太湖流域梁塘河沉积物重金属生态风险评价

研究了太湖流域梁塘河沉积物中6种重金属(砷、镉、铬、铜、汞和铅)的空间分布特征。相关性分析表明:铅、镉和汞有显著的正相关关系;砷和铜也有显著正相关;铬与其他金属均无良好的相关关系。参照SQGs基准,砷、镉、铬、汞、铅含量介于风险评价低值(ERL)与风险评价中值(ERM)之间,可能会对水域生物有一定的毒性;铜含量在部分取样点超过了ERM值,对水生生态系统有很强毒性。Hakanson潜在生态风险指数法研究表明,各取样点的表层沉积物均有一定生态风险,其中5号、6号呈现极强的生态风险;6种元素生态风险由强到弱的顺序为:镉、铜、砷、汞、铅、铬。

ECOLOGICAL RISK ASSESSMENT OF HEAVY METALS IN SEDIMENTS IN LIANGTANG RIVER OF TAIHU BASIN

This paper studied and analyzed the space distribution characteristics of six heavy metals( As，Cd，Cr，Cu，Pb and Hg) in sediments from Liangtanghe River in Taihu Baisn． Correlation analysis showed that the Pb，Cd and Hg had significant positive correlation，the As and Cu also had a significant positive correlation and Cr did't have good relation with other metals． Based on SQGs benchmark，the concentration of As，Cd，Cr，Hg，Pb were between ERL and ERM，they may have certain toxicity to waters; the concentration of Cu in some sampling points were higher than the value of ERM，so Cu may have a very strong toxicity to aquatic ecosystems． Hakanson potential ecological risk index showed that the ecological risk of six heavy metals was in the descending order of Cd，Cu，As，Hg，Pb，Cr，all the sampling points were present some ecological risks and No． 5，No． 6 sampling point are under in a quarter strong ecological risk．