Migration Behavior of Trace Elements at a Coal-Fired Power Plant with Different Boiler Loads

Abstract

Trace elements (TEs) emitted from coal-fired power plants have done great harm on the environment, which has caused widespread concern in the world. In this study, the effects of boiler loads (100 and 75% output) on the migration behaviors of TEs (including Cr, Mn, Co, Ni, Cu, Zn, As, Ba, and Pb) were conducted on a coal-fired power plant with selective catalytic reduction (SCR), electrostatic precipitator (ESP), wet flue gas desulfurization (WFGD), and wet electrostatic precipitator (WESP). Simultaneous sampling of coal, bottom and fly ash, flue gas, and the byproducts from WFGD and WESP was performed. It shows that mass balance rate of TEs at the two loads is in the acceptable range. TEs mainly distribute in bottom and ESP ash in the coal-fired power plant at the two loads. In comparison to the 100% load, the amount of TEs in bottom ash increases at the 75% load. The overall removal rates of TEs through the whole system at the two loads are higher than 99.9%. Except Co and Ba, the overall removal rate a...