Uhfo.ppi

SPECIATION
  jobTitle                             "Uranium redox and speciation"
  mainSpecies                          "U"
  calculationType                      ht1
  calculationMethod                    1
  database                             NAPSI_290502(260802).DAT      # relatively recently revised database for U
  fillColorDictionary                  "fillcolor.dat"
  xmin                                 2.0                 # minimum pH
  xmax                                 9.0                 # maximum pH
  ymin                                 -75.0               # minimum PO2(g) to generate variable redox
  ymax                                 0.0                 # maximum PO2(g)
  resolution                           400

PLOT
  plotTitle                            "U-Fe-C-H<sub>2</sub>O<br>(with adsorbed speciation)"
  xtitle                               pH
  yscale                               pe                  # use pe for the y-scale
  pymin                                -10.0               # on the pe scale
  extraText                            "extratextUhfo.dat"

CHEMISTRY

TITLE U Sorption to ferrihydrite according to DLM and database derived and used by
  Luo et al. Journal of Contaminant Hydrology 92, 129148 (2007)

include 'U-Hfo.dat' 
include 'ht1.inc' 

# first simulation - initial solution calculations
SOLUTION 1
  temp      25
  pH        1.8                                            # initial pH is just less than pHmin
  units     mol/kgw
  Na        0.1
  Fe        1e-4
  U(6)      1e-6
  Cl        0.1   charge

EQUILIBRIUM_PHASES
  Fe(OH)3(am) 0 0                                          # NB name of related mineral is different from wateq4f.dat

SURFACE 1
  Hfo_sOH Fe(OH)3(am)      equilibrium_phase 0.005  53300
  Hfo_wOH Fe(OH)3(am)      equilibrium_phase 0.2
SAVE surface 1
END

# second simulation - loops on the final simulation
USE solution 1
USE surface 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

  Graphite                                 0 0
  UO2(s)                                   0 0
  #Goethite                                0 0
  Siderite                                 0 0
  FeCO3(pr)                                0 0
  #Fe(OH)3(mic)                            0 0
  Schoepite                                0 0
  Rutherfordine                            0 0
  Fe(OH)3(am)                              0 0
  #Fe(cr)                                  0 0
  #Hematite                                0 0
  #Magnetite                               0 0

END