Functional variability of dissolved organic matter from the surface water of a productive lake

WATER RESEARCH

卷:42

Article

Gondar, D.²  Thacker, S. A.¹  Tipping, E.¹  Baker, A.³ 

[1] Ctr Environm, Ctr Ecol & Hydrol, Lancaster LA14AP, England

[2] Univ Santiago de Compostela, Fac Quim, Dept Quim Fis, E-15782 Santiago De Compostela, Spain

[3] Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England

关键词: allochthonous;    autochthonous;    chlorophyll a;    dissolved organic matter;    functions;    lakes;   

DOI  :  10.1016/j.watres.2007.07.006

来源: Elsevier

【 摘 要 】

Functional variability of dissolved organic matter (DOM) from the surface water of Esthwaite Water (N. England) was investigated using a series of 12 standardised assays, which provide quantitative information on light absorption, fluorescence, photochemical fading, pH buffering, copper binding, benzo(a)pyrene binding, hydrophilicity, and adsorption to alumina. Ten lakewater samples were collected at different times of year during 2003-2005, and DOM concentrates obtained by low-temperature rotary evaporation. Suwannee River Fulvic Acid was used as a quality control standard. For nine of the assays, variability among DOM samples was significantly (p < 0.01) greater than could be explained by analytical error. Seasonal trends observed for six of the assays could be explained by a simple mixing model in which the two end-members were DOM from the catchment (allochthonous) and DOM produced within the lake (autochthonous). The fraction of autochthonous DOM predicted by the model is significantly correlated (p<0.01) with chlorophyll concentration, consistent with production from phytoplankton. Autochthonous DOM is less light-absorbing, less fluorescent, more hydrophilic, and possesses fewer proton-dissociating groups, than allochthonous material. (c) 2007 Elsevier Ltd. All rights reserved.

【 授权许可】

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