کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8864373 | 1620303 | 2017 | 47 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Enhanced levels of atmospheric low-molecular weight monocarboxylic acids in gas and particulates over Mt. Tai, North China, during field burning of agricultural wastes
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علم هواشناسی
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چکیده انگلیسی
To understand the source and atmospheric behaviour of low molecular weight monocarboxylic acids (monoacids), gaseous (G) and particulate (P) organic acids were collected at the summit of Mt. Tai in the North China Plain (NCP) during field burning of agricultural waste (wheat straw). Particulate organic acids were collected with neutral quartz filter whereas gaseous organic acids were collected with KOH-impregnated quartz filter. Normal (C1-C10), branched (iC4-iC6), hydroxy (lactic and glycolic), and aromatic (benzoic) monoacids were determined with a capillary gas chromatography employing p-bromophenacyl esters. We found acetic acid as the most abundant gas-phase species whereas formic acid is the dominant particle-phase species. Concentrations of formic (G/P 1 570/1 410 ng mâ3) and acetic (3 960/1 120 ng mâ3) acids significantly increased during the enhanced field burning of agricultural wastes. Concentrations of formic and acetic acids in daytime were found to increase in both G and P phases with those of K+, a field-burning tracer (r = 0.32-0.64). Primary emission and secondary formation of acetic acid is linked with field burning of agricultural wastes. In addition, we found that particle-phase fractions (Fp = P/(G + P)) of formic (0.50) and acetic (0.31) acids are significantly high, indicating that semi-volatile organic acids largely exist as particles. Field burning of agricultural wastes may play an important role in the formation of particulate monoacids in the NCP. High levels (917 ng mâ3) of particle-phase lactic acid, which is characteristic of microorganisms, suggest that microbial activity associated with terrestrial ecosystem significantly contributes to the formation of organic aerosols.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Environment - Volume 171, December 2017, Pages 237-247
Journal: Atmospheric Environment - Volume 171, December 2017, Pages 237-247
نویسندگان
Tomoki Mochizuki, Kimitaka Kawamura, Shinnosuke Nakamura, Yugo Kanaya, Zifa Wang,