Li Kun, Zhang Jun, Bell David M, Wang Tiantian, Lamkaddam Houssni, Cui Tianqu, Qi Lu, Surdu Mihnea, Wang Dongyu, Du Lin, El Haddad Imad, Slowik Jay G, Prevot Andre S H
Environment Research Institute, Shandong University, Qingdao 266237, China.
Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen 5232, Switzerland.
Natl Sci Rev. 2024 Jan 9;11(3):nwae014. doi: 10.1093/nsr/nwae014. eCollection 2024 Mar.
Organic vapors from biomass burning are a major source of secondary organic aerosols (SOAs). Previous smog chamber studies found that the SOA contributors in biomass-burning emissions are mainly volatile organic compounds (VOCs). While intermediate volatility organic compounds (IVOCs) are efficient SOA precursors and contribute a considerable fraction of biomass-burning emissions, their contribution to SOA formation has not been directly observed. Here, by deploying a newly-developed oxidation flow reactor to study SOA formation from wood burning, we find that IVOCs can contribute ∼70% of the formed SOA, i.e. >2 times more than VOCs. This previously missing SOA fraction is interpreted to be due to the high wall losses of semi-volatile oxidation products of IVOCs in smog chambers. The finding in this study reveals that SOA production from biomass burning is much higher than previously thought, and highlights the urgent need for more research on the IVOCs from biomass burning and potentially other emission sources.
生物质燃烧产生的有机蒸汽是二次有机气溶胶（SOA）的主要来源。先前的烟雾箱研究发现，生物质燃烧排放中形成SOA的成分主要是挥发性有机化合物（VOC）。虽然中等挥发性有机化合物（IVOC）是高效的SOA前体，且在生物质燃烧排放中占相当比例，但其对SOA形成的贡献尚未得到直接观测。在此，通过部署新开发的氧化流动反应器来研究木材燃烧产生SOA的过程，我们发现IVOC对生成的SOA贡献约为70%，即比VOC的贡献多两倍以上。这一先前被遗漏的SOA部分被认为是由于烟雾箱中IVOC半挥发性氧化产物的高壁损失造成的。本研究的发现表明，生物质燃烧产生的SOA比先前认为的要高得多，并突出了迫切需要对生物质燃烧以及潜在的其他排放源中的IVOC开展更多研究。
