横山水库底泥重金属含量及其生态风险评价

Heavy metals content and analysis of its ecological risk assessment of bottom sediment of Hengshan Reservoir

为了解宜兴市横山水库底泥中重金属含量现状,于2019年7月与2020年11月采集了共23个点位的底泥样品,文章分析了8种重金属(Cr,Ni,Cu,Zn,As,Cd,Pb和Hg)含量并评价了其潜在生态风险。结果显示,对于横山水库底泥重金属含量,除Cr外的其他7种重金属含量均高于太湖流域底泥重金属背景值,空间上体现为北部及中心区集水区域表层底泥8种重金属含量均相对较高,西部库区较小范围内的表层底泥铬(Cr)和镉(Cd)的含量较高,而东南部库区的重金属含量较低。典型点位重金属含量的垂向分布均表现为随底泥深度的增加而逐渐降低的趋势。重金属潜在生态风险指数值为74.3~236,处于中风险或低风险水平。

In order to know about the present situation of heavy metals content of bottom sediment of Hengshan Reservoir in Yixing,bottom sediment samples from 23 sites were collected in July 2019 and November 2020.The content of eight heavy metals(Cr,Ni,Cu,Zn,As,Cd,Pb and Hg)were analyzed and their potential ecological risks were evaluated.The results show that:the content of the other seven heavy metals except Cr was higher than the background value of Taihu Lake bottom sediment.The content of eight heavy metal in surface bottom sediment in northern and central areas was relatively high,the Cr and Cd content in surface sediment in the small range of western area was higher,and the eight heavy metals content in southeast area was low.The vertical distribution of heavy metal content at typical points showed a decreasing trend with the increase of bottom sediment depth.The value of the potential ecological risk index of heavy metals ranged from 74.3 to 236,which was at the level of medium or low risk.