Groundwater is an essential natural resource, but vulnerable to contamination, so we spend billions of dollars annually on groundwater remediation. One approach to groundwater remediation is injecting solutions that treat contaminants in place, called in-situ remediation. In-situ remediation often requires spreading an injected plume of treatment solution into the contaminated groundwater, but the laminar flows characteristic of porous media prevent the turbulence that generates plume spreading in most engineered reactors. The resulting difficulty in spreading is a widely recognized, fundamental problem in groundwater remediation.
The research described here approaches this fundamental problem using a simple idea from the field of complex systems science: When turbulent mixing is not possible, the best way to spread one fluid into another is by chaotic flow, called chaotic advection. The essence of chaotic advection in laminar flows is actually quite simple: One needs to impose plume stretching and folding as shown in the animations below. This work is the subject of two consecutive research awards from the National Science Foundation, active from 2011-2017.
These two animations, published in the Supporting Information of Mays and Neupauer (2012), illustrate chaotic advection in laminar flows by stretching and folding:
GRAPHICAL USER INTERFACE (GUI)
This GUI allows users to create, test, and export pumping schemes for engineered injection and extraction. To run, open Matlab R2013b (or later) to a working directory containing Mays_Stretching_Folding_GUI.fig and Mays_Stretching_Folding_GUI.m. Enter >>guide at the Matlab prompt, click on tab "Open Existing GUI", select Mays_Stretching_Folding_GUI.fig, and choose Tools/Run.
Complete details are given in the following refereed publications: