Processes > Inverse modelling

How to find rocks related to water formation

(1/1)

Matsumoto:
Hello, everyone

I am hoping to find rocks involved in the water quality formation of solution 2.I want to simulate how water quality can be formed from the rocks found in the survey.
I set up the rocks found in the survey and simulated the following.

SOLUTION 1
    temp      25
    pH        9.4 charge
    pe        4
    redox     pe
    units     mg/l
    density   1
    Ca        4.88
    K         0.5
    Mg        0.42
    Na        2.43
    S(6)      3.64
    -water    1 # kg

SOLUTION 2
    temp      25
    pH        8.1 charge
    pe        4
    redox     pe
    units     mg/l
    density   1
    Ca        71.1
    K         1.3
    Mg        5.8
    Na        4.6
    S(6)      55.6
    -water    1 # kg

INVERSE_MODELING 1
    -solutions      1        2
    -uncertainty    0.05     0.05
    -phases
        Albite
        Quartz
        Chlorite(14A)
        Calcite
        Biotite
        Stibnite
        Lime
       Gypsum
       Goethite
       Chalcedony
        Kaolinite
   
    -tolerance         1e-10
    -mineral_water     true

PHASES
Albite
   NaAlSi3O8 + 8 H2O = Na+ + Al(OH)4- + 3 H4SiO4
   -log_k   -18.002
   -delta_h 25.896 kcal
   -Vm 101.31
Chlorite(14A)
   Mg5Al2Si3O10(OH)8 + 16H+ = 5Mg+2 + 2Al+3 + 3H4SiO4 + 6H2O
   -log_k   68.38
   -delta_h -151.494 kcal
Biotite
        KMg3AlSi3O10(OH)2 + 6H+ + 4H2O = K+ + 3Mg+2 + Al(OH)4- + 3H4SiO4
        log_k  0.0
       
END


Minerals from Albite to Stibnite were found in the survey, and since these were the only minerals that could not form a model, minerals were added hypothetically to form the model.

Question
①Does this result mean that the minerals found in the survey are not enough to form the water quality of solution 2?
②How should I interpret the following results?

Phase mole transfers:                 Minimum        Maximum   Formula             (Approximate SI in solution 1, 2 at 298 K,   1 atm)
         Albite      9.442e-05      0.000e+00      0.000e+00   NaAlSi3O8                  (      ,      )
  Chlorite(14A)      3.200e-05      0.000e+00      0.000e+00   Mg5Al2Si3O10(OH)8          (      ,      )
        Biotite      2.047e-05      0.000e+00      0.000e+00   KMg3AlSi3O10(OH)2          (      ,      )
           Lime      1.112e-03      0.000e+00      0.000e+00   CaO                        (-15.69,-12.78)
         Gypsum      5.410e-04      0.000e+00      0.000e+00   CaSO4:2H2O                 ( -3.84, -1.79)
     Chalcedony     -2.618e-04      0.000e+00      0.000e+00   SiO2                       (      ,      )
      Kaolinite     -8.944e-05      0.000e+00      0.000e+00   Al2Si2O5(OH)4              (      ,      )


I'm sorry I'm not familiar with PHREEQC.
I would appreciate it if you could let me know!

Navigation

[0] Message Index