A Three-Dimensional Lattice-Boltzmann Model for Bacterial Chemotaxis: Traveling Bands and Groundwater Bioremediation

We present a Lattice-Boltzmann model for bacterial chemotaxis that accounts, at the pore scale, for advective-diffusive transport of the bacteria and a reaction of the bacteria with a chemoattractant. 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. Naphthalene was initially uniformly distributed in the void space of a tube. Then, one tube inlet was brought into contact with a bacterial reservoir. We found that the biodegradation process involved the formation of a bacterial band propagating with constant speed into the tube while metabolizing the contaminant. In another set of simulations, we showed that bacterial chemotaxis may significantly effect and improve the biodegradation of a contaminant in flowing groundwater. Two bacterial bands may form if the chemoattractant is initially uniformly distributed: one band traveling upstream (towards a potential contamination source) and the other one downstream.