Roden, E. E. The University of Alabama, eroden@biology.as.ua.edu

 
MODELING IRON CYCLING AND THE INFLUENCE OF MICROBIAL IRON OXIDE REDUCTION ON METHANE PRODUCTION IN FRESHWATER WETLAND SEDIMENTS
 
Recent studies have demonstrated that microbial Fe(III) oxide reduction mediates a substantial fraction (ca. 40%) of anaerobic carbon oxidation in iron-rich sediments of a freshwater wetland in northcentral Alabama, USA. Competition between Fe(III)-reducing and methanogenic bacteria plays an important role in regulating release of methane from these sediments. A multicomponent transport-reaction model simulating the interaction between Fe(III) oxide reduction and methanogenesis has been developed for this system. A major feature of the model is its inclusion of the redox cycling of iron, including the oxidation of aqueous and solid-phase Fe(II) within oxygen microgradients at the sediment-water interface. The model is used to explain observed patterns of Fe(III) oxide reduction and methane production in the Alabama wetland sediments. The model is also used to explore how changes in sediment Fe abundance and cycling intensity could influence the impact of Fe(III) reduction on methane release from different types of freshwater sediments.
 
Day: Friday, Feb. 5
Time: 10:30 - 10:45am
Location: Sweeney Center
 
Code: CS63FR1030S