Date of Award
December 2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Environmental Engineering
First Advisor
Bethany Klemetsrud
Abstract
This study explored the application of repurposed carpet tiles as a solution to address acid mine drainage (AMD), a common issue associated with historical coal mining that was found to affect certain demographic groups disproportionately. The efficiencies and environmental trade-offs of using downcycled carpet tiles were researched as a neutralization agent in remediation systems. Data was generated using life cycle assessment (LCA) and geospatial modeling. The socioeconomic effects of coal mining in the greater Pittsburgh area were analyzed by integrating home sale data, abandoned mine lands (inventory sites), and census demographics into the geospatial model and determined that homes in mining problem areas sold for 28% ($58,600) compared to homes in unaffected areas. Mining problem regions in Allegheny County had a significantly larger Black population and a higher proportion of individuals without postsecondary education, with these disparities more pronounced in urban areas. Logistic regression models showed a negative correlation between home sale prices and the likelihood of being in a mining-affected zone, and a correlation between higher community needs and the probability of living in a mining problem area.
Research showed that carpet tiles, which can contain high amounts of calcium carbonate (CaCO3), successfully neutralized AMD, achieving an approximate 40% efficiency. Carpet backing increased the pH of AMD samples from 3.3 to 6.1 within four hours, significantly reducing the acidity level. The LCA used a functional unit of one cubic meter of AMD water and compared traditional remediation systems with downcycled carpet tiles and various construction methods. Six scenarios analyzed several construction materials, including concrete and plastic liners, as well as neutralization sources such as downcycled carpet tiles and high-purity limestone. Three key midpoint impact categories were analyzed: global warming potential (GWP), fine particulate matter formation (PMFP), and total human toxicity potential (HTP), representing 94% of endpoint outcomes. Limestone neutralization with a plastic liner had the lowest GWP (1.21E-02 kg CO2 eq), PMFP (5.46E-05 kg PM2.5 eq), and HTP (3.41E-03 kg 1,4-DCB). Conversely, using downcycled carpet tiles in a concrete tank resulted in 480% higher GWP, 350% higher PMFP, and 428% higher HTP. Although this downcycling method may yield higher emissions, it extends the lifespan of carpet tiles and reduces the need for additional mining operations.
Recommended Citation
Bram, Lauren, "Evaluation Of Socioeconomic Disparities From Coal Mining And Sustainable Remediation Of Acid Mine Drainage Using Waste Carpet Tiles: A Geospatial And Life Cycle Assessment Approach" (2024). Theses and Dissertations. 6521.
https://commons.und.edu/theses/6521