常見台北地區植物乾濕葉片與枝條滯塵效率的比較研究

Evaluation of Dust Deposition Rates on Dry and Wet Leaves and Stems of Common Trees in Taipei

蔡志明(Chih-Ming Tsai) ； 孫岩章(En-Jang Sun) ； 王亞男(Ya-Nan Wang)

《環境保護》 28卷1期 (2005/06) Pp. 39-52

https://doi.org/10.30017/EP.200506.0004

摘要

本研究設計揚塵器與揚塵箱，利用人工揚塵箱測試13種常見植物葉片對塵土微粒之滯塵效率，並探討葉片噴濕後對塵土及水泥微粒滯塵率是否明顯增加。另測試6種樹木枝條對塵土及水泥微粒之滯塵率，比較各種處理結果之差異性。
結果顯示13種常見植物中以龍柏乾葉片對塵土滯塵率為最高，而褔木為最低。試驗中可得知葉面積小的植物其塵土滯塵量較葉面積大者為高，另發現在固定風向條件下懸浮微粒會依慣性作用而積聚葉緣地方；而5種植物經噴濕後葉片滯塵量皆比乾燥葉片者為大，其倍率範圍為1.2~2.5倍，葉片經噴濕後不易乾燥者如白千層則具有較大的滯塵量。
對6種樹木枝條的滯塵測試結果皆以噴濕枝條對水泥微粒之滯塵率為最大，且發現塵土或水泥微粒皆傾向於累積在枝條迎風面。各種噴濕枝條的滯塵量皆比乾燥者增多，其中塵土之倍率範圍為1.1~3.4倍，而水泥微粒之倍率範圍為1.9~5.2倍。枝條經噴濕後不易乾燥者如正榕及楓香則會具有較大的滯塵量，此種現象與葉片者相同，而且微粒因慣性作用在植物的沈積分佈亦可作為環境中微粒監測之參考依據。

關鍵字

微粒 ； 塵土 ； 水泥灰 ； 沉降率 ； 揚塵器

並列摘要

A dust generator and an exposure chamber were designed to evaluate the dust deposition rates on common tree species at Taipei. Leaves of 13 tree species were exposed in this chamber to soil dust and cement dust. Five of them were determined for their dust deposition rates after completely spayed with water.
Stems from six species with diameter of ca. 0.5~1.5 cm were also tested for their dust deposition rates with and without spraying with water. Results showed that among 13 tree species the dragon juniper (Juniperus chinensis) had the highest dust deposition rates on their leaves. While the common garcinia (Garcinia subelliptica) had the least. Generally the trees with smaller leaf area had higher dust deposition rates per unit area. The dust particles tended to deposit onto leaf marginal portion for broad leaves. The wet leaves of all five species generally had higher dust deposition rates than the dry ones. The ratios of the deposition rate between wet and dry leaves ranged from 1.2 to 2.5. We found that those leaves not easy to be dry by win d had higher dust deposition rates after spaying with water.
The tests of tree stems from six species with soil and cement dust showed that cements dust had the highest dust deposition rates on wet stems for all species. All soil and cement dust particles tended to deposit on windward side of each stems. All wet stems had higher deposition rates than dry stems with ratios of soil particle ranging from 1.1 to 3.4 and cement particles from 1.9 to 5.2. Generally the stems not easy to be dry by win g had higher ratios, such as Indian laurel fig (Ficus microcarpa) and Formosan sweet gum (Liquidambar formosana). The deposition pattern on leaves and stems had to be considered when people want to use surface particle counting as a biomonitoring tool in the field.

並列關鍵字

Particle ； Soil dust ； Cement dust ； Deposition rate ； Dust generator