辽河水体中溶解有机质的光谱初步研究

Preliminary Spectroscopic Study on Dissolved Organic Matter in Liaohe River

文章分析了辽河流域水体中溶解有机质的吸收光谱,荧光特性及其主要来源。对比紫外可见吸收和散射2种模型,结果表明DOM对紫外可见光既有吸收也有散射。运用平行因子分析法(parallel factor analysis,PARAFAC),对三维荧光激发-发射矩阵(EEM)进行分析,发现3种荧光团,包括1种类蛋白荧光团和2种类腐殖质荧光团。荧光指数(FIX)为1.60～2.10,初步认为此时段辽河流域DOM的来源为多重来源,生物源比重较大。大多数SUVA_(254)在1.22～2.82L/(mg·m)之间,同文献报导的来自于土壤或者高等植物的DOM相比,值相对较小,DOM的芳构化程度较低,进一步表明DOM来源以生物源为主。

Absorption and fluorescence characters of dissolved organic matter （DOM） and its source in the watershed of Liaohe River were studied. By Comparison between an ultraviolet-visible light absorption model and a light-scattering model, it was found that DOM both absorbed and scattered the UV-Vis light comparably. Excitation-emission fluorescence matrices （EEMs） of water samples were analyzed with a parallel factor analysis （PARAFAC）, and three kinds of fluorophores were identified, one similar to proteins and two to humic substances. Fluorescence index （FIX） ranged between 1.60 and 2.10, thereby indicating that DOM in the watershed has multiple origins and that microbial origins contribute substantially. SUVA254 values were relatively small compared with the relatively large values for those DOM derived from soils/vascular plant reported in the literature, ranging between 1.22 and 2.82 L/（mg·m） for most water samples and thereby pointing to low aromaticity of DOM, which further indicated the dominance of microbial origin for DOM in the watershed.