洛阳市工业区及郊区土壤的重金属含量分析与评价

Analysis and Evaluation on Concentration of Heavy Metals in Soils of Industrial Area and Suburb Cropland of Luoyang City

通过现场采样及室内分析测试,对洛阳城市工业区及郊区农田表土中重金属(Pb、Zn、Cu、Cr、Fe、Mn)的含量及分布进行了研究。结果表明,洛阳工业区表土中Pb、Zn、Cu、Cr和Fe的含量均高于郊区农用地土壤,Mn的含量稍低于郊区土壤。工业区南北两侧农田的重金属含量分布表明,随着与工业区距离的增加,郊区农田土壤的Pb、Zn、Cu和Cr有下降趋势。以该区重金属自然土壤元素背景值作为评价标准,计算出各采样点土壤的单因子和综合污染指数,计算数据显示,工业区土壤Pb、Zn、Cu和Cr污染严重,郊区农田土壤也受到一定程度的污染。相关分析结果表明,交通和工业排放可能是工业区土壤重金属的主要来源,郊区农田中Pb、Zn、Cu和Cr的来源可能是附近的工业活动造成的污染物颗粒沉降及农业面源污染(如农药、化肥、污灌等)。

The concentration and distribution character of Pb, Zn, Cu, Cr, Fe and Mn in industrial district of Luoyang City was studied preliminarily. The average concentrations of Pb, Zn, Cu, Cr, Fe and Mn in industrial districts were higher than those in suburb cropland, but the concentration of Mn was less than that in suburb cropland. With the increasing of the distance from industrial area, the concentrations of the heavy metals went down. According to the background contents of these elements under the natural soil condition, the status of soil pollution by heavy metals was evaluated by using single factor pollution index （PI） and integrated pollution index （IPI）. The results indicated that not only the soils in industrial area but also the cropland were polluted by Pb, Zn, Cu, and Cr. The main sources of heavy metals in soils of industrial district were industrial pollutant discharge and vehicle emission, while, Pb, Zn, Cu and Cr in suburb cropland mainly attributed to the sedimentation of pollutants caused by industrial production and agricultural pollution, such as pesticides, fertilizer, sewage irrigation, etc.