【摘要】 为研究保定市大气颗粒物中水溶性无机离子的质量浓度水平、季节变化和粒径分布特征,于2010年8月-2011年8月利用Andersen分级采样器采集大气颗粒物样品,并用离子色谱分析其中的离子组成.结果表明,细粒子(PM2.1)中主要水溶性无机离子为SO42-、NO3-和NH4+,三者质量浓度平均值分别为23.18、21.99和11.44μg/m3;粗粒子(PM>2.1)中主要水溶性无机离子为NO3-、Ca2+和SO42-,三者质量浓度平均值分别为10.60、10.39和10.14μg/m3.细粒子中ρ(SO42-)、ρ(NO3-)、ρ(NH4+)、ρ(Cl-)和ρ(K+)的季节性变化相似,均为冬季>秋季>夏季>春季;粗粒子中ρ(NH4+)、ρ(K+)和ρ(NO3-)呈现出与细粒子不同的季节性变化趋势,ρ(NH4+)和ρ(K+)均为冬季>夏季>秋季>春季,而ρ(NO3-)则为夏季>秋季>冬季>春季.粗、细粒子中ρ(Ca2+)和ρ(Mg2+)的季节性变化特征相似,均为冬季最高、夏季最低.ρ(SO42-)、ρ(NO3-)、ρ(Na+)和ρ(K+)均呈双峰分布,分别在>0.43～1.1μm和>4.7～5.8μm出现峰值;ρ(NH4+)和ρ(Cl-)呈细模态单峰分布,在>0.43～1.1μm出现峰值;ρ(Mg2+)和ρ(Ca2+)呈粗模态单峰分布,在>4.7～5.8μm出现峰值.二次源和生物质燃烧是细粒子的主要来源,扬尘对粗粒子影响较大.更多还原

【Abstract】 To investigate the concentration levels,seasonal variations and size distributions of water soluble inorganic ions(WSI),size-segregated aerosol samples were collected using Andersen cascade sampler from August 2010 to August 2011 in Baoding.The WSI were analyzed by IC.The results indicated that secondary water-soluble ions(SWSI)(SO42-,NO3-and NH4+) were the main components,and mainly found in the fine particles with the concentration of 23.18,21.99 and 11.44 μg/m3 respectively.In the coarse particles,NO3-,Ca2+ and SO42-were the dominant contributions of WSI with the concentration of 10.60,10.39 and 10.14 μg/m3 respectively.In the fine mode,the seasonal variations of SO42-,NO3-,NH4+,Cl-and K+were similar,following the order of winter>autumn>summer>spring.Meanwhile,Ca2+ and Mg2+ presented the similar seasonal change with the order of winter>autumn>spring>summer.In the coarse mode,the seasonal variations of NH4+,K+and NO3-were different from that in the fine mode,with the highest concentrations in winter and the lowest concentration in spring for NH4+ and K+.The concentrations of NO3-were summer>autumn>winter>spring.SO42-,NO3-,Na+and K+showed a bimodal size distribution with the fine mode at >0.43-1.1 μm and the coarse mode at >4.7-5.8 μm.NH4+ and Cl-were unimodal with the peak in the fine mode of >0.43-1.1 μm,Ca2+and Mg2+were unimodal with the peak in the coarse mode of >4.7-5.8 μm.Source analyses indicated that the secondary formation and coal burning emission were the major sources of the fine particles,while the dust was the main source of the coarse particles.更多还原