淮河安徽段沉积物中重金属污染及其潜在生态风险评价

Ecological Risk Assessment of Sediment Heavy Metals Pollution in Anhui Reach of Huaihe River

目的了解淮河安徽段沉积物中重金属污染现状,为淮河流域水环境质量的综合评价及污染治理等提供科学依据。方法于2007年3月,在淮河安徽段上设置6个采样断面(分别是王家坝、田家庵、蚌埠闸、吴家渡、临淮关和小柳巷),在每个采样断面设置3～5个采样点,采集每个断面各采样点表层(0～20cm)的沉积物样品,测定样品中Cu、Pb、Zn、Cr、Cd、As、Hg元素的质量浓度,并采用单因子指数法、综合污染指数法和Hakanson潜在生态危害指数法进行评价。结果沉积物中重金属污染物除Zn、Cu为中等程度污染外,其余均为低程度污染,污染程度顺序为Zn>Cu>As>Cd>Pb>Cr>Hg;重金属的潜在生态风险评价显示,除田家庵断面的Hg和吴家渡断面的Hg、Cd属于中等生态危害程度外,其他各点重金属的潜在生态危害都很轻微,潜在生态危害顺序为Cd>Hg>As>Cu>Pb>Cr>Zn。结论淮河安徽段沿岸人类的活动尚未对沉积物中重金属构成造成影响,河流沉积物中重金属污染不显著,处于轻微污染水平。

Objective To know the heavy metal pollution in the sediment in the Anhui reach of Huaihe. Methods In March,2007,the surface samples of sediment (0 to 20 cm) were collected in 6 sampling sections in Anhui reach of Huaihe River, including 3～5 sites in each section. The concentration of Cu,Pb,Zn,Cr,Cd,As,Hg was determined. The single factor index,integrated pollution index and potential ecological risk index presented by Hakanson were used to assess the ecological risk of heavy metals. Results The results showed that the contamination level of surface sediments was light except Zn, Cu, it ranked as Zn>Cu>As>Cd>Pb>Cr>Hg. The results of ecological risk assessment revealed that except in a few sections, the potential ecological risk was light, the order of potential ecological risk was Cd>Hg>As>Cu>Pb>Cr>Zn. Conclusion Human activities developed along the Huaihe River does not influence the concentration of heavy metals in the sediment, no serious contamination of heavy metals in the sediment is found in the present investigation.