Atmospheric Particle Number Concentration And Particle Size Characteristics In Xuzhou City Based On High Precision,Gridding And Mobile Observation

Fine particulate matter is one of the important pollutants in the atmosphere,which affects the quality of atmospheric environment and climate change,and even threatens the health of people.Particle size distribution is an important indicator of particulate matter,which can provide effective information for studying the physicochemical properties and pollution sources of particulate matter.As the central city of Huaihai Economic Zone,Xuzhou City has improved its air quality in recent years,but particulate matter pollution events still occur.Current research on atmospheric particulate matter pollution in Xuzhou City mainly focuses on the temporal variation of concentration and spatial distribution,and there is less research on the number concentration and particle size distribution of particulate matter.The research is based on the data processing method of orthogonal empirical function EOF to analyze the atmospheric particulate matter data for 2016 and 2022from the atmospheric environment observatory of China University of Mining and Technology,to study the particle size distribution characteristics of Xuzhou urban area,and to identify high number concentration pollution events by EOF,to study the potential sources of particulate matter during the pollution period,and to use the data of Xuzhou gridded monitoring stations to explore the Xuzhou PM_2.5 spatial distribution,and use small,low-cost particulate matter monitors to conduct mobile observations of Xuzhou city community streets.Details are as follows:（1）The mean value of particle number concentrations larger than 0.25μm particle size in Xuzhou city during the study period was（704.03±412.70）particles/cm³,with particles in the 0.25～1μm particle size range occupying the major components.The maximum concentration of number in winter in the seasonal variation,and the higher concentration of number in December and January in the monthly average variation,where the concentration of number of particles with small particle size is more in January.The particles in the 0.5～1μm particle size band are significantly higher in the daily variation in winter than in the other three seasons,while the particles in the0.25～0.5μm range in summer are different from the other seasons reaching the maximum at 14:00 pm.（2）Based on EOF to identify high number concentration pollution events,the temporal variation of two pollution events in 2016 and 2022 was analyzed,and particles of 0.28～0.3μm particle size dominated in both events,and the local contribution dominated in both events by PSCF and CWT potential source analysis methods,compared to 2016.2022 WPSCF and WCWT value ranges are larger and the local contribution becomes relatively less.（3）The annual average PM_2.5 concentrations at the gridded monitoring stations in Xuzhou show that the urban concentrations are significantly higher than the non-urban ones,and the spatial distribution of PM_2.5 in Xuzhou shows a high spatial distribution in the middle and west and a low spatial distribution in the east,and the PM_2.5 in Xuzhou in winter shows obvious spatial differences.（4）Based on the multiple linear regression model,the portable particle meter was compared with the high-precision instrument in the experiment,and the results correlated well.The spatial distribution of PM_2.5 and number concentrations in the residential area and commercial street are higher and the lowest in Huai Tower.The thesis has 25 figures,12 tables and 120 references.