Polymer Additives Homogenize Flow in Underground Environments, Richard Huang, UG '23, (3964616)
Underground rocks and soil have microscopic pores in them able to hold groundwater. Approximately 22% of groundwater in the U.S. is contaminated, while 50% of drinking water in the U.S. is sourced from groundwater. One existing means of cleaning up groundwater is a direct injection of some cleaning solution into the groundwater. A problem encountered when doing so is that underground environments are not homogeneous, differences exist between different regions. In particular, how able any particular region is to accept flow through it, known as the permeability. High permeability regions accept flow much more readily, so that any solution injected preferentially flows towards those over lower-permeability regions, resulting in poor remediation efficacy in low-permeability regions because little flow is actually reaching there. In this work, we investigated the influence of polymer additives on flow behavior to address this issue. We found that polymers dramatically increased the flow rate in low-permeability regions relative to the flow rate without polymers under the right flow conditions. Polymer solutions are thus able to partially disregard permeability differences between regions of an underground environment, homogenizing the flow behavior between them.