Characteristics and Sources of Carbon Components in PM2.5 During Autumn and Winter in Panjin City

Abstract

In order to study the pollution characteristics and sources of carbon in Panjin City during autumn and winter, PM2.5 samples were collected at three monitoring points in October 2016 and January 2017. Pollution characteristics and sources of carbon components in PM2.5 were analyzed by the OC/EC ratio method, EC tracer method, and principal component analysis method. The results showed that the PM2.5 concentration exceeded the ambient air quality standard (GB 3095-2012) and that the average concentrations of OC and EC were 10.02 μg·m-3 and 3.91 μg·m-3 in autumn, respectively, and 16.04 μg·m-3 and 5.62 μg·m-3 in winter. According to the OC/EC ratio method, the OC/EC ratios were more than 2.0 during the sampling periods, indicating that there was secondary pollution in autumn and winter. Spearman correlation analysis and linear fitting indicated that the OC and EC sources were complex in development zones and that secondary school and cultural park areas may have similar sources during autumn and winter. SOC was quantitatively estimated by the EC tracer method, with concentrations of 7.21 μg·m-3 and 23.07 μg·m-3 in autumn and winter, respectively. The absolute and relative errors of SOC uncertainty were 0.98 μg·m-3 and 14.00% in autumn, respectively, and 1.87 μg·m-3 and 8.21% in winter. Based on the method of principal component analysis, the carbon components in autumn and winter were mainly derived from coal combustion, biomass burning, and vehicle exhaust.