کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4439412 | 1311018 | 2011 | 8 صفحه PDF | دانلود رایگان |
We studied the suspended particulate matter (SPM) collected in Akita Prefecture, Japan from April 2008 to January 2009 for inorganic ion composition and nitrogen isotopic ratio (δ15N) of NH4+ and NO3−. The results showed an average SPM concentration of 15.6 μg m−3. The seasonal trend for SPM was higher values in the spring, lower in the winter. The major cations were Na+, NH4+, Ca2+ and major anions were SO42−, NO3−, Cl−. The annual correlation coefficient of ions indicates a very high value with NH4+ and SO42− (R = 0.93), NO3− and K+ (R = 0.65), NO3− and Ca2+ (R = 0.62). The high springtime values are the apparent result of the dust stream from Asia. Average δ15N–NH4+ and δ15N–NO3− were 16.1‰ and −0.69‰, respectively. δ15N–NH4+ increased slightly in summer, and δ15N–NO3− increased considerably in winter. The trends indicated conversely. The heavy δ15N–NH4+ in summer appears to be from agricultural sources such as animal waste and fertilizer. In addition, according to the difference in isotopes of NOx sources as the precursor of NO3−, the dominant origin of heavy δ15N–NO3− in winter could be NOx emitted from fossil fuel combustion at low temperature. Moreover, the average δ15N–NO3− seemed to be made to baseline (approximately 0%) by vehicle emissions at high temperature. These results are considered to be very reasonable.
► We investigated ammonium and nitrate source in aerosol to use nitrogen isotope.
► Stable nitrogen isotope ratio of ammonium and nitrate for long range were analyzed.
► Nitrate in winter seemed to be affected a long-range effect of coal combustion.
Journal: Atmospheric Environment - Volume 45, Issue 35, November 2011, Pages 6309–6316