Conceptual Models > Database selection and modification

Cannot recognise masterspecies

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ACH:
Hi,
I am new to PHREEQC. I am trying to run a batch experiment with a fixed volume, using a solution of seawater. The goal is to add CO2 in gas phase in steps and see how this affects pH of the solution. For this purpose, I want to use the phreeqc.dat database, but for some reason it can't recognise CO2 and other species at all. I have also tried to make a manuel database but that doesnt work either.


--- Code: ---DATABASE phreeqc.dat


SOLUTION 1 Seawater
    units           mmol/kgw
    temp            25
    pH              8.2 charge
    pe              4
    redox           pe
    density         1.023
    -water          1
    Na              470.869
    Cl              546.448

   
GAS_PHASE 1
    -pressure       1.0
    -volume         1.0
    CO2(g)          0.0

REACTION 1
    CO2(g)          1.0
    0.01 moles in 10 steps

SELECTED_OUTPUT
    -file           output.txt
    -reset          false
    -solution       true
    -state          true
    -pH             true
    -pe             true
    -temperature    true
    -alkalinity     true
    -ionic_strength true
    -totals         CO2(g) CO3 HCO3 H2CO3
    -activities     CO2 HCO3- CO3-2 H+
    -saturation_indices Calcite Gypsum Halite

END


--- End code ---

The errors is as follows: WARNING: Did not find master species, CO2(g).
WARNING: Did not find master species, CO3.
WARNING: Did not find master species, HCO3.
WARNING: Did not find master species, H2CO3.
Calculation time: 0,06 s. Estimated CO2 emission: 0,00 g.

I hope anyone can help!

dlparkhurst:
In SELECTED_OUTPUT, -totals refers to element totals, not aqueous species. The elements are defined in SOLUTION_MASTER_SPECIES in the database file. For carbon, you could select C, total dissolved carbon; C(4), TDIC; or C(-4), methane.


--- Code: ----totals         C C(4) C(-4)

--- End code ---

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