中文摘要：

溶解性有机质（DOM）作为水生生态系统中一种重要的有机配体,是控制水体中重金属形态和生物有效性的重要影响因素之一。该文分析了DOM的组成、分子结构特征及其成分鉴别、分离常用的方法,总结了DOM与重金属间的相互作用及其对重金属生物有效性的影响,从DOM分子量和三元配合物的形成探讨了DOM影响重金属生物有效性的作用机理。文章指出金属元素-DOM-藻类的三元配合物的模型能较好地弥补现有的二元模型对重金属生物有效性的解释。在探讨DOM影响重金属生物有效性的作用机理时,区分不同分子量、不同组分的DOM是至关重要的一步。

英文摘要：

Dissolved organic matter （DOM）, as an important natural organic ligand in aquatic ecosystem, is an important factor in controlling metal speciation and bioavailability. The article analyzes the characteristics of DOM composition and molecular structure, and the common methods of its identification and separation. It summarizes the interactions between DOM and heavy metals, as well as its application to the evaluation of heavy metals bioavailability in the presence of DOM. The article discusses the mechanism of DOM＇s influence on heavy metals bioavailability in respect of the molecular weight of DOM and the formation of the ternary complex of metal-DOM-algae. It was pointed out that the ternary complex model could better explain the heavy metal bioavailability than the present binary model as a good supplement, and it is important to consider the effect of different molecular weights of DOM in the study of the bioavailability of heavy metals coexisted with DOM.