北京大兴6种常见绿化树种吸附PM_(2.5)能力研究

Study on Adsorption Ability of PM_(2.5) about Six Common Landscape Plants in Daxing District, Beijing

该文以北京大兴南海子公园6种常见园林绿化树种为研究对象,应用气溶胶再发生器对植物叶片PM_(2.5)吸附量进行了定量研究,分析了叶表面微形态特征。结果表明:单位叶面积PM_(2.5)吸附量油松和白皮松最大,其次为柳树、五角枫,杨树和银杏最小,且针叶树种PM_(2.5)吸附能力强于阔叶树种;不同树种单位叶面积PM_(2.5)吸附量均值:4月在(0.008±0.002)^(0.053±0.008)μg/cm2之间、5月在(0.010±0.001)^(0.067±0.017)μg/cm2之间、6月在(0.014±0.001)^(0.328±0.073)μg/cm2之间,从不同月份看,表现为6月(0.093±0.124)μg/cm2>5月(0.031±0.023)μg/cm2>4月(0.027±0.019)μg/cm2;油松、白皮松叶表面凹凸不平,粗糙度较大,且气孔密集,开度较大,从而致使其吸附PM_(2.5)能力最强;而杨树、银杏、五角枫叶表面光滑,气孔较少,颗粒物不易附着,且因蜡质的疏水特性,对植物表面具有一定的清洁作用,其吸附PM_(2.5)能力较弱;此外,叶表面存在绒毛有利于植物叶片吸附PM_(2.5)等颗粒物。因此,在绿化造林时可优先考虑种植叶表面粗糙、有绒毛存在的针叶树种,将更有利于PM_(2.5)等颗粒物的吸收,从而提高植物的环保效益。

This paper studied the adsorbing capacity of PM_（2.5）about six common landscape plants in Daxing District, Beijing with aerosol generator for analyzing superficial micromorphology of leaves. Results showed that PM_（2.5）adsorbing capacity with unit leaf area of Pinus tabulaeformis and Pinus bungeana were bigger than the others, followed by Salix babylonica and Acer elegantulum, and Populus L. and Ginkgo biloba as the minimum. PM_（2.5）adsorbing capacity of coniferous species was stronger than that of deciduous species. Average values of PM_（2.5）adsorbing capacity with different tree species respectively were 0.008 ±0.002 μg/cm2 to 0.053±0.008 μg/cm2 in April, 0.010±0.001 μg/cm2 to 0.067±0.017 μg/cm2 in May and 0.014±0.001 μg/cm2 to 0.328±0.073 μg/cm2 in June, with average values of PM_（2.5）adsorbing capacity in different months presented as June（0.093 ±0.124 μg/cm2） 〉May（0.031±0.023 μg/cm2）〉 April（0.027±0.019 μg/cm2）. The leaf surface of Pinus tabulaeformis and Pinus bungeana were not smooth, and stomas were dense with fine apertures, leading to the strongest adsorption ability of PM_（2.5）.The leaf surface of Acer elegantulum, Ginkgo biloba and Populus L. were smooth with few stomas, so that the particulate matters were hard to stay on the leaf surface, and hydrophobic properties of the wax could weep particulate matters, leading to PM_（2.5）adsorption ability of them were weaker, moreover, tomentum was beneficial to adsorb PM_（2.5）. It should give priority to consider planting coniferous species which are good for adsorbing PM_（2.5）, improving the environmental benefit of plants.