Purpose

Changes in the magnetic phase, magnetic concentration, and/or magnetic grain-sized of dust-bound iron-bearing minerals depend on both lithogenic components and anthropogenic inputs. Knowledge of the magnetic properties of road dusts in various road ecosystems is of paramount importance to control dust pollution for the benefit of the environment and human health.

Methods

The magnetic characteristics of road dusts, collected in the coastal areas of southern Fujian, China, were determined via magnetic measurements, X-ray diffraction analysis, Mössbauer spectroscopy (MS), and scanning electron microscopy with integrated energy-dispersive X-ray spectrometry.

Results

Analyses of the temperature dependence of magnetization, backfield demagnetization, and hysteresis loops suggested that the main magnetic carriers in road dusts were low-coercivity minerals with minimal antiferromagnetic phases derived from anthropognic sources. The coefficients of variation for χLF, SIRM, and χARM were 53.46%, 50.98%, and 58.56%, respectively. Samples with high values of χLF had a high ratio of iron ions in the octahedral B and tetrahedral A sites in magnetite. The most common iron oxides in the dust-bound iron-bearing minerals were non-stoichiometric magnetite, hematite, and possibly metallic iron. Elevated concentrations of trace metals (e.g., Cd, Cr, Co, and V) in the dust-bound iron-bearing minerals partially confirmed the coexistence of magnetic minerals and trace metals in the road dusts.

Conclusions

Analysis of the spatial characteristics of magnetic concentration–related parameters will be useful in accurately documenting and tracking levels of pollution.

中文翻译：

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地面道路扬尘中含铁矿物质的赋存特征：以福建南部沿海地区为例

目的

受粉尘约束的含铁矿物的磁相，磁浓度和/或磁粒度的变化取决于成岩成分和人为输入。了解各种道路生态系统中道路尘埃的磁性对于控制粉尘污染，造福环境和人类健康至关重要。

方法

通过磁测量，X射线衍射分析，穆斯堡尔光谱（MS）以及带集成能量色散X射线光谱仪的扫描电子显微镜，确定了福建南部沿海地区收集的道路扬尘的磁特性。

结果

对磁化，后场退磁和磁滞回线的温度依赖性的分析表明，道路扬尘中的主要磁性载体是低矫顽力矿物，具有最小限度的反铁磁相。χLF，SIRM和χARM的变异系数分别为53.46％，50.98％和58.56％。χLF值高的样品在磁铁矿的八面体B和四面体A位置具有较高的铁离子比例。粉尘结合的含铁矿物中最常见的氧化铁是非化学计量的磁铁矿，赤铁矿，可能还有金属铁。粉尘结合的含铁矿物中痕量金属（例如Cd，Cr，Co和V）的浓度升高，部分证实了道路矿物粉尘中磁性矿物和痕量金属的共存。

结论

磁性浓度相关参数的空间特征分析将有助于准确记录和跟踪污染水平。