Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
Environ Pollut. 2019 Jun;249:831-842. doi: 10.1016/j.envpol.2019.03.106. Epub 2019 Mar 27.
Oxygenated volatile organic compounds (OVOCs) are critical atmospheric ozone and secondary organic aerosol (SOA) precursors and radical sources, while understanding of OVOC sources in the atmosphere, especially with large anthropogenic emissions, still has large uncertainties. A high-sensitivity proton transfer reaction mass spectrometer (PTR-MS) was deployed in vastly different atmospheres in southern China, including an urban site (SZ-U), a regional site (NA-R), and a background site (NL-B). Four critical OVOCs, i.e., methanol, acetone, methyl ethyl ketone (MEK) and acetaldehyde, five groups of aromatic hydrocarbons, isoprene and acetonitrile were measured with a high time resolution. The featured relative abundance and diurnal variations of the OVOCs indicated that methanol, acetone and MEK had prominent contributions from urban industrial activities, while acetaldehyde was closely related to the photochemical formation at all three sites. The photochemical age-based parameterization method was improved locally and then applied to quantify different sources of daytime OVOCs: anthropogenic secondary and biogenic sources (together 60-73%) were always the dominant source for acetaldehyde in various atmospheres; in addition to a significant background for methanol, acetone and MEK, anthropogenic primary emissions (mostly industrial) were their dominant source at SZ-U (38-73%), while biogenic sources played the key role for them at NL-B (30-43%); biomass burning contributed a small fraction of 5-17% for the four OVOCs at the three sites.
含氧挥发性有机化合物（OVOCs）是大气臭氧和二次有机气溶胶（SOA）的关键前体和自由基源，然而，对于大气中 OVOC 来源的理解，特别是在存在大量人为排放的情况下，仍然存在很大的不确定性。一台高灵敏度质子转移反应质谱仪（PTR-MS）被部署在中国南方的不同大气环境中，包括一个城市站点（SZ-U）、一个区域站点（NA-R）和一个背景站点（NL-B）。四种关键的 OVOCs，即甲醇、丙酮、甲乙酮（MEK）和乙醛，以及五组芳香烃、异戊二烯和乙腈，都以高时间分辨率进行了测量。这些 OVOCs 的特征相对丰度和日变化表明，甲醇、丙酮和 MEK 主要来自城市工业活动，而乙醛与所有三个站点的光化学形成密切相关。光化学年龄基参数化方法在当地进行了改进，然后用于量化白天 OVOCs 的不同来源：人为二次和生物源（总共 60-73%）始终是各种大气中乙醛的主要来源；除了甲醇、丙酮和 MEK 的显著背景外，人为初级排放（主要是工业）是它们在 SZ-U 的主要来源（38-73%），而生物源在 NL-B 对它们起着关键作用（30-43%）；生物质燃烧对这四个 OVOCs 在三个站点的贡献只有 5-17%。
