包头某铜厂周边土壤重金属分布特征及来源分析

通过测定包头某铜厂周边4方向不同水平距离及深度处64个土壤样品中Cu、Cd、Pb、Zn、Mn、Cr 6种重金属含量,探讨其空间分布特征及可能来源。结果表明,铜厂周边土壤中6种重金属均已呈现不同程度的富集,其中Cu、Cd、Pb污染普遍且严重,且Cu受人为活动干扰最为强烈。6种重金属含量分布主要取决于其所在位置距铜厂的水平距离和土层深度,其中:0~20 cm表层土壤中重金属含量随水平距离增加呈现先增大后减小的规律,Pb、Cr和Cu、Zn、Mn分别在100 m和300 m处达到峰值;在距铜厂不同水平距离的样品中,各重金属含量均随土层深度增加而减小,但相距50 m处减小缓慢,100 m、300 m处减小迅速。土壤重金属来源解析表明,铜厂周边土壤中Cr、Cd、Cu来自复合污染源,Pb、Zn的外源污染主要来自交通源,Mn主要来自自然源。

Distribution characteristics and source analysis of heavy metals in soil around a copper plant in Baotou, China

Understanding spatial distribution and sources of soil heavy metals is critical to the control and remediation of soil heavy metal pollution. In this investigation, we collected 64 soil samples from 4 directions with different horizontal distances from a copper plant in Baotou, to analyze the spatial distribution characteristics and possible pollution sources of soil heavy metals. Six heavy metals (Cu, Cd, Pb, Zn, Mn, and Cr) were measured. Results showed that these heavy metals had different extents of accumulation in this area. Cu, Pb, and Cd pollution was common and serious due to human activities, with Cu being affected most by human activities. In addition, the distribution of six heavy metals was dependent on horizontal distance away from the copper plant and soil depth. Heavy metal content in surface soil (0 to 20 cm) first increased and then decreased as the horizontal distance increased. The content of Pb, Cr and Cu, Zn, Mn was the highest at 100 m and 300 m from the copper plant, respectively. All six heavy metals decreased with increasing soil depths. However, the rates of such de creases were low at the distance of 50 m, but high at 100 m and 300 m. Source analysis indicated that soil Cr, Cd, and Cu were resulted from compound pollution sources, while Pb and Zn from traffic sources, and Mn from natural sources.