Mineral Characteristics Analysis of PM2.5 in Northern China

PM2.5 (sandstorm-related) was sampled at four sites near dust source areas in Northern China in spring 2012. Every site was away from obvious pollution source. After drying 24 hours in a dry dish, X-ray diffraction (XRD), x-ray fluorescence (XRF) and scanning electron microscope (SEM) of all the samples were examined. The main phases were quartz, albite, calcite and mica. SEM observations showed that the particles were mainly irregular shaped, but different sample the particle morphology is slightly different. And the surface was rough because of erosion mark or pores on them. The chemical composition of PM2.5 is characteristic of high SiO2 and CaO, while low K2O, Na2O. Main elements of the samples were Si, Al, Fe, Ca, which were familiar with crust elements and dust fall components [1], but some samples also contained low-level heavy metals like As and Pb.