植物表面燃油火力電廠黑煙微粒之顯微鏡鑑定

Abstract

台北縣萬里鄉大坪村海芋、芥菜及甘藍菜表面，及基隆市瑪西里一帶之文旦、甘藍表面上之黑煙，經以光學顯微鏡觀察，發現皆以小於l微米之粉狀黑煙及1至3微米，平均2微米之反光球狀黑煙為主要成員，而此2種典型黑煙與萬里鄉東方10公里一座燃油火力電廠之排煙具有相同之形態及組成。利用掃描式電子顯微境加以觀測，亦能得到相同的結果，而X光微量分析的結果，發現花葉表面2微米之黑煙主含Si及Al二元素，與電廠排煙中2微米者相同，而與3微米以止或蜂窩狀黑煙者不同。而基隆市附近5家其他工廠之排煙發現皆與花葉上所見者完全不同。珍91年4月l日至5月12日於萬鄉大坪村設站採集到31批共60個樣品中發現皆含有上述典型顆粒，此與採樣期間每日皆有東風吹龍有關。綜合研判可知燃油火力電廠之排煙確實可以傳送沈降於10公里外之花葉表面，唯其與地形之關係，及沈降詳細途徑皆尚待學界繼續研究。 The black smoke particles heavily deposited on the surfaces of calla flowers, mustard and cabbage leaves collected from Ta-Pin hill area of Wanli, Taipei County, and those on the wentan and cabbage leaves at Ma-Shi hill area of Keelung City were found to consist of 1-3 µ light-reflecting black spheres and many submicron amorphous -particulates when observed under a metallurgical microscope. The composition of deposited particles on vegetation surface was found to be similar to that emitted from an oil-fired power plant located about 10 km east from Ta-Pin hill of Wanli, but differed to those from two heavy oilfired boilers from nearby textile factories, one fertilizer factory, one steel refinery and exhausts from various vehicles. Scanning electron microscopy of the deposited 1-3 u particles also showed the same appearance as those collected from the stack of the oil-fired power plant. Further analysis with an energy-dispersive X-ray microanalyzer showed that both particles mostly contained Si and Al, although larger particles collected from electrostatic precipitator of the power plant might contain more S and V other than Si and Al. Sixty petridish samplers from two particle collection stations collected daily from April 1 to May 12, 1991 in the farms at Ta-Pin hill showed that typical 1-3 µ particles deposited on this area everyday, while simultaneous meteorological data indicated that east wind dominated or existed during each collecting day in this period. These evidences revealed that the heavily deposited particles on the vegetation surface were from the upwind power plant 10 km away.