Magnetic properties, microstructure and mineralogical phases of technogenic magnetic particles (TMPs) in urban soils: Their source identification and environmental implications.
Magnetic properties, microstructure and mineralogical phases of technogenic magnetic particles (TMPs) in urban soils: Their source identification and environmental implications.
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DOI：
10.1016/j.scitotenv.2015.11.046
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发表时间：
2016-02
期刊：
影响因子：
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通讯作者：
Shenggao Lu;Xiulin Yu;Yuyin Chen
中科院分区：
文献类型：
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作者：
Shenggao Lu;Xiulin Yu;Yuyin Chen
磁测量是确定重金属污染空间分布和污染程度，识别各种重金属人为来源的有效方法。本研究的目的是表征城市土壤中技术磁性颗粒（TMPs）的磁性、微观结构和矿物学阶段，并讨论其潜在的环境影响。中国洛阳市的土壤表层土壤与土壤表层土壤分离。利用矿物磁性测量、扫描电子显微镜、能量色散x射线能谱（SEM/EDS）、x射线衍射和基于同步辐射的微探针研究了TMPs的磁性、形貌和矿物相。城市表层土壤TMPs含量在0.05 ~ 1.95%之间，平均0.32%。磁化率范围为4559 × 10−8 ~ 23661 × 10−8m3kg−1，平均为13637 × 10−8m3kg−1。热磁和体x射线衍射分析表明，tmp的主要磁性矿物为磁铁矿（Fe3O4）和赤铁矿（α-Fe2O3）。扫描电镜观察到的TMPs形貌包括三种形状类型：球状、不规则和聚集颗粒。球形TMPs的尺寸范围为30 ~ 200 μm左右，其中30 ~ 50 μm所占比例最大。基于同步辐射的微探针（μ-XRF和μ-XRD）表明，TMPs中富集了Pb、Cd、Zn、Cu和Cr等重金属，这些重金属以晶格形式存在或吸附在磁铁矿/赤铁矿表面。TMPs含量与Tomlinson污染负荷指数（PLI）呈显著相关（R2= 0.467），可作为城市土壤重金属污染程度的代理指标。TMPs的磁性、微观结构和矿物学相可以作为城市土壤污染源的识别指标。
Magnetic measurement is an effective method to determine spatial distribution and the degree of heavy metal pollution and to identify various anthropogenic sources of heavy metals. The objectives of this investigation are to characterize the magnetic properties, microstructure and mineralogical phases of technogenic magnetic particles (TMPs) in urban soils and to discuss their potential environmental implications. The TMPs are separated from the urban topsoils of Luoyang city, China. The magnetic properties, morphology, and mineral phase of TMPs are studied using mineral magnetic measurement, scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction, and synchrotron–radiation-based microprobe. The content of TMPs in urban topsoils ranges from 0.05 to 1.95% (on average 0.32%). The magnetic susceptibility of TMPs ranges from 4559 × 10− 8to 23,661 × 10− 8m3kg− 1(on average 13,637 × 10− 8m3kg− 1). Thermomagnetic and bulk X-ray diffraction analyses indicate that main magnetic minerals of TMPs are magnetite (Fe3O4) and hematite (α-Fe2O3). The morphology of TMPs observed by SEM includes three shape types: spherule, irregular-shaped, and aggregate particles. The size of spherical TMPs ranges from 30 to about 200 μm, with the largest percentage of 30–50 μm. Synchrotron–radiation-based microprobe (μ-XRF and μ-XRD) indicates that TMPs are enriched with heavy metals Pb, Cd, Zn, Cu, and Cr, which are incorporated into lattice or adsorbed on the surface of magnetite/hematite. The content of TMPs significantly relates with the Tomlinson Pollution Load Index (PLI) (R2= 0.467), suggesting that it can be used as proxy indicator of degree of heavy metal contamination in urban soils. The magnetic properties, microstructure and mineralogical phases of TMPs can serve as the identification of pollution sources in urban soils.