Biogeochemical fate of ferrihydrite-model organic compound complexes during anaerobic microbial reduction

Journal Article · Fri Mar 01 00:00:00 EST 2019 · Science of the Total Environment

DOI:https://doi.org/10.1016/j.scitotenv.2019.02.441· OSTI ID:1527276

Wordofa, Dawit N. ^[1]; Adhikari, Dinesh ^[2]; Dunham-Cheatham, Sarrah M. ^[1]; Zhao, Qian ^[3]; Poulson, Simon R. ^[1]; Tang, Yuanzhi ^[4]; Yang, Yu ^[1]

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1. Univ. of Nevada, Reno, NV (United States)
2. Univ. of Nevada, Reno, NV (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
3. Univ. of Nevada, Reno, NV (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
4. Georgia Inst. of Technology, Atlanta, GA (United States)

Associations of organic carbon (OC) with iron (Fe) oxide minerals play a vital role in regulating the stability of OC in soil environments. Knowledge about the fate and stability of Fe-OC complexes is impaired by the heterogeneity of OC. Additional biogeochemical variables in soil environments, such as redox conditions and microbes, further increase complexity in understanding the stability of mineral-associated soil OC. This study investigated the fate and stability of model organic compounds, including glucose (GL), glucosamine (GN), tyrosine (TN), benzoquinone (BQ), amylose (AM), and alginate (AL), complexed with an Fe oxide mineral, ferrihydrite (Fh), during microbial reduction. During a 25-d anaerobic incubation with Shewanella putrefaciens CN32, the reduction of Fe followed the order of Fh-BQ>Fh-GL>Fh-GN>Fh-TN>Fh-AL>Fh-AM. In terms of OC released during the anaerobic incubation, Fh-GN complexes released the highest amount of OC while Fh-AM complexes released the lowest. Organic carbon regulated the reduction of Fe by acting as an electron shuttle, affecting microbial activities, and associating with Fh. Benzoquinone had the highest electron accepting capacity, but potentially can inhibit microbial activity. These results provide insights into the roles of different organic functional groups in regulating Fe reduction and the stability of Fh-bound OC under anaerobic conditions.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE; USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
• Grant/Contract Number: AC52-07NA27344; SC0014275
• OSTI ID: 1527276
• Alternate ID(s): OSTI ID: 1564372; OSTI ID: 1499767
• Report Number(s): LLNL-JRNL--773257; 965250
• Journal Information: Science of the Total Environment, Journal Name: Science of the Total Environment Journal Issue: C Vol. 668; ISSN 0048-9697
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
Electron transport
Ferrihydrite
Microbial reduction
Organic carbon
Quinone