大冶湖滨岸带重金属水-土迁移特征与风险评价 |
摘要点击 4806 全文点击 1842 投稿时间:2014-04-09 修订日期:2014-06-17 |
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中文关键词 大冶湖 滨岸带 水-土 重金属 风险评价 |
英文关键词 Daye Lake the riparian zone water-soil heavy metal risk assessment |
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中文摘要 |
于2013年3月,采集大冶湖枯水期滨岸带水和表层土壤样品(上层0~10 cm、下层10~20 cm)各20个,并用火焰原子吸收分光光度法测定其重金属(Cu、Pb、Cd、Zn)的含量. 结果表明,沿岸水中Cu、Pb、Cd、Zn的平均值分别为7.14、25.94、15.72、37.58μg·L-1,其中Cd超出了Ⅴ类地表水环境质量标准. 上下层土壤中Cu、Pb、Cd、Zn的平均含量分别为108.38、53.92、3.55、139.26 mg·kg-1和93.00、51.72、2.08、171.00 mg·kg-1,其中上下层土壤中Cd均远超出土壤环境质量Ⅲ级标准. Pb在土壤和水体中的迁移性较为稳定,而Zn的迁移性受土壤性质及周边环境影响较大. 西岸带重金属可迁移性较东岸带大,具有较强的潜在环境风险. Cu、Pb、Cd、Zn均主要以残渣态形式存在. 重金属元素整体迁移顺序是: Pb>Cu>Cd>Zn,其中Cu、Pb有50%以上可能发生迁移,对环境存在较大的污染风险. 通过风险评价指数与潜在风险系数得出Cd为主要污染因子,且上层土壤重金属污染均高于下层土壤. |
英文摘要 |
Each 20 water samples and soil samples(0-10 cm, 10-20 cm) were collected from the riparian zone of Daye Lake in dry season during March 2013. Heavy metals(Cu, Pb, Cd, Zn) have been detected by flame atomic absorption spectrometric(FAAS). The results showed that the average concentrations of Cu, Pb, Cd, Zn in the water were 7.14, 25.94, 15.72 and 37.58μg·L-1, respectively. The concentration of Cu was higher than the five degree of the surface water environment quality standard. The average concentrations of Cu, Pb, Cd, Zn in soil(0-10 cm) were 108.38, 53.92, 3.55, 139.26 mg·kg-1 and in soil(10-20 cm) were 93.00, 51.72, 2.08, 171.00 mg·kg-1, respectively. The Cd concentrations were higher than the three grade value of the national soil environment quality standard. The transportation of Pb from soil to water was relatively stable, and Zn was greatly influenced by soil property and the surrounding environment from soil to water. The transformation of heavy metal in west riparian zone was higher than that of east riparian zone. The potential environmental risk was relatively high. Cu, Pb, Cd, Zn were dominated by residue fraction of the modified BCR sequential extraction method. The overall migration order of heavy metal element was: Pb>Cu>Cd>Zn. There were stronger transformation and higher environmental pollution risk of Cu, Pb. The index of assessment and potential ecological risk coefficient indicated that heavy metal pollution in soil(0-10 cm) was higher than the soil(10-20 cm), Cd was particularly serious. |
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