利用植物監測及淨化大氣微粒污染之研究

Abstract

本研究於2007年4月至6月間，利用無破壞性之沖洗秤重法，在無遮蔽環境與有遮蔽環境分別測試8種與7種常見樹種葉表之滯塵能力，結果顯示正榕、竹柏以及杜鵑有較高的滯塵量。 在有遮蔽環境的實驗中，對7種樹種之葉表日滯塵量以及環保署古亭觀測站提供之PM10濃度進行相關係數分析，發現其範圍在0.4~0.6之間，顯示有遮蔽環境下葉表之每日滯塵量與環境PM10濃度間呈現高度正相關性。此一結果顯示葉表滯塵量可為大氣PM10之另一指標，此應可提供吾等一種較便宜且深入鄉下之微粒汙染監測方式。 利用一長寬高3.5 X 2.4 X 2.3 m之空曠室內空間測試植物與空氣清淨生態箱(105 X 45 X 60 cm)對室內微粒污染之淨污，結果顯示葉面乾燥的植物會增加室內微粒濃度，葉面噴濕後則對微粒有淨污效果，而加裝了活性炭與濾棉之空氣清淨生態箱，淨污能力最為顯著，而在其內部擺設室內植物對微粒淨污並無更進一步之影響。 在2007年4月4日沙塵暴襲台後，於台北市台大校園及長興街一帶對26種受汙染植物進行採樣，並藉由上光源暗視野顯微鏡進行沙塵暴微粒之鏡檢鑑定，結果顯示黃金榕、桂花、血桐、鵝掌藤、茅草、桑樹、珊瑚刺桐、喜樹、番石榴及馬拉巴栗之葉表滯塵量顯著高於平時對照組者，相反地梅花和春不老則於平時之滯塵量顯著高於受沙塵暴汙染者，顯示採樣時應考慮背景值高低之問題。

By the means of the non-destructive leaf-washing method, we measured the dust deposition by plant of 7 and 8 tree species, under shelter and without shelter, respectively. The measurements were conducted from April to June, 2007 at Taipei. Results showed that generally Nagi Podocarp, Indian Laurel Fig and Rhododendron have highest dust deposition in Taipei area. Deposition data with trees under shelter showed significantly high correlation with ambient PM10 data of Gu-Ting monitoring station by Taiwan EPA (Environmental Protection Administration). The correlation coefficients ranged from 0.4 to 0.6, indicated the positive correlations between the daily dust deposition and PM10 pollution. This result provides us a different approach to measure the particulate pollution in a cheaper way and in a wider area. In an empty room, with space of 3.5 X 2.4 X 2.3 m, we measured the particulate-cleaning efficacyby a canopy of 12 pots of indoor plant and an air-cleaning ecosystem tank with size of 105 X 45 X 60 cm (Sentai Technology Co., Ltd.). Results showed that canopy with dry leaf surface may increase the indoor particulate concentration, while plants with wet surface can reduce particulate concentration. The air-cleaning ecosystem tank equipped with activated carbon and fiber filters showed the significant efficacy in particulate cleaning. However, deployment of 6 pots of plants inside the air-cleaning ecosystem tank did not show additional effect on particulate cleaning. On April 4, 2007 there was a severe sand storm attacking Taiwan. After that, we collected leaf samples of 26 plant species in campus of NTU and along Chang-Hsing St., Taipei. By the means of a top-illumination dark field microscopy, we measured and compared the dust storm deposition on leaf surfaces. Results showed that Golden chinese banyan, Osmanthus, Macaranga, Scandent schefflera, Lalang grass, Taiwan mulberry, Coral bean tree, Common camptotheca, Guava and Malabar chestnut have significantly higher deposition of dust storm particulate than normal time. For Plum blossom and Ceylon ardisia, however, they did not have higher deposition of sand particles. This result suggests that the background dust particulate on the leaves should be considered when doing the comparison.