prevalent organic contamination. The sources of variation in the dataset were explored using cluster analysis and dominant biogeochemical processes under varying hydrologic conditions were obtained using reactive transport modeling. Sulfate reduction was found to be an important redox process within most soil columns. Results indicated that while hydrological perturbations triggered redox reactions in homogeneous soil columns, structural heterogeneity in the form of clay lenses and macropores enhanced biogeochemical activity by modifying transport timescales.