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Investigation of electron transfer reactions in bioreduced Fe-bearing clay minerals


EMSL Project ID
51570

Abstract

The focus of this project is to investigate the redox state of Fe in bioreduced clay minerals to understand the role of lignin in the Fe reduction process. Nontronite was used as an environmentally relevant model of iron-bearing clay with a high Fe content [1]. Lignin has been hypothesized to serve as both an electron donor and an electron shuttle in the iron reduction process. The present limited scope project would complement synchrotron-based micro-fluorescence mapping (µ-XRF) and X-ray absorption near edge structure (XANES) spectroscopy experiments to characterize and map the Fe chemical speication in the samples. The specific aim of this project is to understand how lignin abiotically and biotically affects the redox cycling of structural Fe in clay minerals. This will help us to better understand the electron transfer capacity of soil organic matter (SOM) and has significant implications for Fe-C cycle in soils and sediments.

Project Details

Project type
Limited Scope
Start Date
2020-06-15
End Date
2020-08-15
Status
Closed

Team

Principal Investigator

Ritimukta Sarangi
Institution
Stanford Linear Accelerator Center

Team Members

Jocelyn Richardson
Institution
Stanford Linear Accelerator Center

Hailiang Dong
Institution
Miami University

Related Publications

Ethan Coffin, Hailiang Dong, Jinglong Hu, Ravi K. Kukkadapu, Gary A. Lorigan, Robert M. McCarrick, Shuisong Ni, Yizhi Sheng, Andre J. Sommer, Qiang Zeng, Simin Zhao. 2021. "Lignin-enhanced reduction of structural Fe(III) in nontronite: Dual roles of lignin as electron shuttle and donor." Geochimica et Cosmochimica Acta 307:1-21. https://doi.org/10.1016/j.gca.2021.05.037