兰州市交通干道土壤重金属污染及其对植物的影响

发布时间：2019-06-02 20:35

【摘要】：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CuPbCrZn,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.
[Abstract]:In order to study the heavy metal pollution caused by soil and greening plants on the opposite side of highway operation, two main traffic roads in Lanzhou City, North Binhe Road and Anning East and West Road, were selected to Cr,Cu,Zn,Pb,Mn, in the soil and greening plant leaves beside the highway. The distribution characteristics and potential ecological risks of Ni,Fe,Ca and other elements were analyzed. The results showed that the heavy metal w (Cr), w (Pb), w (Zn), w (Cu), w (Mn) in the soil on the side of the highway was significantly higher than that in the park and university campus far from the main road, but there was no significant difference in w (Ni). The pollution degree of heavy metals in soil caused by traffic operation is that CuPbCrZn,Mn,Ni does not reach the pollution level. The w (Cr), w (Pb), w (Zn), w (Cu) in the soil on the side of the road is significantly higher than that in other sampling points when there are traffic jams, many bends, frequent brakes and large traffic flow on the same road. It is shown that the emission of motor vehicle exhaust, the dust produced by friction between automobile parts and tire and road surface are the main reasons for the pollution of these four kinds of heavy metals in the soil on the side of the road. More Pb,Zn,Mn, accumulated in the leaves of Populus tomentosa, which survived in soil with low mass fraction of heavy metals, indicating that the roots of Populus tomentosa have a strong ability to absorb these three heavy metals and transport them to the above ground parts. The accumulation of Pb,Zn,Mn in the leaves of plants living in the heavy metal soil of Anning East-West Road was the highest, and the accumulation of Ca in the leaves of most plants on Anning East-West Road was significantly higher than that of most greening plants on North Binhe Road.
【作者单位】：西北师范大学生命科学学院;
【基金】：甘肃省科技支撑计划项目(144FKCA059) 兰州市科技计划项目(2011-1-142)
【分类号】：X173;X53

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