利用多重環境介質模式探討戴奧辛類化合物之傳輸行為

Transfer Behaviors of PCDD/Fs in the Multiphases Environment by the Fugacity Approach

陳子畇(Tzu-Yun Chen)

指導教授 ： 林傑

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00174

摘要

人類文明的進步，相對的提升人們對人類活動產生的環境污染物質之關注。這類人造化學物質中最被環境科學家重視的毒性指標污染物在過去十年中戴奧辛及呋喃化合物最具代表性。戴奧辛類化合物為非極性、親脂性和化學穩定性高的物質，其中含有毒性強度的多寡和苯環上氯鍵結的位置有關，210種同類物中以17種在2,3,7,8位置被氯取代之戴奧辛及呋喃化合物毒性較高亦成為環境法規標準中採用定量毒性之依據。戴奧辛類化合物主要可能之排放類別可分為燃燒來源、金屬熔煉和精煉流程、化學製造業、自然排放源及其他環境區域。透過大氣的傳輸、擴散和沉降可轉移至土壤、水體和底泥中。本研究藉由蒐集鄉村型垃圾焚化爐周遭空氣中的戴奧辛類化合物濃度分佈和其他研究相互比較，特別比較不同排放源周遭大氣樣品濃度之差異及同構物特徵剖面。排放源包含都會型垃圾焚化爐和煉鋼工業專區，並和環境背景濃度相互比較濃度之差異和同構物之特徵剖面。逸壓概念利用熱平衡原理取代化學潛勢之運算已被化工製程大量應用於實務設計上。利用逸壓原理可方便計算環境中之化學物質是否達到平衡態和其於不同環境介質中之分佈，藉由數學模式運算定量描述擴散和傳輸行為介於環境不同相中，如空氣、水、土壤等。本研究利用Fugacity模式Level Ⅲ 評估排放源之重要性，將模式模擬結果和實測排放源周界空氣採樣加以比對。結果顯示，排放源之周界大氣實測濃度介於1.0~4.9 pg/m3，經由煙道廢氣高低濃度輸入後之周界大氣模擬濃度值介於0.8~48.8 pg/m3，周界土壤之實測濃度介於62.2~218 pg/g，經由模式評估計算之土壤模擬濃度值介於7.0~475.7 pg/g，屬於相同範疇。但戴奧辛類化合物同構物剖面卻顯示不同之高氯數化合物消長，這些數據之比較和觀察對於未來戴奧辛類化合物之指紋比對可提供參考，但更多污染源數據之蒐集如露天燃燒等和模式中引用之環境參數敏感度分析更需要未來之研究。

關鍵字

戴奧辛 ； 逸壓模式 ； 多重相性環境介質 ； 傳輸行為

並列摘要

Since the development of civilization, there has been growing concern about contamination of the environment by the anthropogenic chemicals. The most important category compound which draws a lot of attention by the environmental scientists are Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during the past decade. These toxic compounds are nonpolar, lipophilic, and chemically stable. Their toxicity varies considerably depending on the exact positions of the chlorine atoms on the rings. Of the 210 possible PCDD/F congeners, only 17, the 2,3,7,8-substituted congeners, are known to be highly toxic and have been assigned toxic equivalence factors by the regulatory emissions standard. The dominant and identified sources of environmental releases are group into broad categories: combustion sources, metals smelting, refining and process sources, chemical manufacturing sources, natural sources, and environmental reservoirs. Atmospheric transport and deposition are responsible for the ubiquitous presence of PCDD/Fs in soil, water, sediment, and air. This study is to collect the concentrations and profiles of atmospheric PCDD/Fs around the MSWI and compare the results with peer investigations. Of particular interest is comparison among the MSWI site, the steel plant expected to be a source region and the urban/rural sites representing the regional background. The concept of fugacity, which was introduced as a more convenient thermodynamics equilibrium criterion then chemical potential, has been widely used in chemical process calculation. Its convenience in environmental chemical equilibrium or partitioning calculations has become apparent. It transpires that fugacity is also a convenient quantity for describing mathematically the rates at which chemical diffuse, or are transported, between environmental phases, such as air water, and soil. The ambient concentrations of PCDD/Fs ranged from 1.0 to 4.9 pg/m3 and the soil concentrations of PCDD/Fs ranged from 62.2 to 218.8 pg/g, respectively. To evaluate the relative importance of the emission sources to explain prevailing air concentrations, this study run a Level III fugacity model, results of the model yielded estimated air concentration in the 0.8~48.8 pg/m3 range and the concentration of surface soil is 7.0~475.7 pg/g. In the case, The Level III fugacity model indicated that estimated air concentrations in the range similar to prevailing air concentrations the field investigation measured. However, these crude estimations should be used with caution since, according to the congeners profiles by the Level III model predictions is different far from the measured data. These observations suggest that a continued effort is need to asses the release of other potential emission sources and the sensitivity of the environmental parameters applied to the fugacity model.

並列關鍵字

PCDD/Fs ； Fugacity Model ； Multiphases Environmental Medium ； Transfer Behaviors

參考文獻

李俊賢，詹長權，王榮德，1999，「從戴奧辛毒性談台灣醫療事業廢棄物焚化處理」，中華衛誌，第18卷，第237-240頁。

Adrian, M. C., and Paul. T. W., 2006, “Influence of temperature on PCDD/PCDF desorption from waste incineration flyash under nitrogen” Chemosphere, Vol. 66, pp. 1146-1152.

Adrian, M. C., and Paul. T. W., 2007, “Desorption of PCDD/Fs from municipal solid waste incinerator flyash under post-combustion plant conditions, ” Chemosphere, Vol. 68, pp. 1723-1732.

Alcock, R. E., and Jones, K. C., 1996, “Dioxins in the Environment: a Review of Trend Data,” Environmental Science ＆ Technology Vol. 30, pp. 3133-3143.

Dickson, L. C., Lenoir, D. and Hutzinger, O. 1989, “Surface-catalyzed Formation of Chlorinated Dibenzodioxins and Dibenzofurans during Incineration,” Chemosphere, Vol. 19, pp. 277-282.