摘要
利用三维荧光光谱(EEMs)并结合平行因子分析(PARAFAC)模型,研究了2008年6月"水库型"河流闽江中溶解有机物(DOM)的荧光组分特征及其分布变化,以探讨河流DOM的来源、动力学过程及主要控制因素。闽江DOM包括类腐殖质组分C1(<250,325/424nm)、C2(270,395/482nm)与类蛋白质组分C3(<250,280/358nm)等三种荧光组分,其中类腐殖质组分占绝对优势。利用荧光组分可对上游三条支流之间的混合进行灵敏的指纹示踪。闽江干流DOM荧光组分的含量基本一致,反映了大型水库修建对闽江有机碳循环尚未产生显著影响。利用相关和主成分分析揭示出闽江类腐殖质组分主要来源于流域土壤的冲刷,它与吸收系数a(355)之间的关系密切;而类蛋白质组分主要在水环境中产生,可用于示踪水体中总溶解氮(TDN)的变化。利用荧光组分的多元线性回归可有效地对溶解有机碳(DOC)的含量进行示踪,表明EEMs-PARAFAC是研究河流DOM动力学过程的重要手段。
The fluorescent components and their distribution and variation of dissolved organic matter(DOM) were examined using excitation emission matrix fluorescence spectroscopy-parallel factor analysis technique(EEMs-PARAFAC) for samples collected during June,2008 from Minjiang River,a typical subtropical reservoir-type river ecosystem.Three separate fluorescent components were identified by PARAFAC,including two dominant humic-like components(C1: 250,325/424 nm;C2: 270,395/482 nm) and one protein-like component(C3: 250,280/358 nm),of which humic-like components were dominant.Fluorescence analysis provided a 'fingerprint' technique to trace the mixing of DOM between three tributaries in the upstream of Minjiang River.The nearly constant concentration and composition in the main stream of Minjiang River reflected the effect of dam construction.Correlation and principal component analysis(PCA) revealed that humic-like components were principally derived from flushing of watershed soils,while protein-like component was formed from in-situ production which could be used as a proxy of the concentration of total dissolved nitrogen(TDN).Multi-linear regression of fluorescent components C2 and C3 can be used to trace the variation of dissolved organic carbon(DOC) concentration.This study demonstrates that Minjiang is a typical subtropical reservoir-type river which still keeps relatively 'unpolluted' aquatic environment.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2011年第2期427-430,共4页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(40776041
40810069004)
新世纪优秀人才支持计划项目
福建省环保局科技计划项目闽环科项目[2007]43号和国家(863计划)项目(2007AA091704)资助
关键词
溶解有机物
激发发射矩阵光谱
平行因子分析
水库
闽江
Dissolved organic matter
Excitation-emission-matrix spectroscopy
Parallel factor analysis(PARAFAC)
Reservoir
Minjiang river