Date of Award

Spring 1-1-2014

Document Type

Thesis

Degree Name

Master of Science (MS)

First Advisor

Roseanna M. Neupauer

Second Advisor

David C. Mays

Third Advisor

John P. Crimaldi

Abstract

Energy-efficient methods of remediating contaminated groundwater, such as in-situ remediation, have become increasingly relevant given the current state of rising water and energy usage across the globe. During in-situ remediation, a treatment solution is injected into a contaminated aquifer to degrade the groundwater contaminant in place. Since contaminant degradation reactions only occur at locations where the treatment solution and groundwater contaminant overlap each other, advective spreading of the treatment solution into the contaminated region is necessary. However, spreading in aquifers is generally poor as groundwater flow is laminar, and lacks turbulent eddies responsible for spreading in open flow systems. Researchers have demonstrated that stretching and folding can lead to spreading in laminar flow environments. These findings motivated the development of a technique known as engineered injection and extraction (EIE), which incorporates the principles of stretching and folding to improve spreading during in-situ remediation. During EIE, clean water is injected and extracted at wells surrounding a contaminant plume to create transient flow fields that stretch and fold the interface between the treatment solution and contaminant. Other researchers have conducted simulations to show that this technique leads to enhanced spreading; however, no evidence has been presented that enhanced spreading correlates to enhanced reaction. This study demonstrates that EIE enhances degradation of groundwater contamination in homogeneous and heterogeneous aquifers. Furthermore, this study shows that the reaction provided by the spreading due to EIE is greater than the reaction due to spreading from heterogeneity alone.

Available for download on Friday, July 17, 2020

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