三峡水库小江回水区溶解有机物的三维荧光光谱特征

THREE-DIMENSIONAL FLUORESCENCE SPECTROSCOPY CHARACTERIZATION OF DISSOLVED ORGANIC MATTER IN XIAOJIANG RIVER BACKWATER AREA,THREE GORGES RESERVOIR

为了解三峡水库水体中溶解有机物(DOM)的特征及来源,以小江回水区为研究对象,对其DOM的三维荧光光谱进行了测定与分析,探讨了荧光强度与DOC、CODMn和叶绿素a的关系。结果显示:小江回水区DOM的三维荧光光谱主要表现出3个峰,类腐殖质荧光峰A、类蛋白荧光峰B和C;DOM荧光强度与DOC、CODMn相关性较好,表明荧光溶解有机物质的含量可以较好反映水体中有机碳和可被氧化有机物的含量;在8月份非水华暴发时期荧光强度和叶绿素a相关性较差,表明DOM荧光物质主要不是由浮游植物产生。综合分析可以推断小江回水区DOM的来源既有外源输入,也有内源输入,且外源输入对DOM荧光物质的贡献大于内源输入。

To understand the characteristics and the sources of the dissolved organic matter（DOM） in Three Gorges Reservoir,taking Xiaojiang River backwater area as the research object,three-dimensional fluorescence spectroscopy was measured and analyzed.The relationship between fluorescence intensity and DOC,CODMn or chlorophyll a was studied.The results showed that： three major peaks,humus-like fluorescence peak A,protein-like fluorescence peaks B and C appeared on the three-dimensional fluorescence spectroscopy;the DOM fluorescence intensity was well related with DOC and CODMn,indicating that fluorescence dissolved organic matter content can reflect both the organic carbon content and the organic matter content by oxidation in the water in August,during the non-algae bloom outbreak period,fluorescence intensity had a poor correlation with chlorophyll a,indicating that phytoplankton was not the main source of the fluorescent substances.Based on the comprehensive analysis,it can be inferred that both internal pollution sources and external pollution sources existed in the Xiaojiang River backwater area,and the contribution of the external pollution sources to the fluorescence dissolved organic matter was bigger than the internal pollution sources.