1. General Model Information

Name: Flow and Transport in the Saturated and Unsaturated Zones in 2 or 3 Dimensions

Acronym: BIOFT3D

Contact:

Author(s):

Abstract:

All too often simplified assumptions are made to simulate flow and transport of contaminants at sites with complex physical, chemical and biological conditions to enable use of analytical or less rigorous numerical models. But typical contaminated field sites have complicated heterogeneous and/or anisotropic hydrogeology, some have fractures undergoing significant mass exchange with surrounding porous media. The sources of contamination are spatially distributed and/or changing with time. Microbial metabolism activities can proceed in the presence of a variety of electron acceptors. When a site's complexities are ignored, results can often be erroneous and meaningless.

Draper Aden Environmental Modeling, Inc. has developed a finite element model, BIOF&T-3D, that allows:

• Transient 1-D or 2-D Cartesian (x, z) or 2-D Radial (r, z) water flow and multispecies dissolved phase transport solution in the unsaturated zone uncoupled with 2-D or 3-D flow and multicomponent aqueous phase transport in groundwater aquifers. This feature enables computationally efficient simulations with a model that gives due regard to the dimensionality of the problem and is hydrogeologically defensible.
• An option for fully coupled 3-D simulations of unsaturated and saturated zones for extremely complicated conditions.
• Temporal and spatial variations in the source (i.e., residual dense or light nonaqueous phase liquids and/or other nonpoint contaminations), and, given the initial conditions, changes in loading to groundwater are computed and updated internally.
• Spatial variation in recharge/injection and/or pumping/extraction.
• Simulation of heterogeneous and/or anisotropic porous media with (or without) fractures based on a dual porosity approach.
• Rectangular 2-D/3-D prism or isoparametric quadrilateral/hexahedral elements to accurately model irregular domain and material boundaries, hydraulic and physical boundaries.
• Convection, dispersion, diffusion, adsorption, desorption, and microbial processes based on oxygen limited, first order, or Monod type biodegradation kinetics, as well as anerobic sequential degradation involving multiple daughter products. This allows real world modeling not accomplished in similar biodegradation packages.
• Computationally efficient matrix solution by conjugate gradient method with preconditioning.

Output

FLOW

• Spatial distribution of water pressure with time
• Spatial distribution of water saturation with time
• Velocity distribution with time
• Pumping/injection rates and volume vs. time

For each species:

• Spatial distribution of concentration with time
• Mass dissolved in water vs. time
• Mass remaining in NAPL phase vs. time
• Mass adsorbed on the solid phase vs. time

II. Technical Information II.1 Executables:
Hardware requirements:

• 486 processor or higher

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  II. Technical Information

  II.1 Executables:

  Operating System(s): Hardware requirements:
  • 486 processor or higher
  • Math coprocessor
  • At least 8MB of RAM, 16MB for 3D
  • 2.5MB of hard disk space
  2-D version with 1,500 finite element nodes and 3-D version with 10,000 nodes availableOrder Sheet and pricing information
  
  

  II.2 Source-code:

  Programming Language(s):
  
  

  II.3 Manuals:

  Included in Package (see II.1)
  
  

  II.4 Data:

  
  

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  III. Mathematical Information

  
  

  III.1 Mathematics

  
  

  III.2 Quantities

  
  

  III.2.1 Input

  III.2.2 Output

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  IV. References

  
  

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  V. Further information in the World-Wide-Web

  BIOF&T - 3-D

  
  

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  VI. Additional remarks

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  Last review of this document by: T. Gabele: 16. 6. 1997 -
  Status of the document:
  last modified by Tobias Gabele Wed Aug 21 21:44:39 CEST 2002

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