水生植物腐解有机质释放对水环境典型污染物影响机理研究

采用高等水生植物净化水体是水体生态修复的重要措施，但水生植物腐解有机质释放会给已修复的水体带来负面影响。水生植物腐解过程中释放的不同结构特征的溶解性有机质(DOM)如何对水环境中典型污染物如重金属和有机污染物产生影响，已经成为急需研究的问题。本研究根据不同生物量的水生植物腐解模拟实验，综合利用紫外-可见光谱、荧光光谱、红外光谱、核磁共振（NMR）、元素分析、透射电镜等技术，研究腐解过程中释放的DOM结构演化、不同组分DOM与水环境中重金属及有机污染物的络合过程与影响机制，揭示了水环境中有机质增加对重金属和有机污染物向水体中释放机理。本研究为科学评价水生植物腐解增加沉积物中重金属和有机污染物释放风险提供基础，有助于更好地利用水生植物对污染水体进行修复。

Macrophyte plants play an important role in purification of water environment, but their decomposition can cause negative effects on water environment. It has become very urgent to reveal the influence of dissolved organic matter (DOM) structure change on the complexing action of heavy metal and organic pollutants in water. In this research, based on the macrophyte decomposition simulation experiments with different biomass, we explore the evolution of DOM molecular composition and structures, and the complexing action process of DOM with heavy metal and organic pollutant as well as its influence mechanism, using a range of methods such as ultraviolet-visible spectroscopy, fluorescence spectroscopy, infrared spectroscopy, nuclear magnetic resonance(NMR), elemental analysis, transmission electron microscopy and diffusive gradients in thin-films technique (DGT), which is essential for the quantitive assessment of the influence of organic matter released from macrophyte deposition on typical pollutants in water. This project makes a deep research on the environmental effects of macrophyte deposition, and can promote the use of macrophyte in purifying polluted water environment.