a Beijing Milu Ecological Research Center , Beijing , China.
b School of Geography, Earth and Environmental Sciences , University of Birmingham , Edgbaston , Birmingham , UK.
Int J Phytoremediation. 2019;21(4):334-351. doi: 10.1080/15226514.2018.1524834. Epub 2019 Jan 16.
To provide more insight into the removal ability of urban air dust and associated metals by plant leaves, and thus guide urban green planning to improve air quality, 15 plant species leaves collected from Beijing roadside were analyzed for size fractions of leaf surface dust (SD) and inner wax dust (WD). Seven associated metals Cd, Cr, Cu, Fe, Mn, Pb and Zn were also measured. Metal Accumulation Index (MAI) was calculated for different species leaves at various dust sizes and soluble forms, respectively. Cluster analysis was used for the plant species and correlations between dust and metal concentrations and for inter-metal concentrations were calculated for both surface and inner wax dust. Mean leaf total dust TD (SD + WD), SD and WD were measured as 1159, 817 and 342 mg m, respectively, with the highest values observed all in Euonymus japonicus. Most species leaves collected larger ratios of SD than WD except Salix babylonica and Robinia pseudoacacia. While SD was presented at all particle size fractions for all plants, nearly all species leaves collected higher proportions of WD >10 µm. Mean metal levels of leaf TD of all species ranged from high to low as Fe > Cr > Zn > Pb > Cu > Mn > Cd, but with different orders for individual species. Metals were observed in all sizes of SD/WD, although the size distributions were various for certain metals. Intercorrelations of metal concentrations in leaf SD/WD were positively significant except Pb, which may have different emission sources. Species Prunus cerasifera f. atropurpurea, Syringa oblata, Malus micromalu, Koelreuteria paniculata and Robinia pseudoacacia may possess better overall metal collection ability due to their relatively higher MAI values, but species Euonymus japonicus, Malus micromalu, Ligustrum x vicaryi and Koelreuteria paniculata were identified as the best choices in removing air dust based on cluster analysis and suggested to be planted at heavy trafficked road site for air quality improvement.
为了更深入地了解植物叶片对城市灰尘及相关金属的去除能力，从而指导城市绿化规划以改善空气质量，本研究分析了采集自北京路边的 15 种植物叶片的表面灰尘（SD）和内蜡灰尘（WD）的大小分数。还测量了 7 种相关金属 Cd、Cr、Cu、Fe、Mn、Pb 和 Zn。分别计算了不同物种叶片在不同灰尘大小和可溶性形态下的金属积累指数（MAI）。采用聚类分析对植物物种进行了分类，并计算了灰尘和金属浓度之间的相关性，以及表面和内蜡灰尘中各金属之间的浓度相关性。叶片总灰尘（TD）（SD+WD）、SD 和 WD 的平均值分别为 1159、817 和 342mg m，Euonymus japonicus 的值最高。除了柳树（Salix babylonica）和刺槐（Robinia pseudoacacia）外，大多数采集的植物叶片的 SD 比例都大于 WD。虽然所有植物的 SD 都存在于所有颗粒大小的分数中，但几乎所有采集的植物叶片都收集到更高比例的 WD>10µm。所有植物叶片 TD 的金属平均水平从高到低依次为 Fe>Cr>Zn>Pb>Cu>Mn>Cd，但对于个别物种则有不同的顺序。金属在 SD/WD 的所有大小中都有观察到，尽管某些金属的大小分布有所不同。叶片 SD/WD 中的金属浓度之间的相关性除 Pb 外均呈显著正相关，Pb 可能具有不同的排放源。由于其相对较高的 MAI 值，Prunus cerasifera f. atropurpurea、Syringa oblata、Malus micromalu、Koelreuteria paniculata 和 Robinia pseudoacacia 等物种可能具有更好的整体金属收集能力，但基于聚类分析，Euonymus japonicus、Malus micromalu、Ligustrum x vicaryi 和 Koelreuteria paniculata 等物种被鉴定为去除空气灰尘的最佳选择，并建议在交通繁忙的道路站点种植，以改善空气质量。
