Scalable Modeling of Carbon Tetrachloride Migration at the Hanford Site Using the STOMP Simulator

White, Mark D.; Oostrom, Mart; Rockhold, Mark; Rosing, Matthew

doi:10.2136/vzj2007.0070

Cited by 24 publications

(19 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As numerical models are becoming much more efficient, comprehensive, and numerically accurate, their application to a large number of theoretical and practical problems is becoming increasingly widespread. This is true not just for the HYDRUS models but also for other models addressing various soil, hydrologic and environmental science, and engineering problems such as the TOUGH models (Finsterle et al, 2008), STOMP (White et al, 2008), SWAP (van Dam et al, 2008), VS2DI (Healy, 2008), and many other models as discussed by Vereecken et al (2016). As we noted earlier in our 2008 paper (Šimůnek et al, 2008b), we believe that these various models and modeling tools have served, and will continue to serve, an extremely important role in vadose zone research.…”

Section: Discussionmentioning

confidence: 99%

Recent Developments and Applications of the HYDRUS Computer Software Packages

Šimůnek

Genuchten

Šejna³

2016

Vadose Zone Journal

722

336

View full text Add to dashboard Cite

The HYDRUS-1D and HYDRUS (2D/3D) computer software packages are widely used finite-element models for simulating the one-and two-or three-dimensional movement of water, heat, and multiple solutes in variably saturated media, respectively. In 2008, Šimůnek et al. (2008b) described the entire history of the development of the various HYDRUS programs and related models and tools such as STANMOD, RETC, ROSETTA, UNSODA, UNSATCHEM, HP1, and others. The objective of this manuscript is to review selected capabilities of HYDRUS that have been implemented since 2008. Our review is not limited to listing additional processes that were implemented in the standard computational modules, but also describes many new standard and nonstandard specialized add-on modules that significantly expanded the capabilities of the two software packages. We also review additional capabilities that have been incorporated into the graphical user interface (GUI) that supports the use of HYDRUS (2D/3D). Another objective of this manuscript is to review selected applications of the HYDRUS models such as evaluation of various irrigation schemes, evaluation of the effects of plant water uptake on groundwater recharge, assessing the transport of particle-like substances in the subsurface, and using the models in conjunction with various geophysical methods.Abbreviations: CRS, cosmic-ray sensing; EC, electrical conductivity; ERT, electrical resistivity tomography; FEM, finite element mesh; GPR, ground-penetrating radar; GUI, graphical user interface; TDT, time-domain transmissometry.The HYDRUS-1D and HYDRUS (2D/3D) software packages (Šimůnek et al., 2008b) are finite-element models for simulating the one-and two-or three-dimensional movement of water, heat, and multiple solutes in variably saturated media, respectively. The standard versions, as well as various specialized add-on modules, of the HYDRUS programs numerically solve the Richards equation for saturated-unsaturated water flow and convection-dispersion type equations for heat and solute transport. The flow equation incorporates a sink term to account for water uptake by plant roots as a function of water and salinity stress. Both compensated and uncompensated water uptake by roots can be considered. The heat transport equation considers movement by both conduction and convection with flowing water. The governing convection-dispersion solute transport equations are written in a relatively general form by including provisions for nonlinear, nonequilibrium reactions between the solid and liquid phases and linear equilibrium reactions between the liquid and gaseous phases. The transport models also account for convection and dispersion in the liquid phase as well as diffusion in the gas phase, thus permitting the models to simulate solute transport simultaneously in both the liquid and gaseous phases. Hence, both adsorbed and volatile solutes, such as pesticides and fumigants, can be considered.The solute transport equations further incorporate the effects of zero-order production, first-o...

show abstract

Section: Discussionmentioning

confidence: 99%

Recent Developments and Applications of the HYDRUS Computer Software Packages

Šimůnek

Genuchten

Šejna³

2016

Vadose Zone Journal

722

336

View full text Add to dashboard Cite

show abstract

“…Liquid CT was previously disposed at the surface and resulted in a CT distribution within the approximately 80 m thick vadose zone and the underlying groundwater (Department of Energy [DOE] 2007). Numerical simulations have indicated that the water added to the vadose zone during waste disposal operations has substantially drained such that moisture conditions have reverted back to near the initial conditions except for the high silt zones of the vadose zone (Oostrom et al 2007;White et al 2008). Operational data suggest that SVE has been effective in the permeable formations and that residual contamination in the low-permeability Cold Creek unit (CCU) will be the primary contaminant source in the vadose zone over the long term.…”

Section: Methodsmentioning

confidence: 99%

Three‐Dimensional Simulation of Volatile Organic Compound Mass Flux from the Vadose Zone to Groundwater

Oostrom¹,

Truex²,

Tartakovsky³

et al. 2010

Groundwater Monitoring Rem

View full text Add to dashboard Cite

Low‐permeability layers of the vadose zone containing volatile organic compounds (VOCs) may persist as source zones for long time periods and may provide contamination to groundwater. At sites with low recharge rates, where vapor migration is the dominant transport process, the impact of vadose zone sources on groundwater may be difficult to assess. Typical assessment methods include one‐dimensional numerical and analytical techniques. The one‐dimensional approaches only consider groundwater coupling options through boundary conditions at the water table and may yield artificially high mass flux results when transport is assumed to occur by gas‐phase diffusion between a source and an interface with a zero concentration boundary condition. Improvements in mass flux assessments for VOCs originating from vadose zone sources may be obtained by coupling vadose zone gas transport and dissolved contaminant transport in the saturated zone and by incorporating the inherent three‐dimensional nature of gas‐phase transport, including the potential of density‐driven advection. This paper describes a series of three‐dimensional simulations using data from the U.S. Department of Energy's Hanford site, where carbon tetrachloride is present in a low‐permeability zone about 30 m above the groundwater. Results show that, for most cases, only a relatively small amount of the contaminant emanating from the source zone partitions into the groundwater and that density‐driven advection is only important when relatively high source concentrations are considered.

show abstract

“…For a field-scale reactive transport model with explicit representation of geologic heterogeneity on a fine grid, the number of grid cells could be very large [e.g. millions (White et al, 2008)]. Therefore, computational demands of the direct coupling approach may be prohibitive.…”

Section: Coupling the Constraint-based Model With Reactive Transport mentioning

confidence: 99%

Coupling a genome‐scale metabolic model with a reactive transport model to describe in situ uranium bioremediation

Scheibe

Mahadevan

Fang

et al. 2009

Microbial Biotechnology

102

View full text Add to dashboard Cite

SummaryThe increasing availability of the genome sequences of microorganisms involved in important bioremediation processes makes it feasible to consider developing genome‐scale models that can aid in predicting the likely outcome of potential subsurface bioremediation strategies. Previous studies of the in situ bioremediation of uranium‐contaminated groundwater have demonstrated that Geobacter species are often the dominant members of the groundwater community during active bioremediation and the primary organisms catalysing U(VI) reduction. Therefore, a genome‐scale, constraint‐based model of the metabolism of Geobacter sulfurreducens was coupled with the reactive transport model HYDROGEOCHEM in an attempt to model in situ uranium bioremediation. In order to simplify the modelling, the influence of only three growth factors was considered: acetate, the electron donor added to stimulate U(VI) reduction; Fe(III), the electron acceptor primarily supporting growth of Geobacter; and ammonium, a key nutrient. The constraint‐based model predicted that growth yields of Geobacter varied significantly based on the availability of these three growth factors and that there are minimum thresholds of acetate and Fe(III) below which growth and activity are not possible. This contrasts with typical, empirical microbial models that assume fixed growth yields and the possibility for complete metabolism of the substrates. The coupled genome‐scale and reactive transport model predicted acetate concentrations and U(VI) reduction rates in a field trial of in situ uranium bioremediation that were comparable to the predictions of a calibrated conventional model, but without the need for empirical calibration, other than specifying the initial biomass of Geobacter. These results suggest that coupling genome‐scale metabolic models with reactive transport models may be a good approach to developing models that can be truly predictive, without empirical calibration, for evaluating the probable response of subsurface microorganisms to possible bioremediation approaches prior to implementation.

show abstract

Scalable Modeling of Carbon Tetrachloride Migration at the Hanford Site Using the STOMP Simulator

Cited by 24 publications

References 29 publications

Recent Developments and Applications of the HYDRUS Computer Software Packages

Recent Developments and Applications of the HYDRUS Computer Software Packages

Three‐Dimensional Simulation of Volatile Organic Compound Mass Flux from the Vadose Zone to Groundwater

Coupling a genome‐scale metabolic model with a reactive transport model to describe in situ uranium bioremediation

Contact Info

Product

Resources

About