沙尘天气细粒子污染快速来源解析初步研究

A Preliminary Study on Rapid Source Appropriate of Fine Particles Pollution in Dust Weather

指出了对颗粒物化学组成及其来源的研究是识别区域污染形成机制、制定有效控制措施的重要基础。单颗粒气溶胶质谱仪(Single particle aerosol mass spectrometer,SPAMS)已广泛用于分析大气颗粒物,通过采集数以万计的颗粒物,实时在线分析颗粒物的粒径大小、化学组分,是实现快速源解析的有效手段。2016年3月底在郑州市捕捉到一次典型的沙尘天气,共采集到118375个颗粒进行了分析。研究结果表明:该地区的大气颗粒物类型主要可分为8种:元素碳(EC)、混合碳(ECOC)、有机碳(OC)、钠钾(NaK)、富钾颗粒(K)、左旋葡聚糖颗粒(LEV)、矿物质颗粒(SIO)、重金属颗粒(HM)。在污染过程中,各类型颗粒物数量浓度均有一定程度的增加,SIO增加最为明显。分析表明,扬尘源的增加和机动车尾气源占比居高不下是此次沙尘天气的主要因素。

The study on the chemical composition and source of particulate matter was an important basis for identifying the mechanism of regional pollution formation and establishing effective control measures.Single particle aerosol mass spectrometer(SPAMS)was widely used in the analysis of atmospheric particles.It could also analyze particle size and chemical composition through collecting tens of thousands of particulate matters.It was an effective method to achieve fast source resolution.A typical dust weather was captured at the end of March 2016 in Zhengzhou.Nearly 1.2×105 fine particles were characterized by the SPAMS.Results showed that all the particles were classified into8 main categories:elemental carbon(EC)-Fresh,internally mixed elemental-organic carbon(ECOC),organic carbon(OC),K-rich/Na-rich,K-rich,Levoglucosan(LEV),minerals(SIO)and heavy metal particles.The concentration of all kinds of particles had a certain extent where SIO increased most obviously in the process of pollution.The analysis showed that the increase of dust and the high proportion of motor vehicle exhaust were the main factors of this dust weathers.