Key Laboratory of Northwest Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
School of Geography and Environment, Shandong Normal University, Jinan 250358, PR China; Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China.
Sci Total Environ. 2022 Jul 15;830:154663. doi: 10.1016/j.scitotenv.2022.154663. Epub 2022 Mar 19.
Organic aerosols (OAs) in particulate matter with an aerodynamic diameter of smaller than 2.5 μm (PM) can affect the atmospheric radiation balance through varying molecular structure and light absorption of the aerosols. In this study, daytime and nighttime PM mass, and contents of OA including nitrated aromatic compounds (NACs), polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and hopanes were measured from April 11th to May 15th, 2017, at the coastal Sanya, China. The average concentration of 18 total quantified PAHs (∑PAHs) was 2.08 ± 1.13 ng·m, which was 2.8 and 12 times higher than that of ∑NACs and hopanes, while was 7.5 times lower that of n-alkanes. Combustion-derived PAHs contributed 74% to the ∑PAHs. This finding, in addition to a high benzo[a]pyrene/(benzo[a]pyrene+benzo[e]pyrene) ratio, indicates that the PAHs mainly derived from fresh fuel combustion during the sampling periods. Furthermore, dramatic day-night differences were observed in the loadings of total NACs, PAHs, and n-alkanes, which had a high coefficient of divergence values of 0.67, 0.47, and 0.32, respectively. Moreover, hopanes exhibited similar variation as well. The proportion of dimethyl-nitrophenol (DM-NP), dinitrophenol (DNP), and nitrosalicylic acid (NSA) in PM were higher in the daytime than at nighttime, suggesting the co-influence of primary emissions and secondary formation related to biomass combustion. The positive matrix factorization (PMF) model revealed that motor vehicle and biomass burning emissions were the two main pollution sources in the daytime, contributing 51.7% and 24.6%, respectively, of the total quantified OAs. The proportion of industrial coal combustion emissions was higher at nighttime (20.6%) than in daytime (10%). Both the PAHs and NACs displayed light absorbing capacities among OAs compounds over Sanya City, and thus their influence on solar radiation must be considered in the future control policies.
颗粒物中空气动力学直径小于 2.5μm 的有机气溶胶（OAs）可通过改变气溶胶的分子结构和光吸收来影响大气辐射平衡。本研究于 2017 年 4 月 11 日至 5 月 15 日在我国沿海三亚市测量了白天和夜间的 PM 质量，以及包括硝芳烃（NACs）、多环芳烃（PAHs）、正烷烃和藿烷在内的 OAs 含量。18 种总定量 PAHs（∑PAHs）的平均浓度为 2.08±1.13ng·m，分别是∑NACs 和藿烷的 2.8 倍和 12 倍，而 n-烷烃则低 7.5 倍。燃烧源 PAHs 对∑PAHs 的贡献率为 74%。除了较高的苯并[a]芘/（苯并[a]芘+苯并[e]芘）比值外，这一发现表明，在采样期间，PAHs 主要来自新鲜燃料燃烧。此外，总 NACs、PAHs 和正烷烃的负荷昼夜差异明显，发散系数值分别为 0.67、0.47 和 0.32。藿烷也表现出相似的变化。二甲基硝基苯酚（DM-NP）、二硝基苯酚（DNP）和硝水杨酸（NSA）在 PM 中的比例在白天高于夜间，这表明生物质燃烧的一次排放和二次形成之间存在共同影响。正定矩阵因子分解（PMF）模型表明，机动车和生物质燃烧排放是白天的两个主要污染源，分别占总定量 OAs 的 51.7%和 24.6%。工业燃煤排放的比例在夜间（20.6%）高于白天（10%）。在三亚市，PAHs 和 NACs 都表现出 OAs 化合物对太阳辐射的吸光能力，因此在未来的控制政策中必须考虑到它们对太阳能的影响。
