Analysis Of Organic Compounds In Taiyuan City In Aerosol Particles PM_2.5

Due to human activities and the advancement of industrialization, aerosol pollution has become one of the most serious urban pollution problems. Particulate matter is the major polluting factor of most city in China. PM2.5,which has smaller size is easier to enter human cells and brings more dangerous, and also has a significant impact on the formation of urban haze weather. Organic compounds, as an important part of toxic substances in PM2.5, occupies a large proportion. And Taiyuan, a heavy industries city, surrounded by mountains on three sides, has a long heating period,all these results in its more serious particulate air pollution and prominent organic matter pollution.The sampling periods were winter (December) in2011,and spring (March),summer (June), fall (September) and winter (December) in2012, and131PM2.5samples were collected with high volume particulate sampler. The qualitative identification of organic composition in PM2.5is analysed by GC-MS. This paper mainly studied PAEs, n-alkanes and PAHs the three kinds of organic matter in PM2.5. PAEs includes DINP, DOP, DIBP and DBP. PAHs includes NAP, PHE, ANT, FLT and PYR. n-alkanes contains dodecane, tetradecane, pentadecane, hexadecane and heptadecane. The area peaks of every compound were obtained by GC. This article studied the seasonal and the day-night variation features of the content of PM2.5and every kinds of organic compounds.Study shows that the24-hour concentration of PM2.5during the whole samling period in2012is226.71μg/m3±121.14, and the maximum is544.11μg/m3which is appeared in winter and minimum is49.95μg/m3appeared in summer. Compared to the limit value of24-hour concentrations of PM2.5set in ambient air quality standards (GB3095-2016), over-limit ratio is high during the sampling period. The seasonal feature is the concentration of PM2.5in winter and spring is higher than summer and autumn. Day-night variation characteristic is not evident. PM2.5concentration in2011and2012is327.93μg/m3and336.01μg/m3respectively, both higher than in Beijing, Tianjin, and Xi’an. The regression analyses showed that PM2.5concentration has negatively correlation with temperature (***p<0.001), weak negative correlation with humidity and wind force. The pollution of PM2.5in Taiyuan is very serious.Organics analysis shows that because of the enhancement of coal consumption in heating period, the seasonal variations of PAEs, PAHs and n-alkanes are the content in winter and spring higher than in summer and autumn. And the content in night is higher than in day. Each organic compound of the same kind has a great relationship which The relationship of every meteorological factor and the content of each organic compound are that temperature and wind is negatively related to the organics, and humidity is positively related to the organics. There is secondary aerosol pollution in Taiyuan City.