泰山顶夏季大气气溶胶中水溶性离子的浓度及其粒径分布研究

为研究我国华北地区大气污染区域传输过程,2006-06在泰山日观峰上的泰山气象站,利用Andersen分级采样器同步进行了大气气溶胶采样,样品用离子色谱(IC)进行了分析.结果表明,SO2-4、NH 4、K 的浓度在0.43～0.65 μm出现峰值;Ca2 、Mg2 的浓度在4.7～5.8 μm出现峰值;NO-3、Na 、Cl-的浓度在0.43～0.65 μm和4.7～5.8 μm出现峰值.观测期间,高浓度的硫酸盐的质量中位直径在0.5～0.8 μm,属于"液滴模态".二次离子(SO2-4-、NH 4、NO-3)和K 浓度变化很剧烈,其它离子浓度变化不大.其中SO2-4的变化幅度最大,最低浓度为4.0 μg穖-3,最高浓度达到42.3 μg穖-3.来自泰山南方潮湿的气团是形成二次离子高值的原因.

Concentrations and Size Distributions of Water Soluble Ions of Atmospheric Aerosol at the Summit of Mount Tai

In order to research on the air pollutants' long-range transportation in North China, aerosol samples were collected with Andersen cascade sampler at the summit of mount Tai during June 2006, in Shandong Province. The water soluble ionic concentrations were analyzed by IC. It shows that there are three types of size distribution: 1) ions whose mass resided mainly within the accumulation mode with the peak at 0.43-0.65 microm (SO4(2-), NH4+, K+); 2) Ions whose mass resided mainly within coarse particles with the peak at 4.7-5.8 microm (Ca2+, Mg2+); 3) Ions which were two modes with the peak at 0.43-0.65 microm and 4.7-5.8 microm (NO3-, NO3-,Cl-). The mass median diameter of SO4(2-) with high concentration is between 0.5 microm and 0.8 microm, and belongs to the "drop mode". The concentration of ions such as SO4(2-), NO3-, NH4+ and K+ has a huge variety and the sulfate has the most great variety with the lowest concentration which is 4.0 microg x m(-3) and the highest concentration which is 42.3 microg x m(-3). The ions (SO4(2-), NO3-, NH4+) reach the high value when the humid air mass comes from the south.