By

Traylor, Julia H.Ìý1Ìý;ÌýNeupauer, Roseanna M.Ìý2Ìý;ÌýPiscopo, Amy N.Ìý3

1ÌýUniversity of babyÖ±²¥app Boulder-CEAE
2ÌýUniversity of babyÖ±²¥app Boulder-CEAE
3ÌýUniversity of babyÖ±²¥app Boulder-CEAE

Groundwater comprises about 30 percent of Earth’s available freshwater; however, this vital resource is often contaminated by industrial or agricultural sources. The efficiency of existing groundwater remediation methods must be improved, especially as global consumption of water and energy rises. During in situ remediation, a chemical treatment solution is injected into the contaminated aquifer to degrade the groundwater contaminant. Simulations have demonstrated that spreading of the treatment solution through a series of engineered injection and extractions (EIE) of clean water at wells surrounding the contaminated region increases the contact area between the treatment solution and contaminant, thereby increasing the amount of contaminant degradation reactions. Past studies have evaluated the amount of reaction during EIE in simulations where the initial injection of treatment solution was modeled as a circular, filled plume. This study modifies the initial configuration of treatment solution by injecting clean water at the center of the treatment solution plume to change its shape to a toroid, which increases the length of the shared interface with the contaminant plume. An optimal initial radius of the interior clean water plume that minimizes the amount of treatment solution injected and maximizes the amount of contaminant degraded is determined. Preliminary work conducted for a homogeneous aquifer shows that the volume of the treatment solution can be reduced by 25 percent compared to previous studies, while contaminant degradation only decreases by two percent. Since most aquifers are not homogenous, this study explores a similar scenario for a heterogeneous aquifer.As material conservation is important to any engineering project, this study also evaluates the trade-off between the cost of treatment solution and the impact of less contaminant degradation, as the interior clean water plume increases.