(354a) Transport and Dispersion of Active Particles in Porous Media

Understanding the transport of micro-organisms and self-propelled particles in crowded environments has important consequences in human health as well as in microbial ecology. One clear example is the spreading of contaminants in groundwater aquifers, where transport is affected by biology (bacterial size and motility) as well as chemistry (adhesion forces, chemoattractants, bacterial growth), geometry (porosity and soil shape), external fields and hydrodynamics. Motivated by the necessity of understanding active particle dispersion in complex media, we have developed a macro-continuum model for the long-time transport of active Brownian particles in two-dimensional periodic lattices, which we use to explore the effects of bacterial motility, geometry, applied flows and chemical gradients. Our predictions are tested against discrete Brownian dynamics simulations, which we also extend to the case of unstructured media in three dimensions.