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Supported features

PhreeqPython wraps a subset of PHREEQC as Python objects. Those objects stay in the engine, so you can query and change them stepwise. Anything without an object API is listed under Not supported yet.

You can run these examples

Click Run (or Ctrl+Enter), or Run all to execute every editor in order. The first run loads Pyodide and can take a few seconds. Editors on this page share a session, so later cells can reuse pp and solution.

Object-oriented PHREEQC

Solutions, gases, and equilibrium phases are objects. You create them on a PhreeqPython instance, call methods, and read properties. PhreeqPython generates the PHREEQC snippets and keeps the numbered entities in memory.

Editor (session: features)Run 
from phreeqpython import PhreeqPython

pp = PhreeqPython()
solution = pp.add_solution({
    'pH': 7,
    'units': 'mmol/kgw',
    'Ca': 1,
    'C': 2,
    'Na': 2,
    'Cl': 2,
})
print(solution.pH)
OutputClear

Mixing uses ordinary Python operators (solution * 0.5 + other * 0.5). Copies, dumps, and custom master species / solution species are also available.

Speciation and solution properties

After each calculation you can read speciation and bulk properties without a SELECTED_OUTPUT block:

  • pH, pe, temperature, ionic strength
  • specific conductivity, density, mass, volume
  • element totals and aqueous species (moles, molalities, activities)
  • saturation indices and saturation ratios for mineral and gas phases

Editor (session: features)Run 
print(solution.pH)
print(solution.sc)
print(solution.species['HCO3-'])
print(solution.si('Calcite'))
OutputClear

Reactions and phases

Change a solution in place, or equilibrate it with one or more pure phases:

  • add, remove, or change amounts (add, remove, change)
  • set pH or temperature
  • saturate, desaturate, or equalize with named phases (Calcite, Gypsum, …)
  • keep a reusable EquilibriumPhase and interact with it

Changes are additive

solution.add('NaOH', 0.5) changes the solution in place. If you run this cell again, another 0.5 mmol of NaOH is added. To start over, rerun the first editor, which creates a new solution.

Editor (session: features)Run 
solution.add('NaOH', 0.5)
print('pH', solution.pH)
solution.desaturate('Calcite')
print('Ca mmol', solution.total('Ca'))
print('SI Calcite', solution.si('Calcite'))
OutputClear

Gases

Gas phases are objects as well: fixed pressure or fixed volume, optional equilibration when created, then interaction with a solution.

Editor (session: features)Run 
air = pp.add_gas({'O2(g)': 0.2, 'N2(g)': 0.78, 'CO2(g)': 0.00042})
solution.interact(air)

print(air.pressure)
print(air.partial_pressures)
print('pH', solution.pH)
OutputClear

You can query moles, mole fractions, partial pressures, and dry fractions after each interaction.

Not supported yet

These PHREEQC capabilities have no PhreeqPython objects yet:

  • Ion exchange (EXCHANGE)
  • Transport and advection (TRANSPORT, ADVECTION)
  • Surface complexation (SURFACE)
  • Solid solutions (SOLID_SOLUTIONS)
  • Inverse modelling (INVERSE_MODELING)
  • Native PHREEQC kinetics (KINETICS, RATES)