Aqueous speciation of sparkling mineral water

In this example, we calculate the aqueous speciation in a famous sparkling bottled water. This water is not naturally sparkling. To get it fuzzy, gaseous CO\(_2\) is injected in the solution, which equilibrates with a high CO\(_2\) partial pressure. CO\(_2\) is an acid and is thus responsible for a decrease of the pH.

Step 1 - Primary species Only

TITLE Speciation of a sparkling mineral water - Step 1

RUNTIME
Database ../../CrunchDatabase_ThermoChimie_v12a.dbs
Speciate_Only true
END

PRIMARY_SPECIES
H2O
H+
HCO3-
Ca+2
Cl-
Na+
SO4-2
Mg+2
Sr+2
NO3-
K+
F-
END

CONDITION Sparkling Mineral Water
Units           mmol/kgw
Temperature     10 ! Chilled bottle water
pH              7.6
HCO3-       4.00
Ca+2        4.15
Cl-     1.40
Na+     1.30
SO4-2       4.18
Mg+2        2.06
Sr+2        0.033
NO3-        0.045
K+      0.053
F-      0.026   
END

Step 2 - Primary species + secondary species

TITLE Speciation of a sparkling mineral water - Step 2

RUNTIME
Database ../../CrunchDatabase_ThermoChimie_v12a.dbs
Speciate_Only true
END

PRIMARY_SPECIES
H2O
H+
HCO3-
Ca+2
Cl-
Na+
SO4-2
Mg+2
Sr+2
NO3-
K+
F-
END

SECONDARY_SPECIES   
OH- 
CO3-2                                                      
CO2
Ca(SO4)
Mg(SO4)
Sr(SO4)
Na(HCO3)
Ca(HCO3)+
Mg(HCO3)+
Sr(HCO3)+
Mg(CO3)
END

CONDITION Sparkling Mineral Water
Units           mmol/kgw
Temperature     10 ! Chilled bottle water
pH              7.6
HCO3-       4.00
Ca+2        4.15
Cl-     1.40
Na+     1.30
SO4-2       4.18
Mg+2        2.06
Sr+2        0.033
NO3-        0.045
K+      0.053
F-      0.026   
END

Step 3 - Primary species + secondary species + charge

TITLE Speciation of a sparkling mineral water - Step 3

RUNTIME
Database ../../CrunchDatabase_ThermoChimie_v12a.dbs
Speciate_Only true
END

PRIMARY_SPECIES
H2O
H+
HCO3-
Ca+2
Cl-
Na+
SO4-2
Mg+2
Sr+2
NO3-
K+
F-
END

SECONDARY_SPECIES   
OH- 
CO3-2                                                      
CO2
Ca(SO4)
Mg(SO4)
Sr(SO4)
Na(HCO3)
Ca(HCO3)+
Mg(HCO3)+
Sr(HCO3)+
Mg(CO3)
END

CONDITION Sparkling Mineral Water
Units           mmol/kgw
Temperature     10 ! Chilled bottle water
pH              7.6
HCO3-       charge
Ca+2        4.15
Cl-     1.40
Na+     1.30
SO4-2       4.18
Mg+2        2.06
Sr+2        0.033
NO3-        0.045
K+      0.053
F-      0.026   
END

Step 4 - Primary species + secondary species + charge + add gas to get it sparkling

The gas in the headspace of a bottle has a

TITLE Speciation of a sparkling mineral water - Step 4

RUNTIME
Database ../../CrunchDatabase_ThermoChimie_v12a.dbs
Speciate_Only true
END

PRIMARY_SPECIES
H2O
H+
HCO3-
Ca+2
Cl-
Na+
SO4-2
Mg+2
Sr+2
NO3-
K+
F-
END

SECONDARY_SPECIES   
OH- 
CO3-2                                                      
CO2
Ca(SO4)
Mg(SO4)
Sr(SO4)
Na(HCO3)
Ca(HCO3)+
Mg(HCO3)+
Sr(HCO3)+
Mg(CO3)
END

GASES
CO2(g) 
END

CONDITION Sparkling Mineral Water
Units           mmol/kgw
Temperature     10
pH              CO2(g) 1 ! 1 atm of CO2 partial pressure in the headspace of the bottle
HCO3-       charge
Ca+2        4.15
Cl-     1.40
Na+     1.30
SO4-2       4.18
Mg+2        2.06
Sr+2        0.033
NO3-        0.045
K+      0.053
F-      0.026   
END