| 连霍高速郑商段路旁土壤重金属积累及潜在风险 |
| 摘要点击 2579 全文点击 1153 投稿时间：2008-03-15 修订日期：2008-06-16 |
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| 中文关键词 连霍高速 路旁土壤 重金属积累 重金属潜在污染风险 |
| 英文关键词 Lianyungang-Huoerguosi highway roadside soils heavy metal accumulation potential risk of heavy metal |
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| 中文摘要 |
| 以连霍高速郑商段不同通车时间的湾刘（通车11 a）和小王庄断面（通车4 a）为研究对象，根据距离公路远近不同布设土壤采样点，用原子吸收分光光度法测定土壤Cd、Cu、Pb、Zn、Ni和Cr含量.在计算表层土壤重金属积累速率和通量的基础上，探讨了路旁土壤重金属的分布特征、积累状况及潜在污染风险.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.湾刘断面土壤Pb、Cd、Cu的平均含量分别为14.52、 1.32、 73.54 mg·kg-1，小王庄断面分别为12.41、 0.98、 43.64 mg·kg-1.大部分样点Pb、Cu和Cd的积累速率和通量为正值，且Cu>Pb>Cd，小王庄断面大于湾刘断面. 2个断面土壤Cd已经发生污染；Cu的潜在污染风险在百年时间尺度之内，大部分样点在未来5～30 a中可能发生污染，潜在风险大；Pb的潜在污染风险都在千年尺度以上，潜在风险极小. |
| 英文摘要 |
| Two typical sampling transects along the Zhengzhou-Shangqiu section，Lianyungang-Huoerguosi highway，were chosen to investigate the accumulation of heavy metals in roadside soils.The highway section at Wanliu transect has been operated since 1994，and that at Xiaowangzhuang section since 2001. Soil samples were collected along the two transects according to the distances from the highway.In laboratory，the concentrations of Cd，Cu，Pb，Zn，Ni and Cr in the soils were measured using AAS.The accumulation of these metals in roadside soils is analyzed in terms of annual accumulation rates and fluxes.The spatial patterns and potential risk of the metals are also discussed.There are several findings in this case study.Along the two transects，the concentrations of Cd，Cu and Pb in the soils increase from the highway first，and then decrease to the control values gradually.So they are typical traffic-source (anthropogenic) heavy metals.In contrast，Cr，Ni and Zn are nature-source metals.The highest concentrations of the anthropogenic metals in the soils occur between 25-50 m from the highway.The average values of concentration of Pb，Cu and Cd in the soils along Wanliu transect are 14.52 mg·kg-1，1.32 mg·kg-1，and 73.54 mg·kg-1 respectively，and 12.41 mg·kg-1，0.98 mg·kg-1，and 43.64 mg·kg-1 along Xiaowangzhuang transect respectively.The annual accumulation rates and fluxes of Pb，Cu and Cd in most samples are positive，Cu>Pb>Cd，and the values on Xiaowangzhuang transect are higher than those on Wanliu transect.Potential risk of Cd in all sample are negative，indicating that the soils have been polluted by Cd.In contrast，potential risk of Cu and Pb in most sample sites are positive，but the potential risk of Cu in the soils is much higher than that of Pb.Most sample sites within 300 m from the highway should be polluted by Cu in the future of five to thirty years，but polluted by Pb in the future of many more than one thousand years. |
