PHREEQC modelling was carried out using Phreeqc Interactive 3.1.7-9213
using the llnl database provided with the software and the script below:

SOLUTION 1
    temp      25
    pH        7 charge
    pe        4
    redox     pe
    units     mol/kgw
    density   1
    Alkalinity 0
    -water    1 # kg
EQUILIBRIUM_PHASES 1
#   Calcite 0 1000
#   Portlandite 0 1000
    CO2(g)    -3.408822658 100
#   NO2(g)    -5.149185348 100
    SO2(g)    -5.149185349 100
END



For each condition described in the paper (see table 1), the gas phases,
the gas concentrations and the solid phases were modified by commenting
or un-commenting the code with a hashtag. The example above, for instance,
is a model with only CO2 and SO2 as gas phases and no solid phases.

Full models produced by PHREEQC for each case discussed within hte paper
are reported in the attached pdf files:

PHREEQC_model_with_CO2+SO2+NO2_(no_solid_phases).pdf
PHREEQC_model_with_CO2+SO2_(no_solid_phases).pdf
PHREEQC_model_with_CO2+NO2_(no_solid_phases).pdf

PHREEQC_model_with_CO2+SO2+NO2+Calcite.pdf
PHREEQC_model_with_CO2+SO2+Calcite.pdf
PHREEQC_model_with_CO2+NO2+Calcite.pdf

PHREEQC_model_with_CO2+NO2+SO2+Calcite+Portlandite.pdf
PHREEQC_model_with_CO2+NO2+Calcite+Portlandite.pdf
PHREEQC_model_with_CO2+SO2+Calcite+Portlandite.pdf

PHREEQC can be freely downloaded at the URL:
http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/