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Improved leaching test methods for environmental assessment of coal ash and recycled materials used on construction
Citation:
THORNELOE, S., D. Kosson, G. HELMS, AND A. C. Garrabrants. Improved leaching test methods for environmental assessment of coal ash and recycled materials used on construction. In Proceedings, 12th International Waste Management and Landfill Symposium, Cagliari, ITALY, October 05 - 09, 2009. (2009).
Impact/Purpose:
Symposium paper
Description:
Changes in air pollution control at coal-fired power plants will result in lower emissions of mercury and other pollutants. Fly ash, flue gas desulfurization gypsum, and other air pollution control residues are used in agricultural, commercial, and engineering applications. Research is being conducted to evaluate the fate and environmental stability of mercury and other metals found in coal combustion residues resulting from changes in air pollution control at coal-fired power plants in the U.S. The pathway of most concern is leaching of metals to groundwater and surface water. Improved leaching test methods are being used that evaluate the range of field conditions that coal ash is exposed to. Results are considered more representative of actual field conditions than single-point pH tests which have historically been used in evaluating use of CCRs and other secondary materials. This paper provides an overview of the leaching test procedures being used in this research and application to a range of CCRs resulting from more stringent air pollution control at coal-fired power plants. The results of this research are helping to ensure that the use of fly ash or other secondary materials are being managed in a manner that is protective of human health and the environment.
