Experimental Sensitivity Analysis of Oxygen Transfer in the Capillary Fringe

Christina M. Haberer, Olaf A. Cirpka, Massimo Rolle, Peter Grathwohl

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Oxygen transfer in the capillary fringe (CF) is of primary importance for a wide variety of biogeochemical processes occurring in shallow groundwater systems. In case of a fluctuating groundwater table two distinct mechanisms of oxygen transfer within the capillary zone can be identified: vertical predominantly diffusive mass flux of oxygen, and mass transfer between entrapped gas and groundwater. In this study, we perform a systematic experimental sensitivity analysis in order to assess the influence of different parameters on oxygen transfer from entrapped air within the CF to underlying anoxic groundwater. We carry out quasi two-dimensional flow-through experiments focusing on the transient phase following imbibition to investigate the influence of the horizontal flow velocity, the average grain diameter of the porous medium, as well as the magnitude and the speed of the water table rise. We present a numerical flow and transport model that quantitatively represents the main mechanisms governing oxygen transfer. Assuming local equilibrium between the aqueous and the gaseous phase, the partitioning process from entrapped air can be satisfactorily simulated. The different experiments are monitored by measuring vertical oxygen concentration profiles at high spatial resolution with a noninvasive optode technique as well as by determining oxygen fluxes at the outlet of the flow-through chamber. The results show that all parameters investigated have a significant effect and determine different amounts of oxygen transferred to the oxygen-depleted groundwater. Particularly relevant are the magnitude of the water table rise and the grain size of the porous medium.
Original languageEnglish
JournalGround Water
Volume52
Issue number1
Pages (from-to)37-49
Number of pages13
ISSN0017-467X
DOIs
Publication statusPublished - 2014
Externally publishedYes

Keywords

  • Water Science and Technology
  • Computers in Earth Sciences
  • Anoxic groundwater
  • Average grain diameter
  • Biogeochemical process
  • Flow-through experiments
  • Ground water table
  • High spatial resolution
  • Oxygen concentrations
  • Shallow groundwater
  • Experiments
  • Groundwater
  • Porous materials
  • Sensitivity analysis
  • Oxygen
  • capillarity
  • capillary fringe
  • experimental study
  • flow velocity
  • grain size
  • numerical model
  • oxygen
  • porous medium
  • sensitivity analysis
  • spatial resolution
  • water table
  • ground water
  • article
  • chemistry
  • computer simulation
  • gas
  • hydrology
  • methodology
  • theoretical model
  • water flow
  • Computer Simulation
  • Gases
  • Hydrology
  • Models, Theoretical
  • Water Movements
  • GEOSCIENCES,
  • WATER
  • FLUCTUATING WATER-TABLE
  • TRAPPED GAS-PHASE
  • SATURATED POROUS-MEDIA
  • KINETIC-MODEL
  • VADOSE ZONE
  • SAND COLUMN
  • EXCESS AIR
  • TRANSPORT
  • FLOW
  • GROUNDWATER
  • S88TT14065 Oxygen
  • SENSITIVITY analysis

Cite this

Haberer, Christina M. ; Cirpka, Olaf A. ; Rolle, Massimo ; Grathwohl, Peter. / Experimental Sensitivity Analysis of Oxygen Transfer in the Capillary Fringe. In: Ground Water. 2014 ; Vol. 52, No. 1. pp. 37-49.
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abstract = "Oxygen transfer in the capillary fringe (CF) is of primary importance for a wide variety of biogeochemical processes occurring in shallow groundwater systems. In case of a fluctuating groundwater table two distinct mechanisms of oxygen transfer within the capillary zone can be identified: vertical predominantly diffusive mass flux of oxygen, and mass transfer between entrapped gas and groundwater. In this study, we perform a systematic experimental sensitivity analysis in order to assess the influence of different parameters on oxygen transfer from entrapped air within the CF to underlying anoxic groundwater. We carry out quasi two-dimensional flow-through experiments focusing on the transient phase following imbibition to investigate the influence of the horizontal flow velocity, the average grain diameter of the porous medium, as well as the magnitude and the speed of the water table rise. We present a numerical flow and transport model that quantitatively represents the main mechanisms governing oxygen transfer. Assuming local equilibrium between the aqueous and the gaseous phase, the partitioning process from entrapped air can be satisfactorily simulated. The different experiments are monitored by measuring vertical oxygen concentration profiles at high spatial resolution with a noninvasive optode technique as well as by determining oxygen fluxes at the outlet of the flow-through chamber. The results show that all parameters investigated have a significant effect and determine different amounts of oxygen transferred to the oxygen-depleted groundwater. Particularly relevant are the magnitude of the water table rise and the grain size of the porous medium.",
keywords = "Water Science and Technology, Computers in Earth Sciences, Anoxic groundwater, Average grain diameter, Biogeochemical process, Flow-through experiments, Ground water table, High spatial resolution, Oxygen concentrations, Shallow groundwater, Experiments, Groundwater, Porous materials, Sensitivity analysis, Oxygen, capillarity, capillary fringe, experimental study, flow velocity, grain size, numerical model, oxygen, porous medium, sensitivity analysis, spatial resolution, water table, ground water, article, chemistry, computer simulation, gas, hydrology, methodology, theoretical model, water flow, Computer Simulation, Gases, Hydrology, Models, Theoretical, Water Movements, GEOSCIENCES,, WATER, FLUCTUATING WATER-TABLE, TRAPPED GAS-PHASE, SATURATED POROUS-MEDIA, KINETIC-MODEL, VADOSE ZONE, SAND COLUMN, EXCESS AIR, TRANSPORT, FLOW, GROUNDWATER, S88TT14065 Oxygen, SENSITIVITY analysis",
author = "Haberer, {Christina M.} and Cirpka, {Olaf A.} and Massimo Rolle and Peter Grathwohl",
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Experimental Sensitivity Analysis of Oxygen Transfer in the Capillary Fringe. / Haberer, Christina M.; Cirpka, Olaf A.; Rolle, Massimo; Grathwohl, Peter.

In: Ground Water, Vol. 52, No. 1, 2014, p. 37-49.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Experimental Sensitivity Analysis of Oxygen Transfer in the Capillary Fringe

AU - Haberer, Christina M.

AU - Cirpka, Olaf A.

AU - Rolle, Massimo

AU - Grathwohl, Peter

PY - 2014

Y1 - 2014

N2 - Oxygen transfer in the capillary fringe (CF) is of primary importance for a wide variety of biogeochemical processes occurring in shallow groundwater systems. In case of a fluctuating groundwater table two distinct mechanisms of oxygen transfer within the capillary zone can be identified: vertical predominantly diffusive mass flux of oxygen, and mass transfer between entrapped gas and groundwater. In this study, we perform a systematic experimental sensitivity analysis in order to assess the influence of different parameters on oxygen transfer from entrapped air within the CF to underlying anoxic groundwater. We carry out quasi two-dimensional flow-through experiments focusing on the transient phase following imbibition to investigate the influence of the horizontal flow velocity, the average grain diameter of the porous medium, as well as the magnitude and the speed of the water table rise. We present a numerical flow and transport model that quantitatively represents the main mechanisms governing oxygen transfer. Assuming local equilibrium between the aqueous and the gaseous phase, the partitioning process from entrapped air can be satisfactorily simulated. The different experiments are monitored by measuring vertical oxygen concentration profiles at high spatial resolution with a noninvasive optode technique as well as by determining oxygen fluxes at the outlet of the flow-through chamber. The results show that all parameters investigated have a significant effect and determine different amounts of oxygen transferred to the oxygen-depleted groundwater. Particularly relevant are the magnitude of the water table rise and the grain size of the porous medium.

AB - Oxygen transfer in the capillary fringe (CF) is of primary importance for a wide variety of biogeochemical processes occurring in shallow groundwater systems. In case of a fluctuating groundwater table two distinct mechanisms of oxygen transfer within the capillary zone can be identified: vertical predominantly diffusive mass flux of oxygen, and mass transfer between entrapped gas and groundwater. In this study, we perform a systematic experimental sensitivity analysis in order to assess the influence of different parameters on oxygen transfer from entrapped air within the CF to underlying anoxic groundwater. We carry out quasi two-dimensional flow-through experiments focusing on the transient phase following imbibition to investigate the influence of the horizontal flow velocity, the average grain diameter of the porous medium, as well as the magnitude and the speed of the water table rise. We present a numerical flow and transport model that quantitatively represents the main mechanisms governing oxygen transfer. Assuming local equilibrium between the aqueous and the gaseous phase, the partitioning process from entrapped air can be satisfactorily simulated. The different experiments are monitored by measuring vertical oxygen concentration profiles at high spatial resolution with a noninvasive optode technique as well as by determining oxygen fluxes at the outlet of the flow-through chamber. The results show that all parameters investigated have a significant effect and determine different amounts of oxygen transferred to the oxygen-depleted groundwater. Particularly relevant are the magnitude of the water table rise and the grain size of the porous medium.

KW - Water Science and Technology

KW - Computers in Earth Sciences

KW - Anoxic groundwater

KW - Average grain diameter

KW - Biogeochemical process

KW - Flow-through experiments

KW - Ground water table

KW - High spatial resolution

KW - Oxygen concentrations

KW - Shallow groundwater

KW - Experiments

KW - Groundwater

KW - Porous materials

KW - Sensitivity analysis

KW - Oxygen

KW - capillarity

KW - capillary fringe

KW - experimental study

KW - flow velocity

KW - grain size

KW - numerical model

KW - oxygen

KW - porous medium

KW - sensitivity analysis

KW - spatial resolution

KW - water table

KW - ground water

KW - article

KW - chemistry

KW - computer simulation

KW - gas

KW - hydrology

KW - methodology

KW - theoretical model

KW - water flow

KW - Computer Simulation

KW - Gases

KW - Hydrology

KW - Models, Theoretical

KW - Water Movements

KW - GEOSCIENCES,

KW - WATER

KW - FLUCTUATING WATER-TABLE

KW - TRAPPED GAS-PHASE

KW - SATURATED POROUS-MEDIA

KW - KINETIC-MODEL

KW - VADOSE ZONE

KW - SAND COLUMN

KW - EXCESS AIR

KW - TRANSPORT

KW - FLOW

KW - GROUNDWATER

KW - S88TT14065 Oxygen

KW - SENSITIVITY analysis

U2 - 10.1111/gwat.12028

DO - 10.1111/gwat.12028

M3 - Journal article

C2 - 23406417

VL - 52

SP - 37

EP - 49

JO - Ground Water

JF - Ground Water

SN - 0017-467X

IS - 1

ER -