黄河兰州段、白银段重金属污染的磁学指标初探

Feasibility study of using magnetic parameters as indicator of heavy metals in water and sediment of Yellow River in Lanzhou and Baiyin

对黄河兰州段、白银段的水样及沉积物样进行了环境磁学研究,并对部分样品进行了重金属含量分析。结果表明,污水的输入对河水的磁化率产生影响,且磁化率变化因污染源而异;亚铁磁性矿物主导了沉积物的磁性特征。重金属含量与磁参数的相关性均不显著,但在黄河白银段东大沟以下河段,重金属含量与非磁滞剩磁(ARM)、ARM/SIRM(SIRM为饱和等温剩磁)、频率磁化率(χfd%)等磁参数有同步增强趋势,可能与细磁性晶粒对重金属的吸附作用有关。综合分析磁参数与重金属含量变化发现,河水χfd%和ARM/SIRM可作为衡量部分重金属污染程度的参数。

This study was conducted to determine the feasibility of using magnetic parameters as indicators of heavy metals present in water and sediment of Yellow River in Lanzhou and Baiyin sections. Numerous water and sediments samples were taken from Lanzhou and Baiyin sections of Yellow River and polluted Wanchuan River. Susceptibility was measured for the water samples; susceptibility, anhysteretic remnant magnetization （ARM） and isothermal remnant magnetization fIRM） were measured for the sediment samples. The river water susceptibility was affected by the heavy metal loadings and the flow pattern of discharges into the river. Although the data do not show strong correlations between magnetic parameters and heavy metal contents, they do suggest that such magnetic parameters as Zfd% and ARM/SIRM of the sediments may be employed as indicators of heavy metal pollution in Lanzhou and Baiyin.