| 北京城市流域底泥重金属形态特征及其生态风险评价 |
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| 引用本文： | 吴金莲.北京城市流域底泥重金属形态特征及其生态风险评价[J].水土保持研究,2017(5):321-328. |
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| 作者姓名： | 吴金莲 |
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| 作者单位： | 南京大学环境学院,江苏省农村环境保护与生态修复工程中心,南京210023 |
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| 摘 要： | 为了解北京城市流域底泥重金属污染现状及其生态风险,研究分别在北京市永定河流域、潮白河流域、温榆河流域、拒马河流域和泃河流域五大河系(北京段)共设置84个检测样点,采集底泥样品,利用ICP-MS分析法和BCR连续提取法测定北京城市流域底泥中铜(Cu)、锌(Zn)、铬(Cr)、镉(Cd)、镍(Ni)和砷(As)6种主要重金属的含量,分析其分布特征及养分变化,同时运用潜在生态危害指数法和地累积指数法综合评价流域底泥中重金属的生态风险。结果表明:(1)以北京土壤质量标准为北京市参比值,北京流域中下游底泥富营养化严重,重金属富集强弱依次为Cd(Cr,As,Zn)(Cu,Ni);(2)底泥重金属潜在生态危害评价,其危害程度依次为Cd(Cr,As,Zn)(Cu,Ni),其中五大河流下游潜在生态风险较大,生态风险最大的是拒马河水域;(3)地累积指数法进行污染评价,北京河流污染程度依次为下游中游下游,底泥中污染最大的重金属为Cd,其次为Cr,As和Zn,污染较小的为Cu和Ni。综上所述,北京污染较大的河流依次是拒马河、永定河、潮白河、温榆河和泃河,特别是河流下游区域底泥重金属累积较多,潜在生态危害最大。
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| 关 键 词： | 北京 流域 底泥 重金属 生态风险 |
Distribution Characteristics and Ecological Risk Assessment of Heavy Metals in the Sediments of Watershed in Beijing |
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| Abstract: | In order to investigate heavy metal pollution and its potential ecological risk in sediments of watershed in Beijing,84 test sample sites were set up in Yongding River Basin,Chaobai River Basin,Wenyu River Basin,Juma River Basin and Ju River Basin.Sediment samples have been collected to measure the contents of copper (Cu),zinc (Zn),Chromium (Cr),cadmium (Cd),nicked (Ni) and arsenic (As) of sediment by analysis methods of ICP-MS and BCR continuous extraction,distribution characteristics of heavy metals and the change of nutrient were analyzed.At the same time,potenstial ecological harm index and cumulative index method were used to compresively evaluate the ecological risk of heavy metals in sediment of river basin.It turned out that with soil quality standard of Beijing for the value of ratio,sediment eutrophication of middle and lower reaches was serious in rivers of Beijing,heavy metal enrichment strength decreased in the order:Cd＞(Cr,As,Zn)＞(Cu,Ni).As the sediment potential ecological risk assessment of heavy metals,extent of injury decreased in the order:Cd＞(Cr,As,Zn)＞(Cu,Ni),the potential ecological risk of down stream was the biggest,the biggest ecological risk was found tin Juma River.According to pollution assessment by method of cumulative index,the pollution degree of rivers in Beijing decreased in the order:downstream＞middle＞ lower reaches,the largest pollution of heavy metal was Cd in sediment,followed by Cr,As and zinc,less polluting was Cu and Ni.To sum up,pollution degree of rivers in Beijing decreased in the order:J uma River ＞ Yongding River＞Chaobai River＞Wenyu River＞Ju River.Especially,the accumulation of heavy metals of downstream in sediment was more,and had the largest potential ecological risk. |
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| Keywords: | Beijing drainage basin sediment heavy metal ecological risk |
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