镇江市老城区不同功能区街道灰尘中重金属污染的粒径分布及来源解析

摘要

在镇江市老城区的6个功能区(商业区、交通区、居民区、文教区、江滨公园、大市口)布设采样点,测定了街道灰尘样品中所含的7种重金属的含量,分析了街道灰尘中重金属污染的粒级效应；并基于主成分分析法对重金属的来源进行了解析.结果表明,总体来说,镇江市老城区街道灰尘中的重金属污染显示出明显的粒级效应,随灰尘粒径减小,重金属含量呈明显的递增趋势；镇江市老城区街道灰尘中的重金属来源有:(1)交通污染源,特征元素为Cu、Zn、Pb；(2)生活污染源,特征物质为有机质；(3)工业污染源,特征元素为Ni、Mn、Cr;(4)自然沉降源,即与成土母质的地质背景有关的土壤颗粒的再悬浮或迁移；(5)建筑废弃物及土壤扬尘,或是由几者产生的混合污染.%18 sampling sites were laid in six different functional areas (commercial area, traffic area, residential area, cultural and educational area, Riverside Park and Dashikou) of old town of Zhenjiang to collect the street dust samples. The content of 7 heavy metals in street dust was determined, the granularity effect of contaminated street dust was analyzed and the possible pollution source of heavy metals was investigated by using principal component analysis. The results indicated that the heavy metal pollution of street dust in Zhenjiang old town presented significant granularity effect, that was the content of heavy metals were greatly increased with the decreasing of dust size. The possible pollution sources of heavy metal in street dust were: (1) traffic emission, the feature elements were Cu, Zn and Pb; (2) domestic pollution, the feature elements was organic matter; (3) industrial pollution, the feature elements were Ni, Mn, Cr; (4) the re-suspension and transportation of soil particles which relating to geologic setting of parent material; (5) construction garbage and soil dust or the composite pollution from different source.