Studies On Abilities Of Community Plant Foliage In Retention Of Atmospheric Particulate Matters

PM, the so-called particulate matter, is generic terms of all kinds of particulate matters in atmospheric environment. Particulate matter can be divided in colloidal dispersion system (aerodynamic equivalent diameter>10μm) and Coarse particle dispersion system (aerodynamic equivalent diameter between0.001-10μm) by aerodynamic equivalent diameter. In China recently, air environmental pollution caused by particulate matter, namely haze weather, has created serious damage in production, livelihood and physical fitness of population. In this paper, we focus on scattered plants in resident community in Beijing and Chongqing, and do research on ability in retention of particulate matters which dispersed in air environment of these plants. Main research results as follow:1We used retention mass of all kinds of particulate matter per square meter as a standard On this account, we established and optimized the measuring methods on the mass of all kinds of particulate matter in different size (coarse particle, PM10, PM2.5) in air environment accurately. We abandoned the obsolete pattern of measuring small size particulate matter with the methods of nylon membrane filters and suction filtration. We got more accurate results and patent of this method has been declared, and this kind of technology can provide a foundation of research methods in pollution control by plants.2In this research, we picked24scattered plants in community in Beijing and Chongqing during12months. We gathered fresh plant foliage in72hours after the last rain for experimental measurement every20days. And researchers found that in Beijing City community, Pinus tabulaeformis, Platycladus orientalis, Catalpa speciosa, Malus micromalus and Euonymus japnoicus show the better ability on retention of particulate matter which size is greater than10μm, and the highest value reached to0.6062g per square meter foliage in Malus micromalus. In research on retention of particulate matter which size is ranged from10μm to2.5μm, the results indicated that Pinus tabulaeformis, Syzygium aromaticum, Ginkgo biloba show the better ability and the highest value reached to0.0362g per square meter foliage in Pinus tabulaeformis. After the research of scattered plants in Chongqing community, the results indicated that, Ficus microcarpa, Osmanthus fargrans show the better ability on retention of particulate matter which size is greater than10μm, and the highest value reached to2.9143g per square meter. And Magnolia grandiflora, Pittosporum tobira show the better ability on retention of particulate matter which size is ranged from10μm to2.5μm, the highest value reached to0.0085g per square meter foliage.3We did the deeper research on retention of particulate matter which size less than2.5μm behind experiment we have noted. We selected some kind of plants which have different abilities on retention of larger particulate matter into this research. And between Pinus tabulaeformis, Platycladus orientalis, Euonymus japnoicus, Ficus microcarpa, Bambusa multiplex, Osmanthus fargrans and Pittosporum tobira, we found Pinus tabulaeformis, Ficus microcarpa, Osmanthus fargrans show the better ability on retention of this size of particulate matter, and the highest value reached to0.9319g per square meter foliage in Pinus tabulaeformis.4Environment scanning electron microscope (ESEM) had been used on plants mentioned in previous section. The results show that plants have good ability in retention particulate matters can secrete emplastic, and there are many stomas and trench structures. This characteristic makes contribute to ability of plants in retention of particulate matters. In northern of China, evergreen species like Platycladus orientalis, Pinus tabulaeformis, Euonymus japnoicus have a longer life cycle, and compared to deciduous species, the ability about retention of particulate matters can be used in a longer term.5The research have a profound, lasting meaning, and application of the results is widely used. On the condition of haze is becoming more and more serious every day, the achievement of research can be turned into a guidance standard of selecting and growing plants in community. And a good influence can be happened on healthy maintain of population. At last, we made a help to the study of air pollution abatement by plants.