Abstract |
The report gives results of a comprehensive multimedia emissions assessment of a coal-fired boiler equipped with electrostatic precipitators (ESPs) and a dual-alkali flue gas desulfurization system. Flue gas pollutant concentrations were measured at the inlet and outlet of both control devices. Scrubbing efficiency for SO2 was 88%. Particulate removal efficiencies were 99.7% across the ESPs and 19% across the scrubbers for a total removal efficiency of 99.86%. Particulates (exclusive of H2SO4 aerosol) less than 3 micrometers in diameter accounted for 59% by weightof total particulate emissions. Emissions of primary sulfate removal efficiencies were 48% across the ESPs and 77% across the scrubbers. Particulate sulfate emissions after scrubbing accounted for about 50% by weight of total particulate emissions. The two liquid streams discharged from the site showed concentrations of Al, Ca, Cd, Fe, Mn, Ni, P, and Pb at levels of potential environmental concern. However, in most cases, the levels discharged to the river were not significantly different from those found in makeup water from the river. Waste solids consisted of three collected ash streams and scrubber filter cake. The ashes contained several elements of potential health and ecological concern but few organics (0.04-0.48 mg/kg). |