摘要
为了研究兰州市2006年3月31日沙尘暴过程对大气PM_(10)组成变化的影响,利用场发射扫描电镜(FESEM)和图像分析技术研究了该沙尘暴期间及其发生前后PM_(10)中的单颗粒特征。结果表明,沙尘暴发生前后,PM_(10)主要由燃煤飞灰、烟尘集合体组成,其次是少量的矿物颗粒,而沙尘暴高峰期则相反。与沙尘暴发生前后相比,沙尘暴高峰期矿物颗粒的数量百分比(59.31%)和体积百分比(99.39%)有明显增加,而其数量和体积粒度分布则相反。根据该沙尘暴过程中PM_(10)的组成变化特征,可将其划分为四个不同的阶段:本地污染物清除阶段、新污染物携入阶段、本地新污染物吹入及外来沙尘颗粒减少阶段、沙尘颗粒基本清除阶段。
To investigate the composition variation of airborne inhalable particulate matters（PM10） collected in the non-dust storm and the dust storm episode occurred in Lanzhou city on March 31,2006,a high resolution Field Emission Scanning Electron Microscopy（FESEM） and image analysis（IA） were used to study the characteristics of individual particles.The results show that the particles in PM10 collected in the non-dust storm are composed of coal fly ash,soot aggregate and little mineral while the particles in PM10 collected during the peak of the dust storm episode are dominated by various minerals,followed by a small amount of fine coal fly ash and soot aggregate.Comparing with the non-dust storm episode,the percentage of mineral particle numbers and volume in PM10 collected during the peak of the dust storm episode increases significantly（59.31% and 99.39%,respectively）,while its number-size and volume-size distribution decreases.All these reveal that the dust storm episode can be divided into four stages：1） clean-out of local pollutants;2） input of new non-local pollutants;3） input of new local pollutants and reduction of dust and 4） clean-out of dust.
出处
《辽宁工程技术大学学报（自然科学版）》
CAS
北大核心
2010年第3期506-508,共3页
Journal of Liaoning Technical University (Natural Science)
基金
国家自然科学青年基金资助项目(40805062)
关键词
沙尘暴
单颗粒
兰州
颗粒物组成
粒度分布
dust storm episode
individual particles
Lanzhou
composition
size distribution
