Heavy metal pollution in farmland irrigated with river water near a steel plant—magnetic and geochemical signature
Heavy metal pollution in farmland irrigated with river water near a steel plant—magnetic and geochemical signature
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DOI：
10.1093/gji/ggs079
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发表时间：
2013-03
影响因子：
2.8
通讯作者：
Chunxia Zhang;E. Appel;Q. Qiao
中科院分区：
文献类型：
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作者：
Chunxia Zhang;E. Appel;Q. Qiao
环境中的重金属（HMs）是对人类的主要威胁。磁性代用指标为评价环境中重金属污染程度提供了一种快速的方法。以湖南省娄底市某钢铁厂附近受污染河水灌溉的农田土壤为研究对象，探讨了磁法检测重金属污染程度的有效性。磁性和非磁性（微观，化学和统计）的方法来表征这些农田土壤。在耕层上部（0-20 cm），磁浓度值增加，这与10~30 μ m的球形磁铁矿颗粒有关。农田土壤中磁浓度和重金属含量的空间分布与河流沉积物中这些参数的空间格局相匹配。这些结果表明，农田土壤重金属污染主要是由污水灌溉引起的。Zn、Pb、Cu、Cd、Co、Ni、V的HMs与磁化率（χ）有较好的相关性。污染负荷指数（PLI）与log10（χ）呈显著正相关。利用线性PLI − log10（χ）函数，χ值可以作为一个方便的工具，用于半定量研究农田土壤最上层20 cm重金属污染程度。这些研究结果表明，磁性方法通常可以作为一个方便的工具，用于检测和映射重工业活动附近的废水灌溉农田土壤中的HM污染。
The presence of heavy metals (HMs) in the environment is a major threat for humans. Magnetic proxies provide a rapid method for assessing the degree of HM pollution in environment. We have studied farmland soil irrigated with polluted river water in the vicinity of a steel plant in Loudi city (Hunan Province, China) to test the efficiency of magnetic methods for detecting the degree of HM pollution. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these farmland soils. Enhanced magnetic concentration values were found in the upper arable soil horizon (0–20 cm), which is related to the presence of spherical ∼10 to 30 μm sized magnetite particles. The spatial distribution of magnetic concentration and HM contents in the farmland soils matches with the spatial pattern of these parameters in river sediments. These findings provide evidence that HM pollution of the farmland soil is mainly caused by irrigation with wastewater. HMs Zn, Pb, Cu, Cd, Co, Ni, V are well correlate with magnetic susceptibility (χ). The pollution load index (PLI) of all nine anthropogenic HMs (including also Cr and Mo) and log10(χ) are significantly correlated. Using the resulting linear PLI−log10(χ) function, values of χ can serve as a convenient tool for semi-quantifying the degree of HM pollution in the uppermost ∼20 cm of the studied farmland soils. These findings suggest that magnetic methods can generally serve as a convenient tool for detecting and mapping HM pollution in farmland soil irrigated with wastewater from sites nearby heavy industrial activities.