Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; University of Science and Technology of China, Hefei 230031, China.
Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; CAS Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
J Environ Sci (China). 2022 Jan;111:118-129. doi: 10.1016/j.jes.2021.03.004. Epub 2021 Mar 24.
A thorough understanding of chemical composition, particle pH, and pollutant emissions is essential to address the climate and human health effects of atmospheric particles. In this study, we used a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and Scanning Mobility Particle Sizer (SMPS) to characterize the composition of submicron particles. Moreover, we applied the ISORROPIA-II model to analyze the particle acidity effect on the compositional characterization of submicron particles from December 22, 2016 to January 7, 2017 in Albany, New York, USA. The results indicated that aerosols with mobility diameter from SMPS in the range 200-400 nm were the main contributors to the mass during the measurement period. The dominance of organics (47%) and sulfate (16%) was similar to previous observations in the eastern United States in Winter 2015, while the fraction of nitrate (23%) was much higher. Moreover, nitrate could easily form at colder temperatures and lower RH levels even when there were more acidic particle periods during the measurement period in Albany. The ISORROPIA-II model indicated that there were more acidic particles, which was estimated using pH values. Lower temperature conditions tended to favor nitrate formation. The nitrate concentration exceeded that of sulfate in the measurement period, even though the SO and NO emissions were similar. The organics in submicron particles were strongly influenced by the local emissions in winter. However, the inorganic compounds in submicron particles could be derived from regional transport as their pollution sources originated from different directions. This may help strategize emission reductions in the future.
深入了解化学组成、颗粒物 pH 值和污染物排放对于解决大气颗粒物对气候和人体健康的影响至关重要。在本研究中，我们使用高分辨率时间飞行气溶胶质谱仪（HR-ToF-AMS）和扫描迁移率颗粒物粒径谱仪（SMPS）来表征亚微米颗粒物的组成。此外，我们应用 ISORROPIA-II 模型来分析美国纽约奥尔巴尼 2016 年 12 月 22 日至 2017 年 1 月 7 日期间，颗粒物酸度对亚微米颗粒组成特征的影响。结果表明，SMPS 测量范围内粒径在 200-400nm 的气溶胶是测量期间质量的主要贡献者。有机物（47%）和硫酸盐（16%）的主导地位与 2015 年冬季美国东部的先前观测结果相似，而硝酸盐（23%）的比例要高得多。此外，即使在测量期间存在更多酸性颗粒期，硝酸盐仍能在更冷的温度和更低的 RH 水平下轻易形成。ISORROPIA-II 模型表明，有更多酸性颗粒，这是使用 pH 值估计的。较低的温度条件往往有利于硝酸盐的形成。尽管 SO 和 NO 排放相似，但在测量期间，硝酸盐浓度超过了硫酸盐浓度。亚微米颗粒中的有机物在冬季受当地排放的强烈影响。然而，亚微米颗粒中的无机化合物可能来自于区域传输，因为它们的污染源来自不同的方向。这有助于未来制定减排战略。
