兰州大气细颗粒物中有机碳与元素碳的污染特征  

Characteristics of organic and element carbon in fine particles in Lanzhou

作　　者：李英红[1,2] 段菁春[3] 郑乃嘉 谭吉华[2,4] 饶志国[1] 马永亮[4] 贺克斌[4] 

机构地区：[1]兰州大学西部环境教育部重点实验室/西部环境与气候变化研究院,兰州730000 [2]中国科学院大学资源与环境学院,北京100049 [3]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012 [4]清华大学环境学院环境模拟与污染控制国家重点联合实验室,北京100084

出　　处：《中国科学院大学学报（中英文）》2015年第4期490-497,共8页Journal of University of Chinese Academy of Sciences

基　　金：国家自然科学基金(41475116;41275134);国家环境保护大气复合污染来源与控制重点实验室基金(SCAPC201401);中国环境科学研究院中央级公益性科研院所基本科研业务专项(2012ysky09)资助

摘　　要：采集兰州冬季采暖期及夏季PM2.5样品共60个,通过DRI测定有机碳(OC)和元素碳(EC).结果显示:冬季OC和EC平均质量浓度分别为(35.39±13.88)μg/m3和(13.80±5.41)μg/m3,夏季分别为(9.74±3.30)μg/m3和(4.44±2.00)μg/m3,冬季污染远高于夏季.冬夏季OC和EC相关系数分别为0.91和0.76,表明冬季兰州PM2.5中OC和EC的来源相似.二次有机碳质量浓度冬夏季分别为(8.48±6.10)μg/m3和(3.07±2.20)μg/m3,约占OC含量的(22.46±11.93)%和(31.29±18.51)%,表明兰州冬夏季PM2.5中OC的来源均以一次排放为主,夏季二次源贡献高于冬季.对8种不同温度段碳质组分分析表明,兰州冬季生物质燃烧较夏季有所增加,夏季可能主要为机动车尾气.A total of 60 PM2. 5samples were collected during winter and summer seasons in Lanzhou city. OC and EC were measured by the thermal / optical method using DRI-2001 A. The results indicated that carbonaceous aerosol in winter was significantly higher than that in summer. The average concentrations of OC and EC were（ 35. 39 ± 13. 88） μg / m^3and（ 13. 80 ± 5. 41） μg / m^3 in winter and（ 9. 74 ± 3. 30） μg / m^3and（ 4. 44 ± 2. 00） μg / m^3 in summer,respectively. Thecorrelation between OC and EC was 0. 91 in winter and 0. 76 in summer,which revealed that OC and EC had similar sources. The concentrations of SOC were（ 8. 48 ± 6. 10） μg / m^3and（ 3. 07 ±2. 20） μg / m^3 in winter and summer,and they were about（ 22. 46 ± 11. 93） % and（ 31. 29 ＋18. 51） % of OC in PM2. 5,respectively,which manifested that OC was mainly from primary sources and the contribution of secondary transformation was higher in summer than in winter. Analysis on the eight fractions of carbonaceous aerosol within the different temperature ranges showed that biomass burning had a high contribution for carbonaceous aerosol in PM2. 5in winter,but vehicle emissions might be the major source in summer.

关 键 词：PM2.5 有机碳 元素碳 二次有机碳 季节变化 

分 类 号：X513[环境科学与工程—环境工程]