乌鲁木齐城市表土重金属污染的环境磁学记录

Magnetic records of heavy metals pollution in urban topsoil of Urumqi City

通过对乌鲁木齐市85件表土磁性特征和重金属质量分数的分析,探讨了乌鲁木齐市土壤的磁性特征及其对重金属污染的响应.结果表明:乌鲁木齐城市表土样品的磁性特征以低矫顽力亚铁磁性矿物为主导,磁化率值远高于背景值;磁化率值>300×10^(-8)m^3/kg的范围与PLI>2的圈定范围基本一致,显示磁化率对于圈定城市表土重金属污染范围具有独特的优势.由于工业污染与交通污染的差异性,在运用磁化率对综合性城市的土壤重金属污染进行监测时,应首先对不同的功能区进行必要的区分,建立针对不同类型污染的磁化率评价指标体系.

A systematic analysis of the magnetic characteristics and heavy metal elements was made of soil samples collected from Urumqi, Xinjiang. 85 surface soil samples were measured to study the feasibility and effectiveness of environmental magnetism for evaluating heavy metal pollution in urban soils and the results showed that low-coercivity magnetite dominated the magnetic properties in the samples and the values of magnetic susceptibility were much higher than the background values. The areas of magnetic susceptibility 〉300×10-8m3/kg were fundamentally consistent with the distribution of PLI 〉 2, indicating that environmental magnetic technology can be an effective method in determining the bounds and levels of pollution. It is necessary to distinguish functional types first and then establish an evaluation index system of magnetic susceptibility when the mag- netism method is used to estimate the degrees of pollution of topsoils in urban areas due to the significant difference between industrial and traffic pollution.