The uptake of chemical elements from coal ash and settling basin effluent by primary producers I. Relative concentrations in predominant plants

Abstract

Chemical elements are released to the surface waters in large concentrations from coal ash, when ash is sluiced from the plant to a settling basin, or disposed on land surfaces. The role of primary producers growing in the drainage system receiving ash basin effluent, in removal or cycling of chemical elements from coal ash, has been investigated. Aquatic plants in the drainage system were collected and analyzed by neutron activation to determine concentrations of 23 chemical elements present in the coal ash effluent. The predominant aquatic producers present were Lemna perpusilla (duckweed), Typha Latifolia (cattail), Pontederia sp., Taxodium distichum (bald cypress), and the algae Oscillatoria sp. and Hydrodictyon sp. Leaves were collected from cattail, cypress and Pontederia sp., and the entire plants were collected from duckweed, Oscillatoria sp. and Hydrodictyon for analysis. Analysis of concentrations showed that duckweed, cattail, Oscillatoria sp. and Hydrodictyon sp. were the most efficient biomagnifiers of the 23 chemical elements. All elements were concentrated by the majority of the plants present relative to the concentration of the elements in the water in which the plants grew. This biomagnification of chemicals appears to be an important mechanism for removal of these elements from the drainage system water.