石家庄夏季道路尘有机碳和元素碳特征及来源

CHARACTERISITICS AND SOURCE OF ORGANIC CARBON AND ELEMENT CARBON FROM PAVED ROAD DUST IN SHIJIAZHUANG DURING SUMMER

为明确石家庄市夏季道路尘中有机碳和元素碳污染特征及来源,用样方法采集市区4种不同类型共8条铺装道路尘样,处理后经热光碳分析仪测定有机碳(OC)和元素碳(EC)组分。结果表明:总碳(TC)在道路尘PM_(2.5)、PM_(10)中质量分数分别为129 465.2,103 911.4μg/g;PM_(2.5)和PM_(10)中OC和EC相关系数分别为0.94和0.86,可认为OC、EC来源基本一致;OC/EC均>2,表明存在二次有机碳(SOC)的贡献;通过OC/EC最小比值法估算得出SOC占PM_(2.5)和PM_(10)中OC总量的42.5%和32.8%,一次有机碳(POC)贡献较大;夏季道路积尘中的碳主要来自于汽、柴油车尾气排放、大气降尘中燃煤成分和生物质燃烧。

In order to analyze pollution characteristics of OC and EC from road dust in Shijiazhuang in summer,road dust samples were collected from 8 paved roads dividied into 4 types. Thermal/optical carbon analyzer（IMPROVE-TOR） was employed to detect the concentrations of 8 carbon fractions in dust samples. Results showed that the concentration of total carbon（TC） of PM2.5 and PM10 were 129 465. 2,103 911. 4 μg/g. The correlation between concentration of OC and EC in PM2.5 and PM10 was significant for R = 0. 94,0. 86,which indicated that they had similar source. All OC/EC ratios exceeded2,that suggested that there existed SOC contributing to OC. Mass concentration of SOC occupied 42. 5% and 32. 8% of OC in PM2.5 and PM10 estimated by minimum OC/EC ratio method. POC had significant contribution to OC. Both OC/EC analysis and principal component analysis indicated that vehicle exhaust,deposition of coal combustion and biomass combustion were the primary sources of OC and EC from road dust in Shijiazhuang during summer.