Pollution Characteristics And Source Apportionment Of Water-Soluble Ions In Aerosol Fine Particles In Fengfeng Mining Area

Handan City is one of the cities with poor air quality in China,and particulate matter pollution is serious.The analysis of water-soluble ion pollution characteristics of particulate matter in Fengfeng mining area of Handan City can lay a theoretical foundation for air pollution and prevention in this region,and provide a scientific basis for regional atmospheric environment control.This study sampled PM_2.5 and PM₁₀ in typical months of each season in 2017 and 2018.Mass concentrations of 10 water-soluble inorganic ions such as Na⁺?NH₄⁺?K⁺?Mg²⁺?Ca²⁺?F^-?Cl^-?NO₂^-?SO₄^2-and NO₃^-in PM_2.5and PM₁₀ were detected by ion chromatograph.Mass concentrations of PM_2.5,PM₁₀ and their water-soluble ions were analyzed.The sources of water-soluble inorganic ions in PM_2.5 and PM₁₀ were studied comprehensively and systematically.The main conclusions are as follows:The average annual mass concentration of PM_2.5 and PM₁₀ in Fengfeng Mining area of Handan City in 2017 was（111.32±49.47）μg/m³ and（194.88±65.55）μg/m³.In 2018,the average annual mass concentration of PM_2.5 and PM₁₀ was（129.79±70.62）μg/m³ and（239.91±114.37）μg/m³,both exceeding the national secondary standard.The annual mean values of PM_2.5/PM₁₀ in 2017 and 2018 were 0.57 and 0.54,respectively,indicating that PM_2.5 is an important component of PM₁₀,and the concentration values of PM_2.5 and PM₁₀ both show the highest characteristics in winter.The linear correlation analysis results of PM_2.5 and PM₁₀ concentration in different seasons showed that PM_2.5 and PM₁₀showed a good correlation in spring,summer,autumn and winter,indicating that the two have similar or the same source in each season.In 2017,WSIIs in PM_2.5 and PM₁₀ was（40.75±29.56）μg/m³ and（50.75±36.95）μg/m³,respectively.In 2018,the WSIIs values of PM_2.5 and PM₁₀ were（65.76±52.05）μg/m³ and（83.39±69.75）μg/m³,respectively.SNA accounted for 78.38%and 71.19%of WSIIs in PM_2.5 and PM₁₀ respectively in 2017,82.08%and 82.06%of WSIIs in PM_2.5and PM₁₀ in 2018,respectively,accounting for more than 50%of the content,this indicates that SNA is the most important component of the water-soluble ions of PM_2.5and PM₁₀.The mean values of NO₃^-/SO₄^2-in PM_2.5 and PM₁₀ in the spring and winter of 2017and 2018 are all greater than 1,indicating that the water-soluble components of atmospheric particles in Fengfeng mining area are mainly affected by mobile pollution sources in the spring and winter,and are mainly affected by fixed pollution sources in summer.Correlation analysis showed that Na⁺had a good correlation with SO₄^2-and NO₃^-,indicating that they may have similar sources.The strong correlation between Ca²⁺and Mg²⁺indicates that they may have the same origin.Principal component analysis shows that secondary pollution sources,combustion sources,soil sources and industrial sources are the main sources of PM_2.5 and PM₁₀ in Fengfeng mining area of Handan City,and the contribution rate of secondary pollution sources to PM_2.5 is greater than that of PM₁₀.The backward trajectory analysis shows that the pollution of Fengfeng mining area is mainly in short distance transmission in spring and winter,while in summer and autumn it is affected by both short distance and long distance transmission.