| Fine particulate matter PM2.5 and PM1 are the key factors that restrict the improvement of air quality in urban environment,which makes the source analysis of fine particulate matter to be a hotspots in the field of atmospheric environment.In order to improve the ambient air quality in Suizhou,the study collects and analyzes the chemical composition of some fine particulate matter samples from two representative A and B positions in the Suizhou from February 2017 to March 2018,and the PMF model is used to carry out the analysis of the source of fine particles in the city area of Suizhou.The main conclusions are as follows:1.Monitoring statistics show that the fine particles pollution in Suizhou city is serious,and the annual average concentration of PM2.5 is 82?g/m3,which is 2.3 times more than that of the national secondary standard limit,and the PM1 concentration also reaches 42?g/m3.At the same time,the concentration of fine particulate matter has obvious spatial and temporal distribution characteristics.The concentration of PM2.5 and PM1 show different seasonal variations that PM2.5 is higher in autumn and winter and lower in spring and summer,while PM1 is higher in summer and autumn and lower in spring and winter.The fine particle concentration at point B is generally higher than point A.The analysis of PM1/PM2.5 ratio shows that fine particles are more likely to be concentrated in PM1.2.Water soluble ions in fine particles exhibit obvious spatiotemporal variations.Among them,SO42-,NO3-and NH4+are the main ions in 8 water-soluble ions,which account for 78.7%(PM2.5)and 76.9%?PM1?of all ions.The concentrations of SO42-and NO3-are the highest in winter and lowest in summer,while NH4+is highest in spring and summer and lowest in autumn and winter.The concentrations of SO42-and NO3-in PM2.5and PM1 at point B are both higher than those at point A,while Cl-concentration at point B is lower than point A.The annual average ratios of NO3-/SO42-in PM2.5 and PM1 at points A and B are 1.01 and 0.95 respectively,indicating that the stationary source emissions in the study area are comparable to those from mobile sources.3.The results of crustal element analysis show that the concentration of Al,Fe,Zn,Ca,Mg and K in fine particles is significantly higher than that of other crustal elements,with obvious seasonal variation.The sum of the concentrations of these 6 elements account for 81.82%-98.46%(PM2.5)and 80.51%-97.30%?PM1?of the total elements.Enrichment factor analysis shows that V,Cr,Cu,Zn,As,Cd,Sn,Sb,Ba,Pb,and Hg mainly come from anthropogenic sources.The crustal elements in PM2.5 and PM1 have the same origin.4.OC and EC have obvious temporal and spatial variation.Among them,OC concentration is the highest in winter,and EC is the highest in spring.In general,the concentration of OC at point A is obviously lower than point B,and the concentration of EC is the opposite.The OC/EC ratio shows that vehicle exhaust emission is the main source of OC and EC in fine particulate matter.On this basis,an evaluation index?SOCOC for characterizing and evaluating OC oxidation to SOC was proposed.The correlation coefficient R>0.6 between?SOCOC and O3 concentration indicates that SOC oxidation generation index?SOCOC has practical value.5.The Results of using PMF model to analyze PM2.5:industrial/coal-fired sources?28.4%?,construction/road dust sources?23.1%?,motor vehicle exhaust sources?20.7%?,secondary inorganic sources?18.6%?.The Results of using PMF model to analyze PM1:secondary inorganic sources?33.3%?,motor vehicle exhaust sources?24.9%?,industrial/coal-fired sources?22.9%?,and construction/road dust sources?8.5%?,Biomass combustion source?6.2%?,other sources?4.2%?.Therefore,strengthening the emission control of industrial/combustion coal sources,construction/road dust sources,and motor vehicle sources plays an important role in reducing the concentration of PM2.5 and PM1and improving regional air quality. |
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