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| Hauptseite > Publikationsdatenbank > Analyses of locally measured bromide breakthrough curves from a natural gradient tracer experiment at Krauthausen |
| Hauptseite > Publikationsdatenbank > Analyses of locally measured bromide breakthrough curves from a natural gradient tracer experiment at Krauthausen |
| Journal Article | PreJuSER-46875 |
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2001
Elsevier Science
Amsterdam [u.a.]
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Please use a persistent id in citations: doi:10.1016/S0169-7722(00)00176-5
Abstract: Solute travel time distributions were derived from breakthrough curves (BTCs) of bromide concentrations, which were measured during a large-scale tracer experiment in a quaternary fluviatile aquifer at Krauthuusen. Travel time distributions to a specific point in the aquifer were derived from locally measured BTCs, using averaged absolute concentrations (c) over cap (abs)(x(1),t), normalized concentrations (c) over cap (norm)(x(1),t), and velocity-weighted normalized concentrations (c) over cap (vw)(x(1),t). The travel time distributions were characterized in terms of equivalent convective-dispersive transport parameters: the equivalent solute velocity and equivalent dispersivity. Parameters were derived from BTCs using moment analyses and least-squares fits of the 1-D convection-dispersion equation (CDE).Both local and averaged BTCs showed pronounced tailing which was not well described by the 1-D CDE and which indicates the presence of macroscopic regions with low velocities in the aquifer. Therefore, dispersivities derived from CDE fits were significantly smaller than those derived from time moments. The BTCs of (c) over cap (abs)(x(1),t) were dominated by only a few local BTCs with high concentrations and were less representative fur the travel time distribution than BTCs of averaged normalized concentrations. Dispersivities derived from (c) over cap (norm)(x(1),t) and (c) over cap (vw)(x(1),t) were very similar. Finally, estimates of dispersivities and vertical correlation length of in K, gamma (3), from BTCs were in agreement with a first-order estimate of the dispersivity and gamma (3) based on grain size data and flow meter measurements. (C) 2001 Elsevier Science B.V. All rights reserved.
Keyword(s): J ; breakthrough curves (auto) ; bromide tracer (auto) ; dispersivity (auto) ; hydraulic conductivity (auto) ; heterogeneity (auto) ; groundwater (auto)
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