宝鸡市街尘重金属元素含量、来源及形态特征  

Content,Source and Speciation of Heavy Metal Elements of Street Dusts in Baoji City

作　　者：王利军[1] 卢新卫[1] 雷凯[1] 翟雨翔[1] 黄静[1] 

机构地区：[1]陕西师范大学旅游与环境学院,西安710062

出　　处：《环境科学》2011年第8期2470-2476,共7页Environmental Science

基　　金：教育部新世纪优秀人才支持计划项目(NCET-05-0861);陕西师范大学青年基金项目

摘　　要：利用XRF和AAS研究了宝鸡市街尘中重金属元素的含量水平.结果表明,街尘中Cu、Pb、Zn、Mn、Co、Ni、Cr和Cd的平均含量分别是123.2、408.4、715.1、804.2、15.9、48.8、126.7和5.5μg.g-1,均高于世界、中国、陕西省土壤元素背景值,其中Cu、Pb、Zn和Cd超标最为突出.利用相关分析、主成分分析、聚类分析等多元统计方法解析了宝鸡市街尘中重金属元素的来源,结果表明,Ni和Cr是自然来源(当地土壤),Cu、Pb、Mn和Co是人为(交通和工业)和自然(当地土壤)的混合来源;Zn和Cd是人为来源(交通来源和工业来源).同时,利用修正的BCR连续提取技术,借助ICP-MS研究了宝鸡市街尘中重金属元素的形态特征,结果表明,街尘中Mn、Co、Ni和Cr主要以残余态形式存在(48.52%以上),Zn和Cd主要以乙酸可提取态形式存在(44.43%和44.08%),Cu主要以可氧化态和残余态形式存在(48.22%和37.65%),Pb主要以可还原态形式存在(45.42%),重金属元素的迁移顺序是Cd(90.11%)>Pb(82.33%)>Zn(79.32%)>Cu(62.35%)>Mn(51.48%)>Co(29.02%)>Ni(23.62%)>Cr(18.68%),其中Cd、Pb、Zn、Cu和Mn有50%以上可以发生迁移,易被生物利用,危害较大.Heavy metal concentrations in street dust of Baoji City were investigated by using X-Ray fluorescence spectrometry（XRF） and atomic adsorption spectrometry（AAS）.The results show that the mean concentrations of Cu,Pb,Zn,Mn,Co,Ni,Cr and Cd are 123.2,408.4,715.1,804.2,15.9,48.8,126.7 and 5.5 μg·g-1,respectively,which are higher than those of the element background values of International,Chinese,and Shaanxi Soil,especially for Cu,Pb,Zn and Cd.The source of heavy metal elements in street dust of Baoji City was identifed by multivariate statistics analysis（correlation analysis,principal component analysis and cluster analysis）,and the results show that Ni and Cr mainly originate from natural source（local soil）;Cu,Pb,Mn and Co have mixed sources of human activities（industry and traffic） and nature（local soil）;Zn and Cd represent traffic and industry sources.At the same time,the speciation characteristics of heavy metals in street dust of Baoji City were investigated by using the modified BCR sequential extraction procedure and ICP-MS.The results show that Mn,Co,Ni and Cr are dominated by residue（over 48.52%）,Zn and Cd mainly exist in acetic acid extractable part（44.43% and 44.08%）,Cu is rich in oxidizable（48.22%） and residual（37.65%） parts,Pb is mainly in reducible part（45.42%）.The order of mobility of heavy metal elements is Cd（90.11%） Pb（82.33%） Zn（79.32%） Cu（62.35%） Mn（51.48%） Co（29.02%） Ni（23.62%） Cr（18.68%）,in which of them,Cd,Pb,Zn,Cu and Mn have stronger transformation（over 50%） and higher potential harm.

关 键 词：街尘 重金属元素 来源 形态 宝鸡市 

分 类 号：X53[环境科学与工程—环境工程]