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为了研究公路运营对路侧土壤和绿化植物造成的重金属污染状况,选取兰州市的两条交通干道北滨河路和安宁东西路,对公路旁土壤和绿化植物叶片中Cr、Cu、Zn、Pb、Mn、Ni、Fe、Ca等元素的分布特征及其潜在的生态风险进行分析.结果表明:公路路侧土壤重金属w(Cr)、w(Pb)、w(Zn)、w(Cu)、w(Mn)明显高于远离交通主干道的公园和大学校园,而w(Ni)无明显差异,交通运营造成的土壤重金属污染程度表现为Cu>Pb>Cr>Zn,Mn、Ni未达到污染水平;同一条公路的车辆拥堵、弯道多、十字路口等刹车频繁及车流量大的路段,路侧土壤中w(Cr)、w(Pb)、w(Zn)、w(Cu)明显高于其他采样点,表明机动车尾气的排放、汽车机件间摩擦和轮胎与路面间摩擦产生的粉尘是造成路侧土壤这4种重金属污染的主要原因;低质量分数重金属土壤中生存的大叶黄杨叶片积累了较多的Pb、Zn、Mn,说明大叶黄杨的根系对这3种重金属的吸收及向地上部分转运的能力强;安宁东西路高质量分数重金属土壤中生存的植物叶片Pb、Zn、Mn的积累量最高;安宁东西路的大多数植物叶片中积累的Ca量明显高于北滨河路的大多数绿化植物.
In order to study the heavy metal pollution caused by highway operation on roadside soil and green plants, we selected two main traffic roads, Beibinhe Road and Anning East Road, in Lanzhou City to study the effects of Cr, Cu, Zn, Pb, Mn, Ni, Fe, Ca and so on, and the potential ecological risks were analyzed.The results showed that the contents of heavy metals w (Cr), w (Pb), w (Zn), w (Mn) was significantly higher than that of parks and university campuses far away from the traffic main road, while w (Ni) showed no obvious difference. The heavy metal pollution caused by traffic operation was Cu> Pb> Cr> Zn, Mn and Ni did not reach the pollution level (Cr), w (Pb), w (Zn), w (Cu) in the roadside soil were significantly higher than those in the same road due to traffic congestion, cornering, intersections, Other sampling points indicate that the emission of motor vehicle exhaust, the friction between automobile parts and the friction between tire and road surface are the main causes of the four heavy metal pollution on roadside soil. The low mass fraction of Euonymus japonicus The leaves accumulated more Pb, Zn, Mn, indicating that the roots of Euonymus japonica on this The absorption of three heavy metals and their ability to transport to the aboveground were strong. The accumulation of Pb, Zn and Mn in plant leaves with high-quality heavy metal content in Anning Road was the highest. The accumulation of Ca in the leaves of most plants in Anning Road Significantly higher than most of the green plants at North Riverside.