| 孟博,刘静玲,李毅,史璇.北京市凉水河表层沉积物不同粒径重金属形态分布特征及生态风险[J].农业环境科学学报,2015,34(5):964-972. |
| 北京市凉水河表层沉积物不同粒径重金属形态分布特征及生态风险 |
| Speciation and Ecological Risk Assessment of Heavy Metals in Surficial Sediments of Liangshui River in Beijing |
| 投稿时间：2015-02-02 |
| DOI：10.11654/jaes.2015.05.020 |
| 中文关键词: 凉水河 沉积物 重金属形态 粒径 生态风险 |
| 英文关键词: Liangshui River sediments heavy metal speciation particle size ecological risk |
| 基金项目:国家水体污染控制与治理科技重大专项:海河流域河流物理过程演变与环境流量保障技术与应用示范(2012ZX07203-006) |
|
| 摘要点击次数: 3316 |
| 全文下载次数: 2198 |
| 中文摘要: |
| 河流沉积物是污染物的储存库之一,研究沉积物中粒径及不同粒径中重金属形态分布特征对于明晰河流污染生态风险具有重要意义。运用Hakanson潜在生态风险指数法和BCR法,以北京市凉水河为研究对象,用ICP-AES测定沉积物样品,研究了表层沉积物重金属形态、空间分布、来源、生态风险及闸坝影响,研究结果表明:沿河流流向,沉积物总体呈现出细化的趋势;大红门闸、马驹桥闸及张采路橡胶坝、 吴营村橡胶坝上下粒径由746.70、113.10、137.80 μm和88.63 μm降至475.20、59.05、53.77 μm和53.89 μm,闸坝对凉水河沉积物的细化作用显着;凉水河沉积物中,重金属形态含量大致为残渣态 >>可氧化态 >弱酸可提取态 >可还原态;在所测位点中,综合风险指数RI最高为311.75,最低为442.90,处于较高生态风险水平,且Cd的单一风险指数Eir最大,为225.46～309.10,Zn的风险指数最小,为0.25～0.61,对综合生态风险指数的贡献大,贡献率超过60%;形态含量表现出粒度效应,在粒径<0.2 mm时,Cr、Cd、Zn非稳态含量与粒径大小呈显着负相关,重金属毒性随粒径降低而升高;Cd在上游和中游河段的富集系数(EF)达到1.65和1.59,高于1.5,存在明显的人为输入。 |
| 英文摘要: |
| The water environment problem of urban river with unconventional water sources is becoming more and more serious. To evaluate the ecological integrity of urban river, physical properties and heavy metal pollution characteristics of surficial sediments collected from Liangshui River in Beijing were studied. The BCR methodology was applied to measure speciation of heavy metals, and Hakanson's methodology was used to determine contamination degree and ecological risk of heavy metals:Cr, Cd, Cu, As and Zn. Results showed that average particle size of sediments decreased along the flow of Liangshui River. The presence of dams and gates played a profound role in reducing sediment particle sizes. The content of speciation of heavy metals in Liangshui River sediments followed an order of residual>> oxidizable > acid soluble> reducible fraction. The composite potential ecological risk index of Cr, Cd, Cu, As and Zn in Liangshui River showed that heavy metal pollution risk was relatively high(RI=396.952 on average). The potential risk of individual heavy metal(Eri value) revealed that Cd risk was the greatest in the upstream and midstream of Liangshui River, mainly from anthropogenic sources. At sediment particle size < 0.2 mm, the content of non-steady fractions of Cr, Cd, Cu, As and Zn increased with decreasing particle sizes. The content of heavy metals(As, Cd, Pb and Zn) was higher in urban reach than in rural reach sediments. |
| HTML
查看全文
查看/发表评论 下载PDF阅读器 |
|
|
|
