| 摘要: | 本研究探討民俗節慶活動之大氣氣膠化學組成特性變異，研究採集鹽水元宵節時期的沿街繞轎活動以及煙火蜂炮近活動源微粒，並在鹽水國中的頂樓及鹽水武廟附設會館的頂樓採樣，探討當地活動進行前後的大氣氣膠，且在研究初期偶遇一高污染事件(PM episode)也一併探討。主要分析的物種為無機鹽類、羧酸、有機碳及重金屬，以瞭解民俗節慶活動時期的環境氣膠之化學組成及粒徑分佈之特性。
元宵節時期大氣氣狀物之全日平均濃度高低為NH3 >SO2 > HNO2 >HNO3 > HCl > oxalic acid，其中SO2、HCl及HNO3均是日間大於夜間，而HNO2為夜間大於日間，顯示日間之HNO3為HNO2經由光化轉變而成。研究初期的高污染事件，PM2.5無機鹽類全日平均濃度高低為NO3- > SO42- > NH4+，顯示在PM episode發生時NO3-為PM mass最主要的物種。元宵節時期，在鹽水武廟及鹽水國中之PM2.5無機鹽類K+之濃度為元宵節前後時期10倍，此外，Na+、Mg2+、Ca2+、Cl-、PO4-3亦在元宵節期間較元宵節前期明顯上升，顯示元宵節煙火的燃放活動會使上述物種之濃度明顯上升，而以K+最為顯著。元宵節時期之PM2.5氣膠羧酸以oxalic acid之濃度佔最高，而glutaric acid在元宵節時期為元宵節前期的13.9倍，顯示glutaric acid在煙火燃放中有特殊高比例的增加，故為煙火燃燒之重要指標物種。而malonic acid/succinic acid之比值> 3，顯示元宵節慶之大氣氣膠另有光化反應後的二次產物。而acetic acid/formic acid (A/F)的比值遠大於1，顯示元宵節慶之大氣氣膠亦有來自原生物種之貢獻。此外levoglucosan在元宵節慶中亦有高濃度的上升趨勢顯示爆竹煙火的燃放存在植物纖維的原生燃燒產物。元宵節前後時期之質量濃度粒徑主要分佈在droplet mode上，Na+在元宵節時期粒徑在奈米的部分有明顯的增加，煙火的燃放對於K+在droplet mode的增量有明顯的貢獻。鹽水武廟及鹽水國中在元宵節前後及元宵節期間的oxalic acid波峰均落在droplet mode上與SO42-有非常相似之粒徑濃度分佈。火藥主要原料為硝酸鉀，顯現在元宵節現場煙火與蜂炮燃煙之重金屬主要以K佔最大濃度，同時導致元宵節期間PM2.5之K+的高濃度。
The subject of this report is focused on the chemical properties of aerosol in ambient environment and near activity sources during the folk festival events. The collection of air samples was conducted from the roof top of Yanshui Junior High School and Temple of the Martial Deity. There occurred a PM episode during the intensive program. The main species in aerosol to discuss are inorganic species, carboxylic acids, anhydrosugars and metals. The results demonstrate chemical compositions and size distributions in aerosols during the folk festival events.
The concentration of gaseous pollutants in the atmosphere Latern Festival is the following order NH3> SO2> HNO2> HCl> HNO3> oxalic acid. There are high concentrations of SO2, HCl and HNO3 in the daytime, meanwhile high concentration of HNO2 occurred in the nighttime, indicating that during the daytime HNO2 is converted to HNO3 by photochemical reactions in atmosphere.
During the PM episode, the PM2.5 concentration of inorganic species is the following order NO3- > SO42-> NH4+ iIndicating in the PM episode occurs, NO3-is the most important species in PM mass. Compared to before and after Lantern Festival, K+ concentration during the Latern Festival increased 10 times. Furthermore, during the Latern Festival Na+、Mg2+、Ca2+、Cl-、PO43-concentration are much higher than those before Latern Festival, indicating burning of fireworks will significantly increase the concentration of above-mentioned species, specifically K+. During the Latern Festival, oxalic acid is the most dominant carboxylic acid in PM2.5. However, glutaric acid increase 13.9 times, compared to before Lantern Festival, indicating glutaric acid in burning of fireworks significantly increase and is regarded as an important emission indicator of firework. The ratio of malonic acid/succinic acid is > 3, indicating during Lantern Festival there also occurred apparent secondary photochemical reaction. The ratio of acetic acid/formic acid is > 1, indicating during Lantern Festival there exists the primary emission released from the fireworks. Levoglucosan is the most important anhydrosugar species during the activity program. During the Latern Festival, the major mass with peak concentration at droplet mode, the Na+ has increased significantly at nuclei mode during the burning of fireworks, K+ at the droplet mode of significant incremental contribution. Oxalic was major at droplet mode, and SO42- are very similar. The main raw material in fireworks is potassium nitrate. In burning of fireworks, K mainly accounted for the highest concentration of metals, which also led to the high concentration of PM2.5 K + during the Lantern Festival. |
