长江(湖北段)沉积物中微量元素的分布特征及镉的形态  

DISTRIBUTION OF TRACE ELEMENTS AND CADMIUM FORMS IN SEDIMENTS FROM THE MIDDLE REACHES OF YANGTZE RIVER, HUBEI PROVINCE

作　　者：闭向阳[1] 马振东[2] 任利民[2] 龚敏[2] 金志升[1] 

机构地区：[1]中国科学院贵阳地球化学研究所环境地球化学国家重点实验室 [2]中国地质大学地球化学研究所,武汉430074

出　　处：《环境化学》2005年第3期260-264,共5页Environmental Chemistry

基　　金：国家自然科学基金(40473049);中国地质调查局(200214200024)资助项目

摘　　要：对长江(湖北段)不同时期沉积物中的微量元素(Cd,Zn,Pb,Cu,As,Hg,Cr,Ni,Mn)进行了研究.结果表明,从早期(一万年至两千年前)到现代(2002年),长江沉积物中多数微量元素的含量有明显的增加,尤其是Cd,Pb和Hg,由早期的0.25mg·kg-1,20.1mg·kg-1和0.046mg·kg-1分别增加至现代的0.71mg·kg-1,42.1mg·kg-1和0.098mg·kg-1.用连续提取法对沉积物中Cd赋存形态的测定结果显示,从早期到现代,碳酸盐结合态Cd所占比例有明显的增长,由早期的14.5%增加至现代的28.7%,松结和紧结有机结合态Cd也有不同程度的增加;铁锰氧化物结合态Cd的比例显著降低,由早期的31.3%变为现代的14.9%;残渣态Cd的百分率也有一定程度的降低.Nine trace elements in sediments of different horizons from Yangtze river along the reaches of Yichang to Wuhan were analyzed. Many elements had great increase in content from early time (2000 to 10000 year ago) to present, especially for Cd, Pb and Hg which content was by early 0.25 mg·kg^(-1), 20.1 mg·kg^(-1)and 0.046 mg·kg^(-1) increased to present 0.71mg·kg^(-1), 42.1 mg·kg^(-1) and 0.098 mg·kg^(-1) respectively. Forms of cadmium in sediment were studied using sequential chemical extraction procedure, the result showed that from early to present,Carbonate bonded state-Cd had obvious growth in percentage, which increased from 14.5% to 28.7%. Organic bonded state-Cd also increased in various degrees.Fe-Mn oxide bonded state-Cd, in contrast, appear to reduce notablywhich turn from 31.3% into 14.9%. The percentage of residual state-Cd had reducing of a certain degree too.

关 键 词：长江 沉积物 微量元素 分布特征 镉 形态 生态环境 

分 类 号：X131.2[环境科学与工程—环境科学]