As5-shvrfig7.ppi

SPECIATION
  calculationType                      species                       # plot all As species f(pH) including adsorbed species
  calculationMethod                    1
  mainSpecies                          "As"                          #
  xmin                                 3.0
  xmax                                 12.0
  resolution                           100                           # controls the number of points at which speciation is calculated
  loopFile                             "loopfig7.dat"                # defines <loop1> and <loop2> which are used below
  numericTags                          <AsT> = <loop1> \
                                       <mass> = <loop2>
PLOT
  plotTitle                            "CD-MUSIC: As(V) surface speciation<br>(after Stachowicz et al., 2006, Fig. 7)"
  xtitle                               pH
  customxcolumn                        2                             # 2nd column in selected output created by adsspeciesvsph.inc
  pxmin                                3                             # plot xmin
  labelSize                            1.5
  minimumyvalueforplotting             0.1                           # can be used to omit plotting of species that are always below this value
                                                                     # here the As(3) species
  extratext                            "extratextfig7.dat"
  legendTextSize                       0                             # turn off legend to the right of the plot

CHEMISTRY

include 'adsspeciesvsph.inc'                                         # this controls exactly what is plotted (see the system directory for the file)
                                                                     # must 'punch' x-axis, y-axis pairs
SELECTED_OUTPUT
  -reset false

SOLUTION 1
   Temp      25
   pH        2.9
   units     mol/kgw
   As(5)     <AsT> mmol/kgw                                          # total As(5) concn
   Na        1e-1                                                    # background electrolyte
   N(5)      1e-1                                                    # N(5) only stable in oxidising environments

include 'cdmusic_hiemstra.dat' 

#
#   Arsenate - these are the actual figures used in the SHR2006 paper and change the speciation from the above database slightly
#

SURFACE_SPECIES

        Goe_uniOH-0.5 + 2H+ + AsO4-3 = Goe_uniOAsO2OH-1.5 + H2O
            log_k    26.62 # SHR2006  26.60   # SHR2008
            -cd_music  0.30 -1.30 0 0 0

        2Goe_uniOH-0.5 + 2H+ + AsO4-3 = (Goe_uniO)2AsO2-2 + 2H2O
             log_k    29.29 # SHR2006  29.77  # SHR2008
             -cd_music  0.47  -1.47  0 0 0

        2Goe_uniOH-0.5 + 3H+ + AsO4-3 = (Goe_uniO)2AsOOH- + 2H2O
             log_k     32.69 # SHR2006  33.00  # SHR2008
             -cd_music  0.58 -0.58 0 0 0

PHASES
Fix_H+; H+ = H+ ; log_k 0

SURFACE 1
  Goe_uniOHH0.5 3.45 98 <mass>                                       # sites/nm2  m2/g  g
    -cap    0.85  0.75                                               # C1  C2  (in F/m2)
  Goe_triOH0.5  2.7
    -cd_music
    -sites_units density

EQUILIBRIUM_PHASES 1
    Fix_H+  -<x_axis> NaOH
      -force_equality true
    O2(g)  -0.67
END