Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
J Environ Sci (China). 2020 Mar;89:35-46. doi: 10.1016/j.jes.2019.09.015. Epub 2019 Oct 21.
The Sichuan Basin has experienced serious air pollution from fine particulate matter (PM) in the past few years with biomass burning has been identified as a major source of PM in this region. We used single particle aerosol mass spectrometer to investigate the characteristics of biomass burning particles in three interacting cities representing different types of urban environment in the Sichuan Basin. A total of 739,794, 279,610, and 380,636 biomass burning particles were detected at Ya'an, Guang'an, and Chengdu, which represented 42%, 69%, and 61%, respectively, of the total number of particles. We analyzed the chemical composition, transportation, and evolution of biomass burning particles. The contribution of K-elemental carbon and K-secondary inorganic particles was highest in Ya'an (36%) and Guang'an (47%), respectively, reflecting the important role of fresh biomass burning particles and long-distance transport in these two cities. Air masses originating from different directions corresponded to different levels of PM and the contributions of polluted clusters increased significantly on polluted days. Fresh and secondary inorganic biomass burning particles increased pollution at Ya'an and Guang'an, respectively, but dominated different stages of pollution in Chengdu. K-nitrate particles were formed by photochemical reactions, whereas K-sulfate particles were formed by both photochemical and liquid-phase reactions. Investigation of the degree of particle aging showed that there were more fresh particles at Ya'an and more aged particles at Guang'an. These results are useful in helping our understanding of the characteristics of biomass burning particles and evaluating their role in PM pollution in the Sichuan Basin.
过去几年，四川盆地经历了严重的细颗粒物（PM）空气污染，生物质燃烧已被确定为该地区 PM 的主要来源。我们使用单颗粒气溶胶质谱仪研究了代表四川盆地不同城市环境类型的三个相互作用城市中生物质燃烧颗粒的特征。在雅安、广安和成都共检测到 739794、279610 和 380636 个生物质燃烧颗粒，分别占颗粒总数的 42%、69%和 61%。我们分析了生物质燃烧颗粒的化学组成、传输和演化。在雅安（36%）和广安（47%），K 元素碳和 K 二次无机颗粒的贡献最高，分别反映了新鲜生物质燃烧颗粒和长距离传输在这两个城市中的重要作用。不同来源的气团对应于不同水平的 PM，污染日污染集群的贡献显著增加。新鲜和二次无机生物质燃烧颗粒分别增加了雅安和广安的污染，但在成都污染的不同阶段占主导地位。K 硝酸盐颗粒是通过光化学反应形成的，而 K 硫酸盐颗粒是通过光化学和液相反应形成的。对颗粒老化程度的调查表明，雅安有更多的新鲜颗粒，而广安有更多的老化颗粒。这些结果有助于我们了解生物质燃烧颗粒的特征，并评估它们在四川盆地 PM 污染中的作用。
