城市不同功能区内叶面尘与地表灰尘的粒径和重金属特征  

The characteristic of particulate size and heavy metal in foliar dust and surface dust from different urban areas

作　　者：庞博[1] 张银龙[1] 王丹[1] 

机构地区：[1]南京林业大学森林资源与环境学院//江苏省林业生态工程重点实验室,江苏南京210037

出　　处：《生态环境学报》2009年第4期1312-1317,共6页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(30771710);江苏省林业生态工程重点实验室开放性研究课题(FEE0701)

摘　　要：在城市粉尘污染研究中,叶面尘与地表灰尘被认为是新的切入点。以南京市不同功能区为例,分别收集了各功能区典型绿化树种的叶面尘与同区域的地表灰尘,采用激光粒径分析仪测定了叶面尘与地表灰尘的粒径分布规律,应用ICP-AES对样品重金属含量进行了测定,并以此为基础,对重金属的生态风险进行了评价,最后分析了叶面尘与地表灰尘所含重金属元素之间的相关性。结果表明,叶面尘与地表灰尘中颗粒物粒径集中分布于100μm以内,两者粒径累积曲线均呈现正态单峰分布,其中商业区和工业区颗粒物粒径较小。不同功能区重金属含量差异显著,污染水平递减顺序为:商业区、工业区、交通枢纽区、街道复层绿化区、科教生活区。潜在生态危害评价表明,叶面尘的生态危害大于地表灰尘,除科教生活区外,叶面尘在其余四个功能区均产生中等生态危害。重金属Pearson相关分析发现,叶面尘与地表灰尘存在相似来源,即主要来自交通排放、工业污染等人为源。粒径与重金属两方面的研究指示出南京市粉尘污染最严重的是商业区与工业区,这为进一步控制城市粉尘污染提供了有力依据。Foliar dusts and surface dusts are reckoned as the two aspects mostly feature the situation of unban dust pollution. Taking five different urban areas with typical trees in Nanjing as plots, where foliar dusts of and surface dusts were collected. The particulate size of foliar dusts and surface dusts were determined with a Laser Particle Sizer, the total concentrations of heavy metals in dusts were determined with ICP-AES, on which the potential risk of heavy metals was evaluated, and then the correlation of various heavy metals was analyzed. Results showed that the size of most foliar dusts and surface dusts was less than 100pro, the size accumulation curve of dusts obeyed the normal distribution with single-apices, while particulate size of dusts in commercial area and industrial area were finer than other areas. The concentration of heavy metals decreased in this order： commercial area, industrial area, traffic hub area, street multi-layer greening area, educational and residential area, and the difference was significant. Potential ecological risk assessment showed that ecological risk of foliar dusts was more serious than surface dusts, and besides educational and residen- tial area, foliar dusts in other areas have all reached the medium risk level. Pearson correlation analysis indicated that foliar dusts and surface dusts had similar sources such as industrial pollution, vehicle emission and other anthropogenic sources. According to the research on particulate size and heavy metals, it could be concluded that the dust pollution of commercial and industrial areas in Nanjing is at alarming risk, which shows controlling the unban dust pollution is in badly need.

关 键 词：叶面尘 地表灰尘 粒径 重金属 

分 类 号：X173[环境科学与工程—环境科学]