title: Methane and Carbon Dioxide in the Sediment of a Eutrophic Reservoir: Production Pathways and Diffusion Fluxes at the Sediment-Water Interface.
abstract: The estimated diffusion fluxes of methane (CH4) and carbon dioxide (CO2) at the sediment-water interface in the Rzeszów Reservoir in southeastern Poland are presented. The relevant studies were conducted during 2009, 2010, and 2011. Calculated fluxes ranged from 0.01 to 2.19 mmol m-2day-1and from 0.36 to 45.33 mmol m-2day-1for methane and carbon dioxide, respectively. While the values for calculated diffusion fluxes of methane are comparable with those reported for other eutrophic reservoirs, much higher values were obtained here for carbon dioxide. The resulting values of δ13C-CH4and the fractionation coefficients between methane and carbon dioxide (αCH4-CO2) suggest that methane in the sediment of the Rzeszów Reservoir is produced by acetate fermentation, while the hydrogenotrophic methanogenic process is of successively greater importance with increasing depth. In the top layer of the sediment, 24-72 % of CO2came from methanogenesis, while the contribution made by the degradation of organic matter by methanogenesis to CO2was greater in the deeper layer.
authors: Faculty of Civil and Environmental Engineering, Department of Environmental and Chemistry Engineering, Rzeszów University of Technology, al. Powstańców Warszawy 6, 35-959 Rzeszów, Poland.
authors: Renata
authors: R
authors: Gruca-Rokosz
authors: Faculty of Civil and Environmental Engineering, Department of Environmental and Chemistry Engineering, Rzeszów University of Technology, al. Powstańców Warszawy 6, 35-959 Rzeszów, Poland.
authors: Janusz A
authors: JA
authors: Tomaszek
keywords: Carbon dioxide; Methane; Sediment; δ13C-CH4; δ13C-CO2