Photo-Oxidation and Photobleaching of Chromophoric Dissolved Organic Matter in Coastal Waters

近年来，大量证据表明，海水中溶解有机物的地球化学转化在很大程度上是由光和痕量金属催化作用完成的。在这个项目中，首席研究员将对沿海水域中有色(即有色)溶解有机物(CDOM)的光氧化动力学进行全面研究。实验室研究将在存在和不存在各种自由基清除剂和氧气的情况下进行，并使用动力学模型进行解释。为了研究氢氧自由基的参与，在没有光的情况下，氢氧化物将以化学或辐射方式生成。将讨论的具体主题包括：(1)铁在CDOM光氧化、光漂白和海水中产物形成中的重要性；(2)在没有铁的情况下CDOM漂白的光机理；(3)Fe-CDOM相互作用的机理。

ABSTRACTOCE-9819089In recent years, significant evidence has accumulated suggesting that the geochemical transformations of dissolved organic matter in marine waters is mediated in large measure by light and trace metal catalysis. In this project the principal investigator will conduct a comprehensive study of the kinetics of photooxidation of chromophoric (i.e., colored) dissolved organic matter (CDOM) in coastal waters. Laboratory studies will be conducted in the presence and absence of various radical scavengers and oxygen and interpreted using kinetic modeling. To study the involvement of hydroxide radical, hydroxide would be generated chemically or radiolytically in the absence of light. The specific topics that will be addressed include: (1) the importance of Fe in CDOM photooxidation, photobleaching and product formation in seawater; (2) the photomechanism of CDOM bleaching in the absence of Fe; and (3) the mechanisms of Fe-CDOM interactions.