摘要
为了解不同大气污染程度下大气细颗粒物中水溶性化合物和含碳物质的污染特征,使用瑞士万通850 professional IC型色谱仪和Model 2001热光碳分析仪分别对2015年南京北郊冬季清洁、轻/中度污染和重度污染程度下的水溶性离子、OC(有机碳)和EC(元素碳)进行了分析.结果表明,重度污染中PM_(2.5)日平均浓度为清洁天的4.0倍,SO_4^(2-)、NO_3^-和NH_4^+这3种主要二次离子平均浓度则分别为清洁天的6.4、3.1和3.9倍,且它们均以(NH_4)_2SO_4和NH_4NO_3的形式存在于清洁天和污染天中.两种呈酸性的污染天均主要受流动源影响.OC与EC的最高浓度均出现在重度污染天,分别达到49.8μg·m^(-3)和10.3μg·m^(-3).清洁天中SOC平均浓度最低(4.28μg·m^(-3)),但SOC占OC质量分数却高于另外两种污染天(41.14%).通过碳组分丰度值发现燃煤燃烧和汽油车尾气排放是观测期间内碳质颗粒物的共同主要贡献源.
PM2.5 samples were collected in a northern suburb of Nanjing during the winter of 2015. Water soluble ions and carbonaceous substances under different air quality levels were analyzed by an 850 professional IC-type ion chromatograph produced by Metrohm and a Model 2001A carbon analyzer. The results show that the average mass concentration of PM2. 5 , SO2 -4 , NO -3 , and NH ＋4 during heavy pollution days was 4. 0, 6. 4, 3. 1, and 3. 9 times higher than on clear days, respectively. Three main secondary ions were all in the form of （NH4 ） 2 SO4 and NH4 NO3 on all days. Two kinds of acid pollution days were mainly affected by the flow source. The proportion of fixed sources on the heavy pollution days was greater than on the light/ moderate pollution days. The highest mass concentrations of organic carbon （OC） and elemental carbon （EC） were 49. 8 μg·m - 3 and 10. 3 μg·m - 3 , respectively. The average concentration of SOC on clear days was the lowest （4. 28 μg·m - 3 ）. The proportion of secondary organic carbon （SOC） in the OC on clear days was more than on the other two pollution days （41. 14% ）. Coal combustion and motor vehicle exhaust emissions were the main contributors to carbonaceous substances by abundances of carbonaceous components.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第12期4932-4942,共11页
Environmental Science
基金
国家重点研发计划项目(2016YFC0203501)
国家自然科学基金项目(91544229,41475142,41775154)
江苏省高校“青蓝工程”项目
江苏高校优势学科建设工程项目(PAPD)
