金川矿区表土金属空间污染特征及磁学响应

采集金川铜镍矿区及周边表层土壤样品26个，基于环境磁学方法对样品开展了金属元素（Cu、Ni、Cr、Fe、Sr、Ti、Pb和Mn）的含量分析及相关分析，采用单因子污染指数和内梅罗污染指数评价方法对研究区域表土金属污染状况进行评价.研究区域表土磁学特征与金属元素含量呈明显空间分布差异，体现为：矿区源地 > 加工区域 > 繁忙路段 > 门岗区域 > 其他区域；受Cu和Ni元素污染的土壤样品为重度污染，Cr、Pb、Ti、Sr等金属为轻度污染和中度污染；χ_lf、SIRM、χ_ARM和HIRM数值相对较高，表明研究区域亚铁磁性矿物含量较高；研究区表层土壤样品磁晶粒度特征以较粗的假单畴（PSD）和多畴（MD）颗粒为主导；相关分析结果表明Cu、Ni、Cr、Fe、Pb和Mn元素之间皆存在较好的相关性，其中Cu、Ni显著（R=0.91）；χ_lf和SIRM、χ_ARM与各金属的相关性较为突出（0.52≤R≤0.78），表明磁参数可有效监测城市表土重金属污染状况，快速圈定重金属污染的区域与范围，为城市表土污染监测工作提供快速有效的数据支持.

Spatial pollution characteristics and magnetic response of surface soil heavy metals in Jinchuan mining area

26surface soil samples were collected from the Jinchuan mine area. Environmental magnetism and heavy metal element (Cu, Ni, Cr, Fe, Sr, Ti, Pb and Mn) content analysis were related analysis on the samples, and carried out by using single factor pollution index and Nemero pollution index evaluation methods to evaluate the heavy metal pollution degree. The magnetic characteristics of the surface soil and the content of heavy metal elements showed obvious spatial distribution differences:mine area> outer processing area> high traffic section> gate area> other areas. The samples were contaminated up to100% by Cu and Ni, showing the high levels of pollution. While metal pollution of Cr, Pb, Ti, and Sr was between the warning line and moderate pollution. Then, the values of χ_l、SIRM、χ_ARM and HIRM were relatively high, indicating that the content of magnetic mineral particles was extremely high, and the magnetic particles were dominated by ferrimagnetic mineral types. The magnetic grain size characteristics of the surface soil samples were dominated by coarser pseudo-monodomain (PSD) and multi-domain (MD) particles. Correlation analysis results were shown that there was an excellent correlation between Cu、Ni、Cr、Fe、Pb and Mn, especially, the correlation of Cu、Ni was excellent (R=0.91) among them. χ_lf, SIRM, and χ_ARM had an excellent correlation with various metals(0.52≤R≤0.78), it showed that the heavy metal pollution of urban surface soil was effectively monitored by magnetic parameters, quickly delineating the area and scope of heavy metal pollution, and providing rapid and effective data support for urban surface soil pollution monitoring.