HR: 0800h
AN: H11D-1298    [Abstracts]
TI: Modeling of Bioremediation in Groundwater: a Three-Dimensional Lattice-Boltzmann Method for Bacterial Chemotaxis
AU: * Long, W
EM: wlong4@jhu.edu
AF: Johns Hopkins University, Department of Geography and Environmental Engineering, 313 Ames Hall, 3400 N. Charles St., Baltimore, MD 21218 United States
AB: Responding to changes in the environment is a fundamental property of a living bacterium. Chemotaxis, the migration of microorganisms under the influence of a chemical gradient, navigates bacteria to an optimum environment. Chemotactic bacteria can either move towards a chemoattractant following a chemical gradient, or move away from a chemorepellent. Understanding chemotactic behavior is important for understanding biodegradation in groundwater systems. A numerical model based on a Lattice-Boltzmann method was developed to simulate chemotaxis in free liquids and porous media. This model accounts for bacterial chemotaxis and reactive transport of a chemoattractant. The microorganisms and chemoattractant are represented by quasi-particles that move, collide, and react with each other on a three-dimensional numerical lattice. The model was validated by simulating experiments on the degradation of naphthalene by Pseudomonas putida in a capillary tube containing either bulk liquid or glass beads. The agreement between the simulation results and the experimental data is excellent. From the simulations, we found that a fraction of bacteria detaches from the bacterial reservoir to form a traveling band, which enhances naphthalene removal in the capillary tube. In another set of simulations, we showed that bacterial chemotaxis may significantly effect and improve the biodegradation of a contaminant in flowing groundwater.
DE: 0515 Cellular automata
DE: 0792 Contaminants (0432)
DE: 1831 Groundwater quality
DE: 2753 Numerical modeling
SC: Hydrology [H]
MN: Fall Meeting 2005