کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6343554 | 1620526 | 2014 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Variability, formation and acidity of water-soluble ions in PM2.5 in Beijing based on the semi-continuous observations
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علم هواشناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Daily PM2.5 and hourly water-soluble inorganic ions in PM2.5 and gaseous precursors were measured during June-November 2009 at an urban site in Beijing. The average mass concentration of the total water-soluble ions was 44 μg mâ 3, accounting for 38% of PM2.5. Sulfate (SO42 â), nitrate (NO3â) and ammonium (NH4+) were dominant ions. The summer-fall difference in seasonal average mass concentrations was smaller than 30% for SO42 â, but was up to a factor of 2.0 for NO3â and NH4+. A pronounced diurnal cycle was found for most ions and gaseous precursors and could be explained by their respective sources, formation mechanisms and meteorological conditions. The average oxidation/conversion ratio for SO42 â (SOR), NO3â (NOR) and NH4+ (NHR) were estimated to be 63%, 15% and 15%, respectively. The low NHR value suggests that NH3 was mainly from local sources and that excessive NH3 existed and thus was not a limiting factor in the formation of NH4+. As a result, the diurnal pattern of NH4+ was similar to that of SO42 â to some extent, but differed significantly from that of NH3. Based on the estimated H+ concentration and acidity purity (f), 75% of data samples were strongly acidic and a few percent might be alkaline. Seasonal variations in aerosol acidity and chemical forms of major ions were also briefly discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Research - Volumes 145â146, AugustâSeptember 2014, Pages 1-11
Journal: Atmospheric Research - Volumes 145â146, AugustâSeptember 2014, Pages 1-11
نویسندگان
Guoyuan Hu, Yangmei Zhang, Junying Sun, Leiming Zhang, Xiaojing Shen, Weili Lin, Yun Yang,