汞在北京大气中细颗粒物上的分布

Distribution of Mercury on the Aerosol in the Atmosphere of Beijing

为了解汞在北京大气中细颗粒上的分布 ,用 AN- 2 0 0型安德森冲击式分级采样器于 1 997年 1 1月 3 0日～ 1 998年 2月 8日 (采暖期 ) ,在北京 3个采样点同步采取不同粒径 (4.7～ 1 0 ,1 .1～4.7和 0 .43～ 1 .1 μm)的颗粒物 ,测定了其上汞的质量浓度 .影响大气中颗粒态汞的因素较多 ,释放源是其中之一 .3个采样点中最大颗粒物态汞浓度并未在工业区出现 ,表明北京市大气中颗粒态汞的环境行为复杂 ,可能具有广域扩散性 .3个采样点颗粒物态总汞质量分数为 (0 .98～ 2 .90 )× 1 0 -6。

To evaluate the distribution of mercury in atmosphere of Beijing the aerosol samples with different size (4.7～10,1.1～4.7 and 0.43～1.1 μm) was collected and their Hg content was detected in heating season by means of fraction collector. The particles with different size in atmosphere combine Hg in different amounts. The higher content of Hg was in the fraction with small size. The total Hg on particulate in atmosphere were in the range of 0.36～0.44 ng/m 3. The highest is not near the site of industrial discharge, indicating the complicated environmental behaviour of particulate Hg and the possibility of its diffuse in wide area. The mass fraction of Hg on the aerosol was in the range of( 0.98～2.90)×10 -6 at three sampling sites in Beijing which is higher than 0.71×10 -6 on aerosol from American city.