HR: 1340h
AN: H53A-1236    [Abstracts]
TI: Modeling Hematite Bioreduction under Growth Conditions
AU: * Yu, J
EM: ji324333@pegasus.cc.ucf.edu
AF: University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816 United States
AU: Chen, C
EM: ch674162@pegasus.cc.ucf.edu
AF: University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816 United States
AU: Yeh, G
EM: gyeh@mail.ucf.edu
AF: University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816 United States
AU: Burgos, W D
EM: wdb3@psu.edu
AF: The Pennsylvania State University, 212 Sackett Bldg, University Park, PA 16802 United States
AU: Mynyard, M L
EM: mminyards@psu.edu
AF: The Pennsylvania State University, 212 Sackett Bldg, University Park, PA 16802 United States
AB: The focus of this work is on simulating and analyzing bioreduction kinetics of natural hematite-coated sand by dissimilatory metal-reducing bacterium (DMRB), Shewanella putrefaciens CN32, under growth conditions with lactate as the electron donor. A reaction-based biogeochemical model was used. A series of batch experiments with different initial conditions were performed to determine the rate formulations/parameters for hematite bioreduction and related reactions. Three different kinetic reaction rate formations were used to model hematite bioreduction. The consistency of mass conservation equations was assessed. Assumptions regarding equilibrium reactions were also assessed. Column experiments focused on transient reactive transport were conducted under otherwise identical conditions, except that the flow rate was systematically varied. The determined rate formulations/parameters were systematically tested with these column experiments using a reactive biogeochemical transport model that coupled hydrologic transport and reactive biogeochemistry. The model simulated the hematite bioreduction of hematite-coated sand in column experiments reasonably well using rate formulation/parameters determined from batch experiments. This study supports the hypothesis that mechanistic-based reaction rates of batch experiments can be scaled up and ported to column experiments.
DE: 1899 General or miscellaneous
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
DE: 1099 General or miscellaneous
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting