The emission concentration of ash particles smaller than 10μm in diameter(PM10)in a 200 MW thermal power plant boiler equipped with electrostatic precipitator(ESP)and wet flue gas desulphurization(WFGD)was examined using a Dekati low pressure impactor(DLPI).The effect of flue gas treatment facilities on PM emission was analyzed.The results show that the PM10 had made up around 55%of the total ash released from the power plant

while that for PM2.5was 24%.The ESP had an overall removal efficiency over 97%for PM1.0

PM2.5

PM10

and the larger the particle size

the higer the removal efficiency.For the WFGD device

due to reasonable design and operation of the demisterand relative large diameter for the limestone tower

the outlet flue gas flow rate could be controlled at a low rate.Consequently

the PM2.5removal efficiency could reach 70%.