Chemical composition and source apportionment of PM2.5 in typical heavy industrial cities
In this study,the mass concentrations of carbon components and water-soluble inorganic ions in PM2.5 were monitored in real time in Handan urban area in 2019.We analyzed the variation characteristics of PM25 components for the whole year of 2019.And the evolutions of PM2.5 and its components under different pollutions conditions were mainly discussed.Meanwhile,the positive matrix factorization and backward trajectory model were used to explore the sources of PM2.5 and its components.The results showed that the monthly and daily variation characteristics of OC and EC in PM2.5 in Handan City during the research period are similar.The seasonal concentration of water-soluble inorganic ions was winter＞autumn＞spring＞summer,NO3-,SO42-and NH4+were the main water-soluble inorganic ion components,which were significantly correlated with PM2.5 in different seasons.PM2.5 in Handan City was slightly alkaline during the study period.NH4+were primarily in(NH4)2SO4,NH4NO3 and NH4C1 forms in PM25.OC,EC,and secondary inorganic ions increased on PM2.5-polluted days and O3-polluted days.With the aggravation of pollution levels in winter,the mass concentrations of carbon components and water-soluble ions increased with the increase of PM2.5,the percentage of OC and EC decreased,the percentage of SO42-and NO3-increased,and the SOR and NOR increased gradually.Through the iterative calculation of PMF,the main potential sources of PM2.5 were determined,which were second generation,traffic-related source and combustion source.The backward trajectory results revealed that Handan is mainly affected by the transmission from northern Henan,northwestern Shandong,central Shanxi and southern Hebei.This study will provide the important scientific theoretical bases for the prevention and control of air pollution in heavy industrial cities.
万方数据
