Resumen de Understanding Our Energy Footprint: Undergraduate Chemistry Laboratory Investigation of Environmental Impacts of Solid Fossil Fuel Wastes
Michael Berger, Jillian L. Goldfarb
Engaging undergraduates in the environmental consequences of fossil fuel usage primes them to consider their own anthropogenic impact, and the benefits and trade-offs of converting to renewable fuel strategies. This laboratory activity explores the potential contaminants (both inorganic and organic) present in the raw fuel and solid waste remaining after thermal conversion. Using portable X-ray fluorescence, students analyze the heavy metals present in these solid samples following Environmental Protection Agency (EPA) method 6200. Sample extracts were analyzed via gas chromatography–mass spectrometry to measure polycyclic aromatic hydrocarbons, byproducts of incomplete combustion, in the samples using a semiquantitative internal standard approach. Across a series of raw, semicarbonaceous char and ash samples from oil shale and coal, students found levels of arsenic and naphthalene exceeding EPA regional screening levels for industrial soils. This exercise teaches students about X-ray safety, EPA measurement protocol, solid–liquid extraction techniques, gas chromatograph–mass spectrometry, and semiquantitative analysis techniques, and more broadly about the environmental externalities of solid fuel use. The experimental results provide a basis for a discussion about the risks posed by disposal of energy processing waste on the environment, impediments to potential byproduct utilization, and the sustainability of alternative energy sources.
