湖泊沉积物重金属赋存形态研究进展

 综述了近年来湖泊沉积物重金属赋存形态的研究进展。总结了中国典型湖泊沉积物中重金属的形态赋存特征，各湖泊可提取形态所占比例各异，除Pb、Cd（Pb可提取态占50%以上，Cd可提取态占70%以上）外其他元素所占比重较小，绝大部分以残渣态存在；比较了沉积物中重金属形态不同连续提取方法（Tessier、原始BCR、改进的BCR）之间的差异以及存在的缺陷，改进的BCR具有更好的提取效果、利用更广，但也存在提取时间较长的缺陷，利用超声波、微波辅助可加速提取、缩短提取时间；阐述了影响重金属在沉积物中赋存形态的因素（pH值、氧化还原电位、粒度、有机质含量等）；归纳了基于赋存形态及生物毒性的各种评价方法之间的优缺点及适用范围；展望了沉积物重金属形态的分析提取技术和评价方法。

Research progress on the speciation of heavy metals in lake sediments

This paper reviews the recent research advances in heavy metal speciation in the sediments of lakes, and summarizes the morphological speciation characteristics of heavy metals in sediments from typical lakes in China. The percentages of heavy metals that can be extracted from sediments are different:the extractable Pb accounts for more than 50%, extractable Cd for more than 70%, and other extractable elements for much small percentages, most of which are in residual states. Different continuous extraction methods including Tessier, original BCR and improved BCR are compared. It is shown that the improved BCR has the best extraction effect, thus is being used widely, but its shortcoming is long extraction time. Using ultrasonic and microwave assisted method can greatly shorten the extraction time. The paper also describes the factors that influence heavy metal speciation in sediments, such as pH, oxidation reduction potential, particle size, organic matter content, etc. The advantages, disadvantages and applicable scopes of various evaluation methods are discussed based on speciation and biotoxicity. Finally, future extraction and analysis technology for heavy metal speciation in sediments and corresponding evaluation methods are prospected.