太湖水华前表层水CDOM的光谱特征与来源解析

有色溶解性有机质（CDOM）是水生态系统中营养盐生物地球化学循环的重要环节，为探究太湖水华前表层水中CDOM的组分特征与来源，采用紫外-可见光谱与激发发射矩阵荧光光谱-平行因子分析（EEM-PARAFAC）技术对表层水中的CDOM组分进行了解析，结合CDOM光学参数（a₃₅₅、SUVA₂₅₄、a₂₅₀/a₃₆₅、FI、BIX和HIX）辨识其空间差异与污染来源，并与太湖CDOM组分历史数据进行了初步对比.结果表明，a₃₅₅、SUVA₂₅₄和a₂₅₀/a₃₆₅显示太湖东部表层水CDOM呈现高浓度、高芳香性和低相对分子量的特征，而北部与之相反.平行因子分析法从CDOM中分离出4个组分，类酪氨酸（C1）、两种类色氨酸（C2、C4）和类富里酸（C3），且主要组分C1与C2和C3组分具有较强的线性关系，不同组分来自相似污染源，荧光指数显示，太湖CDOM不同区域间受内源与陆源输入影响存在差异，但整体腐殖化程度较低.这表明太湖CDOM组分以类蛋白（C1、C2和C4）为主（>85%）且以自生源为主，可生化利用性好.

Spectral Characteristics and Source Analysis of Chromophoric Dissolved Organic Matter in Surface Water of Taihu Lake Before Cyanobacterial Blooming

Chromophoric dissolved organic matter (CDOM) is an important part of the nutrient biogeochemical cycle in aquatic ecosystems. To explore the characteristics and sources of CDOM components in the surface water of Taihu Lake, UV-visible spectroscopy and excitation emission matrix fluorescence spectroscopy-parallel factor analysis were used to analyze CDOM components in surface water. Combined with CDOM optical parameters (a₃₅₅, SUVA₂₅₄, a₂₅₀/a₃₆₅, FI, BIX, and HIX), the spatial differences and pollution sources were identified, and a preliminary comparison was made between this study and the historical data of CDOM components in Taihu Lake. According to the results, a₃₅₅, SUVA_254, and a₂₅₀/a₃₆₅ showed the characteristics of high concentration, high aromatic ability, and low relative molecular weight of CDOM in the surface water of the eastern part of Taihu Lake; however, the northern part showed the opposite characteristics. Four components were isolated from CDOM using parallel factor analysis:one tyrosine-like (C1), two types of tryptophan (C2 and C4), and one fulionic acid (C3). The main component C1 had a strong linear relationship with the C2 and C3 components, suggesting that different components originated from similar pollution sources. The fluorescence index showed that CDOM in different areas of Taihu Lake were differently affected by endogenous and terrestrial inputs; however, the overall humification degree was low. This indicated that the CDOM components in Taihu Lake were primarily protein-like (C1, C2, and C4) (>85%) and autogenous, with good biochemical availability.