Holder A L, Gullett B K, Urbanski S P, Elleman R, O'Neill S, Tabor D, Mitchell W, Baker K R
U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, NC 27711, USA.
U.S. Forest Service, Missoula Fire Science Laboratory, Rocky Mountain Research Station, 5775 US Hwy 10W, Missoula, MT 59808, USA.
Atmos Environ (1994). 2017;166:22-33. doi: 10.1016/j.atmosenv.2017.06.043.
Prescribed burns of winter wheat stubble and Kentucky bluegrass fields in northern Idaho and eastern Washington states (U.S.A.) were sampled using ground-, aerostat-, airplane-, and laboratory-based measurement platforms to determine emission factors, compare methods, and provide a current and comprehensive set of emissions data for air quality models, climate models, and emission inventories. Batch measurements of PM, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs), and continuous measurements of black carbon (BC), particle mass by size, CO, CO, CH, and aerosol characteristics were taken at ground level, on an aerostat-lofted instrument package, and from an airplane. Biomass samples gathered from the field were burned in a laboratory combustion facility for comparison with these ground and aerial field measurements. Emission factors for PM, organic carbon (OC), CH, and CO measured in the field study platforms were typically higher than those measured in the laboratory combustion facility. Field data for Kentucky bluegrass suggest that biomass residue loading is directly proportional to the PM emission factor; no such relationship was found with the limited wheat data. CO and BC emissions were higher in laboratory burn tests than in the field, reflecting greater carbon oxidation and flaming combustion conditions. These distinctions between field and laboratory results can be explained by measurements of the modified combustion efficiency (MCE). Higher MCEs were recorded in the laboratory burns than from the airplane platform. These MCE/emission factor trends are supported by 1-2 min grab samples from the ground and aerostat platforms. Emission factors measured here are similar to other studies measuring comparable fuels, pollutants, and combustion conditions. The size distribution of refractory BC (rBC) was single modal with a log-normal shape, which was consistent among fuel types when normalized by total rBC mass. The field and laboratory measurements of the Angstrom exponent (α) and single scattering albedo (ω) exhibit a strong decreasing trend with increasing MCEs in the range of 0.9-0.99. Field measurements of α and ω were consistently higher than laboratory burns, which is likely due to less complete combustion. When VOC emissions are compared with MCE, the results are consistent for both fuel types: emission factors increase as MCE decreases.
在美国爱达荷州北部和华盛顿州东部，利用地面、浮空器、飞机和实验室测量平台对冬小麦茬和草地早熟禾田地的规定燃烧进行了采样，以确定排放因子、比较方法，并为空气质量模型、气候模型和排放清单提供一套当前全面的排放数据。在地面、浮空器搭载的仪器包以及飞机上，对颗粒物（PM）、挥发性有机化合物（VOCs）、多环芳烃（PAHs）和多氯二苯并二恶英/二苯并呋喃（PCDDs/PCDFs）进行了批量测量，并对黑碳（BC）、按粒径划分的颗粒物质量、一氧化碳（CO）、二氧化碳（CO₂）、甲烷（CH₄）和气溶胶特性进行了连续测量。从田间采集的生物质样本在实验室燃烧设施中燃烧，以便与这些地面和空中实地测量结果进行比较。在实地研究平台上测量的PM、有机碳（OC）、CH₄和CO的排放因子通常高于在实验室燃烧设施中测量的排放因子。草地早熟禾的实地数据表明，生物质残渣负荷与PM排放因子成正比；有限的小麦数据未发现这种关系。实验室燃烧试验中的CO和BC排放高于实地排放，这反映出更高的碳氧化和明火燃烧条件。实地和实验室结果之间的这些差异可以通过修正燃烧效率（MCE）的测量来解释。实验室燃烧记录的MCE高于飞机平台。地面和浮空器平台的1 - 2分钟抓取样本支持了这些MCE/排放因子趋势。这里测量的排放因子与其他测量可比燃料、污染物和燃烧条件的研究相似。难熔黑碳（rBC）的粒径分布呈单峰对数正态形状，按总rBC质量归一化后，在不同燃料类型中是一致的。在0.9 - 0.99范围内，随着MCE增加，埃斯特朗指数（α）和单次散射反照率（ω）的实地和实验室测量呈现出强烈的下降趋势。α和ω的实地测量值始终高于实验室燃烧测量值，这可能是由于燃烧不完全所致。当将VOC排放与MCE进行比较时，两种燃料类型的结果是一致的：排放因子随着MCE降低而增加。
