上海城市表土磁性特征对重金属污染的指示作用  

Magnetic property of urban topsoil and its implication of heavy metal pollution in Shanghai

作　　者：王冠[1] 陈裕颖 夏敦胜[2] 任非凡[3] 方爱冬 马丽娟 WANG Guan;CHEN Yuying;XIA Dunsheng;REN Feifan;FANG Aidong;MA Lijuan(Department of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093;Key Laboratory of the West Enviromnental System,Lanzhou University,Lanzhou 730000;Key Laboratory of Geoteehnieal and Underground Engineering of the Ninistry of Education,Tongji University,Shanghai 200092)

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]兰州大学西部环境教育部重点实验室,兰州730000 [3]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《环境科学学报》2018年第8期3302-3312,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41001331);上海市自然科学基金(No.15ZR1428700)~~

摘　　要：选取上海市城市表土作为研究对象,结合磁学方法与传统化学方法,研究了上海市192件表土样品的磁性特征和重金属含量,并探讨了磁学参数指示重金属污染的可行性.结果表明,上海市表土磁化率平均值为187.66×10^(-8)m^3·kg^(-1),亚铁磁性矿物占主导地位,颗粒较粗.上海市表土重金属Zn、Pb、Cu、Cr、Ni、Mn、Fe含量均超过背景值,属于轻度污染.重金属和磁学参数(磁化率、饱和等温剩磁)具有相似的空间分布,高值集中在宝山区和闵行区,低值集中在崇明区.工业生产和交通活动是上海市表土重金属、磁性矿物的主要来源.磁化率χlf指示污染负荷指数的半定量结果为:χlf<38.90×10^(-8)m^3·kg^(-1)时,土壤属于清洁状态,无污染;38.90×10^(-8)m^3·kg^(-1)≤χlf<258.69×10^(-8)m^3·kg^(-1)时,土壤遭受轻度污染;258.69×10^(-8)m^3·kg^(-1)≤χlf<793.45×10^(-8)m^3·kg^(-1)时,土壤遭受中度污染;χlf≥793.45×10^(-8)m^3·kg^(-1)时,土壤遭受重度污染.因此,磁学参数对城市表土重金属污染有着一定的指示意义.In this study,we combined magnetic and traditional chemical methods to study the magnetic characteristics and heavy metal concentrations of 192 topsoil samples in Shanghai and explored the feasibility of using magnetic parameters to indicate heavy metal pollution. The results show that the average magnetic susceptibility of topsoil in Shanghai is 187.66×10-8 m3·kg-1. Coarse ferrimagnetic minerals dominate magnetic properties of the samples.The contents of Zn,Pb,Cu,Cr,Ni,Mn and Fe exceed the background value,suggesting that Shanghai topsoil is slightly polluted. Heavy metals and magnetic parameters（ magnetic susceptibility and saturation isothermal remanent magnetization） have similar spatial distribution,with the higher values occured in the Baoshan and Minhang District,and lower values in the Chongming District. Industrial and traffic activities are the main sources of heavy metals and magnetic minerals of topsoil in Shanghai city. Semi-quantitative analysis enables that magnetic susceptibility can be used as an indicator of PLI,with the following category defined： χlf〈38.90×10-8 m3·kg-1,no pollution; 38.90×10-8 m3·kg-1≤χlf〈258.69×10-8 m3·kg-1,slight pollution; 258.69×10-8 m3·kg-1≤χlf〈793.45×10-8 m3·kg-1,moderate pollution; χlf≥793.45×10-8 m3·kg-1,heavy pollution. Our study show that magnetic parameters of topsoil can be indicative of heavy metal pollution in urban environment.

关 键 词：上海市 表土 磁学参数 重金属 污染负荷指数(PLI) 

分 类 号：X53[环境科学与工程—环境工程]