The Difference and Reason of the Correlation Between Magnetic Susceptibility and Cu,Cd in the Beach Topsoil of Xiaojiang River
The correlation between magnetic susceptibility and heavy metal elements is the premise of using magnetic susceptibility to evaluate regional heavy metal pollution.By measuring the magnetic susceptibility and Cu,Cd elements of 30 beach topsoil samples in Xiaojiang River Valley,Dongchuan,it was found that the average value of magnetic susceptibility(low frequency)of the beach topsoil was 218.46×10-8 m3/kg,and the percentage of frequency magnetic susceptibility was 0.87％.The average contents of Cu and Cd were 130.86 mg/kg and 0.18 mg/kg,respectively.The magnetic susceptibility was positively correlated with the content of Cu and Cd at P＜0.01 level,but the correlation between magnetic susceptibility and Cu(R=0.624)was significantly higher than that of Cd(R=0.495).X-ray diffraction identification and electron microscopy observation show that the main magnetic material of the surface soil of the river beach(the material that contributes mainly to the magnetic susceptibility of the surface soil)is multi-domain magnetite with a particle size of 10～200 μm.The results of Cu and Cd elements in magnetic materials showed that the average content of Cu in magnetic materials was 420.95 mg/kg,which was more than three times higher than the average value of the surface soil samples,the average content of Cd was 0.16 mg/kg,which was lower than the average value of the topsoil samples.The results show that there is a homologous(associated)emission relationship between magnetic materials and Cu,but the probability of such relationship with Cd is low,which may be the main reason why the correlation between magnetic susceptibility and Cu is higher than that of Cd.
magnetic susceptibilitymagnetic carriermagnetic monitoringCu and Cd element
万方数据
维普
