湖北省某矿山河道底泥重金属污染调查与评价

Assessment of heavy metal pollution of river sediment in mine of Hubei province

对湖北某有色金属矿区排污河道底泥中铜、锌、铅、镉、镍含量进行了分析测试,主要采用变异系数法、地累积指数法和潜在生态危害指数法对底泥重金属污染状况及潜在生态风险进行评价.结果表明,排污河道底泥受到一定程度的重金属污染,铜、锌、铅、镉、镍含量均超过湖北省土壤背景值;底泥重金属富集程度为镉>铜>锌>镍>铅,其中镉的富集程度为3级中-强度污染;铜和锌变异系数较大,沿程分布变化明显;以湖北省土壤背景值为参比,排污河道底泥5种重金属的生态危害顺序为镉>铜>镍>铅>锌,总体表现为中度-重度的生态危害,镉是主要的潜在生态风险因子.

Contents of Cu,Zn,Pb,Cd,Ni were tested and analyzed with the variation coefficient,accumulation index and potential ecological risk index to evaluate the degree of heavy metal pollution and potential ecological risk in the sewage river sediment of a non-ferrous metal mine of Hubei province.The results show that the sewage river sediment is polluted by heavy metal; contents of Cu,Zn,Pb,Cd,Ni are over soil background values of Hubei province; enrichment of heavy metals in sediment is Cd ＞ Cu ＞ Zn ＞Ni ＞ Pb,in which the enrichment degree of Cd is 3; Cu and Zn have larger coefficient variation and more significant distribution along the way; refering to soil background value of Hubei province,ecological risk of five kinds of heavy metals in the sewage river sediment is Cd ＞ Cu ＞ Ni ＞ Pb ＞ Zn,displaying ecological harm performance with moderate to high degree on the whole,in which Cd is the main potential ecological risk factor.