CO2goethitefit.ppi

SPECIATION
  database                             wateq4f.dat
  rewriteInputFile                     T
  calculationType                      fit
  calculationMethod                    1
  numericTags                          <sa> = 70 \
                                       <z1> = -<z0> \
                                       <molCO2> = <C4>*1e-3

FIT
  dataFile                             villalobos2000.txt
  dependentVariableColumnObs           obsSorbed
  dependentVariableColumnCalc          sorbedC
  fitFiniteDiffStepSize                1.0E-2
  fitWeightingMethod                   2
  weightColumn                         weight
  fitParameterNames                    log_k z0
  fitLogParameters                     0 0
  fitAdjustableParameters              1 1
  fitParameterValues                   22.429768684377 0.72590217292346
  updateFitParameters                  T

PLOT
  plotTitle                            "Carbonate sorbed on goethite vs pH<br>(Villalobos & Leckie (2000) data & CD-MUSIC)"
  xtitle                               "pH"
  ytitle                               "Carbonate sorbed (\mmol/m<sup>2</sup>)"
  lines                                sorbedC
  lineWidth                            0.4
  changeColor                          T
  customXcolumn                        pH
  points                               observed
  pointSize                            2 0.1
  labels                               ""
  labelSize                            1.5
  labelEffort                          2
  extraText                            extratextCO2.dat 

CHEMISTRY
  TITLE Villalobos and Leckie JCIS 22, 3787-3802 (2000) Fig. 6(a)
  include "cdmusic_hiemstra.dat"
  SURFACE_SPECIES
    2Goe_uniOH-0.5 + 2H+ + CO3-2 = (Goe_uniO)2CO- + 2H2O
    log_k     <log_k>
      -cd_music  <z0>  <z1>  0 0 0
  SURFACE 1
    Goe_uniOHH0.5 3.45 <sa> <mass>
      -cap    0.85  0.75
    Goe_triOH0.5  2.7
      -cd_music
      -sites_units density
  PHASES
    Fix_H+
    H+ = H+
    log_k  0.0
  SOLUTION 1
    Na     <Na> mol/kgw
    Cl     <Cl> mol/kgw charge
  SELECTED_OUTPUT
      -high_precision TRUE
      -reset FALSE
  USER_PUNCH
      -headings pH dissC totC sorbedC pCO2 Alk
    10 totC = SYS("C")
    20 sorbedC = SURF("C","Goe")*1e6/(<sa>*<mass>)
    30 dissC = tot("C")*1e6
    40 pCO2 = SI("CO2(g)")
    50 punch -la("H+"), dissC, totC, sorbedC, pCO2, Alk
  EQUILIBRIUM_PHASES 1
    Fix_H+   -<obspH>   NaOH    10.0
      -force_equality true
  GAS_PHASE
      -fixed_volume
    N2(g)  1.0
    CO2(g) 0.0
      -volume <Vg>
  REACTION
    CO2 1.0
    <molCO2>
  END