沉积物金属元素变化的粒度效应——以太湖沉积岩芯为例  

The influence of grain size composition on metal content in the sediment: the case of core sediment in Lake Taihu

作　　者：刘恩峰[1] 沈吉[1] 朱育新[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所,南京210008

出　　处：《湖泊科学》2006年第4期363-368,共6页Journal of Lake Sciences

基　　金：中国科学院知识创新工程重要方向项目(KZCX3-SW-348);中国科学院知识创新工程重大项目(KZCX1-SW-12-I)共同资助

摘　　要：水体沉积物中金属元素含量变化除了与人为污染有关之外,在很大程度上受沉积物粒度、矿物组成等沉积物性质的影响．在进行沉积物金属元素研究中,要充分考虑沉积物金属元素含量变化的粒度效应．本文通过对太湖MS岩芯中17种金属元素、沉积物粒度、矿物组成等指标的分析,研究了金属元素变化特征以及与沉积物粒度组成的关系．MS岩芯金属元素变化可分为两类,第一类主要为Al、Fe、K等,该类元素在沉积岩芯中下部含量较高,岩芯上部含量较低;第二类为Na元素,在沉积岩芯中下部含量较低,岩芯上部含量升高．MS岩芯中金属元素与粘土含量之间具有显著相关关系,经沉积物粒度(粘土含量)校正后,沉积岩芯中金属元素含量趋于稳定．因此,沉积物粒度组成(粘土含量)是影响金属元素含量的主要因素,在研究太湖沉积物金属元素变化规律及进行金属污染评价时,应对金属元素含量进行粒度校正．The metal contents in the sediments are influenced not only by human pollutants, but also by grain size and mineral composition of the sediments, which should be evaluated in the study of heavy metal. The metals contents and their correlations with grain size in sediments of core MS from Lake Taihu are studied in this paper in order to evaluate the grain size effects on metals contents. The metals in core MS can be classified into two categories according to their variation characteristics. Al, Fe, K etc belong to one category, the contents of which are high in the middle-lower section of the sediment core and low in the upper section ; Na belongs to the other category, the variation of its content is opposite with the first category. According to the correlations of the metals and grain size, clay content was selected as the normalization component of metals. After normalized by the clay content, the metals contents take on consistent variation along the sediment core. The analysis results show that the metals contents in Core MS are influenced mainly by grain sizes composition and the normalization of metals content must be taken during the study of metals variation and pollution evaluation.

关 键 词：沉积物 金属元素 粒度 含量校正 太湖 

分 类 号：X524[环境科学与工程—环境工程]