Characterization of volatile organic compound emissions from anthropogenic and emerging biogenic sources
PhD: University of Colorado Boulder, 2018.
Volatile organic compounds are emitted by myriad sources. This thesis investigates trends in emissions on global, regional, and local scales. Globally, an increasing trend in ethane and propane emissions was observed, mainly as a result of oil and natural gas (O&NG) development. Regionally, air composition varied as a result of the efficacy of emission controls from mobile and industrial sources, and unconventional O&NG development. Unconventional O&NG development has also had a demonstrated effect of Colorado's Northern Front Range. An elevation gradient was observed that suggests emissions from metropolitan and O&NG development centers in this area influence air composition in the adjacent foothills. A spatial gradient of O&NG tracers was also observed; mixing ratios increased as distance to an area of concentrated O&NG development decreased. Given the ever increasing proximity of O&NG emissions to population centers, concerned citizens desire a method to assess air quality in and around their homes, schools, and offices. An affordable method for measuring C3-C5 alkanes was developed utilizing passive adsorbent sampling cartridges, though further experimentation is needed to determine the absolute accuracy of these devices. Finally, VOC emissions from soil and bacteria are characterized. Soil VOC emissions mirrored the "Birch Effect", and spiked following a wetting event. Bacterial VOC emission profiles displayed strong taxonomic and phylogenetic signals, and suggest VOC play a role in finer-scale patterns of ecological diversity.