Insight into the formation and evolution of secondary organic aerosol in the megacity of Beijing, China
Insight into the formation and evolution of secondary organic aerosol in the megacity of Beijing, China
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深入了解中国北京特大城市二次有机气溶胶的形成和演化
DOI：
10.1016/j.atmosenv.2019.117070
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发表时间：
2020
影响因子：
5
通讯作者：
Wang Yuesi
中科院分区：
文献类型：
--
作者：
Li Jiayun;Liu Zirui;Gao Wenkang;Tang Guiqian;Hu Bo;Ma Zhiqiang;Wang Yuesi
有机气溶胶是大气亚微米颗粒物中含量最丰富的组分，但有机气溶胶的化学特征尚未完全了解。2015年9月1日至30日，利用Aerodyne高分辨率飞行时间气溶胶质谱仪对北京城区二次有机气溶胶（SOA）的形成和演变进行了评估。亚微米气溶胶颗粒物主要为有机物（平均占总质量的43.2%），其次为硝酸盐（19.8%）、硫酸盐（19.2%）、铵（10.2%）、黑碳（BC）（8.5%）和氯化物（1.4%）。高分辨率有机气溶胶质谱的正矩阵分解确定了两种含氧有机气溶胶（OOA）组分：氧化程度较低的OOA（LO-OOA）和氧化程度较高的OOA（MO-OOA）。MO-OOA和LO-OOA的质量浓度与奇数氧（Ox = O3+二氧化氮（NO2））相关性很好，斜率分别为1.15 μg m− 3/10 ppb Ox和0.48 μg m− 3/10 ppb Ox，表明光化学处理在OOA产生中的重要作用。此外，还观察到当RH > 60%时，水相加工显著有助于MO-OOA的产生，并且RH抑制LO-OOA的形成。进一步的情景分析表明，在污染初期，气相反应是有机物氧化的主要驱动力，在此期间，LO-OOA逐渐向MO-OOA转化，表现为最易氧化离子（CO2+）的增加和中等易氧化离子（C2 H3 O+）的减少。与初始污染阶段相比，峰值污染阶段白天的气相氧化作用大大增强，MO-OOA对Ox浓度的依赖性更强。此外，增强的水相氧化和分区过程都有助于在夜间在高气溶胶水含量的存在下，将含氧物种纳入颗粒相。
Organic components are the most abundant fraction of atmospheric submicron particles, but the chemical characteristics of organic aerosols (OA) remain not fully understood. Here, the formation and evolution of secondary organic aerosol (SOA) was evaluated using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer at an urban site in Beijing from 1 to 30 September 2015. The submicron aerosol particles were dominated by organics (accounting for an average of 43.2% of the total mass), followed by nitrate (19.8%), sulfate (19.2%), ammonium (10.2%), black carbon (BC) (8.5%) and chloride (1.4%). Positive matrix factorization of high-resolution organic aerosol mass spectra identified two oxygenated organic aerosol (OOA) components: a less oxidized OOA (LO-OOA) and a more oxidized OOA (MO-OOA). The mass concentrations of MO-OOA and LO-OOA correlated well with the odd oxygen (Ox = O3+nitrogen dioxide (NO2)), with slopes of 1.15 μg m−3per 10 ppb Ox and 0.48 μg m−3per 10 ppb Ox, respectively, suggesting the important role of photochemical processing in OOA production. In addition, aqueous-phase processing was also observed to contribute substantially to MO-OOA production when RH > 60%, and RH suppressed LO-OOA formation. Further episode analysis showed that the gas-phase reaction was the main driving force for organic oxidation during the initial pollution stage, during which LO-OOA gradually transformed to MO-OOA as indicated by an increase in the most oxidized ion (CO2+) and a decrease in a moderately oxidized ion (C2H3O+). Compared with the initial pollution stage, gas-phase oxidation was largely enhanced during the daytime in the peak pollution stage which showed a stronger dependence of MO-OOA on Ox concentration. In addition, enhanced aqueous-phase oxidation and the partitioning process both contributed to the incorporation of oxygenated species into the particle phase during the nighttime in the presence of high aerosol water content.
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DOI：
10.1073/pnas.1001043107
发表时间：
2010-04
期刊：
Proceedings of the National Academy of Sciences
影响因子：
--
作者：
J. Pankow
通讯作者：
J. Pankow
水相和光化学处理对中国北京二次有机气溶胶形成和演化的影响
影响因子：
11.4
作者：
Xu Weiqi;Han Tingting;Du Wei;Wang Qingqing;Chen Chen;Zhao Jian;Zhang Yingjie;Li Jie;Fu Pingqing;Wang Zifa;Worsnop Douglas R.;Sun Yele
通讯作者：
Sun Yele
DOI：
--
发表时间：
2010
期刊：
--
影响因子：
--
作者：
通讯作者：
--
影响因子：
6.3
作者：
Yele Sun;Qi Zhang;J. Schwab;K. Demerjian;W. Chen;M. Bae;H. Hung;O. Hogrefe;Brian P. Frank
通讯作者：
Yele Sun;Qi Zhang;J. Schwab;K. Demerjian;W. Chen;M. Bae;H. Hung;O. Hogrefe;Brian P. Frank
影响因子：
11.4
作者：
A. Lambe;T. Onasch;D. R. Croasdale;J. Wright;Alexander T Martin;J. Franklin;P. Massoli;J. Kroll;M. Canagaratna;W. Brune;D. Worsnop;P. Davidovits
通讯作者：
A. Lambe;T. Onasch;D. R. Croasdale;J. Wright;Alexander T Martin;J. Franklin;P. Massoli;J. Kroll;M. Canagaratna;W. Brune;D. Worsnop;P. Davidovits