近60年来星云湖沉积物中重金属污染记录

Heavy Metal Pollution Record of Xingyun Lake in the Past 60 Years

中文关键词:  星云湖  210Pb  137Cs  重金属  地积累指数评价法

英文关键词:Xingyun Lake  210Pb  137Cs  Heavy metals  Geo-accumulation index

中文摘要:

      文章以星云湖08XY -4号钻孔岩芯为研究对象,通过对岩芯的137Cs和2100Pb测年和多种元素组分(重金属元素Cd、Cr、Cu、Pb、Zn,成岩组分Fe、Mg、Al、有机质、碳酸盐和烧失量)的含量分析,系统研究了星云湖近60年来底泥中重金属的来源和污染历史,并借助地积累指数法对星云湖的重金属污染程度进行了评定.结果表明20世纪80年代末期以前,星云湖沉积物中元素Cd、Cr、Cu主要为自然来源,之后受当地工业化蓬勃发展的影响,人类活动对湖泊重金属含量的影响显著增强；元素Pb的污染历史早于20世纪50年代,与全球很多区域Pb污染要早于其它多数重金属污染这一现象相似；此外,可能受当地特殊的工业发展历史影响,1973～1991年期间星云湖遭受严重的Zn污染,平均污染指数值达到3.25,按Muller污染指数分级属4级偏重污染.综合来看,当前星云湖的污染程度仍然较轻,但是近期人类活动的影响已明显显现,需要加以重视.

英文摘要:

      This paper focused on the change of heavy metal concentration in sediments from the deepest part of Xingyun Lake.Based on the analyses of 137Cs and 210Pb activities and heavy metals(Cd,Cr,Cu,Pb,Zn),diagenetic elements(Fe,Mg,Al),LOI550/950,the sources and pollution history of heavy metals were systematically investigated.The geo-accumulation index(Igeo) has also been used to assess their contamination levels.It showed that,before 1987 the influence of human activities was relatively small,and the heavy metals(Cd,Cr,Cu) was mainly originated from the nature.After 1987,due to the influence of local industrialization,the influence of anthropogenic activities is apparently enhanced.The results also show that,the Pb pollution began earlier than 1950s,coinciding with many other places in the world.The Zn in the lake was "strongly polluted"(3