Resources & Systems International, Inc.
Watershed Planning • Resources Management • Environmental Solutions • Ecological Risk Assessment

BIOF&T 3-D Flow and Transport in the Saturated and Unsaturated Zones in 2 or 3 Dimensions 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. BIOF&T -- a finite element model from Resources & Systems International, Inc. allows: Transient 1-D or 2-D Cartesian (x, 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. 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 micraobial processes based on oxygen limited, first order, or Monod type biodegradation kinetics, as well as anaerobic 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.