北京地区空气中PM10的元素组分及其变化

2000年6—7月,12月和2001年4—5月在北京北郊分别采集了代表夏季、冬季和春季的大气颗粒物样品,经分析后获得了不同季节、不同大气污染情况下气溶胶中Ca,S,Al,Fe,K,Zn等30种元素质量浓度。对不同污染情况下PM₁₀中元素组分的变化分析表明,PM₁₀中的元素总质量浓度呈现出明显的季节变化,即春季最高,冬季次之,夏季最低,Ca,Fe,K,Al,S是PM₁₀中的5种主要元素。随着空气污染的加重,PM₁₀中的元素总质量浓度明显增加,在春季这一增加达到7倍之多。在重污染情况下,无论在近地面,还是在边界层,PM₁₀中的主要元素排序夏季以地壳元素为首,而冬春季均以污染元素为首。一般情况下,PM₁₀中的元素总质量浓度在近地层中随高度升高而降低,降低幅度约为20%。分析结果还表明,随着空气污染的加重,PM₁₀中的污染元素,尤其是As,Cr,Co,Cu,Ni,PPb,Se,Zn等低浓度污染元素的浓度明显增加。 

Chemical Composition of PM10 and Its Variation in the Atmosphere in Beijing Area

Particle samples were taken in June to July,December 2000 and April to May 2001 in order to determine temporal and spatial variations of particle concentration and chemical composition in the atmosphere.About 30 chemical elements such as Ca,S,Al,Fe,K,Zn,etc.,are obtained in various seasons and under different air pollution condition.Variations of element composition in PM_(10) show obvious seasonal variations of total element concentration in PM_(10) with the highest total element concentration in the spring,the second one in the winter and the lowest one in the summer.Ca,Fe,K,Al and S are five main elements in PM_(10).The total element concentration increased obviously with the increase of air pollution,and the increase is as much as 7 times in the spring.In the heavy pollution days,both at near surface and in the boundary layer,the crustal elements occupied first place in the summer.In average,total element concentration in PM_(10) decreased by about 20% with height increase in the near surface atmosphere.The results also showed evident increase of low concentration elements,such as As,Cr,Co,Cu,Ni,P,Pb,Se,Zn,etc.in heavy pollution days.