滇池北部沉积物孔隙水中溶解性有机质的光谱特性与空间分异  

Spectrum characteristics and spatial distribution of dissolved organic matter in sediment porewater from northern Dianchi Lake

作　　者：王立英[1] 张润宇[1] 吴丰昌[2] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002 [2]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012

出　　处：《生态学杂志》2014年第12期3416-3422,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41273148;40903051和41273151)资助

摘　　要：运用紫外-可见吸收光谱和荧光光谱研究滇池北部沉积物孔隙水中溶解有机质（DOM）的含量组成和剖面分布,并探讨DOM的主要来源及其水环境影响。结果表明,表层沉积物孔隙水中DOC浓度最高,随沉积深度的增加先下降,在4~10 cm处达到最小值,之后呈上升趋势。孔隙水DOM的α253/α203、E3/E4值分别为0.03~0.22、5.3~8.8,反映了DOM的腐殖化和芳香性程度较低,以小分子量富里酸为主。三维荧光谱图明显观察到类富里酸荧光峰A和C,而类蛋白荧光峰B和D仅在上覆水和表层2 cm孔隙水内检测到。孔隙水DOM荧光指数为1.8~2.0,表明以水生生物来源为主。研究表明,滇池沉积物孔隙水DOM的地球化学特性与水体富营养化和区域蓝藻水华关系密切,其潜在水环境效应值得重视。Concentration, composition and vertical distribution of dissolved organic matter（ DOM） were investigated in sediment porewater from the north part of Dianchi Lake by UV-visible and fluorescence spectroscopy,and its main source and potential environmental effect were also revealed. DOC concentration was highest in the uppermost layer,with a sharp decrease within the sediment depth of 4-10 cm,and then increased. The ratios of α253 / α203 and E3 / E4 ranged from 0. 03 to 0. 22 and 5. 3 to 8. 8 respectively,which implied that the DOM in sediment porewater had relatively low humification and aromaticity with the predominance of small molecular weight fulvic acid. Humic-like peaks A and C were two dominant fluorophores in three-dimensional fluorescence spectroscopy,whereas protein-like fluorescence peaks B and D were observed only in the overlying water and top 2 cm porewater. Fluorescenee index（ f450 / f500） of DOM in sediment porewater varied from 1. 8 to 2. 0,indicating the majority nature of endogenous aquatic organisms. The results suggested that the geochemical characteristics of DOM in sediment porewater were related to lake eutrophication and regional cyanobacterial blooms in Dianchi Lake,and more attention should be paid to its potential effect on water environment.

关 键 词：溶解有机质 沉积物孔隙水 光谱特征 滇池 

分 类 号：X52[环境科学与工程—环境工程]