gridSe.ppi

SPECIATION
  jobTitle                             "Plutonium redox and speciation"
  Database                             wateq4f.dat             # contains Se species
  calculationType                      grid
  calculationMethod                    1
  mainSpecies                          "Se"
  xmin                                 2.0                 # pH 2 to 10
  xmax                                 10.0
  ymin                                 -80.0               # redox
  ymax                                 0.0
  resolution                           100                 # some low-angled boundaries could benefit from higher resolution or more smoothing
  fillColorDictionary                  ..\Se\fillcolor.dat

PLOT
  plotTitle                            "Selenium protonation and redox<br>(no adsorption)"
  xtitle                               pH
  ytitle                               "log <i>f</i> O<sub>2</sub>(g)"
  labelSize                            2.0
  extraText                            ..\Se\extratextSe.dat 

CHEMISTRY

# first simulation - initial solution calculation

include 'ht1.inc'

SOLUTION 1
   temp  25
   pH    1.8                                               # start out at pH<xmin
   units mol/kgw
   Se    1e-3                                              # total Se
   Na    1e-1
   Cl    1e-1
   S     1e-3
END


# second simulation - equilibrate
USE solution 1
EQUILIBRIUM_PHASES 1
   Fix_H+ -<x_axis>  NaOH 10
     -force_equality true
   O2(g)  <y_axis>  0.1
   CO2(g) -3.5      1.0

  Se(s)                          0 0                       # possible Se minerals
  Mirabilite                     0 0
  Thenardite                     0 0
  Sulfur                         0 0
  SeO2                           0 0
END