Natural organic matter quantification in the waters of a semiarid freshwater wetland (Tablas de Daimiel, Spain)  

作　　者：Montserrat Filella Juan Carlos Rodríguez-Murillo Franc ois Quentel 

机构地区：[1]Institute F.-A. Forel, University of Geneva,10 route de Suisse,CH-1290 Versoix, Switzerland [2]Museo Nacional de Ciencias Naturales, CSIC,Serrano 115, E-28006 Madrid,Spain [3]Laboratoire de Chimie Analytique, UMR-CNRS 6521, Universit de Bretagne Occidentale,6 avenue V.Le Gorgeu,CS 93837,F-29238 Brest Cedex 3,France

出　　处：《Journal of Environmental Sciences》2013年第1期114-123,共10页环境科学学报（英文版）

摘　　要：Dissolved organic matter （DOM） concentrations have been measured in the waters of a semiarid freshwater wetland, the Tablas de Daimiel, Spain, when the system-characterised by variable hydroperiodicity conditions, was completely flooded （February 2011）. Fluxes of DOM from the wetland soils to the overlying waters were measured by using a passive diffusion sampler （peeper）. Not only dissolved organic carbon （DOC） concentrations were measured but refractory organic matter （ROM, usually known as humic substances） was also quantified using a novel voltammetric method. Fluorescence spectra were recorded to help in selecting the appropriate standard for ROM quantification, test the homogeneity of DOM in the waters and get an indication of their source. The results obtained show a 7-fold increase in measured ROM concentrations from the Gigtiela River to the outlet, which points to a net exportation of ROM from the wetland and to the existence of an internal source of ROM in the system, probably diffusion from the wetland soils. This hypothesis is confirmed by the flux of ROM from the soils to the water column measured with the peeper and by the common fluorescence characteristics of colunm and interstitial waters. The smaller increase in DOC concentrations along the wetland, in spite of the higher DOC fluxes from soils, suggests that there is significant turnover of organic carbon （OC） in the water column. The system acts as a major carbon sink but, when flooded, exports .OC as DOM.Dissolved organic matter （DOM） concentrations have been measured in the waters of a semiarid freshwater wetland, the Tablas de Daimiel, Spain, when the system-characterised by variable hydroperiodicity conditions, was completely flooded （February 2011）. Fluxes of DOM from the wetland soils to the overlying waters were measured by using a passive diffusion sampler （peeper）. Not only dissolved organic carbon （DOC） concentrations were measured but refractory organic matter （ROM, usually known as humic substances） was also quantified using a novel voltammetric method. Fluorescence spectra were recorded to help in selecting the appropriate standard for ROM quantification, test the homogeneity of DOM in the waters and get an indication of their source. The results obtained show a 7-fold increase in measured ROM concentrations from the Gigtiela River to the outlet, which points to a net exportation of ROM from the wetland and to the existence of an internal source of ROM in the system, probably diffusion from the wetland soils. This hypothesis is confirmed by the flux of ROM from the soils to the water column measured with the peeper and by the common fluorescence characteristics of colunm and interstitial waters. The smaller increase in DOC concentrations along the wetland, in spite of the higher DOC fluxes from soils, suggests that there is significant turnover of organic carbon （OC） in the water column. The system acts as a major carbon sink but, when flooded, exports .OC as DOM.

关 键 词：organic carbon natural organic matter refractory organic matter DOC ROM HUMIC WETLAND Daimiel 

分 类 号：X13[环境科学与工程—环境科学]