白洋淀入淀河流溶解有机物沿程变化特征及来源解析

Variation characteristics and source analysis of dissolved organic matter along the river into Baiyangdian Lake

采用紫外-可见吸收光谱、三维荧光光谱,结合平行因子分析、主成分分析等方法,分析了白洋淀3条入淀河流(府河、孝义河、白沟引河)中发色团溶解有机物(CDOM)的光谱特征,阐释了CDOM组成、来源及对水质的影响机制。结果发现:河流CDOM平均浓度顺序为府河>孝义河>白沟引河,其中,府河CDOM的芳香性与分子量高于其他河流,白沟引河腐殖化程度高于其他河流,孝义河CDOM中内源性物质占比高于其他河流;3条河流均检出类腐殖质组分C1、C2、C3和类蛋白质组分C4,其中C1、C2、C3来源相近,且与C4异源;3条河流各组分最大荧光强度和总荧光强度的沿程变化表明,府河CDOM为点源、面源混合来源,孝义河CDOM以点源输入为主,白沟引河CDOM来自水源本身。

The spectral characteristics of chromophoric dissolved organic matter(CDOM)in three inflow rivers of Baiyangdian Lake(Fu River,Xiaoyi River and Baigouyin River)were analyzed by UV-vis absorption spectroscopy,three-dimensional fluorescence spectroscopy,parallel factor analysis and principal component analysis,and the composition,sources and the influence mechanism of CDOM on water quality were explained.The results showed that the order of CDOM average concentration was Fu River>Xiaoyi River>Baigouyin River.The aromaticity and molecular weight of CDOM in the Fu River were higher than those in other rivers,the degree of humification in the Baigouyin River was higher than those in other rivers,and the proportion of endogenous substances in CDOM in the Xiaoyi River was higher than those in other rivers.Humic-like components C1,C2,C3 and protein-like components C4 were detected in the three rivers,among which C1,C2 and C3 were similar in origin and different from C4.The variation of maximum fluorescence intensity and total fluorescence intensity of each component in the three rivers showed that CDOM of the Fu River was from point and non-point mixed sources,CDOM of the Xiaoyi River was mainly from point sources,and CDOM of the Baigouyin River diversion was contained by the water source itself.