Impacts of Coal Combustion on Trace Elements in the Environment: Wisconsin Power Plant Impact Study

摘要

The impact of a modern coal-fired generating station on the environment, with emphasis on the concentrations and behavior of elements and the disposal of fly ash, was determined by analysis of aerosolic dust, oak leaves, aquatic organisms, water, fly ash, and coal. The major analytical techniques used were neutron activation analysis, x-ray fluorescence analysis, atomic absorption spectrophotometry, electron microscopy, and x-ray diffraction. Calcium, Ba, B, and Th concentrations were relatively high in the fly ash produced. When mixed with water, the fly ash reacts to form a cement-like material that includes pozzolanic mineral phases that were identified by x-ray diffraction and electron microscopy. Aerosolic dust collected in fallout buckets was enrined with Br, Hg, Sb, Se, Th, U, and Zn. Of the organisms tested, Asellus racovitzai and Odanata were most suitable for monitoring ecosystem trace element fluxes. Barium, Cr, Sc, and possibly Sb concentrations were higher in specimens of these organisms exposed to the ash effluent than in control specimens. These increases cannot be attributed to seasonal variability, sample contamination or differences in specimen size and are therefore thought to result from exposure of the organisms to ash effluent. Potential effects of fly ash from the Columbia Generating Station or other aerosolic dust on the concentrations of elements in oak leaves could not be detected.