[Pollution characteristics of organic and elemental carbon in PM2.5 in Taiyuan]

PM2.5 samples were collected at four sampling sites to study pollution characteristics of carbonaceous aerosols in Taiyuan during winter and summer. Organic carbon (OC) and elemental carbon (EC) in PM2.5 were analyzed by carbon analyzer, and the characteristics including pollution levels, temporal and spatial distributions of OC and EC, secondary organic carbon (SOC) and relationships of OC and EC were discussed in detail. The average concentrations of OC and EC in winter were 22.3 μg x m(-3) and 18.3 μg x m(-3), respectively, while in summer were 13.1 μg x m(-3) and 9.8 μg x m(-3), respectively. The concentrations of total carbon aerosol (TCA) accounted for 56.6% of PM2.5 in winter, and 36.5% in summer; the concentrations of OC and EC at four sites in winter were higher than those in summer, OC and EC levels showed a good uniformity in winter while in summer, the spatial distributions of OC and EC were obviously different; SOC levels were lighter than other cities; the correlation between OC and EC was stronger in winter than that in summer.