Chromium isotope fractionation during reduction of Chromium(VI) by Iron(II/III)-bearing clay minerals

CHROMATE INCORPORATION INTO CALCIUM CARBONATE MINERALS AND ASSOCIATED CHROMIUM ISOTOPE FRACTIONATION A Thesis

Reduction of nitroaromatic compounds by iron(ii) reduced clay minerals

Reduction of nitroaromatic compounds by iron(ii) reduced clay minerals." MS (Master of Science) thesis, undergraduate freshman I have had more than just support from this department as this department has become like family to me. I would like to give a special thanks to Dr. Michelle Scherer for giving the privilege to join her research group as an undergraduate student and for guiding me throu...

Physiology of Multiple Sulfur Isotope Fractionation during Microbial Sulfate Reduction

Microbial sulfate reduction (MSR) utilizes sulfate as an electron acceptor and produces sulfide that is depleted in heavy isotopes of sulfur relative to starting sulfate. The fractionation of S-isotopes is commonly used to trace the biogeochemical cycling of sulfur in nature, but a mechanistic understanding of factors that control the range of isotope fractionation is still lacking. This thesis...

Patterns of sulfur isotope fractionation during microbial sulfate reduction.

Studies of microbial sulfate reduction have suggested that the magnitude of sulfur isotope fractionation varies with sulfate concentration. Small apparent sulfur isotope fractionations preserved in Archean rocks have been interpreted as suggesting Archean sulfate concentrations of <200 μm, while larger fractionations thereafter have been interpreted to require higher concentrations. In this wor...

Microbial reduction of Fe(III)-bearing clay minerals in the presence of humic acids

Both Fe(III)-bearing clay minerals and humic acids (HAs) are abundant in the soils and sediments. Previous studies have shown that bioreduction of structural Fe(III) in clay minerals could be accelerated by adding anthraquinone compound as a redox-active surrogate of HAs. However, a quinoid analogue could not reflect the adsorption and complexation properties of HA, and little is known about th...