Production of Secondary Organic Aerosol During Aging of Biomass Burning Smoke From Fresh Fuels and Its Relationship to VOC Precursors
Production of Secondary Organic Aerosol During Aging of Biomass Burning Smoke From Fresh Fuels and Its Relationship to VOC Precursors
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DOI：
10.1029/2018jd029068
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发表时间：
2019-03-27
影响因子：
4.4
通讯作者：
Donahue, N. M.
中科院分区：
文献类型：
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作者：
Ahern, A. T.;Robinson, E. S.;Donahue, N. M.
燃烧生物质产生的烟雾排入大气后，化学和物理过程改变了老化、稀释的羽流中存在的有机气溶胶的组成和数量。在第四次火灾实验室在密苏拉实验，我们进行了烟雾室实验，以调查形成的二次有机气溶胶（SOA）和多相氧化的主要有机气溶胶（POA）。我们模拟大气老化的稀释烟雾从各种生物质燃料，同时测量颗粒组成，使用高分辨率气溶胶质谱。我们使用低挥发性POA的示踪离子作为参考标准（类似于天然存在的内标）来量化SOA的形成。这些烟雾老化实验揭示了可变的有机气溶胶（OA）增强，即使是从类似的燃料和老化机制的烟雾。这种可变的OA增强与测量到的挥发性有机化合物（VOC）的量的差异相关，这些挥发性有机化合物随后可以被氧化形成SOA。对于一些老化实验，我们能够预测SOA生产的2倍内使用燃料特定的VOC排放清单，燃烧特定的甲苯测量缩放。针叶燃料的火灾主要是针燃烧，挥发性生物源化合物是占主导地位的前体类。对于线草火灾，呋喃是主要的SOA前体。我们使用POA示踪离子来计算由于气相氧化和随后的挥发的半挥发性POA的质量损失的量。少于5%的POA质量损失通过多相氧化驱动的蒸发在长达2小时的等效大气氧化。简单的语言摘要我们测量了米苏拉消防实验室的生物质燃烧烟雾的老化。烟雾来自各种燃料，包括绿色树叶和一些草。我们观察到显着的变化，从颗粒的质谱，也是在许多情况下能够描述形成额外的（二次）质量约2倍的挥发性有机化合物的排放量的基础上。然而，我们表明，二次质量的量在很大程度上取决于生物质燃料的类型（绿色叶状树枝与干柴与草等）。
After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog-chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high-resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low-volatility POA as a reference standard (akin to a naturally occurring internal standard). These smoke aging experiments revealed variable organic aerosol (OA) enhancements, even for smoke from similar fuels and aging mechanisms. This variable OA enhancement correlated well with measured differences in the amounts of emitted volatile organic compounds (VOCs) that could subsequently be oxidized to form SOA. For some aging experiments, we were able to predict the SOA production to within a factor of 2 using a fuel-specific VOC emission inventory that was scaled by burn-specific toluene measurements. For fires of coniferous fuels that were dominated by needle burning, volatile biogenic compounds were the dominant precursor class. For wiregrass fires, furans were the dominant SOA precursors. We used a POA tracer ion to calculate the amount of mass lost due to gas-phase oxidation and subsequent volatilization of semivolatile POA. Less than 5% of the POA mass was lost via multiphase oxidation-driven evaporation during up to 2hr of equivalent atmospheric oxidation.Plain Language Summary We measured aging of biomass-burning smoke at the Missoula Fire Laboratory. The smoke was from various fuels containing green foliage as well as some grasses. We observed significant changes in the mass spectra from the particles, and were also in many cases able to describe formation of additional (secondary) mass to within about a factor of 2 based on measured emissions of volatile organic compounds. However, we show that the amount of secondary mass depends heavily on the type of biomass fuel (green foliated branches vs dried firewood vs grasses, etc).