植物叶片对不同粒径颗粒物的吸附效果研究

The Ability of Plant Leaves on Depositing Size-fractionated Particles

在中国北方雾霾天气日益严重的今天,植物通过吸附大气中的颗粒物进而减缓颗粒物污染情况。为研究植物叶片对不同粒径颗粒物的吸附能力,通过对同一区域内的城市道路和校园绿地上的大叶黄杨(Buxus megistophylla)、洋白蜡(Fraxinus pennsylvanica)和毛白杨(Populus tomentosa)进行研究,测定其叶表面和蜡质层对大气中粒径为10~100、2.5~10和0.2~2.5μm的颗粒物的单位叶面积吸附量。研究结果表明:不同植物叶片吸附颗粒物能力差异显著,3种植物中大叶黄杨吸附颗粒物的能力最强,毛白杨与洋白蜡吸附颗粒物的能力相近,洋白蜡叶表面易到达最大饱和滞尘量;道路上的植物叶片吸附颗粒物总量高于校园内的植物,两者滞尘量的差异主要体现在吸附10~100μm粒径的颗粒物上,局地环境会影响叶片滞尘量;不同植物叶片对10~100、2.5~10和0.2~2.5μm粒径的颗粒物吸附百分含量分别在75.4%、15.8%和8.9%左右,植物种类对叶片表面吸附不同颗粒物所占比例无影响;大叶黄杨在道路上吸附颗粒物总量最大,为139.86μg·cm^(-2),它的蜡质层和叶表面对不同粒径颗粒物吸附量均最高,能够有效降低城市中的大气颗粒物,是优良的城市绿化树种。

Nowadays, particulate pollution is increasingly serious in the north of China. Plants can through the accumulation ofatmospheric PM （particulate matter） and slow down the PM pollution situation. In order to study the ability of plant leaves onaccumulating different size-fractionated particles, three common green plants （Buxus megistophylla,Fraxinus pennsylvanica andPopulus tomentosa） on urban roads and green space were selected as test materials. This paper measured the leaf surfaces and inwaxes of three species capture large （10~100 μm）, coarse （2.5~10 μm） and fine （0.2~2.5 μm） particles from air. The results showedthat the quantity of accumulating particles on leaf surface and in wax layer differed significantly between the species. Buxusmegistophylla captured the most PM among the species. The abilities on accumulating particles of Fraxinus pennsylvanica andPopulus tomentosa were similarly. Fraxinus pennsylvanica was easily to reach saturation value. The total amount of PMaccumulation on leaves differed in different places. Plants on urban roads accumulated more PM than the green space. The differencemainly reflected in the accumulation of large （10~100 μm） particles. The percentage of large （10~100 μm）, coarse（2.5~10 μm）andfine （0.2~2.5 μm） particle depositions on different species are about 75.4%, 15.8% and 8.9%. Buxus megistophylla showed high totalPM accumulation on leaves （ 139.86 μg·cm-2）. Its leaf surface and wax layer can accumulate amount of different size of particulatematter. As a shrub near the ground which impact wind speed slightly, Buxus megistophylla is a good choice for landscaping.