Individual Particle Characteristics Of Depositional And Suspended Particles During The Haze Pollution In Handan City

In recent years,haze happened frequently in most areas of China,and it has wide range,long duration and high pollution intensity,which seriously affects the quality of atmospheric environment and endangers human health.Handan is the main coal-fired industrial city in Hebei Province,particulate pollution has been more serious.Therefore,this study select Handan as the research area,four sampling sites in different functional areas,collection of different functional areas throughout the haze pollution process of depositional and suspended particles.The particle size,morphology,mixing state,aging characteristics and surface heterogeneous transformation characteristics of depositional and suspended particles were analyzed by high-resolution transmission electron microscopy(TEM)and scanning electron microscopy(SEM).Handan City depositional particles,mostly mineral particles,mineral particles ratio in haze higher than clear days,the proportion of aggregates of various shapes is increasing in clear days.From the particle size distribution,it can be seen that the contribution of the mineral particles to the large particle size section is larger,and the fly ash contributes to the small size section is larger.Si,Al,K,Fe,Mg,Na and Cl in the depositional particles,and particles in the industrial eara are detected the S elements.Handan City suspended particles mainly spherical particles,mostly sulfate,nitrate and organic particles such as more secondary particles,more complete aging,a small amount of primary particle.The spherical particles contribute to the small particle size of suspended particles.The particles of naked soot aggregates,soot aggregate,aggregates of various shapes and other shapes contribute greatly to the large particle size.By contrasting the morphology and composition of depositional and suspended particles,it was found that the particulate matter in the industrial and industrial residence area was complex and influenced by the acid gas in the atmosphere,and most of them has been aging.Most depositional particles has detected elements S by EDS test which are sampled in industrial and industrial residence area,Elements S is very unfavorable to the human health and the local ecological environment.Compared with the single particle characteristics of depositional and suspended particles,it was found that the effect of functional area on depositional particles was relatively large,and the influence of weather conditions on suspended particles was larger.