Transport in heterogeneous media: Tracer dynamics in complex flow networks

Başağaoğlu, Hakan; Ginn, Timothy R.; Green, Christopher T.; McCoy, Benjamin J.

doi:10.1002/aic.690480521

Cited by 5 publications

(3 citation statements)

References 29 publications

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“…If hyporheic exchange is active, on the other hand, the flow of water across the sediment–water interface will presumably preclude, or sweep away, the concentration boundary layer, in which case the mass transfer bottleneck is solely hyporheic exchange. The “either/or” nature of these two transport processes is consistent with a parallel arrangement of their respective mass transfer resistors (Figure ): R = true( 1 R stream + 1 R hypo true) − 1 Equation implies that mass transport at the sediment–water interface will take the path of “least resistance”, depending on the nature of turbulence above the interface ( u *, U ∞ ,δ,υ), biophysical properties of the sediment bed including porosity (θ) and permeability ( K ), interfacial roughness (roughness scale k s ), and the molecular diffusion coefficient of the tracer ( D m ). If hyporheic exchange is negligible (e.g., because sediment hydraulic conductivity falls below the threshold of ∼1 m day –1 ), then R hypo → ∞ and mass transport is dominated by streamside exchange, R ≈ R stream .…”

Section: Turbulent Mass Transfer Across the Sediment–water Interfacementioning

confidence: 62%

Crossing Turbulent Boundaries: Interfacial Flux in Environmental Flows

Grant

Marušić²

2011

Environ. Sci. Technol.

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Advances in the visualization and prediction of turbulence are shedding new light on mass transfer in the turbulent boundary layer. These discoveries have important implications for many topics in environmental science and engineering, from the transport of earth-warming CO2 across the sea-air interface, to nutrient processing and sediment erosion in rivers, lakes, and the ocean, to pollutant removal in water and wastewater treatment systems. In this article we outline current understanding of turbulent boundary layer flows, with particular focus on coherent turbulence and its impact on mass transport across the sediment-water interface in marine and freshwater systems.

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Section: Turbulent Mass Transfer Across the Sediment–water Interfacementioning

confidence: 62%

Crossing Turbulent Boundaries: Interfacial Flux in Environmental Flows

Grant

Marušić²

2011

Environ. Sci. Technol.

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“…Connected compartments can also be inserted to blend in dead regions with mass transfer or flow. Elaborate assemblages of reactor elements have been proposed to describe heterogeneous mixing (Başaǧaoǧlu et al, 2002). The two-mode model (Chakraborty and Balakotaiah, 2002) is a more sophisticated approach that involves coupled balance equations for the mixing-cup and spatially averaged concentrations, and the exchange between these two modes.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and reactive mixing: Fragmentation and coalescence in turbulent fluids

Madras

McCoy

2004

AIChE Journal

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“…In these models, the storage zones are assumed to be arranged in parallel leading to concurrent hyporheic and surface storage dynamics. Using mathematically similar sets of equations and the idea of flow elements/reactors arranged in series or in parallel, Basagaoglu et al [2002] outline methods to describe tracer transport in heterogeneous porous media in the presence of complex flow networks. Kadlec [1994] used similar methods to describe lithium tracer transport in a free water surface wetland.…”

Section: Introductionmentioning

confidence: 99%

Surface storage dynamics in large rivers: Comparing three‐dimensional particle transport, one‐dimensional fractional derivative, and multirate transient storage models

Anderson

Phanikumar

2011

Water Resources Research

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[1] Large rivers are major conduits for sediment and nutrient transport and play an important role in global biogeochemical cycles. While smaller rivers received attention in recent decades for hyporheic exchange and nutrient uptake, fewer studies have focused on the dynamics of surface storage zones in large rivers. We investigate transport dynamics in the St. Clair River, an international river straddling the U.S.-Canadian border, using a combination of modeling and dye tracer studies. We describe a calibrated three-dimensional hydrodynamic model to generate (synthetic) breakthrough data to evaluate several classes of 1-D solute transport models for their ability to describe surface storage dynamics. Breakthrough data from the 3-D particle transport model exhibited multimodal behavior and complex dynamics that could not be described using a single first-order exchange coefficient-an approach often used to describe surface storage in transient storage models for small rivers. The 1-D models examined include multirate transient storage (MRTS) models in which storage zones were arranged either in series or parallel as well as 1-D models based on fractional derivatives. Results indicate that for 1-D models to describe data adequately, the timing of solute pulses that correspond to various in-channel features such as sandbars, islands or meander bends should be taken into account. As a result, the MRTS model with storage zones arranged in series (i.e., exchange rates triggered sequentially) provided the best description of the data. In contrast, fractional derivative models that assume storage zones were arranged in parallel failed to capture the multimodal nature of the breakthrough curves.Citation: Anderson, E. J., and M. S. Phanikumar (2011), Surface storage dynamics in large rivers: Comparing three-dimensional particle transport, one-dimensional fractional derivative, and multirate transient storage models, Water Resour. Res., 47, W09511,

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Transport in heterogeneous media: Tracer dynamics in complex flow networks

Abstract: Large-scale inhomogeneities in natural porous

Cited by 5 publications

References 29 publications

Crossing Turbulent Boundaries: Interfacial Flux in Environmental Flows

Crossing Turbulent Boundaries: Interfacial Flux in Environmental Flows

Kinetics and reactive mixing: Fragmentation and coalescence in turbulent fluids

Surface storage dynamics in large rivers: Comparing three‐dimensional particle transport, one‐dimensional fractional derivative, and multirate transient storage models

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