Influence Of Coal Combustion Flue Gas Desulfurization Waste On Element Uptake By Maize (Zea Mays L.)

Anna S. Knox¹, John D. Knox², Domy C. Adriano³, and Kenneth S. Sajwan^4
1Savannah River National Laboratory, Westinghouse Savannah River Company, 773-42A, Savannah River Site, Aiken, SC 29808, USA
²Columbia County Board of Education, Appling, GA 30802, USA
³The University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29802, USA
⁴Department of Natural Sciences and Mathematics, Savannah State University, Savannah, GA 31404, USA

 

Abstract
A greenhouse study was conducted to determine the effect of coal combustion flue gas desulfurization (FGD) waste from a coal combustion electric power facility, located in Cope, SC on elemental uptake by maize (Zea mays L.). Unweathered FGD was applied to an Orangeburg series soil (Typic Paleudult) with an initial soil pH_salt of 4.90. The FGD was added at 0, 1, 2, 4, 6, 8, and 10% by weight. The test plant, maize, was harvested after 6 weeks of growth. Within 56 days of the FGD application, all rates of FGD significantly increased pH in the soil and the soil leachate above 6.0. The elemental concentration of the maize tissues indicated a characteristic elevation of B, Se, Mo, and As. However, no visual symptoms of toxicity of B or other elements in plants were observed. Increasing level of FGD caused a steady decline in biomass dry weight, with the highest treatment producing plants, which had approximately half the biomass of the control plants. Due to elevated concentrations of B and other elements (Se, Mo, and As) and due to adverse yield effects measured on plants, we do not recommend using FGD materials as a soil amendment for the purpose of growing agronomic and horticultural crops until sufficient time is allowed to substantially leach soluble salts including B and Se. This will necessitate monitoring the electrical conductivity and B and Se contents of the FGD waste to acceptable levels.