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SURFACE_COMPLEXATION_RXN Card

Specifies parameters for a surface complexation reaction.

Required Cards:

SURFACE_COMPLEXATION_RXN: Opens the block

Optional Cards:

EQUILIBRIUM: Specifies equilibrium kinetic sorption.
MULTIRATE_KINETIC: Specifies multirate kinetic sorption. Requires RATES and SITE_FRACTION cards.
KINETIC: Specifies kinetic sorption.
COMPLEX_KINETICS: Opens a block specifying forward and backward rate constants.
RATES <float ... float>: Toggles on multirate kinetic sorption. Specifies kinetic rates associated with SITE_FRACTIONs. The number of RATES must match the number of SITE_FRACTIONs.
SITE_FRACTION <float ... float>: Specifies site fractions associated with RATES for multirate kinetic sorption. The number of SITE_FRACTIONs must match the number of RATES.
MINERAL <string>: The name of mineral with which the sorption site density is associated (required, but not yet linked to site density).
MULTIRATE_SCALE_FACTOR <float>: Floating point number that scales all rate constants for multirate kinetic sorption.
COLLOID <string>: Name of colloid associated with surface complexation reaction.
ROCK_DENSITY: Flag telling code to calculate surface site concentration based on rock density [i.e. (1-porosity)*soil_particle_density].
SITE <string> <float>: Name of site and site density. Units are (1) [mol/m³_bulk] when no MINERAL or ROCK_DENSITY card is present, (2) [mol/kg_rock] when ROCK_DENSITY is present, or (3) [mol/m³_rock] when MINERAL is present. If both the ROCK_DENSITY and MINERAL cards are present, the code will key off the last card read to determine the units.
COMPLEXES: Opens a block listing the names of surface complexes associated with the surface complexation reaction and the surface site. These are provided by the database file.

Examples

SORPTION
  SURFACE_COMPLEXATION_RXN
    MULTIRATE_KINETIC
    SITE_FRACTION \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02 \
      0.02 0.02 0.02 0.02 0.02
    RATES \
      2.5722E-11  8.5000E-11  1.5972E-10  2.5139E-10  3.6111E-10 \
      4.9167E-10  6.4167E-10  8.1667E-10  1.0167E-09  1.2472E-09 \
      1.5111E-09  1.8111E-09  2.1528E-09  2.5389E-09  2.9722E-09 \
      3.4722E-09  4.0278E-09  4.6667E-09  5.3889E-09  6.2222E-09 \
      7.1389E-09  8.1944E-09  9.3611E-09  1.0722E-08  1.2278E-08 \
      1.4028E-08  1.6056E-08  1.8389E-08  2.1056E-08  2.4139E-08 \
      2.7750E-08  3.1944E-08  3.6944E-08  4.2778E-08  4.9444E-08 \
      5.7778E-08  6.7778E-08  8.0000E-08  9.5000E-08  1.1389E-07 \
      1.3806E-07  1.6944E-07  2.1111E-07  2.6861E-07  3.5000E-07 \
      4.7778E-07  6.8611E-07  1.0778E-06  2.0278E-06  6.6944E-06
    MULTIRATE_SCALE_FACTOR 1000.d0
    MINERAL Kaolinite
    SITE >SiOH 0.00636
    COMPLEXES
      >SiOUO3H3++
      >SiOUO3H2+
      >SiOUO3H
      >SiOUO3-
      >SiOUO2(OH)2-
    /
  /
  SURFACE_COMPLEXATION_RXN
    EQUILIBRIUM
    MINERAL Kaolinite
    SITE >FeOH 0.00636
    COMPLEXES
      >FeOHUO3
      >FeOHUO2++
    /
  /
  SURFACE_COMPLEXATION_RXN
    EQUILIBRIUM
    MINERAL Kaolinite
    SITE >AlOH 0.00636
    COMPLEXES
      >AlOUO2+
    /
  /
END