大气细颗粒物扬尘源单颗粒质谱特征

摘要

Soil dust,road dust,construction dust and coal stock dust in Guangzhou were sampled,The size distributions and chemical composition of fine particles from sampled fugitive dusts were analyzed using a single particle aerosol mass spectrometer (SPAMS).Construction dust and other three types of fugitive dust showed bimodal and unimodal size distribution,respectively.The chemical composition of different dusts had a great diversity.The particles from soil dust were dominated by A1Rich particles,accounting for 37.97％ of the total number of ionized particles;The particles from road dust were dominated by CaRich particles which accounted for 24.92％ of the total number of ionized particles;particles from construction dust were dominated by SiRich particles,accounting for 33.33％ of the total number of ionized particles;particles from coal stock dust were dominated by CaRich particles,accounting for 64.92％ of the total number of ionized particles.It is noted that road dust showed distinct characteristics of soil dust and motor vehicle exhaust.These unique characteristics of fugitive dust enable further source apportionment of dust particles.In addition,the percentage of secondary components was highest in road dust.%对广州市土壤尘、道路扬尘、施工扬尘、堆煤扬尘等开放源颗粒物样品进行采集,并利用单颗粒气溶胶飞行时间质谱仪(SPAMS)对颗粒物的粒径和化学成分进行分析.施工尘和其他几类尘分别呈双峰分布和单峰分布,各类尘样的化学组成差异较为明显,其中土壤扬尘以富铝颗粒为主,占总电离颗粒的37.97％,道路扬尘以富钙颗粒为主,占总电离颗粒的24.92％,施工扬尘以富硅颗粒为主,占总电离颗粒的33.33％,堆煤扬尘以富钙颗粒物为主,占总电离颗粒的64.92％.在道路扬尘中土壤扬尘与机动车污染的特征显著,这些特征为扬尘颗粒物源解析提供了可能.此外,道路扬尘的二次组分所占比例最高.