GMS:Chemical Reaction Package

The Chemcical Reaction Package dialog

The Chemical Reaction Package dialog is used to solve the concentration change due to chemical reactions. Chemical reactions can be defined for the MT3DMS, MT3D-USGS, PHT3D, RT3D, and SEAM3D models. The dialog is reached through the model menu using the Chemical Reactions command. The chemical reactions include linear or nonlinear sorption isotherms and first-order irreversible rate reactions (radioactive decay or biodegradation).

The dialog has the following options:

• Sorption – Select one of the following methods:
  • "(none)"
  • "Linear isotherm"
  • "Freundich isotherm"
  • "Langmuir isotherm"
  • "First-order kinetic sorption (non-equilibrium)"
  • "Dual-domain mass transfer (without sorption)
  • "Dual-domain mass transfer (with sorption)"
• Kinetic rate reaction – Has the following options:
  • "(none)"
  • "First-order irreversible kinetic reaction"
  • "Zero-order reaction (decay or production)"
• Variable input
  • Layer by layer
  • Cell by cell
• Specify IC of sorbed phase
• Layer – Specifies layer to apply chemical reaction.
• Bulk density
• Immobile porosity