连霍高速郑商段路旁土壤重金属积累初探

Accumulation of Heavy Metals in Roadside Soils along the Section of Zhengzhou-Shangqiu,Lianhuo Highway

以连霍高速郑州—商丘段路旁土壤为研究对象,在野外调查采样和实验室分析的基础上,探讨了公路交通对周围土壤中Ni、Pb、Cr、Cu、Zn和Cd 6种重金属含量与分布的影响,计算了表层土壤的重金属元素积累速率与积累通量。结果表明:Cu、Pb和Cd是典型的交通源重金属,其含量在公路两侧随着距离的增加,呈先增加后减少的趋势,含量峰值出现在离路基25-50 m之间。公路运营时间越长,交通源重金属含量就越高。两断面绝大部分样点Pb、Cu和Cd的积累速率和通量均为正值,且Cu>Pb>Cd,小王庄断面大于湾刘断面,Cu和Pb的通量远远超过国际上正常土壤标准。

Based on the field investigation, sampling and laboratory analysis, this paper discusses how the highway traffic impacts the accumulation and distribution of heavy metals （Ni, Pb, Cr, Zn, Cu and Cd） in its surrounding soils, and calculates the accumulation rates and fluxes of heavy metals in the surface soils, with a case study on the soils of Zhengzhou--Shangqiu section of the Lian-huo expressway. The results indicate that Cu, Pb and Cd are the typical traffic-source heavy metals. With the increase of distance from the highway, the concentration of them first increased and then decreased, the peak content distributing between 25 -50 meters from the roadbed. In addition, the results also show that the longer the traffic has been in operation, the higher concentration of the traffic-source heavy metals have. In most sample points of both Xiaowangzhuang section and Wanliu section, the accumulation rates and fluxes of heavy metals are all positive values, and the volume order is Cu 〉 Pb 〉 Cd. In comparison, the values of the former is bigger than those of the later, however, the fluxes of Cu and Pb are far over the international normal soil standards.