The environmental impact of trace element contents of Indiana and Western Kentucky coals

摘要

Distribution of trace elements in coal beds influences both the properties of coal combustion products and the level of pollutants to the atmosphere. Because of the planned regulations of emissions from coal-burning power plants, the determination and prediction of HAPS (Hazardous Air Pollutants; Title Ⅲ of the Clean Air Act Amendments of 1990 ) emissions has becomes a very important issue in the United States. This study examines the distribution of trace elements in the Pennsylvanian coal beds of Indiana and Western Kentucky. In these two states, coal is the dominant source of electricity generation (＞ 95 %). Special emphasis is placed on trace elements of major environmental concern such as Hg, Se, As, and Cl. The trends in their distribution have been mapped for the major coal seams in both states. Hg and As commonly show similar distribution patterns, suggesting similar controls on their concentrations, and their association with pyrite in particular. Trends for Se and Cl are different. Based on the trace element distribution, strategies in coal use are suggested to address forthcoming environmental regulations.