| In this paper, we established the atmospheric particles observation point at thesouthern suburbs of Xi’an city, by using the TEOM?series RP-1400a environmentalparticle monitor to record Xi’an city atmosphere high resolution atmospheric particles inreal-time monitoring and seasonal sample collection.during at the station point of Xi’anUniversity of Architecture and Technology during the period of Nov2010to Dec2011.Through the analysis of the data, discusses the variation characteristics of atmosphericaerosol in different time scale, then analyzed the pollution characteristics of theatmospheric particulate carbon fractions at different seasons in Xi’an City.The results showed that, during the monitoring period the PM2.5of annual averageconcentration was99.20μg/m3in Xi’an City, is6.61times of first level cap China’sambient air quality standards （GB3095-2012） of the concentration,2.83times of thesecond level cap standard. It means that PM2.5in Xi’an is severely excessed the standard.The seasonal average mass concentration order （from big to small）: Winter （141.2μg/m3）> autumn （98.42μg/m3）> spring （87.69μg/m3）> summer （69.5μg/m3）.Using time series analyzed the high resolution PM2.5hour mass concentrationduring the periods of Dec.2009to Nov.2011.The results showed that the PM2.5pollution in winter, autumn is relatively serious in Xi’an City, intered the fall the PM2.5mass concentration started fluctuation growth; after entered the winter the pollution isthe highest of the year. Spring season PM2.5concentration than that in winter, autumn islow, affected by the impact of dust storm in spring of PM2.5quality concentration withobvious fluctuations; summer PM2.5concentration reached its lowest level. On the PM2.5（24hours） of average concentration analysis found that, during the SpringFestival （February1st20th） as the public fireworks asgravates air particle pollution,daily maximum concentration reached529.7μg/m3at February3rd.Analyzed the carbon containing component of the sample by high resolution data,the results showed that: organic carbon OC, inorganic carbon EC pollutionconcentration winter> autumn> spring> summer. Between the value of OC/EC andOC, EC relationship, winter aerosol sources than other seasons; spring, summer, autumnthe three season of pollutant source is relatively single, traffic is the main source. Inwinter, carbon aerosol sources mainly coal source, traffic sources, biomass burning, butsummer atmospheric carbonaceous aerosols easy occurred two times pollution, and inautumn presence of biomass combustion phenomenon. Each season PM2.5TCA, OC,EC diurnal variation showed the distribution characteristics of two peaks. SOCestimation analysis showed: Xi’an city atmospheric SOC concentration is mainlyaffected by the emission sources, and temperature, solar radiation and pollution in thecomprehensive effect, the atmospheric SOC of summer daytime variation is obviousthan the other seasons.Four seasons in Xi’an city carbon aerosol pollution source apportionment resultsshowd: in winter, petrol vehicle emission, coal combustion is higher, respectively is44.16%,37.74%; spring, summer, autumn three season gasoline vehicle emissioncontribution rate is higher, respectively78.10%,80.94%and77.06%. |
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