Speciated and total emission factors of particulate organics from burning western US wildland fuels and their dependence on combustion efficiency
Speciated and total emission factors of particulate organics from burning western US wildland fuels and their dependence on combustion efficiency
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DOI：
10.5194/acp-19-1013-2019
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发表时间：
2018-08
影响因子：
6.3
通讯作者：
C. Jen;L. Hatch;Vanessa Selimovic;R. Yokelson;R. Weber;Arantza E. Fernandez;N. Kreisberg;K. Barsanti;A. Goldstein
中科院分区：
文献类型：
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作者：
C. Jen;L. Hatch;Vanessa Selimovic;R. Yokelson;R. Weber;Arantza E. Fernandez;N. Kreisberg;K. Barsanti;A. Goldstein
抽象的。美国西部荒地频繁发生大规模野火，预计未来还会增加。因此，野火烟雾排放预计将在大气化学中发挥越来越大的作用，同时对区域空气质量和人类健康产生负面影响。了解烟雾对环境的影响是通过确定和量化野火期间排放的化合物，并提供描述排放量和组成如何根据不同的火灾条件和燃料而变化的经验关系来实现的。这项研究检查了美国林业局火灾科学实验室燃烧美国西部常见荒地燃料时排放的颗粒状有机化合物。采用热解吸、在线衍生二维气相色谱仪和电子电离/真空紫外高分辨飞行时间质谱仪(TD-GC×GC-EI/VUV-HRToFMS)分离了数千种中间和半挥发性有机化合物(I/SVOCs)，并将其定量为火灾综合排放因子(EFS)。所附的质谱库中提供了分离化合物的质谱图、作为修正燃烧效率(MCE)的函数的EFS、燃料源和其他定义特征。结果表明，总有机碳(OC)、I/SVOCs化学族和大多数单个I/SVOCs的EFS跨度为2-5个数量级，阴燃条件下(低MCE)的EFS高于燃烧条件下的EFS。对观测数据的对数拟合表明，颗粒性有机化合物的对数(EFS)与MCE成反比。这些测量和关系为有机碳、元素碳(EC)、有机化合物家族和单个I/SVOCs作为火灾条件的函数提供了有用的EFS估计。
Abstract. Western US wildlands experience frequent and large-scale wildfires which are predicted to increase in the future. As a result, wildfire smoke emissions are expected to play an increasing role in atmospheric chemistry while negatively impacting regional air quality and human health. Understanding the impacts of smoke on the environment is informed by identifying and quantifying the chemical compounds that are emitted during wildfires and by providing empirical relationships that describe how the amount and composition of the emissions change based upon different fire conditions and fuels. This study examined particulate organic compounds emitted from burning common western US wildland fuels at the US Forest Service Fire Science Laboratory. Thousands of intermediate and semi-volatile organic compounds (I/SVOCs) were separated and quantified into fire-integrated emission factors (EFs) using a thermal desorption, two-dimensional gas chromatograph with online derivatization coupled to an electron ionization/vacuum ultraviolet high-resolution time-of-flight mass spectrometer (TD-GC × GC-EI/VUV-HRToFMS). Mass spectra, EFs as a function of modified combustion efficiency (MCE), fuel source, and other defining characteristics for the separated compounds are provided in the accompanying mass spectral library. Results show that EFs for total organic carbon (OC), chemical families of I/SVOCs, and most individual I/SVOCs span 2–5 orders of magnitude, with higher EFs at smoldering conditions (low MCE) than flaming. Logarithmic fits applied to the observations showed that log (EFs) for particulate organic compounds were inversely proportional to MCE. These measurements and relationships provide useful estimates of EFs for OC, elemental carbon (EC), organic chemical families, and individual I/SVOCs as a function of fire conditions.