贵州某燃煤电厂周边春季大气颗粒物的汞污染特征

Pollution characteristics of mercury in particulate matters around a coal-fired power plant in Guizhou Province in spring

为分析燃煤电厂周边不同粒径大气颗粒物及其中汞的污染特征,于2017年春季对贵州某燃煤电厂周边TSP、PM_(10)、PM_(2.5)进行样品采集,应用冷原子荧光汞分析仪对颗粒物中汞的浓度进行测定。结果表明:TSP、PM_(10)、PM_(2.5)的体积浓度范围分别为83.7~162、65.2~130、43.6~87.1μg·m-3,超标率分别为0、5.63%、25.7%。汞的体积浓度(Cv(Hg))分别为68.5~102、58.9~84.9、51.4~80.9 pg·m^(-3);汞的质量浓度(Cm(Hg))分别为571~810、627~913、693~1083 ng·g^(-1);从空间分布看,上风向颗粒物样品中汞浓度低于下风向,主导风向高于非主导风向,主要受当地风向和采样点位置影响。汞在颗粒物中的PM_(2.5)/PM_(10)和PM_(10)/TSP值分别为67.5%~95.2%、83.1%~98.8%,明显高于其相应的颗粒物质量浓度比值,表明汞主要在细颗粒物中富集。

To analyze the pollution characteristics of mercury in particulate matters with different sizes,TSP,PM10,and PM2.5 samples were collected around a coal-fired power plant in Guizhou Province in spring of 2017. Concentrations of mercury in these samples were measured by a cold atomic fluorescence mercury analyzer. The results showed that the volume concentrations of TSP,PM10,and PM2.5 were 83.7-162,65.2-130 and 43.6-87.1 μg·m^-3,which exceeded the limit level by 0,5.63%,and 25.7%,respectively. The volume concentrations of mercury（ Cv（ Hg）） in TSP,PM10,and PM2.5 were 68. 5-102,58. 9-84. 9,and 51. 4-80. 9 pg · m^-3 and the mass concentrations of mercury（ Cm（ Hg）） were 571-810,627-913,and 693-1083 ng·g-1,respectively. Spatially,the concentrations of mercury in the samples collected at upwind direction were much lower than that at the downwind direction. Mercury concentration in the samples at dominant wind direction was generally higher than that at the non-dominant wind direction. Therefore,the local wind direction and sampling site influenced mercury concentration. The ratios of mercury in PM2.5 to that in PM10 were 67.5%-95. 2% and the ratio between PM10 to TSP were 83. 1%-98.8%,which were higher than those of particle mass concentrations,indicating that mercury was mainly enriched in fine particles.