Modification, Transport, and Sources of Hydrocarbon Oxidation Products from Groundwater at Crude Oil and Diesel Spill Sites in Minnesota: Unveiling Common “ThEEMs” via Spectroscopy & Chromatography
In this thesis, petroleum-contaminated groundwater from three spill-affected Minnesota sites—two contaminated with crude oil; one with diesel—is investigated to elucidate whether differences in degradation products from different parent oils exist. After spill events, parent molecules from the leaked oil seep underground and undergo microbial degradation over time, transforming into hydrocarbon oxidation products (HOPs), water-soluble contaminants that infiltrate groundwater aquifers, flowing into nearby environments and towns while exhibiting environmental persistence, toxicity to aquatic biota, and potential risks to humans that become exposed. Spectroscopic and chromatographic study of the structural themes and spatial distributions of HOPs reveals preferential degradation of aliphatic (biolabile) over condensed aromatic (biorefractory) HOPs, with distinct diesel trends detected. Thus, correlations between crude oil- and diesel-based degradational products and the parent petroleum at spill sources were exposed at the three contaminated groundwater sites, offering insight for environmental risk assessment and mitigation strategies to better predict spill outcomes
