Effects of Fluidized Bed Combustion Waste on the Ca, Mg, S, and Zn Levels in Red Clover, Tall Fescue, Oat, and Buckwheat1

Abstract

AbstractFluidized bed combustion, a desulfurization process for coal‐fired power plants, produces a waste that contains large amounts of calcium oxide and calcium sulfate. Since approximately 200 kg of fluidized bed combustion waste (FBCW) is generated per metric ton of coal burned, it represents a significant potential source of lime that must be evaluated before it can be properly utilized. In this study, FBCW was compared with calcium hydroxide as a lime source in a greenhouse study with red clover, tall fescue, oat, and buckwheat. The FBCW and calcium hydroxide were applied at rates calculated to adjust the pH of Westmoreland silt loam (Ultic Hapludalf, mixed, mesic) to 5.0, 5.5, 6.0, and 6.5. Though the loading rates from FBCW were higher than those from calcium hydroxide, FBCW treatments increased Ca levels more than did calcium hydroxide only in red clover. Only dry matter yields of buckwheat were higher for FBCW than for calcium hydroxide applications. All species showed higher FBCW‐induced Mg and S increases than hydrated lime. In spite of the Zn loading, Zn levels in herbage decreased as the pH levels increased as a result of FBCW application. Soil pH increases in FBCW and Calcium hydroxide treatments were comparable when the materials were applied in equivalent amounts. It was concluded that FBCW may be valuable as a lime, Mg, or S source when the effects of heavy metals in the material are evaluated.