A time-synchronous domain decomposition code for multiphysics systems

Trefry, M. G.; Ohman, J.; Whyte, David; Davis, Gordon B.

doi:10.21914/anziamj.v42i0.653

Cited by 3 publications

(2 citation statements)

References 8 publications

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“…Alternatively, hydrocarbon concentration changes have been modeled without linkage to oxygen or other major gas concentrations Turczynowicz and Robinson 2001;Ririe et al 2002). Increasingly, vapor modeling has focused on coupled hydrocarbon and oxygen transport to simulate oxygen-dependent biodegradation conditions (Ö hman 1999;Hers et al 2000;Trefry et al 2000;Johnson 2005, 2006;DeVaull 2007). Also, such an approach was reported earlier by Ostendorf and Kampbell (1991).…”

Section: Introductionmentioning

confidence: 99%

Evidence for Instantaneous Oxygen‐Limited Biodegradation of Petroleum Hydrocarbon Vapors in the Subsurface

Davis¹,

Patterson²,

Trefry³

2009

Groundwater Monitoring Rem

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Petroleum hydrocarbon vapors biodegrade aerobically in the subsurface. Depth profiles of petroleum hydrocarbon vapor and oxygen concentrations from seven locations in sandy and clay soils across four states of Australia are summarized. The data are evaluated to support a simple model of biodegradation that can be used to assess hydrocarbon vapors migrating toward built environments. Multilevel samplers and probes that allow near-continuous monitoring of oxygen and total volatile organic compounds (VOCs) were used to determine concentration depth profiles and changes over time. Collation of all data across all sites showed distinct separation of oxygen from hydrocarbon vapors, and that most oxygen and hydrocarbon concentration profiles were linear or near linear with depth. The low detection limit on the oxygen probe data and because it is an in situ measurement strengthened the case that little or no overlapping of oxygen and hydrocarbon vapor concentration profiles occurred, and that indeed oxygen and hydrocarbon vapors were largely only coincident near the location where they both decreased to zero. First-order biodegradation rates determined from all depth profiles were generally lower than other published rates. With lower biodegradation rates, the overlapping of depth profiles might be expected, and yet such overlapping was not observed. A model of rapid (instantaneous) reaction of oxygen and hydrocarbon vapors compared to diffusive transport processes is shown to explain the important aspects of the 13 depth profiles. The model is simply based on the ratio of diffusion coefficients of oxygen and hydrocarbon vapors, the ratio of the maximum concentrations of oxygen and hydrocarbon vapors, the depth to the maximum hydrocarbon source concentration, and the stoichiometry coefficient. Whilst simple, the model offers the potential to incorporate aerobic biodegradation into an oxygen-limited flux-reduction approach for vapor intrusion assessments of petroleum hydrocarbon compounds.

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Section: Introductionmentioning

confidence: 99%

Evidence for Instantaneous Oxygen‐Limited Biodegradation of Petroleum Hydrocarbon Vapors in the Subsurface

Davis¹,

Patterson²,

Trefry³

2009

Groundwater Monitoring Rem

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“…There have been several studies since looking specifically at gasoline‐range vapors above petroleum impacted soil, and groundwater (Fischer et al, 1996; Laubacher et al, 1997; Davis et al, 1998b, 2000, 2001; Franzmann et al, 1999; Hers et al, 2000; Wang et al, 2003). Data from a number of studies were compiled by Roggemans et al (2002) A range of modeling studies has also been performed (Jury et al, 1983; Baehr, 1987; Falta et al, 1989; Sleep and Sykes, 1989; Johnson and Ettinger, 1991; Lahvis and Baehr, 1996; Anderssen et al, 1997; Anderssen and Markey, 1997; Bekins et al, 1998; Johnson et al, 1999; Trefry et al, 2000, 2001; Turczynowicz and Robinson, 2001), some in combination with field studies (Barber and Davis, 1991a, 1991b; Öhman, 1999; Hers et al, 2000).…”

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confidence: 99%

Measurement and Modeling of Temporal Variations in Hydrocarbon Vapor Behavior in a Layered Soil Profile

Davis

Rayner

Trefry

et al. 2005

Vadose Zone Journal

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Jury et al.Fine-scale measurement of gasoline vapors, major gases (O 2 , CO 2 , and Baehr, 1996; Anderssen et al., 1997; Anderssen and N 2 , and CH 4 ), residual nonaqueous phase liquid (NAPL) gasoline, Markey, 1997; Bekins et al., 1998;Johnson et al., 1999; and soil physical properties has allowed detailed assessment of the role of soil layering and seasonal variability on hydrocarbon vapor Turczynowicz and Robinson, fate and biodegradation. In this study we conducted coring and static 2001), some in combination with field studies (Barber depth profile monitoring at the end of summer and end of winter for and Davis, 1991aand Davis, , 1991bÖ hman, 1999;Hers et al., 2000). a layered sandy vadose zone in Perth, Western Australia. Transient Despite the modeling efforts and related work, there on-line monitoring of vapors and O 2 was also performed with in situ are still only limited field data sets with sufficient detail multilevel volatile organic compound (VOC) and O 2 probes. For high for evaluating vapor processes in impacted soil profiles soil moisture contents at the end of winter, vapors were shown to and for model validation. Additional well-documented accumulate beneath a compacted, cemented layer approximately 0.3 m studies are required (Johnson et al., 1999). Also, changes below the ground surface, and O 2 penetrated only to depths of 0.4 m in soil moisture distribution and soil layering have been below ground. At the end of summer, when soil moisture was lower, reported to impact vapor behavior and lead to complica-O 2 penetrated to depths of up to 1.5 m, and hydrocarbon vapors remained at or below this depth. Regardless of seasonal changes, sharp tions when estimating biodegradation rates (Johnson separations were seen between the depth of O 2 penetration from the and Perrott, 1991; Fischer et al., 1996;. ground surface and the depth of penetration of the vapors upwardWe present the results of field research and modelfrom the hydrocarbon-contaminated zone. Modeling of steady-state ing to quantify the role of a fine-scale moisture-retentive O 2 profiles indicated that a number of simple O 2 consumption models layer in a soil profile in changing the subsurface distribumight apply, including point-sink, distributed zero-order, or distribtion of gasoline vapors and the major gases due to seauted first-order models, each leading to different biodegradation rates. sonal changes in moisture contents. Simple analytical Combining independent data with modeling helped determine the and numerical modeling was performed to assess the most appropriate model, and hence estimates of O 2 consumption and impact of moisture variability on estimates of the biohydrocarbon biodegradation. Also, reliable estimates of the biodegdegradation rate based on depth profiles. Coring, depth radation rate could only be calculated after consideration of the layered features.

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A simple numerical approach for assessing coupled transport processes in partitioning systems

Trefry

Ohman

Davis

2001

Applied Mathematical Modelling

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A time-synchronous domain decomposition code for multiphysics systems

Cited by 3 publications

References 8 publications

Evidence for Instantaneous Oxygen‐Limited Biodegradation of Petroleum Hydrocarbon Vapors in the Subsurface

Evidence for Instantaneous Oxygen‐Limited Biodegradation of Petroleum Hydrocarbon Vapors in the Subsurface

Measurement and Modeling of Temporal Variations in Hydrocarbon Vapor Behavior in a Layered Soil Profile

A simple numerical approach for assessing coupled transport processes in partitioning systems

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