Environmental Organic Contaminants in Unconventional Oil and Gas Development: Enhancing Analytical Techniques to Inform Fate Modeling

摘要

Technological advancements in unconventional methods of oil and gas extraction have expanded the accessibility of hydrocarbon resources, making North America a dominant contributor in the world energy market. As a result, energy independence is more feasible today than it was 10 years ago. However, the environmental and public health implications of domestic energy production are not well understood, and the colocation of energy extraction technologies with residential zones is increasingly common. Methods to characterize environmental samples associated with unconventional oil and gas development lack both robustness and simplicity, primarily due to the complexity of the fluids and sophisticated instrumentation required for analysis.;Here, I address the issues associated with analytical evaluations of organic compounds in unconventional oil and gas development. I assess the impacts to air and water from (1) hydraulic fracturing operations in northeastern Pennsylvania and (2) oil sands development in Alberta, Canada using novel analytical techniques. Through these two case studies, I identified and addressed limitations in current capabilities to evaluate the fate of relevant organic compounds. My key contributions include enhanced analytical methods with the use of comprehensive two-dimensional gas chromatography (GCxGC).;In this work, I present the largest study of hydrophobic organic compounds in local groundwater near areas of unconventional gas development and systematically assess for source inputs (Chapter 2). This investigation, and others conducted in parallel, identified a class of drilling and hydraulic fracturing fluid additives (linear alcohol ethoxylates) with insufficient quantitative analytical methods, prompting the development of a novel extraction and quantification method to meet those needs (Chapter 3). Then, I leverage the fundamental properties that give rise to chemical separations in GCxGC to model petroleum hydrocarbon partitioning between air, water, and tailings, ultimately leading to estimated emissions from oil sands extraction and waste handling practices in a lab-controlled setting (Chapter 4). Finally, I develop a rigorous data analysis program to enhance certainty in chemical identifications postulated from mass spectral library matches (Chapter 5). This algorithm compares a compound's measured retention index to a predicted retention index for the postulated structure as a means to give secondary confirmation of chemical identity for hundreds to thousands of compounds simultaneously. These tools reduce the time and cost constraints for the collection of chemical-specific data to inform fate modeling of organic contaminants in the environment, thus facilitating US energy independence while minimizing damage to human health and the environment.