| In this paper,the pollution levels and pollution characteristics of water-soluble inorganic ions on atmospheric particulate matter(PM2.5 and PM10)in Jinhua City were studied.The correlation between water-soluble 10ns and meteorological factors(relative humidity,wind speed,temperature and air pressure)and gaseous pollutants(SO2,NO2 and O3)were analyzed.Finally,the sources of water-soluble inorganic ions were analyzed using principal component analysis and backward trajectory methods.The study drew the following main conclusions:(1)The average mass concentrations of PM2.5 and PM10 in Jinhua City were 69.04?g/m3 and 101.55?g/m3,respectively.The annual over-standard rates of PM2.5 and PM10 were 34.5%and 20.2%,respectively.The mass concentration atmospheric particulate matter varies significantly with the seasons.In winter,atmospheric partic-ulate matter is the most serious,followed by spring and autumn,and summer is best.(2)The increase in wind speed is conducive to the diffusion of atmospheric par-ticulate matter,which reduces the concentration of atmospheric particulate matter.The relative humidity of the environment has a significant effect on the mass concentra-tion of atmospheric particulate matter,and the higher the relative humidity,the higher the concentration of particulate matter.The smaller the particle size of atmospheric particulate matter,the more significant the influence of environmental humidity.In different seasons,the influence of ambient temperature on the mass concentration of atmospheric particulate matter is different.In summer and autumn,the higher the temperature,the lower the concentration of atmospheric particulate matter,while in winter and spring,the higher the temperature,the higher the concentration of atmos-pheric particulate matter.This may be related to the tendency to invert temperature in the mixed layers of the atmosphere in winter and spring.(3)SO42-,NH4+and NO3-are the three most important water-soluble inorganic ions in the particles of Jinhua City.SO42-,NH4+ NO3-,K+,Ca2+,and Cl-have the highest concentration in winter samples and the lowest concentration in summer.The concentrations of Mg2+,F-,and Na+did not change significantly during the whole year.PM2.5 and PM10 in Jinhua City are alkaline in winter and acidic in the other three sea-sons.The cause of PM being alkaline in winter may be related to a significant in-crease of NH4+ in winter samples.(4)The correlation between NH4+and NO3-,NH4+and SO42-in PM2.5 and PM10 in Jinhua City in 2018 was the most significant in spring.NH4 in Jinhua District preferentially combines with NO3-to form NH4NO3.In winter and spring,NO3-,SO42-and NH4+are mainly dominated by liquid phase oxidation.In summer,NO3-and SO42-are mainly gas phase oxidation.In the autumn,the gas phase oxidation and liquid phase oxidation of NO3-occur simultaneously.In the autumn,SO42-is mainly based on liquid phase oxidation.In winter,the average value of NOR in PM2.5 and PM10 is the largest,which is most beneficial for the conversion of NO2 into secondary parti-cles.The average value of SOR in autumn is the most favorable,which is beneficial to the conversion of SO2 into secondary particles.(5)Using the principal component analysis method,the source analysis of wa-ter-soluble inorganic 10ns in PM2.5 and PM10 of Jinhua City was carried out.It was found that the secondary particles were the most important components of the wa-ter-soluble 10ns on atmospheric particulate matter in the whole year.Combined with the value of NO3-/SO42-,it can be known that the secondary particles in Jinhua City mainly come from mobile sources.The results of the backward trajectory indicate that atmospheric particulate matter pollution is more affected by exogenous effects in winter and autumn,but is more affected by local sources in spring and summer. |
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