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標題: | 大氣氧化能力對衍生性污染物之影響及控制策略 The impact and control strategies of atmospheric oxidation capacity on secondary pollutants |
作者: | 李冠頡 Kuan-Chieh Lee |
指導教授: | 蕭大智 Ta-Chih Hsiao |
關鍵字: | 能見度,衍生性污染物,大氣氧化能力,正矩陣因子法,揮發性有機化合物, Visibility,secondary pollutants,atmospheric oxidation capacity,PMF,VOCs, |
出版年 : | 2024 |
學位: | 碩士 |
摘要: | PM2.5作為空氣污染中的一個關鍵指標,對人類健康、氣候變化和能見度都有顯著影響。其中,由於能見度是可直接透過肉眼觀察的指標,因此大氣能見度容易受到一般民眾的關注。有鑒於此,本研究採用IMPROVE方法,透過分析PM2.5中各化學成分的消光係數,來建立PM2.5與能見度之間的關聯。我們分析連續三年夏季和秋季的地面觀測數據,以探討PM2.5與能見度的季節性變化和年度趨勢,旨在幫助制定更有效的空氣污染控制策略。
本研究揭示了PM2.5質量濃度在過去三年間的季節性變化特徵:夏季呈現下降趨勢,而秋季則逐漸上升。從能見度的角度分析氣膠的化學成分,發現有機物和衍生性硝酸鹽是兩種需特別關注的成分。此外,通過對硝酸鹽氣體前驅物日變化模式的分析,可看到前驅物和氧化劑的變化受到大氣稀釋效果的顯著影響。在硝酸鹽形成方面,東海測站處於氨過量狀態,意味著我們在研究硝酸鹽的形成過程時,應著重於硝酸生成的途徑。對於硝酸的控制策略而言,有效控制氧化劑將是減少硝酸鹽形成的一個關鍵策略。臭氧,作為一種重要的氧化劑,其控制成為了減少二次氣膠形成的有效途徑。在台中地區,臭氧的形成多數時間受到VOCs的限制。這表明,通過控制VOCs的排放,可以有效降低臭氧的產生,從而降低大氣氧化能力。根據PMF模型的結果,我們確定了五個主要的VOC排放源,包括汽油蒸發、工業相關的溶劑使用、交通排放、生物源和老化空氣團,其中交通源的濃度比例最高,其次是溶劑使用和老化空氣團。在考慮VOC對臭氧和二次有機氣膠生成潛力時,溶工業相關的溶劑使用成為了最需要關注的VOC來源。 最後,我們的研究凸顯了衍生性氣膠在PM2.5濃度與能見度方面的顯著影響。透過對大量長期觀測數據的分析,結合對氣膠生成機制的深入探討,我們提出可能的季節性空氣污染控制策略。此外,我們也從污染物源頭的角度進行了解析,為控制策略提供具體且量化的依據。 PM2.5, as a key indicator in air pollution, significantly impacts human health, climate change, and visibility. As visibility can be directly observed with the naked eye, it frequently attracts the attention of the public. Given this recognition, our study used the IMPROVE method, analyzing the extinction coefficients of various chemical components in PM2.5 to establish a relationship between PM2.5 and visibility. We analyzed ground observation data from summer and autumn over three years, aiming to explore the seasonal variations and annual trends of PM2.5 and visibility. The purpose is to assist in developing effective air pollution control strategies. Our study revealed the seasonal variation of PM2.5 loading over the past three years: a declining trend in summer and an increasing trend in autumn. When analyzing the chemical composition of aerosols from the perspective of visibility, we identified organic matter and nitrates as two components that require special attention. Additionally, our diurnal patterns analysis of the gas precursors revealed that the changes in precursors and oxidants are significantly influenced by atmospheric dilution effects. In terms of nitrate formation, the Tunghai station is often in the condition of excess ammonia, suggesting that in studying the formation of nitrates, focus should be placed on the pathways of HNO3 production. Therefore, effectively controlling oxidants emerges as a key strategy in reducing nitrate formation. O3, as an important oxidant, plays a significant role, and controlling it becomes an effective way to reduce secondary aerosol formation. In the Taichung area, the formation of O3 is mostly VOC-limited. This indicates that effectively controlling VOC emissions can significantly reduce O3 production, decreasing atmospheric oxidation capacity. According to the results of the PMF model, we identified five VOC sources: gasoline evaporation, industrial-related solvent usage, traffic exhaust, biogenic source, and aged airmass, with traffic sources having the highest concentration proportion, followed by industrial-related solvent usage and aged airmass. Considering the O3 formation potential and secondary organic aerosol formation potential, industrial-related solvent usage becomes the most concerning VOC source. Our finding highlights the significant impact of secondary aerosols on PM2.5 and visibility. We proposed possible seasonal pollution control strategies by analyzing long-term observational data and studying the mechanisms of nitrate formation. Furthermore, our analysis from the perspective of pollution sources provides concrete and quantifiable foundations for these control strategies. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/92512 |
DOI: | 10.6342/NTU202400763 |
全文授權: | 同意授權(全球公開) |
顯示於系所單位: | 環境工程學研究所 |
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ntu-112-2.pdf 此日期後於網路公開 2027-02-26 | 5.62 MB | Adobe PDF |
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