SEAM3D Description:

SEAM3D is a reactive transport model used to simulate complex biodegradation problems involving multiple substrates and multiple electron acceptors. It is based on the MT3DMS code. In addition to the regular MT3DMS modules, SEAM3D includes a Biodegradation package and NAPL Dissolution package. SEAM3D was developed by Mark Widdowson at Virginia Tech University.

The model can depict multiple constituents in a three dimensional, anisotropc, heterogeneous domain. Hydrocarbon contaminants are simulated as electron donors for microbial growth, with available EAs used in the following sequence: oxygen, nitrate, oxidized manganese, ferric iron, sulfate, and carbon dioxide. SEAM3D can account for reduced manganese, ferrous iron, hydrogen sulfide, methane, and a user-defined nitrogenous compound as products of biodegradation. In addition, each hydrocarbon substrate can produce a single daughter product. Biodegradation of each substrate follows Monod kinetics, modified to include the effects of EA and nutrient availability. Inhibition functions allow any EA to inhibit utilization of all other EAs that provide less energy to the microbes. Microbial biomass is simulated as scattered microcolonies attached to the porous medium. The model assumes that interphase diffusional limitations to microbial growth are negligible and no geometrical parameters are assigned to the colonies.