Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/4941
標題: 台灣中部地區大氣有機碳及元素碳微粒之特性研究
作者: 藍文農
關鍵字: Thermal Method;熱解法;Elemental Carbon;Organic Carbon;元素碳;有機碳
出版社: 環境工程學系
摘要: 
本研究使用熱解法分析中部地區大氣懸浮微粒中元素碳(EC)與有機碳(OC)含量,首先瞭解不同溫度及不同加熱時間對熱解法的影響,決定較佳的分析條件,並以此方法分析1999年10月至2001年10月於中部地區七測站所採集的PM2.5和PM2.5-10中碳成份,測站包括梧棲、崇倫、草屯、南投、竹山、二林及埔里測站,推估其二次有機碳含量,並分析中部地區懸浮微粒的特性。
溫度和加熱時間為熱解法主要控制參數,由分析的結果得知在通入0.5 Lpm 純氧、溫度為340 ℃及加熱80分鐘為較佳的分析條件,在此分析條件下量測EC的含量較未加純氧、溫度340 ℃而加熱十分鐘的方法所量測之EC值含量低,前者為後者的0.38倍。
結果顯示各測站PM10質量濃度介於24 ~ 163 μg m-3,PM10中TC微粒平均濃度以秋季(99/10/30; 99/11/05-06; 01/10/26-28)最高,在高污染的秋季各測站TC濃度範圍為18 ~ 37 μg m-3之間,TC濃度由沿海往內陸漸增,有機碳亦有相同情形。而EC濃度並無明顯地區性差異,由於EC的化性不活潑,在空氣中停留較長,使得元素碳分佈較為均勻。此外,PM2.5與PM10的(OC/EC)min分別為1.80與1.94,利用(OC/EC)最小比值法推估中部地區二次有機碳質量濃度,結果顯示二次有機碳質量濃度介於2.6至14.7 μg m-3 之間,佔OC質量比例的31 ~ 49 %,佔PM10之質量比例的2.4 ~ 11.7 %。夏季(01/08/27-09/01)及秋季二次有機碳含量較其他季節為高,夏季日照時數長且溫度較高,有助二次有機碳的生成,而在秋季採樣期間適逢臭氧事件日發生,由於臭氧為光化反應的指標污染物,顯示秋季採樣時間光化反應強烈,二次有機碳容易形成,且內陸的埔里地區最容易形成。

Elemental carbon (EC) and organic carbon (OC) particulates were analyzed using thermal method in this study. The optimum condition of separating the elemental and the organic carbon was found by heating the particulate samples with pure oxygen of flow rate 0.5 lpm at the temperature 340 ℃ for 80 minutes. The results showed that the EC concentrations measured previonsly under the condition in on open at air 340 ℃ for 10 minutes was about 0.38 times lower than those measured with optimum condition characteristics of EC and OC particulates measured in central Taiwan during the period from October 1999 to October 2001 were analyzed and secondary OC concentrations were also estimated in this study.
The results revealed the total carbon (TC) and the OC concentrations in PM10 were significantly increased during PM10 episodes in autumn. TC and OC concentrations were found higher at inland site as compared more uniformly distribated in the region. However EC particulates were found with those at coastal sites. The minimum OC/EC ratios of 1.80 and 1.94 were oftained for PM2.5 and PM10, respectively. Those ratios were then used to estimate the concentrations of the secondary OC. The resultes showed secondary OC concentrations in PM10 ranged from 2.6 to 14.7 μg m-3 which contributed 31 to 19 % of OC. Further more the summer and the autumn aerosols observed in this study contained more secondary OC than the other seasons. A good correlation between the secondary OC and the ozone were found in the case of the autumn aerosols.
URI: http://hdl.handle.net/11455/4941
Appears in Collections:環境工程學系所

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