| 三峡库区澎溪河消落带土壤中重金属形态分布与迁移特征研究 |
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| 引用本文： | 王图锦,潘瑾,刘雪莲.三峡库区澎溪河消落带土壤中重金属形态分布与迁移特征研究[J].岩矿测试,2016,35(4):425-432. |
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| 作者姓名： | 王图锦 潘瑾 刘雪莲 |
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| 作者单位： | 重庆交通大学河海学院, 重庆 400074,重庆交通大学河海学院, 重庆 400074,重庆交通大学河海学院, 重庆 400074 |
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| 基金项目： | 重庆市基础与前沿研究计划项目（cstc2014jcyjA20011） |
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| 摘 要： | 消落带是水域与陆地的过渡地带,对水环境有着至关重要的影响。本文以三峡库区消落带面积最大的澎溪河流域作为研究区域,采集消落带土壤及其沿岸土壤样品,分析重金属形态分布特征,并使用地质累积指数法和风险评价准则(RAC)对重金属污染程度及生态风险进行评价。研究表明,消落带土壤中Pb、Cu、Cr、Cd、Zn和Ni平均含量分别为68.70、36.96、55.10、0.68、108.26、31.68 mg/kg,污染程度依次为CdPbZnCuNiCr,以Cd和Pb污染较为突出,普遍高于长江干流土壤,远高于重庆地区土壤。Cd的RAC值为20.62%,呈中等环境风险;其形态稳定性最差,以可还原态和酸提取态为主。Pb、Cu、Cr、Zn、Ni的RAC值为5.45%~10.0%,环境风险较低;且均以残渣态为主,占总量的54.69%~83.05%。以消落带沿岸土壤为对照,消落带形成后土壤中各重金属总量均有不同程度升高,且不同重金属在其增量部分的形态存在差异,Cr和Ni的增量部分以残渣态为主,Cd、Pb、Zn的增量以非残渣态为主。研究发现,由于受到水域与陆地污染源的双重影响,澎溪河流域重金属具有由沿岸向消落带沉积富集的趋势。
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| 关 键 词： | 消落带 土壤 重金属 地质累积指数 生态风险评价 |
| 收稿时间： | 2015/9/22 0:00:00 |
| 修稿时间： | 2016/7/15 0:00:00 |
Speciation and Translocation Characteristics of Soil Heavy Metals in the Water Level Fluctuating Zone of Pengxi River in Three Gorges Reservoir Area |
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| WANG Tu-jin,PAN Jin and LIU Xue-lian.Speciation and Translocation Characteristics of Soil Heavy Metals in the Water Level Fluctuating Zone of Pengxi River in Three Gorges Reservoir Area[J].Rock and Mineral Analysis,2016,35(4):425-432. |
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| Authors: | WANG Tu-jin PAN Jin and LIU Xue-lian |
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| Institution: | School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074, China,School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074, China and School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074, China |
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| Abstract: | The water level fluctuating zone (WLFZ) is a transition belt between the water area and the terrestrial habitat that plays an indispensable role in the water environment. Pengxi River basin with the largest WLFZ area was chosen as the study area. The soils in the WLFZ and the coastal soil samples were collected to analyze the speciation characteristics of heavy metals. Besides, we have evaluated the pollution degree of such metal contaminants as well as the levels of the potential ecological risks with the methods of geo-accumulation index and the risk assessment code (RAC). The average contents of Pb, Cu, Cr, Cd, Zn and Ni in the soils of WLFZ were 68.70, 36.96, 55.10, 0.68, 108.26 and 31.68 mg/kg, respectively. The pollution degree is in the order of Cd > Pb > Zn > Cu > Ni > Cr, among which Cd and Pb pollution were prominent, generally higher than that in soils of mainstream of the Yangtze River and much higher than that in soils of Chongqing area. The RAC value of Cd was 20.62%, showed moderate pollution, and was mainly found in exchangeable and carbonates fraction. The RAC value of Pb, Cu, Cr, Zn and Ni were 5.45%-10.0%, showed low pollution, and were mainly found in residual fraction, accounting for 54.69%-83.05% in the total amount. Compared with the coastal soils, the content of heavy metals was increased in WLFZ soil, but the increased amount of each heavy metal was different. According to fractionation studies, residual fraction was the main part of the increased Cr and Ni. Nevertheless, the main part of the increased Cd, Pb and Zn were found in non-residual fractions. The results of our investigation indicated that under the effect of the terrestrial and aquatic pollution sources, the heavy metals contaminants in the Pengxi River basin were translocated from the coastal soil to the WLFZ, then deposited and enriched. |
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| Keywords: | water-level-fluctuating zone soils heavy metals geo-accumulation index ecological risk assessment |
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