Abstract
In order to study the seasonal variations and pollution sources of carbonaceous species in PM2.5 in Chengde, the concentration of these components was determined in atmospheric PM2.5 samples collected in January, April, July, and October 2019. The change in carbonaceous species were analyzed based on the estimation of the ratio of organic carbon(OC) to elemental carbon(EC), total carbonaceous aerosol(TCA), and secondary organic carbon(SOC). The source of these pollutants was determined by means of the backward trajectory and principal component analysis(PCA). The results showed that the mean mass concentrations of PM2.5, OC, and EC during the sampling period were(31.26±21.39) μg·m-3,(13.27±8.68) μg·m-3, and(2.80±1.95) μg·m-3, respectively. The seasonal variations of PM2.5 were:winter[(47.68±30.37) μg·m-3]>autumn[(28.72±17.12) μg·m-3]>spring[(26.59±15.32) μg·m-3]>summer[(23.17±8.38) μg·m-3], consistent with the trend of total carbon(TC), OC, and EC. The source of OC and EC during winter(R2=0.85) was similar. Based on the ratio of OC/EC, all four seasons were affected by traffic and coal-burning source emissions, and the most affected season by bituminous coal emissions was winter. The average concentration of TCA was(21.38±13.68) μg·m-3, which accounted for 68.39% of PM2.5. The order of secondary conversion rate(SOC/OC) was:spring(54.09%) >autumn(37.64%) >summer(32.91%) >winter(25.43%). The results of the backward trajectory simulation show that the pollutant concentrations carried by air masses are relatively low in spring and summer, and the transport channels of pollutants are southwest in autumn and northwest in winter. The results of the PCA showed that the key to reducing PM2.5 in Chengde is to control emissions from vehicle exhausts, and coal and biomass combustion sources.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.