【摘要】 为深入探讨冬季兰州城市大气中碳气溶胶的污染特征,于2011年12月5—12日采集兰州城市大气PM2.5样品,利用DRI-2001A热/光碳分析仪测量元素碳(EC)和有机碳(OC)的浓度.结果显示:EC和OC的平均质量浓度分别为7.48μg/m3和22.71μg/m3.降雪是EC和OC浓度变化的主要因素.EC和OC的相关系数达到0.98,表明冬季兰州城市大气PM2.5中碳气溶胶的污染来源相对简单且基本相同.二次有机碳(SOC)的质量浓度是3.26μg/m3,仅占OC含量的14.4%,揭示出冬季兰州城市大气PM2.5中OC的主要来源是直接污染源.对碳气溶胶8种组分的因子分析结果表明,燃煤和机动车尾气的排放对冬季兰州城市大气PM2.5中碳气溶胶的污染有最主要的贡献.更多还原

【Abstract】 For studying the concentration characteristics and sources of carbonaceous aerosols during winter in Lanzhou,daily PM2. 5samples were collected during the period from 5 Dec to 12Dec in 2011. Elemental carbon( EC) and organic carbon( OC) were measured by the thermal /optical method using DRI-2001A. The results indicated that the average mass concentrations of EC and OC were 7. 48 and 22. 71 μg / m3,respectively,during winter in Lanzhou. Snow had significanteffect on the ambient concentrations of EC and OC. The correlation coefficient between EC and OC was 0. 98,which revealed that the emission sources of carbonaceous aerosol were relatively simple during winter in Lanzhou and EC and OC had the same sources. Mass concentration of SOC was3. 26 μg / m3,and it was only 14. 4% of the concentration of OC in PM2. 5. Factor analysis on the eight carbon fractions of carbonaceous aerosol indicated that coal combustion and vehicle emissions were the major sources for carbonaceous aerosol in PM2. 5.更多还原