羟基自由基对不同来源溶解性有机质(DOM)的氧化能力  

Oxidization of dissolved organic matters from different sources by hydroxyl radical

作　　者：李宁[1] 乔显亮[1] 刘远[1] 周菲[1] 

机构地区：[1]大连理工大学环境学院,工业生态与环境工程教育部重点实验室,大连116024

出　　处：《环境化学》2015年第7期1246-1251,共6页Environmental Chemistry

基　　金：国家自然科学基金项目(21277018,21137001)资助

摘　　要：采用总有机碳分析仪、紫外-可见吸收光谱以及荧光激发-发射光谱(EEMs)对5种不同来源DOM与·OH的反应过程进行了表征,以考察DOM来源和类别对其与·OH反应的影响.结果表明,不同来源DOM与·OH的反应能力存在显著差异,陆源DOM比水源DOM表现出更强的反应能力.DOM与·OH的反应表现为准一级动力学,以DOC变化表征的反应速率常数kDOC与DOM的芳香碳/脂肪碳的比值(Caro/Cali)有较好的相关性,说明芳香性碳可能是·OH的优先反应位点.以光吸收参数Absave表征的衰减速率常数与kDOC也表现出良好的相关性.因来源与类别的差异,不同DOM不仅初始的EEMs存在差别,而且·OH氧化过程中EEMs的变化也表现出显著的不同.In this study, TOC analyzer, ultraviolet-visible absorption spectra and fluorescence excitation-emission matrices （EEMs） were used to characterize the reactions between -OH and DOM from different sources. Terrestrial DOMs demonstrated higher reactivity with · OH than aquatic DOMs. The reactions followed pseudo-first-order kinetics as characterized by DOC decline. The reaction rate constants kDoc related well to the ratio of aromatic carbon to aliphatic carbon to aliphatic carbon （Caro/Cali ）, which indicated that aromatic carbon might be the preferential reaction sites for · OH, and the attenuation rate constants （kAb ） characterized by light absorption parameter. Due to the difference in origin and type, various DOMs demonstrated not only different EEMs before oxidation, but also various change during the oxidation by · OH.

关 键 词：溶解性有机质 羟基自由基 总有机碳 吸收光谱 三维荧光光谱. 

分 类 号：X52[环境科学与工程—环境工程]