滇池内湖滨带沉积物中重金属形态分析  

Speciation of heavy metals in sediments from inner lakeside belt of Lake Dianchi

作　　者：卢少勇[1] 焦伟[1,2] 金相灿[1] 李光德[2] 刘震[1] 张烨[1] 

机构地区：[1]中国环境科学研究院湖泊环境研究中心国家环境保护湖泊污染控制重点实验室,北京100012 [2]山东农业大学资源与环境学院,山东泰安271000

出　　处：《中国环境科学》2010年第4期487-492,共6页China Environmental Science

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07101,2009ZX07101);国家“863”项目(2005AA60101005);国家“973”项目(2008CB418200)

摘　　要：采用BCR3步分级提取法测定了滇池内湖滨带沉积物中4种重金属(Pb、Cd、Cu和Zn)不同形态的含量,初步评估了这4种重金属的生物有效性.结果表明,Cd和Zn主要以可提取态存在(即弱酸溶解态、可还原态和可氧化态),而Pb和Cu均以残渣态为主要存在形式.通过计算可提取态含量所占总量百分量大小,可知各金属的生物有效性大小排序为:Zn(53.06%)>Cd(50.84%)>Cu(34.62%)>Pb(28.65%).沉积物中总有机碳(TOC)与各金属不同形态间的相关性分析表明,可氧化态重金属与有机碳结合的趋势远大于弱酸溶解态和可还原态.表层沉积物中可提取态重金属的空间分布特征明显表现为草海>外海,除Cu外,大部分样点的可提取态Pb、Cd和Zn含量均随采样深度增加而减少.BCR three stage sequential extraction procedure was applied to examine the speciation and concentration of four heavy metals（Pb,Cd,Cu and Zn） in the sediments from inner lakeside belt of Lake Dianchi,and the bioavailability of these heavy metals was determined. Cd and Zn mainly occurred in weak acid soluble fraction,reducible fraction and oxidisable fraction,while Pb and Cu mainly occurred in residual fraction. According to the percentage of fractions extracted in total content,bioavailability for four metals varied in the descending order of Zn,Cd,Cu and Pb. The relationship between TOC and speciation of these heavy metals showed that the combination of oxidisable fraction and TOC was much stronger than that of weak soluble fraction and reducible fraction,respectively. Total content of fractions extracted of heavy metals in surface sediment was apparently CaohaiWaihai,and the content of Zn,Cd,Pb in fractions extracted by BCR method all decreased with the increase of depth except for Cu.

关 键 词：滇池 内湖滨带 重金属 形态 BCR 

分 类 号：X142[环境科学与工程—环境科学]