State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
Sci Total Environ. 2016 Aug 15;562:812-821. doi: 10.1016/j.scitotenv.2016.04.015. Epub 2016 Apr 23.
An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed along with other observation instruments to measure the characteristics of PM1 (particulate matter with a vacuum aerodynamic diameter of ≤1μm) during the biomass burning period (October 1 to 27; BBP) and the coal combustion period (December 10 to 31; CCP) in Beijing in 2014. The average PM1 mass concentrations during the BBP and CCP were 82.3 and 37.5μgm(-3), respectively. Nitrate, ammonium and other pollutants emitted by the burning processes, especially coal combustion, increased significantly in association with increased pollution levels. Positive matrix factorization (PMF) was applied to a unified high-resolution mass spectra database of organic species with NO(+) and NO2(+) ions to discover the relationships between organic and inorganic species. One inorganic factor was identified in both periods, and another five and four distinct organic factors were identified in the BBP and CCP, respectively. Secondary organic aerosols (SOAs) accounted for 55% of the total organic aerosols (OAs) during the BBP, which is higher than the proportion during the CCP (oxygenated OA, 40%). The organic nitrate and inorganic nitrate were first successfully separated through the PMF analysis based on the HR-ToF-AMS observations in Beijing, and organic nitrate components accounted for 21% and 18% of the total nitrate mass during the BBP and CCP, respectively. Although the PM1 mass concentration during the CCP was much lower than in the BBP, the average concentration of polycyclic aromatic hydrocarbons (PAHs) during the CCP (107.3±171.6ngm(-3)) was ~5 times higher than that in the BBP (21.9±21.7ngm(-3)).
在 2014 年北京的生物质燃烧期（10 月 1 日至 27 日；BBP）和煤炭燃烧期（12 月 10 日至 31 日；CCP）期间，使用 Aerodyne 高分辨率飞行时间气溶胶质谱仪（HR-ToF-AMS）和其他观测仪器来测量 PM1（空气动力学直径≤1μm 的颗粒物）的特性。在 BBP 和 CCP 期间，PM1 质量浓度的平均值分别为 82.3 和 37.5μg/m3。燃烧过程中排放的硝酸盐、铵盐和其他污染物，特别是煤炭燃烧，随着污染水平的升高而显著增加。正矩阵因子分析（PMF）应用于带有 NO(+)和 NO2(+)离子的有机物质的统一高分辨率质谱数据库，以发现有机物质和无机物质之间的关系。在两个时期都鉴定出一个无机因子，在 BBP 和 CCP 分别鉴定出另外五个和四个不同的有机因子。在 BBP 期间，二次有机气溶胶（SOA）占总有机气溶胶（OA）的 55%，高于 CCP（氧化 OA，40%）的比例。通过基于 HR-ToF-AMS 观测的 PMF 分析，首次成功分离了有机硝酸盐和无机硝酸盐，在 BBP 和 CCP 期间，有机硝酸盐成分分别占总硝酸盐质量的 21%和 18%。尽管 CCP 期间的 PM1 质量浓度远低于 BBP，但 CCP 期间多环芳烃（PAHs）的平均浓度（107.3±171.6ng/m3）约为 BBP 的 5 倍（21.9±21.7ng/m3）。
