Chen Yanting, Du Wenjiao, Chen Jinsheng, Hong Youwei, Zhao Jinping, Xu Lingling, Xiao Hang
Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
Environ Sci Pollut Res Int. 2017 Feb;24(6):5877-5887. doi: 10.1007/s11356-016-8314-5. Epub 2017 Jan 7.
Particulate matter (PM) associated with the fractions of organic macromolecules, including humic acid (HA), kerogen + black carbon (KB), and black carbon (BC), was determined during summer and winter at urban and suburban sites in a coastal city of southeast China. The organic macromolecules were characterized by elemental analysis (EA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR), and their sources were identified by using stable carbon/nitrogen isotope (δC/δN) and the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model. The results showed that HA, kerogen (K), and BC accounted for the range of 3.89 to 4.55 % in PM, while they were the dominant fractions of total organic carbon (TOC), ranging from 64.70 to 84.99 %. SEM analysis indicated that BC particles were porous/nonporous and consisted of spherical and non-spherical (i.e., cylindrical and elongate) structures. The FTIR spectra of HA, KB, and BC exhibited similar functional groups, but the difference of various sites and seasons was observed. HA in PM contained a higher fraction of aliphatic structures, such as long-chain fatty and carbohydrates with a carboxylic extremity. The C/N ratio, SEM, and δC/δN values provided reliable indicators of the sources of HA, K, and BC in PM. The results suggested that HA and K majorly originated from terrestrial plants, and BC came from the mixture of combustion of terrestrial plants, fossil fuel, and charcoal. The air masses in winter originated from Mongolia (4 %), the northern area of China (48 %), and northern adjacent cities (48 %), suggesting the influence of anthropogenic sources through long-range transport, while the air masses for the summer period came from South China Sea (34 %) and Western Pacific Sea (66 %), representing clean marine air masses with low concentrations of organic macromolecules.
在中国东南部沿海城市的市区和郊区站点，于夏季和冬季测定了与有机大分子组分相关的颗粒物（PM），这些有机大分子组分包括腐殖酸（HA）、干酪根+黑碳（KB）和黑碳（BC）。通过元素分析（EA）、扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）对有机大分子进行了表征，并利用稳定碳/氮同位素（δC/δN）和混合单粒子拉格朗日积分轨迹（HYSPLIT）模型确定了它们的来源。结果表明，HA、干酪根（K）和BC在PM中的占比范围为3.89%至4.55%，而它们是总有机碳（TOC）的主要组分，占比范围为64.70%至84.99%。SEM分析表明，BC颗粒为多孔/无孔结构，由球形和非球形（即圆柱形和细长形）结构组成。HA、KB和BC的FTIR光谱显示出相似的官能团，但不同站点和季节存在差异。PM中的HA含有较高比例的脂肪族结构，如带有羧基末端的长链脂肪酸和碳水化合物。C/N比、SEM和δC/δN值为PM中HA、K和BC的来源提供了可靠指标。结果表明，HA和K主要源自陆地植物，而BC来自陆地植物燃烧、化石燃料和木炭燃烧的混合源。冬季的气团源自蒙古（4%）、中国北方地区（48%）和北部相邻城市（48%），表明通过长距离传输受到人为源的影响，而夏季的气团来自南海（34%）和西太平洋（66%），代表低浓度有机大分子的清洁海洋气团。
