摘要
在位于浙江省临安市的青山水库采集了具有代表性的8个样点的表层沉积物样品,分析比较了样品中As、Cr、Cu、Ni、Mn、Pb、Zn等7种重金属总量的差异,采用BCR连续提取法对重金属不同形态(酸提取态、可还原态、可氧化态、残渣态)进行分析.采用地积累指数法(I geo)和Hakanson潜在生态风险指数法,对青山水库不同采样点表层沉积物中重金属的污染程度和潜在毒性与生态风险进行评价.结果表明:青山水库表层沉积物重金属污染程度存在明显的空间差异,流经城区和工业园区的青山水库支流入库河口附近的表层沉积物重金属含量明显高于其他采样点.青山水库表层沉积物7种重金属中,Mn主要以酸提取态存在;Cu和Pb主要以可还原态形式存在;As主要以残渣态形式存在.流经城区的支流入库河口附近表层沉积物还原态和酸提取态重金属比例较高,对水生生物有一定的毒性风险.8个样点的表层沉积物7种重金属中,以As污染程度最高,潜在生态风险最大,其次是Cu、Ni、Mn、Pb和Zn,均处于轻度污染状态,而Cr处于清洁水平,潜在生态风险较低.不同采样点比较发现,分别流经城区的锦溪和工业园区的横溪入库河口附近表层沉积物重金属污染程度和潜在生态风险明显高于其他采样点.
A total of 8 representative surface sediment sampling sites were collected from the Qings- han Reservoir in Lin＇an City of Zhejiang Province to investigate the differences in the total concen- trations of As, Cr, Cu, Ni, Mn, Pb, and Zn among the sampling sites. The different forms of the heavy metals, i. e. , acid soluble, easily reducible, easily oxidizable, and residual, were deter- mined by BCR sequential extraction method, and the pollution degrees and potential ecological risks of the heavy metals in the surface sediments at different sampling sites of the Reservoir were as- sessed by using geo-accumulation index （Igeo） and Hakanson potential ecological risk index. There existed obvious spatial differences in the total concentrations of the heavy metals in the surface sedi- ments of the Reservoir. The sampling sites nearby the estuaries of the tributaries flowing through downtowns and heavy industrial parks to the Reservoir had obviously higher heavy metals concentra- tions in surface sediments, as compared to the other sampling sites. In the sediments, Mn was mainly in acid extractable form, Cu and Pb were mainly in reducible form, and As was mainly in residual form. The surface sediments at the sampling sites nearby the estuaries of the tributaries flowing through downtowns to the Reservoir had higher proportions of acid extractable and reducible forms of the heavy metals, which would have definite potential toxic risk to aquatic organisms. Among the 7 heavy metals in the surface sediments, As showed the highest pollution degree, fol- lowed by Cu, Ni, Mn, Pb, and Zn, which were at moderate pollution degree, while Cr was at non-pollution degree, with relatively low potential ecological risk. Through the comparison of the sam- pling sites, it was observed that the surface sediments at the sites nearby the estuaries of Jinxi River and Hengxi River flowing through downtowns and heavy industrial parks to the Reservoir showed ob- viously higher heavy metals pollution degree and potential ecological risk.
出处
《应用生态学报》
CAS
CSCD
北大核心
2013年第9期2625-2630,共6页
Chinese Journal of Applied Ecology
基金
国家水体污染控制与治理科技重大专项(2011ZX07303-001和2011ZX07303-002)资助
关键词
青山水库
沉积物
重金属
化学形态
潜在生态风险
Qingshan Reservoir
sediment
heavy metal
chemical forms
potential ecologicalrisk.
