人工降雨對四種微粒在植物葉表淋洗效率之比較

Rinsing Efficiencies of Four Particles on Plant Leaves by Man-Made Rain Droplets

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

《環境保護》 27卷2期 (2004/12) Pp. 232-241

https://doi.org/10.30017/EP.200412.0007

摘要

以四種空氣污染微粒，包括塵土、水泥、燃煤飛灰及燃油飛灰，在均勻分佈設計下，分別沈降在七種植物，包括正榕(Ficus microcarpa L.)、艷紫荊(Liquidambar formosana Hance)、樟樹(Cinnamomum camphora(L.) Sieb.)、白千層(Melaleuca leucadendron L.)、杜鵑(Rhododendron spp.)、鵝掌藤(Scheffera arboricola Hayata)及月橘(Murraya paniculata (L.) Jack)等之葉表，經顯微鏡觀測洗前顆粒數，再移入人工降雨系統進行淋洗。研究發現當葉片以15°傾斜角經降雨1 mm淋洗後，塵土微粒殘留率以白千層40.8%為最高，艷紫荊9.3%最低；水泥微粒以白千層、樟樹、月橘、正榕及杜鵑最高，其範圍為32.5%~42.0%；燃煤飛灰微粒之殘留率普遍高於塵土及水泥微粒者，且以白千層、正榕、月橘、杜鵑及樟樹最高，其範圍為60.0%~69.5%；燃油飛灰微粒之殘留率更比燃煤者為高，且以杜鵑92.2%為最高，原因應該是燃油飛灰微粒含有油性性質所致。這些結果顯示葉表的滯塵及淋洗能力會因微粒種類及植物種類之不同而有差異，即不同微粒在不同葉表的殘留率並非相同，模擬降雨1 mm之雨量普遍不易淋洗葉表上之污染微粒。

關鍵字

微粒 ； 模擬降雨 ； 沉降率 ； 滯塵能力

並列摘要

The leaves of seven tree species, including Ficus microcarpa L., Liquidambar formosana Hance, Cinnamomum camphora (L.) Sieb., Melaleuca leucadendron L., Rhododendron spp. , Scheffera arboricola Hayata and Murraya paniculata (L.) Jack., were uniformly deposited with four kinds of particles, including soil dust, cement dust, coal-fired fly ash, and oil-fired fly ash. They were then rinsed with 1 mm artificial rain at 15° inclination angle. The rinsing efficiencies were determined after the rinsing and compared with each other. Studies found that Melaleuca leucadendron had the highest rinsing residual rate of 40.8% against the soil dust particles. While Liquidambar formosana had the lowest rate of 9.3%. For cement, Melaleuca leucadendron, Cinnamomum camphora, Murraya paniculata, and Ficus microcarpa had the higher rinsing residual rates, ranging from 32.5% to 42%. Generally the rinsing residual rates of coalfired fly ash were higher than those of soil dust and cement dust. The residual rates of coal-fired fly ash on Melaleuca leucadendron, Ficus microcarpa, Murraya paniculata, Rhododendron sp., and Cinnamomum camphora were higher, ranging from 60.0% to 69.5%. The rinsing residual rates for oil-fired fly ash were, however, the highest, among these four kinds of particles. The azalea (Rhododendron spp.) had the highest rate of 92.2%. This can be explained by the oily characteristics of the oil-fired particles and that 1 mm of precipitation was not enough to remove most kinds of particles on plant leaves.

並列關鍵字

Particle ； Simulated rain ； Deposition rate ； Dustcatching efficiency