义乌市PM2.5中烷烃的污染水平和来源分析  

Characteristics and sources of alkanes in PM2.5 in Yiwu City

作　　者：陈焕兵 常毅[1] 张胜华[1] 黄伊宁[1] 冯加良[1] CHEN Huanbing;CHANG Yi;ZHANG Shenghua;HUANG Yining;FENG Jialiang(School of Environmental and Chemical Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学环境与化学工程学院

出　　处：《上海大学学报（自然科学版）》2019年第4期566-575,共10页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金资助项目(41473088);义乌市环境保护局资助项目(YWCG015051GK)

摘　　要：为了解长三角典型县级市-–义乌市大气PM2.5中烷烃的污染特征和来源,于2015年7月-2016年4月,使用TH-16A四通道采样器分别在义乌市北苑站点和江东站点采集大气PM2.5样品,采用气相色谱-质谱联用仪对正构烷烃(C16~C34)和藿烷(C27~C32)进行定量分析.结果表明,北苑站点和江东站点大气PM2.5中正构烷烃的年均浓度分别为78.0和80.4 ng/m3,站点之间没有明显差异;正构烷烃的浓度存在明显的冬季>秋季>春季>夏季的季节性变化规律.正构烷烃的分布特征、主峰碳数(Cmax)、碳优势指数(carbon preference index, CPI)和植物蜡贡献率(Wax%)都表明化石燃料源是义乌市PM2.5中正构烷烃的主要来源,植物蜡的平均贡献率约为20%.义乌市PM2.5中藿烷的年均浓度在北苑站点和江东站点分别为5.5和4.6 ng/m3,藿烷浓度和正构烷烃浓度之间存在较强的正相关关系.依据藿烷同系物的分布特征,机动车排放是义乌市PM2.5中有机质的重要来源.To understand chemical characteristics and sources of n-alkanes and hopanes in the atmospheric PM2.5 in Yiwu City, a representative county-level city in the Yangtze River Delta region, seasonal atmospheric PM2.5 samples were collected simultaneously at two sites in Yiwu City, Beiyuan and Jiangdong, from July 2015 to April 2016 using TH-16 A four-channel samplers. Concentrations of n-alkanes(C16~C34) and hopanes(C27~C32)in the PM2.5 samples were quantified with gas chromato graphy-mass spectrometer(GCMS). The results show that the annual average concentration of n-alkanes in PM2.5 at Beiyuan and Jiangdong were 78.0 and 80.4 ng/m3, respectively. No statistical difference in concentration of n-alkanes was found between the two sampling sites. A distinct seasonal trend of winter→autumn→spring→summer was found for n-alkanes in Yiwu City. The distribution patterns, carbon number maxima(Cmax), carbon preference index(CPI) and plant wax contribution(Wax%) of n-alkanes all indicated that emissions from fossil-fuel usage was the main source of n-alkanes in PM2.5 in Yiwu City, while the average contribution of plant wax was about 20%. The annual average concentration of hopanes in PM2.5 at Beiyuan and Jiangdong were 5.5 and 4.6 ng/m3, respectively. Strong correlation between the concentrations of hopanes and n-alkanes was found. The distribution pattern and characteristics of hopanes indicated that vehicle emission was an important source of the organic matter in PM2.5 in Yiwu City.

关 键 词：PM2.5 正构烷烃 藿烷 来源识别 长三角 义乌市 

分 类 号：X513[环境科学与工程—环境工程]