ION_EXCHANGE_RXN Card

Specifies parameters for an ion exchange reaction.

Required Cards

ION_EXCHANGE_RXN : Opens the block

MINERAL <string> : Name of the mineral to which the cations sorb

CEC <float> : Cation exchange capacity in equivalents per bulk volume (eq/m^3^_bulk)

CATIONS : Opens block for listing cations participating in the reaction

<Cation species Name> <float> : Name of cation and associated selectivity coefficient. One must select a reference cation with a selectivity coefficient of 1. and convert all the selectivity coefficients to be relative to the reference species selectivity coefficient.

Examples

SORPTION
  ION_EXCHANGE_RXN
    MINERAL Halite
    CEC 750.  ! eq/m^3
    CATIONS
      Na+   1.
      Ca++  0.2953
      Mg++  0.1666
    /
  /
END