台中地區交通污染源懸浮微粒總PAHs濃度及乾沉降日夜間變化之探討

Evaluation of the Particles, Total PAHs during Day and Night Period in the Traffic Area of Taichung, Taiwan

方國權(Guor-Cheng Fang) ； 張鎮南(Cheng-Nan Chang) ； 張冠甫(Kuan-Foo Chang)

《弘光學報》 31期 (1998/04) Pp. 167-182

https://doi.org/10.6615/HAR.199804.31.08

摘要

本研究在台中市忠明國小的屋頂進行對總懸浮微粒、總PAHs之濃度的採樣及量測。採樣點的高度為一層樓高約（4公尺）。懸浮微粒粒徑分佈累積曲線之結果顯示，不論是白天或晚上在風速高的時候在粗微粒的部份會佔較大的比例。在總PAHs方面，在粒徑小於1μm的部份白天和夜晚分別佔了佔了63.8％及54.5%，同時在粒徑小於2.5μm時白天和夜晚則分別佔了83.9％及71.2%。這數據顯示，不論在白天或黑夜總PAHs較容易會和細微粒（＜2.5μm）結合在一起。在總PARs的組成方面在白天會有四個較大的高峰分別為從0.056到3.2μm其相對的PAHs組成濃度為從3274到5962μg/g（平均5265μg/g)。在晚上的部份則是有兩個較大的高峰，分別為0.056~0.31μm及0.31~100μm。總PAHs會和細微粒結合的原因為污染物的排放為一次污染物。在預測乾沈降通量的部份估計/實測值之比值在白天及晚上分別為從0.23到1.28和從0.095到1.40。至於總PAHs方面估計值/實測值之比值針對2~7環之PARs在白天分別為0.058,0.265,3.269,2.928,3.407及0.658。而在晚上則為0.026,0.372,0.547,0.823,1.369及7.672。

並列摘要

The total suspended particle, total polycyclic aromatic hydrocarbons (PAHs) concentration were sampled and measured on the roof of Chung-Ming Elementary School. The sampling site is one store high (about 4 m). The accumulative fraction phenomena explained that coarse particles occupied large portions of total particle mass for the day and night period at high wind speed. The accumulative fraction of total PAHs were 63.8 and 54.5% for particle size less than 1 pm in the day and night time. respectively. And were 83.9 and 71.2% for particle size less than 2.5 pm in the day and night time, separately. The data Showed that the total PAHs were tend to associate in the fine particle mode (＜ 2.5 μm) during day and night time. In the ambient air, during the day time the major peak in particle size distribution for total PAH content is found in a peak size range between 0.056 and 3.2 pm, with PAH concentrations ranging from 3274 to 5962 μg/g (average 5262 μg/g). There were two particle size distribution modes (particle size ranged between 0.056~0.31 μm and, 0.3l~100 μm) for the total PAHs contents for the day and night. The fine particle mode was attributed to primary emissions from combustion sources, whereas the second was attributed to the accumulation of secondary reaction products on primary aerosol particles. The average estimated / measured dry deposition mass flux varied between 0.23 and 1.28 and between 0.095 and 1.40 in the day and night time, respectively. The ratios of estimate / measured of PAHs dry deposition flux which were divided into benzene rings were 0.058, 0.265, 3.269, 2.928, 3.407 and 0.658 for 2~7 rings of PAHs in the daytime, respectively. And were 0.026, 0.372, 0.547, 0.823, 1.369 and 7.672 for rings of PAHs in the night time, respectively. This is because the 2 rings of PAHs were mainly existed in the gas phase. However, dry deposition is contributed by the coarse particle phase thus caused the underestimation of the dry deposition for both day and night period.

參考文獻

Eisenreich, S. J., Looney, B. B. and Thornton, L. D. (1981) Airbon organic contaminants in the Great Lakes ecosystem, environmental Science and technology 15, 30-38.

Jones P. W. and Leber P. (1980) Polynuclear Aromatic Hydrocarbons: 3rd Int. Symp. on Chemistry and Biology Carcinogenesis and Mutagenesis. Ann Arbor Science, Michigan.

Benner B. A., Gordon G. E. and Wise S. A. (1989) Mobile sources of atmospheric polycyclic aromatic hydrocarbons: a roadway tunnel study. Environmental Science and Technology 23, 1269-1277.

Wen-Jhy Lee, Chun-Ching Su, Hwey-Lin Sheu, Yi-Chin Fans, How-Ron Chao, and Guor-Cheng Fang " Monitoring and Modeling of PCB Dry Deposition in Urban Area " Vol. 49, pp. 57-88 (1996) Journal of Hazardous Materials.

Shui-Jen Chen, Shi-Hu Liao, Wei-Jain Jiao, Shui-Chi Chiu and Guor-Cheng Fang "Particle-bound Composition of Polycyclic Aromatic Hydrocarbons and Aerosol Carbons in the Ambient Air" A32(3), 585-604 (1997) Journal of Environmental Science and Health PART A-Environmental Science and Engineering.