應用主動式綠牆減少室內甲醛、二氧化碳和懸浮微粒

甲醛、二氧化碳(carbon dioxide, CO2)和懸浮微粒(particulate matter, PM)為已開發國家中室內主要的汙染物質，前人研究已指出應用植物可以減少室內甲醛、CO2和PM。本研究以木心板或線香作為上述物染物釋放來源，將植物與主動式綠牆模組(Active living wall modules, ALW modules)置於密閉薰氣箱中，探討過高的CO2是否會減少植物吸收甲醛，並測試外加風速對於常見十種室內植物降低甲醛、CO2和PM的影響。另利用掃描式電子顯微鏡(scanning electron microscope, SEM)測試綠牆植物葉片沉降PM之能力。將火鶴花‘粉冠軍’、彩虹竹蕉與白鶴芋‘Petite’分別置於密閉薰氣箱(0.128 m3)，內含會釋放甲醛之木心板，以不同光強度(0、60或120 μmol·m-2·s-1)與500 或1200 ppm CO2濃度處理，探討對其吸收CO2與甲醛能力的影響。結果顯示參試植物在黑暗環境中，無論是否外加CO2處理，薰氣箱於試驗3小時間CO2濃度皆因暗呼吸而提高。參試植物於60 或120 μmol·m-2·s-1光強度環境，以1200 ppm CO2處理者在試驗3小時中薰氣箱內之CO2濃度下降率皆大於500 ppm CO2處理者。不論參試之光度與 CO2濃度，彩虹竹蕉的淨光合作用與氣孔導度皆最低而細胞間隙CO2濃度最高。參試植物於黑暗環境下仍可少量移除木心板釋放之甲醛，但移除量比照光環境下低。隨光強度增加使氣孔導度提高，吸收更多甲醛並提高淨光合作用速率。單位葉面積所移除的甲醛濃度之排序為火鶴花>白鶴芋>彩虹竹蕉。提高CO2濃度由500至1200 ppm使參試植物移除甲醛能力下降。另將ALW modules (長29 cm × 寬22 cm × 高50 cm) 與白鶴芋‘Petite’置於薰氣箱中，測試外加三種風速(0.2、0.4和0.6 m·s-1)對白鶴芋‘Petite’降低薰氣箱中燃燒線香所釋放之甲醛、CO2和PM。結果顯示白鶴芋‘Petite’以外加0.6 m·s-1風速有最高之氣孔導度、淨光合作用速率以及蒸散作用速率，並最快降低薰氣箱內甲醛、CO2和PM的濃度。將ALW modules與十種常見室內植物置入密閉薰氣箱(0.225 m3)，探討0或0.6 m·s-1風速處理對降低薰氣箱中燃燒線香之甲醛、CO2和PM之影響。結果顯示外加0.6 m·s-1風速之ALW modules可以較快降低薰氣箱內汙染物，且十種植物變化趨勢類似，其中以袖珍椰子和中班吊蘭之單位葉面積移除較多甲醛和CO2濃度。另以SEM檢測植物單位葉面積累積PM之能力與葉表特徵之關係，結果顯示葉表溝槽比例以及氣孔面積和葉片累積PM之能力呈正相關，其中以葉表溝槽比例較高( > 15%)之心葉蔓綠絨、粗肋草‘白馬’、白鶴芋‘Petite’和袖珍椰子之單位葉面積累積較多PM。進而將有波士頓腎蕨與袖珍椰子各4盆之ALW modules (長57 cm × 寬22 cm × 高67 cm) 與市售空氣清淨機，分別置入燃燒線香之密閉薰氣箱(1.4 m3)，測試6小時後之結果顯示:以0.6 m·s-1風速之ALW modules比參試空氣清淨機減少更多甲醛(62.9% vs 40.4% - 55.2%)與CO2 (12.5% vs -1.5% - 3.6%)。ALW modules沉降PM之效率低於參試空氣清淨機，但可沉降89.9%的PM10和68.4%的PM2.5。另定植黃金葛、薜荔、越橘葉蔓榕和爬牆虎四種藤蔓植物於長槽(76 cm ×18 cm ×14 cm)中共16盆，每植物各四重複，且每盆種植4株，並倚靠於牆，每隔二週調查其覆蓋面積，並分別於秋季、冬季與春季取剛完全展開葉，進行SEM葉片累積PM能力與葉表形態特徵之分析。結果顯示於2018/5 - 2019/5月共12個月生長期間，薜荔的覆蓋面積最廣達約8000 cm2，且其每mm2葉片分別可累積3100 - 6300個PM10。參試之四種藤蔓植物的葉表溝槽比例和葉片累積PM之能力呈正相關。

關鍵字

主動式綠牆；甲醛；二氧化碳；懸浮微粒；藤蔓植物

並列摘要

The most common indoor air pollutants are formaldehyde, carbon dioxide (CO2) and particulate matter (PM) in developed countries. Potted plants can remove various indoor air pollutants. In this study, we placed plant materials and active living wall modules (ALW modules) in airtight chambers, and the above mentioned air pollutants were produced by a fresh wooden board or burning incense. We determined whether high CO2 concentrations result in stomatal closure and thus might reduce formaldehyde uptake by plants. Also, the study determined the efficiency of ALW modules with various wind speeds and common ten indoor plant species on removal of air pollutants. Besides, the relationship between leaf surface characteristics and PM accumulated capacity was shown by SEM observations. Anthurium andraeanum Linden. ‘Pink Champion’, Dracaena marginata Lam. ‘Tricolor Rainbow’ and Spathiphyllum kochii Engler & Krause ‘Petite’ were placed respectively in airtight chambers, each with a fresh wooden board that releases formaldehyde. The experiment was constructed under three light intensities (0, 60 or 120 μmol·m-2·s-1) and two CO2 concentrations (500 or 1200 ppm) for three hours. Results show that CO2 concentration in the chamber all increased for plants at dark. Chamber CO2 decreased more rapidly with 1200 ppm CO2 than 500 ppm CO2 for plants under 60 or 120 μmol·m-2·s-1. D. marginata Lam. ‘Tricolor Rainbow’ exhibited the lowest net photosynthetic rate (Pn), stomatal conductance (Gs) and highest intercellular CO2 concentration (Ci). Increased light intensity resulted in increased Gs, which led to reduce more formaldehyde concentration in the chamber. The efficiency of removing formaldehyde per leaf area ranked as follows; Anthurium > Spathiphyllum > Dracaena. Plants with 500 ppm CO2 reduced more formaldehyde in the chamber, as compared with those with 1200 ppm CO2. Efficiency of Spathiphyllum kochii Engler & Krause ‘Petite’ in ALW modules (29 cm × 22 cm × 50 cm) with various wind speeds (0.2, 0.4, or 0.6 m·s-1) was compared on removal of air pollutants by burning incense in an airtight chamber (1.4 m3). Results show that plants in ALW modules with 0.6 m·s-1 wind speed had the highest Pn, Gs, and transpiration rate, and reduced most formaldehyde, CO2, and PM in the chamber. Efficiency of ten indoor plants in ALW modules with two wind speeds (0 or 0.6 m·s-1) was compared to reduce air pollutants by burning incense in an airtight chamber (0.225 m3). Results indicate that plants in ALW modules at 0.6 m·s-1 wind speed reduced air pollutants more efficiently than those without wind supply. Opened stomatal area and leaf surface groove were positively correlated to PM10 accumulation on leaf as observed with scanning electron microscope (SEM). More PM10 accumulated on leaves with high leaf groove proportion ( >15%) in Philodendron scandens subsp. Oxycardium (Schott) G. S., Aglaonema commutatum Schott ex Engl. ‘White Tip’, S. kochii Engler & Krause ‘Petite’ and Chlorophytum comosum (Thunb.) Bak. ‘Vittatum’. Efficiency of reducing air pollutants from burning incense in the chamber was compared between the combination ALW modules (57 cm × 22 cm × 67 cm) with total eight Nephrolepis exaltata L. (Schott) ‘Bostoniensis’ and Chamaedorea elegans Mart. and commercial air purifiers. Results show that ALW modules reduced more formaldehyde (62.9% vs 40.4% - 55.2%) and CO2 (12.5% vs -1.5% - 3.6%) after six hours, as compared with commercial air purifiers. PM10 and PM2.5 were reduced by 89.9% and 68.4% by the ALW modules, respectively. Epipremnum aureum (Linden &Andr) G.S. Bunting, Ficus pumila L., Ficus vaccinioides Hemsl. ex King and Parthenocissus tricuspidata (Sieb et Zucc.) Planch. were planted in 16 pots (76 cm ×18 cm ×14 cm), four replicates per plant species, and 4 plants per pot, and placed against the wall. Their covering area was measured every two weeks. Recently developed leaves were sampled during autumn, winter, and spring, respectively to measure PM amount by SEM method. Results show that, after 12 months, F. pumila L. had the highest cover surface area about 8000 cm2 on the wall, and 3100 - 6300 PM10 per mm2 accumulated on leaf. Leaf surface groove proportion was positively related to PM quantity accumulated on leaf.