Adsorption
Use this node to model adsorption of the (fluid phase) solute species onto the surface of the porous matrix. It is available as a subnode to the Porous Medium and the Unsaturated Porous Medium nodes.
Matrix Properties
The density of the porous media is needed when modeling adsorption to the surface of the porous matrix. Choose to input either the Dry bulk density ρ, or the Solid phase density ρs. The former is the density of the porous matrix including empty pores, while the latter corresponds to the density of the pure solid phase. The density can be defined from the domain material by selecting From material, or from a user defined expression. When a Porous Material is used on the selection, the density will be requested from a Solid subfeature. Several Solid features can be used to model a homogeneous mixture of several solid components.
Adsorption
Select an Adsorption isothermLangmuir, Freundlich, Toth, BET, or User defined to specify how to compute cP, the amount of species sorbed to the solid phase (moles per unit dry weight of the solid):
For Langmuir:
Enter a Langmuir constant kL,c (SI unit: m3/mol) and an Adsorption maximum cp,max,c (SI unit: mol/kg).
For Freundlich:
Enter a Freundlich constant kF,c (SI unit: mol/kg), a Freundlich exponent NF,c (dimensionless), and a Reference concentration cref,c (SI unit: mol/m3).
For Toth:
and
Enter a Toth constant bT,c (SI unit: m3/mol), a Toth exponent NT,c (dimensionless), and an Adsorption maximum cp,max,c (SI unit: mol/kg).
For BET (Brunauer-Emmett-Teller):
and
Enter a BET constant KB,c (dimensionless), a Monolayer adsorption capacity c0,c (SI unit: mol/kg), and an Saturation concentration cS,c (SI unit: mol/m3).
For User defined enter an Adsorption isotherm cP,c (SI unit: mol/kg):
For more information, see in the theory section.
Further Reading
See the theory chapter in the section .