| 金山湖闸坝型水体表层沉积物重金属分布特征及生态风险评价 |
| 摘要点击 2846 全文点击 1228 投稿时间：2014-04-01 修订日期：2014-07-02 |
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| 中文关键词 沉积物 重金属 地累积指数 生态风险 金山湖 闸坝 |
| 英文关键词 sediments heavy metals geo-accumulation index ecological risk Jiashan Lake dam |
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| 中文摘要 |
| 采集金山湖闸坝型水体表层沉积物，经HNO3-HF-HClO4消解后，通过电感耦合等离子质谱法（ICP）测定沉积物As、Cu、Pb、Cd、Zn、Cr等6种重金属含量，通过富集系数、地累积指数法、潜在生态风险评价以及溯源分析等对沉积物重金属的分布特征进行综合评价. 结果表明：①金山湖表层沉积物As、Pb、Cu、Zn、Cr、Cd的平均值分别为23.22、26.20、24.42、143.12、245.30、0.67 mg·kg-1，其中，Pb、Cu含量低于土壤环境质量标准一、二级标准，Zn、Cr含量介于土壤环境质量标准一级标准与二级标准之间，As、Cd含量均超过土壤环境质量标准一、二级标准；从空间分布来看，Pb和Zn在北固山广场的1号样点形成最高值，As、Cu、Cr、Cd的含量分别在镇润洲码头附近的12号样点、运粮河河口区域的3号样点、湖中靠近征润州岛的14号样点、春江潮与解放路泵站之间往湖中心处的7号样点处出现最高值. ②富集系数表现为As >Cr >Cd >Pb >Zn >Cu，表明金山湖表层沉积物中As的富集量最大，Cu最小. ③根据地累积指数判断，金山湖未受Cu的污染，Pb、Zn、Cd则为轻度污染，As、Cr表现为偏中度污染；④6种重金属的单项潜在生态危害系数表现顺序为Cd >As >Cr >Pb >Cu >Zn，其中，Cr、Pb、Cu、Zn均为轻微生态危害程度，As和Cd处于中等生态危害程度；从全湖分布看，北固湾广场附近（1号样点）、春江潮与解放路泵站之间靠近岸边区域（6号样）、春江潮与解放路泵站之间往湖中心处（7号样点）以及镇润洲码头附近（12号样点）样点的潜在生态危害为中等，其余采样点均为轻微潜在生态危害；⑤主成分分析结果表明，金山湖沉积物重金属的差异除了受到各样点沉积物环境背景值的影响外，还与各采样点周围人为活动、外源污水排放等有密切关系. ⑥本次研究中发现闸坝对金山湖沉积物重金属分布的影响不明确，该部分内容尚需进行长时间尺度的研究. |
| 英文摘要 |
| In order to reveal the pollution loading of heavy metals in Dammed Jinshan lake, six heavy metals (As, Cu, Pb, Cd, Zn, Cr) from 18 sediment samples were analyzed using ICP, and the distribution characteristics of heavy metals in the sediment were comprehensively evaluated through concentration coefficient, geo-acumulation indexes, potential ecological risk evaluation and traceability analysis. The results showed that ① the average contents of As, Pb, Cu, Zn, Cr, Cd were 23.22, 26.20, 24.42, 143.12, 245.30 and 0.67 mg·kg-1, respectively, in the surface sediments of dammed Jinshan Lake. The average contents of Pb and Cu were lower than the primary standard and secondary standards of soil environmental quality standards. The average contents of Zn and Cr were lower than the primary standard and higher than the secondary standards of soil environmental quality standards. The average contents of As and Cd were higher than the primary and secondary standards of soil environmental quality standards. From the spatial distribution, the contents of Pb and Zn were the highest at sampling site No. 1, which was located at the Beigushan Square. The contents of As,Cu,Cr,Cd were the highest at sampling sites Nos. 12, 3, 14, and 7, respectively; ② The order of concentration coefficient was As >Cr >Cd >Pb >Zn >Cu, which indicated that the enrichment amount of As was the highest and that of Cu was the lowest; ③ Based on the geo-acumulation indexes, the Cu is clean and Pb, Zn, Cd is the light pollution and As, Cr moderate pollution; ④ The order of Potential ecological risk coefficient was Cd >As >Cr >Pb >Cu >Zn, Cr, Pb, Cu, Zn were of light ecological risk and As, Cd were of medium ecological risk. From the spatial distribution, the sampling sites Nos. 1, 6, 7 and 12 had medium potential ecological risk, and the rest sample points had slight potential ecological risk; ⑤ The principal component analysis (PCA) revealed that the main reason for the differences of heavy metals in surface sediments of Jinshan lake was the different sediment environmental background value at the 18 samples sites. Besides, the pollution sources in each sampling sites also contributed to the differences in heavy metals; ⑥ the influence of the dam on the heavy metals distribution was not clear, and requires long-term study. |
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