店埠河农业小流域是巢湖的主要水源地之一, 研究该流域水体溶解性有机质(DOM)组分及来源对了解巢湖水生生态系统至关重要。 本研究结合水体的三维荧光光谱, 利用平行因子分析(PARAFAC)方法对测定的三维荧光光谱矩阵进行拉曼及瑞利散射校正、 组分提取等相关处理, 实现对店埠河农业小流域水体DOM的分析, 包括三维荧光光谱特征分析、 三维荧光组分比例分析、 三维荧光特征参数分析以及荧光特征与水质参数的相关性分析, 以探究该流域水体DOM的组分及来源。 实验结果显示: 店埠河农业小流域水体DOM包含两个有效的荧光组分, 分别为类蛋白质物质(类色氨酸组分)和类腐殖质物质(类富里酸组分), 荧光组分比例表明类色氨酸组分是该流域水体DOM的主要组成部分; 水体的荧光指数FI、 自生源指标BIX以及腐殖化指标HIX指明该水体中DOM具有强自生源特性和弱腐殖化特征, 其内源主要来源于藕塘内部植物及水体其他微生物代谢活动, 外源来自于生活污水及养殖饲料的输入, 其中内源为水体DOM来源的主要贡献; 溶解性有机碳(DOC)与DOM中类色氨酸组分C1呈现极显著正相关, 类蛋白质荧光组分可用于该流域水体的DOC动态追踪; pH值与类富里酸组分C2呈现正相关, 故水体pH值和类富里酸组分同步增加, 说明该流域内水体碱化会伴随着溶解性有机质中类腐殖质物质的增加; 溶解氧(DO)与类色氨酸组分C1呈现负相关, 说明类色氨酸组分受到水体溶解氧含量的影响。 该研究示踪了店埠河农业小流域水体DOM的荧光特征及其组分来源响应机制, 可以更好的理解其在生态系统的功能及其环境地球化学循环过程, 从而为该流域环境综合治理提供一定的科学依据。

The agricultural watershed of the Dianbu River is one of the main water sources of Chaohu Lake. It is very important to understand the aquatic ecosystem of Chaohu Lake to study the composition and source of dissolved organic matter (DOM) in this watershed. In combination with the fluorescence excitation-emission matrix spectroscopy of the watershed, the study made some relative processing with the parallel factor analysis (PARAFAC) method, including the Raman and Rayleigh scattering removing, component extraction and so on for the measured fluorescence spectrum matrix. So we realized to analyze the DOM of the agricultural watershed of Dianbu River, including the excitation-emission matrix fluorescence spectrum characteristics analysis, the fluorescence component ratio analysis and the correlation analysis between the fluorescence characteristics and water quality parameters and explored the DOM components and sources of the watershed. The results showed that the DOM of the agricultural watershed in the Dianbu River contained two effective fluorescence components, namely, one kind of protein (tryptophan-like component) and one kind of humus (fulcrum acid-like component). The proportion of fluorescence components indicated that the tryptophan-like component was the main component of the DOM in the watershed. The fluorescence index FI, the autogenous indicator BIX and humification indicator HIX indicated that the DOM has strong autogenous properties and weak humification characteristics. What’s more, its DOM of endogenous mainly comes from the metabolic activity of plants and other water microbial within the lotus pond, DOM of exogenous input from sewage and aquaculture feed. The endogenous of DOM made the main contribution to the organic matter source in the water; the DOC is positively correlated with the tryptophan-like component C1 of DOM, and the protein-like fluorescence component can be used for dynamic DOC tracking of this watershed. The pH value was positively correlated with the fulcruid-like component C2, so the pH value and the fulcruid-like component increased simultaneously, indicating that the water alkalization in this basin was accompanied by the increase of humus like substances in dissolved organic matter. Dissolved oxygen (DO) was negatively correlated with tryptophan-like component C1, indicating that the tryptophan-like component was affected by the content of dissolved oxygen dissolved oxygen content in water. This study traced the fluorescence characteristics of DOM and its component source response mechanism in the small agricultural watershed of Dianbu River, which could better understand its function in the ecosystem and its environmental geochemical cycle process, thus providing a certain scientific basis for the comprehensive environmental management of the watershed.