Partitioning and Emission of Hazardous Trace Elements in a 100 MW Coal-Fired Power Plant Equipped with Selective Catalytic Reduction, Electrostatic Precipitator, and Wet Flue Gas Desulfurization

Abstract

Hazardous trace elements (HTEs) emitted from coal combustion have caused great harm in the environment and on human health. Partitioning and emission of eight HTEs, namely, Zn, Sb, Pb, Cd, As, Cr, Mn, and Ba, were conducted on a 100 MW coal-fired power plant, which was equipped with selective catalytic reduction (SCR), electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD). US EPA Method 29 was used to sample the eight HTEs in flue gas at the four sites before or after each device, simultaneously. Feed coal, bottom ash, ash from ESP (ESP ash), limestone slurry, and desulphurization wastewater were collected at the same time. Results show that mass balance rates of eight HTEs of the whole system and each device are in the acceptable range of 70%–130%. The studied HTEs are mainly distributed in ESP ash with a relative mass distribution ratio of 86.23%–98.25%, followed by 1.65%–13.67% for bottom ash. Concentrations of Cd, Sb, As, Cr, Pb, Zn, Mn, and Ba in flue gas at the inlet and outlet of...