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INTERACTION OF METHANOGENS WITH CLAY MINERALS, ORGANIC MATTER, AND METALS

ZHANG, JING
http://rave.ohiolink.edu/etdc/view?acc_num=miami1389881682

Abstract Details

2014, Doctor of Philosophy, Miami University, Geology and Environmental Earth Science.
Iron-bearing clay minerals are ubiquitous in soils, sediments and sedimentary rocks. Clay minerals are often associated with organic matter. In addition, methanogens are very abundant in those environments where clay minerals and organic matter are commonly present. Clay mineral-methanogen-organic matter interactions have important implications for remediation of heavy metals. However, the interactions among clay minerals, organic matter, metals and methanogens are poorly understood. My research examines various aspects of this interaction in a logical sequence. The first subproject was designed to understand the bioreduction of Fe(III) in clay minerals by methanogens. Both mesophilic and thermophilic methanogens were able to reduce structural Fe(III) in clay minerals. The bioavailability of structural Fe(III) is correlated to the proportion of smectite in each clay mineral. Bioreduction of Fe(III) in clay minerals by methanogens induced partial dissolution of clay minerals and formation of biogenic high-charge smectite, silica, and vivianite. Reductive dissolution of clay minerals by methanogens may have important consequences for organic matter that is associated with clay minerals. Therefore, the goal of the second subproject of my research was to understand the impact of Fe(III) bioreduction on organic matter preservation within smectite. When structural Fe(III) in nontronite was reduced either biologically or chemically, the intercalated organic matter was partially released with the extent of release correlating with the extent of reduction. Reductive dissolution was a main mechanism for organic matter release from the nontronite structure. Metal-reducing bacteria can not only reduce structural Fe(III) in clay minerals, also heavy metals. The goal of the third subproject was to investigate the capability of methanogens to reduce vanadium at different concentrations under both growth and non-growth conditions. These two methanogens reduced up to 10 mM and 5 mM of V5+, respectively, in a growth medium and induced biogenic solid precipitation, which was +4. My research has shown that methanogens interact with clay minerals, metals, and organic matter via various mechanisms. These results have important implications for carbon cycling, metal mobility and remediation. Further research will investigate more complex interactions under more realistic conditions and the development of practical applications for these interactions.
Hailiang Dong (Advisor)
Mark Krekeler (Committee Member)
John Rakovan (Committee Member)
Jason Rech (Committee Member)
Annette Bollmann (Committee Member)
Abinash Agrawal (Committee Member)
176 p.
Environmental Geology; Geobiology; Geochemistry
METHANOGEN, CLAY MINERALS, ORGANIC MATTER, METAL

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Citations

  • ZHANG, J. (2014). INTERACTION OF METHANOGENS WITH CLAY MINERALS, ORGANIC MATTER, AND METALS [Doctoral dissertation, Miami University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=miami1389881682

    APA Style (7th edition)

  • ZHANG, JING. INTERACTION OF METHANOGENS WITH CLAY MINERALS, ORGANIC MATTER, AND METALS. 2014. Miami University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=miami1389881682.

    MLA Style (8th edition)

  • ZHANG, JING. "INTERACTION OF METHANOGENS WITH CLAY MINERALS, ORGANIC MATTER, AND METALS." Doctoral dissertation, Miami University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1389881682

    Chicago Manual of Style (17th edition)

miami1389881682
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This open access ETD is published by Miami University and OhioLINK.