内蒙古乌梁素海底泥重金属元素污染评价

ASSESSMENT FOR THE HEAVY METAL POLLUTION IN THE SEDIMENTS OF WULIANGSHUHAI LAKE,INNER MONGOLIA

根据乌梁素海底泥(0～20 cm)重金属元素调查数据,利用潜在污染生态危害指数法评价了底泥重金属污染风险.底泥中Pb、Cd、As、Cu、Cr、Hg、Zn之间相关性明显,说明湖泊底泥中这些重金属的成因来源和地球化学行为相同.采用国家海洋沉积物质量一类标准、生态危害临界值(TEL)和国家土壤环境质量一级标准的评价表明,湖泊底泥中重金属的复合污染较严重,污染元素主要为Cu、Cd、Ni、Zn.乌梁素海大部分地区属轻度污染,仅3个排干渠入口附近为极度污染区,其他局部地区为重度污染区.

Based on survey data of the sediments（0-20 cm） collected from Wuliangshu Lake,the risk of heavy metal pollution is assessed by ecological risk index method.According to the national standard of ocean sediment quality（first level）,threshold effective level and national standard of soil quality（first level）,the lake presents a combined pollution,mainly with pollutants of Cu,Cd,Ni and Zn.There are a remarkable correlation among the total contents of Pb,Cd,As,Cu,Cr,Hg and Zn,suggesting the same origin of pollutants.The ecological risk index method shows that most part of the lake is of slight pollution risk.The extreme pollution areas are distributed only near the mouth of three drainage-irrigation channels.The other areas are heavily polluted.