公路两侧土壤中重金属有效态分析及污染源识别

Analysis on Available Contents and Pollution Source Recognition of Heavy Metals in the Soil along the Highway

[目的]研究公路两侧土壤中重金属有效态及其主要污染源。[方法]以经过四平贯穿东北的102和303国道两侧的农用土壤为研究对象,研究了土壤中危害较大的重金属Pb、Zn、Cd、Cr的有效态浸提方法,初次采用变异系数识别法通过计算垂向和轴向重金属元素总量的变异系数,识别土壤中该重金属元素主要污染源,并采用污染指数法评价了土壤污染现状。[结果]公路两侧土壤中Zn、Cr的有效态测定适合采用混酸浸提法,Pb、Cd采用单酸和混酸浸提方法均可;研究区域土壤中Zn、Pb、Cr重金属元素的污染水平较低,而Cd含量严重超标,施用化肥等农业活动是主要污染源。[结论]该研究为交通枢纽型城市的土壤保护、评价、土壤污染源控制提供依据。

[Objective] The aim was to study available contents and pollution source recognition of heavy metals in the soil along the highway.[Method] The farming soil along two sides of highway of across section of the No.102 and No.303 in Siping City was viewed as research objects.The available extract methods of heavy metals contents such as Pb,Zn,Cd and Cr were studied.At first,the Coefficient Variation（Cv） was put forward by calculation total contents of heavy metals of perpendicular and horizontal direction along the highway,and the major pollution source of heavy metals were determined by Cv method.The soil pollution condition was evaluated by the pollution index of the heavy metals.[Results] The contents of Zn and Cr of the soil were distilled by mixed acid leaching state,and Pb and Cd were distilled by monomer acid and mixed acid leaching state.The pollution levels of Zn,Pb and Cr were lower,but the Cd content in the area soil seriously exceeded standard.The source of pollution resulted from farming activity such as usage of fertilizer.[Conclusion] The study provided basis for soil protection,evaluation,pollution sources control of communication-hub type cities.