城市表土磁学特征对污染源的指示

Magnetic Characteristics of Urban Topsoil and the Implications on Pollution Origins

分析徐州市城市表层土壤样品的磁学参数(磁化率、频率磁化率、饱和等温剩磁、非磁滞剩磁磁化率、热磁曲线和磁滞回线)变化特征,结果表明,徐州城市表土主要由单畴(SD)和多畴(MD)的亚铁磁性矿物控制,但也存在一定量的赤铁矿。人类活动导致徐州城市表土磁化率显著增加,交通区、居民区、绿地区的平均磁化率分别为:273.06×10^(-8)、111.02×10^(-8)和65.24×10^(-8)m^3/kg。交通运输是市中心交通区和居民区表土磁化率增加的主要来源,工业区附近道路表土中磁性矿物浓度大于远离工业区的交通道路和居民区,绿地区磁性矿物浓度较低。

A set of environmental magnetic parameters such as χ,χfd%,SIRM,χARM,χ-T curves and hysteresis loop of Xuzhou urban topsoil samples were analyzed.Results indicated that the main magnetic minerals in the samples were multi-domain/single domain magnetite with some hematite.Human activity increased the magnetic susceptibility of urban topsoil.The mean magnetic susceptibility of traffic area,residential area and green area were 273.06×10^-8,111.02×10^-8 and 65.24×10^-8m^3/kg,respectively. Traffic had main contribution to magnetic susceptibility enhancement of the road and residential area.Magnetic mineral concentration near the industrial area was higher than other areas. Green area had lower magnetic susceptibility.