关键词: PM_2.5, 团聚, 脱除, 电除尘, 脱硫废水, 蒸发

Abstract: Emission of fine particles from coal combustion is an important source of atmospheric PM_2.5. The removal of PM_2.5 from coal combustion by electrostatic precipitator (ESP) with adding agglomerant solution and evaporating treatment of desulfurized wastewater was investigated experimentally based on the coal-fired thermal system. Change of concentration and diameter distribution of particles were tested before and after agglomeration, and the influence factors, including concentration of agglomerant solutions, temperature of flue gas at the point of addition，agglomeration solution pH，flue gas flow, and diameter of spray droplets were analyzed. The average diameter of particles could grow more than four times with the effect of wetting, liquid bridge force and adsorption bridging, and the PM_2.5 concentration at ESP outlet could decrease by more than 40% under typical flue gas conditions. Increasing concentration of agglomeration solution could promote PM_2.5 removal. Reducing agglomeration solution pH was better for agglomeration by making the polymer chain more soft stretch. The PM_2.5 concentration at ESP outlet had no change after spraying desulfurized wastewater, and the PM_2.5 concentration decreased when adding agglomeration solution.

Key words: PM_2.5, agglomeration, removal, ESP, desulfurized wastewater, evaporation