By

Abeysinghe, NadeekaÌý1Ìý;ÌýNeupauer, RoseannaÌý2Ìý;ÌýMays, DavidÌý3

1ÌýÀÖ²¥´«Ã½ at Boulder
2ÌýÀÖ²¥´«Ã½ at Boulder
3ÌýÀÖ²¥´«Ã½ at Denver

Remediation of contaminated groundwater may involve the injection of a treatment solution into the aquifer to simulate degradation of contaminants, coupled with removal of water from an extraction well to increase circulation. Ideally the treatment solution should be mixed throughout the contaminated area to optimize the reaction rate. However, due to the laminar flows characteristic in porous media, mixing in groundwater is an inherently slow process governed by molecular diffusion. The reaction can be enhanced by stretching and folding the interface between the treatment solution and the contaminated groundwater, thereby increasing the size of the region where reaction can occur. We explore the use of a four-well system with a novel injection and extraction scheme to create a transient flow field that leads to stretching and folding of the interface. The results of the reactive transport simulations of the four-well system illustrate that the reaction is enhanced.