Characterization of PM10 and PM2.5 Source Profiles of Fugitive Dust in Zhengzhou, China

As a result of rapid urbanization, the road lengths and built-up areas in Zhengzhou are steadily expanding along with increasing fugitive dust emissions. Identifying the physical and chemical characteristics and the chemical profiles of fugitive dust is important in achieving effective atmospheric pollution management. In this study, soil dust, road dust (RD), building demolition dust, and cement (CE) were chosen as the research objects. A total of 94 dust samples were collected from 20 sites. PM2.5 (particulate matter with diameter <= 2.5 mu m) and PM10 (particulate matter with diameter <= 10 mu m) samples were obtained by using a re-suspension device and their physical and chemical properties were analyzed. The scanning electron microscopy of four types of dust particles showed that most of the dust particles presented an irregular shape. In terms of particle size distribution, the mass concentration of PM2.5 accounted for less than 10% of the total PM10, whereas the number concentration of PM2.5 accounted for more than 96% of the total number. Chemical component analysis revealed that crustal elements such as Al, Mg, Fe, and K were abundant in all samples, and they were the most abundant species in PM2.5 and PM10 in the reconstruction results. The percentage of NO3- in the RD sample was higher than that in the other three fugitive dust samples because of the influence of vehicles. Furthermore, the CE sample had higher SO42- and Ca2+ percentages than the other three types of fugitive dust samples. Enrichment factor analysis showed that the significant enrichment of Cd and Ag was mainly caused by anthropogenic sources. The coefficients of divergence values between the profiles for different sites of dust ranged from 0.21 to 0.68, indicating the fugitive dust profiles from various sites mostly different. The chemical profiles of four dust sources obtained from this study is limited in Zhengzhou.