上海市大气可吸入颗粒物的粒度分布分形特征  

Fractal dimensions of size distribution of PM_(10)in Shanghai

作　　者：杨书申[1] 邵龙义[1] 沈蓉蓉[1] 李卫军[1] 张桂林[2] 谈明光[2] 

机构地区：[1]中国矿业大学资源与地球科学系 [2]中国科学院上海应用物理研究所,上海201800

出　　处：《中国环境科学》2007年第5期594-598,共5页China Environmental Science

基　　金：国家自然科学基金资助项目(40575065);教育部新世纪优秀人才支持计划资助

摘　　要：采用分形维数定量表征颗粒物的粒度分布的方法,计算2005年上海市大气可吸入颗粒物粒度分布的分形维数,分析不同采样点颗粒物粒度分布分形维数的变化与可吸入颗粒物粒度分布的关系,讨论采样时气象条件等因素对颗粒物粒度分布分形维数的影响;推导大气颗粒物的粒度分布分形维数与颗粒物表面吸附性能之间的关系,并结合部分金属元素的含量进行讨论.结果表明,上海市可吸入颗粒物粒度分布的分形维数在0.6506～2.9254之间,并且相对湿度较大,风力较小均会使颗粒物的粒度分布分形维数减小;粒度分布分形维数值越大,颗粒物中细颗粒物越多,粒度分布分形维数较好地表征了颗粒物的粒度整体分布.粒度分布分形维数和颗粒物比表面积等物理性能有直接关系,粒度分布分形维数值越大,细粒子所占的比表面积越多,对有毒有害污染物吸附更多.The size distribution of airborne inhalable particulates was quantitatively described by fractal dimensions with the example from the PM10 in Shanghai in 2005. Relationship between variation in fractal dimension of size distribution （FDSD） and the size distribution of the PM10 at the different sampling sites was investigated. Influence of the meteorological conditions during sampling periods on the FDSD of PM10 was discussed. The FDSD in relation to the surface adsorption property of the PM10 was derived, especially to several different heavy metals. The FDSD of the PM10 in Shanghai ranges from 0.6506 to 2.9254,and the lower FDSD values occurred when the humidity increases and the wind speed decreases. It is found that the higher percentage of the finer particles is associated the higher FI）SD values of inhalable particles. Because the finer particles are also associated with the larger surface area, and thus the higher adsorption capacities, the FDSD values is believed to be able to reflect the adsorption capacities to the heavy metals.

关 键 词：可吸入颗粒物 粒度分布 分形维数 表面吸附性能 

分 类 号：X513[环境科学与工程—环境工程]