溶解性有机质特性分析与来源解析的研究进展

溶解性有机质(DOM)是一类包含了复杂结构及交互作用的溶解性有机混合物,其表生行为和环境效应十分丰富.其在水体中滞留时间长,存在状态时刻处于变化中,与多种营养物质存在耦合效应,并影响着污染物的水环境归趋,是既古老又年轻的学科.目前,大多数研究成果都是建立于DOM分析技术与特性解析基础上.为了得到纯化的溶解性有机质,往往需要综合膜过滤、非离子大孔树脂、离子交换树脂、冷冻干燥、真空旋转蒸发、吸附剂富集等技术.光谱、色谱技术、高分辨率质谱等仪器的综合使用为研究溶解性有机质吸附、结合、络合、光诱导等环境行为提供了技术保障.DOM的表观特征广泛应用于研究其在水环境中的存在状态和环境行为,也是监测水处理过程中有机质去除效果的重要手段;其微观形态、分子量分布、化学键组成等内部特征的解析是认知其分子和结构、解释其作用机理和预测其环境归趋的基础.DOM来源复杂,单一指标很难判断有机质的来源,甚至会产生不同的研判结果,而综合运用多种新技术、新方法是DOM来源解析研究的发展趋势.

Advances in the characteristics analysis and source identification of the dissolved organic matter

Dissolved organic matter (DOM) is a group of compounds which have complex chemical structures, multiple interactions with their surrounding materials, and rich environmental behaviors and effects. In the aquatic ecosystems, DOM have a long residence time, variational-existent statuses, coupling effects with nutrients, significant influences on the fate of contaminants. Therefore, it is a promising research field with long history. To date, most DOM-involved research are based on its analytical technologies and characteristic identification. In order to obtain the purified DOM, the membrane filtration, nonionic macroporous resin, ion exchange resins, freeze drying, vacuum rotary evaporator, and enrichment by adsorbents are always comprehensively employed. And the integrated use of spectroscopy, chromatography, and high-resolution mass spectrometry are used to study the DOM's environmental behaviors like adsorption, binding, complexation, and photochemistry. The apparent characteristics of DOM are widely used to study the existent statuses and environmental behavior and its micromorphology, and is also an important means of monitoring removal effect of organic matter in the water treatment. Its internal features, including micromorphology, molecular weight distribution, and composition of functional groups, are used to cognize the molecular structures, to explain the interation mechanisms, and to predict the environmental fates. DOM has complicated sources. It is difficult to identify the source based on one indicator. Various indicators sometimes show opposite results. Therefore, it is the trend for source identification to integrate a variety of new technologies and methods.