Description

This keyword specifies, if the component sorbs in the phase in which it is transported simple retardation. Linear, Freundlich and Langmuir sorption are accounted for. No mass is transferred to the immobile phase. Aqueous and sorbed concentrations are termed C and CS, respectively.

Parameters

$ISOTHERM 0

$ISOTHERM
1 K_D

$ISOTHERM
2 K_fr e

$ISOTHERM
3 K L

Isotherm Method

• -1: No isotherm
• 0: get KD from curve derivative. Give curve_number. curve derivative is taken at the element_concentration.
• 1: Henry Isotherm (Linear isotherm). Give method linear_distribution_coefficient.

  \[ C_S = K_D C \]

• 2: Freundlich Isotherm. Give method Freundlich_coefficient freundlich_exponent.

  \[ C_S = K_{fr} C^e \]

• 3: Langmuir Isotherm. Give param1 param2.

  \[ C_S = \frac{KC}{1+KC} \]

• 4: Linear Isotherm, for fracture surface CMCD
• 5: two-rate model