磁化率对城郊耕地土壤重金属污染的指示研究——以许昌市为例

Research on Magnetic Susceptibility as the Indicator for Heavy Metal Polutions of Chinese Cities——A Case Study of Xuchang City

为探讨磁化率对土壤重金属污染的指示作用,利用磁化率仪和X射线荧光光谱仪对许昌市的城郊耕地土壤样品磁化率和重金属含量进行定量分析。结果显示,许昌城郊耕地土壤磁化率为35×10^(-8)~126×10^(-8)m^3/kg,平均值为94×10^(-8)m^3/kg,频率磁化率变化范围在4.7%~11.6%之间,平均值为7.9%。土壤中Pb、Cu、Zn、Cr含量分别为18.35~53.29、18.66~43.86、55.88~169.81和60.28~82.13μg/g,平均值分别超过背景值1.31、1.23、1.41、1.11倍。磁化率与Pb和Cu呈显著正相关,与Zn和Cr相关性不显著,表明磁化率可以指示Pb和Cu含量。土壤的污染负荷指数为0.95~2.03,平均值为1.24,表明许昌城郊耕地土壤重金属污染主要为中度污染水平,土壤磁化率与重金属污染负荷指数呈显著正相关,磁化率可以指示土壤重金属污染水平。

Magnetic susceptibility and heavy metals concentration in cultivated soil from suburbs of Xuchang City, China were analyzed. Results show that magnetic susceptibility varies in the range of 35×10^-8 - 126×10^-8 m3/kg, with an average of 94×10^-8 m3/kg, and frequency magnetic susceptibility ranges 4.7% - 11.6%, with the average value of 7.9%. Concentrations of Pb, Cu, Zn, and Cr are 18.35-53.29, 18.66-43.86, 55.88-169.81, and 60.28-82.13μg/g, with average values exceeding the background values of 1.31, 1.23, 1.41, 1. 11 times, respectively. Pollution load index is in the range of 0. 95-2.03, with an average of 1.24, indicating that heavy metals in the soil from Xuchang City mainly reach moderate pollution level. Magnetic susceptibility is significantly correlated with Pb and Cu, and not significant correlated with Zn and Cr. A significant positive correlation between magnetic susceptibility and heavy metal pollution load index suggests that magnetic susceptibility can indicate heavy metal pollution of the soil.