(361p) Influence of the Spatial Organization of Contaminants on Bioremediation

Access to clean water is at the forefront of top global challenges that engineers are equipped to tackle. A key source of drinking water for over half of the population in the United States is groundwater; unfortunately, over a third of groundwater sources are contaminated with harmful chemicals. Bioremediation is a promising approach to cleaning up groundwater contaminants that utilizes chemotactic bacteria to actively sense, find, and degrade these contaminants in situ---additionally, it is significantly cheaper than current pump-and-treat methods. However, how these chemotactic bacteria behave in the presence of multiple discrete, spatially-distributed contaminant sources at the pore scale remains poorly understood. To address this issue, we use mathematical modeling and numerical simulations to determine how physiological and environmental conditions influence how bacteria can chemotactically respond to multiple contaminant sources. We use our findings to establish a universal biophysical rule to predict how the dynamics of bacterial chemotaxis, spatial distribution of cells and diffusing contaminant, and overall efficacy of bioremediation depend on cellular properties, contaminant properties, and the spacing between contaminant sources. Our work thus provides a key step towards developing a deeper understanding bioremediation at the pore scale and establishing useful design principles to guide more effective bioremediation strategies.