Physical and Chemical Characteristics and Source of Atmospheric Single Particulate Matter in Rizhao City Based on EPAS Technology

The physical and chemical characteristics of atmospheric aerosol particles in urban areas are complex. It is of great significance to clarify the fine chemical composition and mixing state of a single particle for air pollution traceability and fine control. This study used passive aerosol samplers to collect samples in the urban area and steel park of Rizhao, Shandong Province. The collected samples were analyzed using an intelligent scanning electron microscope environmental particle analysis system (IntelliSEM EPAS). The results show that atmospheric particulates in Rizhao City mainly comprise irregular carbonaceous particles (C-rich), sulfur-containing particles (Ca-S, Na-S-Ca), and mineral particles. Among them, the contribution of C-rich particles in urban samples is 53.5%, which is 2.5 times higher than that in steel park samples. In addition, the number of particles >1 μm is 9.0%, which is 1.7 times that of the samples from the steel park. Urban residents’ activities and industrial processes are the main sources of atmospheric particulate matter, especially secondary fine particles. The quantity contribution of sulfur-containing particles in the samples from the steel park is 72.9%, the quality contribution of sulfur-containing particles is 30.9%, and the quality contribution of iron-rich particles is 5.3%, which are 1.8 times, 3.6 times, and 2.9 times higher than those of urban samples, respectively, indicating that the main sources of atmospheric particles in the steel park include primary pollutants discharged by iron and steel enterprises and secondary fine particles generated through them.