中文摘要：

为研究我国长江三角洲地区气溶胶污染的区域特征,2008年4月、7月、10月和2009年1月,在临安区域本底站利用安德森（Andersen）分级采样器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,临安区域本底站SO2/4-、NH4＋、K＋的浓度在粒径0.43—1.1μm出现峰值;Ca2＋、Mg2＋的浓度在粒径3.3—5.8μm出现峰值;NO3-、Cl-、Na＋的浓度在粒径0.43—1.1μm和3.3—5.8μm出现峰值.气溶胶各个粒径段上的阳、阴离子电荷比均小于2.在降水过程个例分析中,降水之后临安区域本底站的总离子浓度增加了10.9μg·m-3;粒径分布除SO2/4-和K＋有明显变化以外,其它离子没有明显变化.通过霾日和非霾日的浓度变化分析发现,细粒子中SO2/4-、NH4＋的浓度的增加是造成霾天气的主要原因.

英文摘要：

investigate the regional characteristics of aerosol pollution in the Changjiang River Delta area in China, atmospheric aerosol samples were collected with Andersen cascade sampler at Lin＇ an regional background station during April, July, October in 2008 and January in 2009. The water-soluble ion concentrations were analyzed by IC. The results showed three different size distributions for the ions characterized, including masses in ： （i） the accumulation mode, with a peak at 0.43 to 1.1 μm （ SO2/4-, NH4＋ , K ＋ ） ; （ii） the coarse particle mode, with a peak at 3.5 to 5.8 μm （ Ca2＋ , Mg2＋ ） ; and （iii） a bimodal distribution, with peaks at 0.43 to 1.1 μm and 3.3 to 5.8 μm （NO3-, Na ＋, C1-）. The ratios of cations to anions in each size of aerosol were less than 2. The mass concentration of total water soluble ions increased by 10.9 μg. m -3 after precipitation. And the size distributions of the water soluble ions except SO2/4-and K ＋ had little difference before and after precipitation. By comparison of the characteristics of water-soluble ions on typical clear and hazy days, the increase of SO2/4- and NH4＋ concentrations in PM2.5 could be one of the causes for the formation of haze.