摘要
为了解北京大气细粒子(PM2.5)的污染水平和污染特征,在车公庄和清华园进行了连续1年、每周1次同步采样和全样品分析。2个采样点PM2.5的化学组成相似。含碳组分和水溶性离子是主要的组分,其质量浓度之和超过PM2.5的50%。有机碳、元素碳和细粒子PM2.5的季节变化一致,即冬季质量浓度最高,夏季最低。夏季NO-3的质量浓度最低且在采样过程中从特氟隆滤膜上有近50%的挥发。SO2-4不同于PM2.5的季节变化主要取决于SO2的转化率。地壳元素的质量浓度从冬季到春季大幅度上升,春季沙尘天气频是一个重要原因。
This paper describes the PM2.5 (particulate matter with aerodynamic diameters less than 2.5 μm) concentration and composition in the ambient air of Beijing. Weekly samples were simultaneously collected for one year at the Chegongzhuang and Qinghuayuan sites in Beijing. The PM2.5 compositions at the two sampling sites were similar. The principal components were carbonaceous species and watersoluble ions, with their total mass accounting for more than 50% of the total PM2.5 mass. Organic carbon (OC) and elemental carbon (EC) exhibited the same seasonal variations as PM2.5, i.e. the highest mass concentrations occurred in the winter while the lowest in the summer. The lowest nitrate levels were in the summer with nearly 50% of the nitrate volatiles coming from Teflon filters. Sulfates and crustalrelated species showed quite different seasonal trends from those of PM2.5, suggesting that the sulfate levels were mainly determined by the SO2 gas to sulfate transformation rate, while the crustalrelated species were strongly impacted by the frequent dust storms in the spring, resulting in severely elevated concentrations from winter to spring.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2002年第12期1605-1608,共4页
Journal of Tsinghua University(Science and Technology)
