摘要: |
溶解有机质(DOM)是一类结构组成多样、理化性质复杂、分子量分布范围广的混合物质,主要包含腐殖酸、富里酸、蛋白质、脂类等多种有机组分以及羧基、羟基、酚基、醛基等活性基团。DOM在湖泊生态系统中广泛存在,可参与多种生物地球化学过程、影响生源要素及污染物的迁移转化和归趋行为,并在生态系统碳源汇转换中发挥着重要作用。湖泊水体DOM具有多种环境行为,如DOM可吸附至水体颗粒表面,调控DOM在溶解/悬浮相中的分配特征;环境条件下湖泊DOM会经历光及微生物降解过程,改变DOM在湖泊水体中的含量和结构组成;湖泊DOM中的多官能团极易与金属离子发生络合,还可因电子跃迁产生活性氧物种。此外,湖泊DOM还具有显著的生态环境效应,如DOM可负载在胶体颗粒表面,影响胶体颗粒稳定性及水体透明度;DOM与重金属络合会改变重金属离子生物有效性,进而影响湖泊生态系统健康;湖泊DOM可通过活性氧物种媒介作用促进有机污染物降解,也可通过光屏蔽作用抑制污染物的降解。需要指出的是,湖泊DOM行为及生态环境效应与其分子量、活性基团及分子结构组成息息相关。本文系统综述了湖泊DOM行为及生态环境效应,及其与DOM分子结构组成的关联性,以期为湖泊污染过程及机理、湖泊修复及调控、湖泊管理及规划等提供理论指导和技术支持。 |
关键词: 湖泊DOM 环境行为 生态环境效应 分子量分布 结构组成表征 |
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基金项目:国家重点研发计划项目, |
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Progress and prospects on the behaviors and eco-environmental effects of dissolved organic matter in lakes |
徐华成,Li ang
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Abstract: |
Dissolved organic matter (DOM) is a kind of substances with various structural compositions, complex physicochemical properties and wide molecular weight distribution, which mainly contains humic acids, fulvic acids, proteins, lipids and other organic components, as well as carboxylic acid, hydroxyl, phenolic, aldehyde and other reactive groups, etc. DOM exists widely in lake ecosystems, and it can participate in a variety of biogeochemical processes, influence the migration transformation and behavior of biotic elements and pollutants, and play an important role in the conversion of carbon sinks in ecosystems. DOM in lake water has various environmental behaviors. For example, DOM can be adsorbed to the surface of water particles, and the distribution of DOM in the dissolved/suspended phase can be regulated; DOM in lakes will undergo photo- and microbial degradation, which will change the content and structural composition of DOM samples; the multifunctional groups in DOM in lakes can be easily complexed with metal ions, and can also undergo electron transfer to produce reactive oxygen species. In addition, lake DOM also has significant ecological and environmental effects. DOM can be loaded on the surface of colloidal particles, affecting the stability of colloidal particles and transparency of the water body; DOM binding with heavy metals will change the bioavailability of heavy metal and the health of lake ecosystems; lake DOM can promote organic pollutant degradation through the mediating role of reactive oxygen species, or inhibit pollutant degradation through the role of light shielding. It should be pointed out that the behavior and ecological effects of lake DOM are closely related to its molecular weight, active group and molecular structure. In this paper, we systematically review the behavior and ecological effects of lake DOM and its correlation with the molecular structure compositions. Results obtained can provide theoretical guidance and technical support for the process and mechanism of lake pollution, lake restoration and regulation, lake management and planning. |
Key words: Lake DOM Environmental behavior Ecological effects Molecular weight distribution Structural composition characterization |