PHREEQC is a useful tool for hydrochemical modeling. However, I hear more and more complains from people using MacOS or Linux who don’t know how to install (compile it). Here is what we’ll have to do:

First, we have to download it. Unlike for Windows, there exists no GUI for Linux and MacOS. For Linux and MacOS we get the batch version of PHREEQC.

$ mkdir PHREEQC
$ cd PHREEQC
$ curl -OLC - https://water.usgs.gov/water-resources/software/PHREEQC/phreeqc-3.4.0-12927.zip
$ unzip phreeqc-3.4.0-12927.zip
$ cd phreeqc-3.4.0-12927
$ ./configure
$ make
$ sudo make install

Now we can run it on an example and figure out if it works correctly. First, we have to copy the thermodynamic database we want to use into the folder of our files. Afterwards, we can run phreeqc and view our results:

$ cd examples
$ less ex1
TITLE Example 1.--Add uranium and speciate seawater.
SOLUTION 1  SEAWATER FROM NORDSTROM AND OTHERS (1979)
        units   ppm
        pH      8.22
        pe      8.451
        density 1.023
        temp    25.0
        redox   O(0)/O(-2)
        Ca              412.3
        Mg              1291.8
        Na              10768.0
        K               399.1
        Fe              0.002
        Mn              0.0002  pe
        Si              4.28
        Cl              19353.0
        Alkalinity      141.682 as HCO3
        S(6)            2712.0
        N(5)            0.29    gfw   62.0
        N(-3)           0.03    as    NH4
        U               3.3     ppb   N(5)/N(-3)
        O(0)            1.0     O2(g) -0.7
SOLUTION_MASTER_SPECIES
        U       U+4     0.0     238.0290     238.0290
        U(4)    U+4     0.0     238.0290
        U(5)    UO2+    0.0     238.0290
        U(6)    UO2+2   0.0     238.0290
SOLUTION_SPECIES
        #primary master species for U
        #is also secondary master species for U(4)
        U+4 = U+4
                log_k          0.0
        U+4 + 4 H2O = U(OH)4 + 4 H+
                log_k          -8.538
                delta_h        24.760 kcal
        U+4 + 5 H2O = U(OH)5- + 5 H+
                log_k          -13.147
                delta_h        27.580 kcal
        #secondary master species for U(5)
        U+4 + 2 H2O = UO2+ + 4 H+ + e-
                log_k          -6.432
                delta_h        31.130 kcal
        #secondary master species for U(6)
        U+4 + 2 H2O = UO2+2 + 4 H+ + 2 e-
                log_k          -9.217
                delta_h        34.430 kcal
        UO2+2 + H2O = UO2OH+ + H+
                log_k          -5.782
                delta_h        11.015 kcal
        2UO2+2 + 2H2O = (UO2)2(OH)2+2 + 2H+
                log_k          -5.626
                delta_h        -36.04 kcal
        3UO2+2 + 5H2O = (UO2)3(OH)5+ + 5H+
                log_k          -15.641
                delta_h        -44.27 kcal
        UO2+2 + CO3-2 = UO2CO3
                log_k          10.064
                delta_h        0.84 kcal
        UO2+2 + 2CO3-2 = UO2(CO3)2-2
                log_k          16.977
                delta_h        3.48 kcal
        UO2+2 + 3CO3-2 = UO2(CO3)3-4
                log_k          21.397
                delta_h        -8.78 kcal
PHASES
        Uraninite
        UO2 + 4 H+ = U+4 + 2 H2O
        log_k          -3.490
        delta_h        -18.630 kcal
END
$ cp /usr/local/share/doc/phreeqc/database/phreeqc.dat ./
$ phreeqc ex1
$ less ex1.out
   Input file: ex1
  Output file: ex1.out
Database file: phreeqc.dat

------------------
Reading data base.
------------------

	SOLUTION_MASTER_SPECIES
	SOLUTION_SPECIES
	PHASES
	EXCHANGE_MASTER_SPECIES
	EXCHANGE_SPECIES
	SURFACE_MASTER_SPECIES
	SURFACE_SPECIES
	RATES
	END
------------------------------------
Reading input data for simulation 1.
------------------------------------

	TITLE Example 1.--Add uranium and speciate seawater.
	SOLUTION 1  SEAWATER FROM NORDSTROM AND OTHERS (1979)
	        units   ppm
	        pH      8.22
	        pe      8.451
	        density 1.023
	        temp    25.0
	        redox   O(0)/O(-2)
	        Ca              412.3
	        Mg              1291.8
	        Na              10768.0
	        K               399.1
	        Fe              0.002
	        Mn              0.0002  pe
	        Si              4.28
	        Cl              19353.0
	        Alkalinity      141.682 as HCO3
	        S(6)            2712.0
	        N(5)            0.29    gfw   62.0
	        N(-3)           0.03    as    NH4
	        U               3.3     ppb   N(5)/N(-3)
	        O(0)            1.0     O2(g) -0.7
	SOLUTION_MASTER_SPECIES
	        U       U+4     0.0     238.0290     238.0290
	        U(4)    U+4     0.0     238.0290
	        U(5)    UO2+    0.0     238.0290
	        U(6)    UO2+2   0.0     238.0290
	SOLUTION_SPECIES
	        U+4 = U+4
	                log_k          0.0
	        U+4 + 4 H2O = U(OH)4 + 4 H+
	                log_k          -8.538
	                delta_h        24.760 kcal
	        U+4 + 5 H2O = U(OH)5- + 5 H+
	                log_k          -13.147
	                delta_h        27.580 kcal
	        U+4 + 2 H2O = UO2+ + 4 H+ + e-
	                log_k          -6.432
	                delta_h        31.130 kcal
	        U+4 + 2 H2O = UO2+2 + 4 H+ + 2 e-
	                log_k          -9.217
	                delta_h        34.430 kcal
	        UO2+2 + H2O = UO2OH+ + H+
	                log_k          -5.782
	                delta_h        11.015 kcal
	        2UO2+2 + 2H2O = (UO2)2(OH)2+2 + 2H+
	                log_k          -5.626
	                delta_h        -36.04 kcal
	        3UO2+2 + 5H2O = (UO2)3(OH)5+ + 5H+
	                log_k          -15.641
	                delta_h        -44.27 kcal
	        UO2+2 + CO3-2 = UO2CO3
	                log_k          10.064
	                delta_h        0.84 kcal
	        UO2+2 + 2CO3-2 = UO2(CO3)2-2
	                log_k          16.977
	                delta_h        3.48 kcal
	        UO2+2 + 3CO3-2 = UO2(CO3)3-4
	                log_k          21.397
	                delta_h        -8.78 kcal
	PHASES
	        Uraninite
	        UO2 + 4 H+ = U+4 + 2 H2O
	        log_k          -3.490
	        delta_h        -18.630 kcal
	END
-----
TITLE
-----

 Example 1.--Add uranium and speciate seawater.

-------------------------------------------
Beginning of initial solution calculations.
-------------------------------------------

Initial solution 1.	SEAWATER FROM NORDSTROM AND OTHERS (1979)

-----------------------------Solution composition------------------------------

	Elements           Molality       Moles

	Alkalinity        2.406e-03   2.406e-03
	Ca                1.066e-02   1.066e-02
	Cl                5.657e-01   5.657e-01
	Fe                3.711e-08   3.711e-08
	K                 1.058e-02   1.058e-02
	Mg                5.507e-02   5.507e-02
	Mn                3.773e-09   3.773e-09
	N(-3)             1.724e-06   1.724e-06
	N(5)              4.847e-06   4.847e-06
	Na                4.854e-01   4.854e-01
	O(0)              4.376e-04   4.376e-04  Equilibrium with O2(g)
	S(6)              2.926e-02   2.926e-02
	Si                7.382e-05   7.382e-05
	U                 1.437e-08   1.437e-08

----------------------------Description of solution----------------------------

                                       pH  =   8.220    
                                       pe  =   8.451    
      Specific Conductance (µS/cm,  25°C)  = 52630
                          Density (g/cm³)  =   1.02323
                               Volume (L)  =   1.01282
                        Activity of water  =   0.981
                 Ionic strength (mol/kgw)  =   6.747e-01
                       Mass of water (kg)  =   1.000e+00
                    Total carbon (mol/kg)  =   2.182e-03
                       Total CO2 (mol/kg)  =   2.182e-03
                         Temperature (°C)  =  25.00
                  Electrical balance (eq)  =   7.936e-04
 Percent error, 100*(Cat-|An|)/(Cat+|An|)  =   0.07
                               Iterations  =   7
                                  Total H  = 1.110147e+02
                                  Total O  = 5.563054e+01

---------------------------------Redox couples---------------------------------

	Redox couple             pe  Eh (volts)

	N(-3)/N(5)           4.6750      0.2766
	O(-2)/O(0)          12.4062      0.7339

----------------------------Distribution of species----------------------------

                                               Log       Log       Log    mole V
   Species          Molality    Activity  Molality  Activity     Gamma   cm³/mol

   OH-             2.705e-06   1.647e-06    -5.568    -5.783    -0.215     -2.63
   H+              7.984e-09   6.026e-09    -8.098    -8.220    -0.122      0.00
   H2O             5.551e+01   9.806e-01     1.744    -0.009     0.000     18.07
C(4)          2.182e-03
   HCO3-           1.485e-03   1.003e-03    -2.828    -2.999    -0.171     26.98
   MgHCO3+         2.560e-04   1.610e-04    -3.592    -3.793    -0.201      5.82
   NaHCO3          1.658e-04   1.936e-04    -3.781    -3.713     0.067      1.80
   MgCO3           8.747e-05   1.022e-04    -4.058    -3.991     0.067    -17.09
   NaCO3-          6.682e-05   4.990e-05    -4.175    -4.302    -0.127      2.88
   CaHCO3+         4.453e-05   3.081e-05    -4.351    -4.511    -0.160      9.96
   CO3-2           3.752e-05   7.803e-06    -4.426    -5.108    -0.682     -1.97
   CaCO3           2.703e-05   3.158e-05    -4.568    -4.501     0.067    -14.60
   CO2             1.186e-05   1.385e-05    -4.926    -4.858     0.067     34.43
   UO2(CO3)3-4     1.252e-08   1.173e-10    -7.902    -9.931    -2.028     (0)  
   UO2(CO3)2-2     1.837e-09   5.716e-10    -8.736    -9.243    -0.507     (0)  
   MnCO3           2.550e-10   2.979e-10    -9.593    -9.526     0.067     (0)  
   MnHCO3+         6.475e-11   4.294e-11   -10.189   -10.367    -0.178     (0)  
   UO2CO3          7.662e-12   8.950e-12   -11.116   -11.048     0.067     (0)  
   (CO2)2          3.015e-12   3.522e-12   -11.521   -11.453     0.067     68.87
   FeCO3           1.796e-20   2.098e-20   -19.746   -19.678     0.067     (0)  
   FeHCO3+         1.505e-20   1.124e-20   -19.823   -19.949    -0.127     (0)  
Ca            1.066e-02
   Ca+2            9.634e-03   2.409e-03    -2.016    -2.618    -0.602    -16.69
   CaSO4           9.548e-04   1.115e-03    -3.020    -2.953     0.067      7.50
   CaHCO3+         4.453e-05   3.081e-05    -4.351    -4.511    -0.160      9.96
   CaCO3           2.703e-05   3.158e-05    -4.568    -4.501     0.067    -14.60
   CaOH+           8.711e-08   6.505e-08    -7.060    -7.187    -0.127     (0)  
   CaHSO4+         5.915e-11   4.418e-11   -10.228   -10.355    -0.127     (0)  
Cl            5.657e-01
   Cl-             5.657e-01   3.568e-01    -0.247    -0.448    -0.200     18.79
   MnCl+           1.053e-09   6.985e-10    -8.977    -9.156    -0.178     -2.79
   MnCl2           9.314e-11   1.088e-10   -10.031    -9.963     0.067     85.89
   MnCl3-          1.612e-11   1.069e-11   -10.793   -10.971    -0.178     45.79
   FeCl+2          1.519e-18   2.939e-19   -17.818   -18.532    -0.713     (0)  
   FeCl2+          7.062e-19   4.684e-19   -18.151   -18.329    -0.178     (0)  
   FeCl+           7.392e-20   5.521e-20   -19.131   -19.258    -0.127     (0)  
   FeCl3           1.431e-20   1.671e-20   -19.844   -19.777     0.067     (0)  
Fe(2)         6.492e-19
   Fe+2            4.892e-19   1.121e-19   -18.311   -18.950    -0.640    -20.71
   FeCl+           7.392e-20   5.521e-20   -19.131   -19.258    -0.127     (0)  
   FeSO4           4.443e-20   5.190e-20   -19.352   -19.285     0.067     18.97
   FeCO3           1.796e-20   2.098e-20   -19.746   -19.678     0.067     (0)  
   FeHCO3+         1.505e-20   1.124e-20   -19.823   -19.949    -0.127     (0)  
   FeOH+           8.698e-21   5.768e-21   -20.061   -20.239    -0.178     (0)  
   Fe(OH)2         6.840e-24   7.990e-24   -23.165   -23.097     0.067     (0)  
   Fe(OH)3-        7.284e-26   4.831e-26   -25.138   -25.316    -0.178     (0)  
   FeHSO4+         2.753e-27   2.056e-27   -26.560   -26.687    -0.127     (0)  
Fe(3)         3.711e-08
   Fe(OH)3         2.771e-08   3.237e-08    -7.557    -7.490     0.067     (0)  
   Fe(OH)4-        7.114e-09   4.804e-09    -8.148    -8.318    -0.171     (0)  
   Fe(OH)2+        2.287e-09   1.544e-09    -8.641    -8.811    -0.171     (0)  
   FeOH+2          1.481e-13   2.866e-14   -12.829   -13.543    -0.713     (0)  
   FeCl+2          1.519e-18   2.939e-19   -17.818   -18.532    -0.713     (0)  
   FeSO4+          1.174e-18   7.786e-19   -17.930   -18.109    -0.178     (0)  
   FeCl2+          7.062e-19   4.684e-19   -18.151   -18.329    -0.178     (0)  
   Fe+3            3.432e-19   2.727e-20   -18.464   -19.564    -1.100     (0)  
   Fe(SO4)2-       5.939e-20   4.436e-20   -19.226   -19.353    -0.127     (0)  
   FeCl3           1.431e-20   1.671e-20   -19.844   -19.777     0.067     (0)  
   Fe2(OH)2+4      2.359e-24   2.210e-26   -23.627   -25.656    -2.028     (0)  
   FeHSO4+2        4.038e-26   1.256e-26   -25.394   -25.901    -0.507     (0)  
   Fe3(OH)4+5      1.053e-29   7.130e-33   -28.978   -32.147    -3.169     (0)  
H(0)          0.000e+00
   H2              0.000e+00   0.000e+00   -44.470   -44.402     0.067     28.61
K             1.058e-02
   K+              1.040e-02   6.483e-03    -1.983    -2.188    -0.205      9.66
   KSO4-           1.756e-04   1.186e-04    -3.755    -3.926    -0.171     34.85
Mg            5.507e-02
   Mg+2            4.754e-02   1.372e-02    -1.323    -1.863    -0.540    -20.41
   MgSO4           7.170e-03   8.375e-03    -2.144    -2.077     0.067      5.84
   MgHCO3+         2.560e-04   1.610e-04    -3.592    -3.793    -0.201      5.82
   MgCO3           8.747e-05   1.022e-04    -4.058    -3.991     0.067    -17.09
   MgOH+           1.151e-05   8.107e-06    -4.939    -5.091    -0.152     (0)  
Mn(2)         3.773e-09
   Mn+2            2.097e-09   4.806e-10    -8.678    -9.318    -0.640    -16.36
   MnCl+           1.053e-09   6.985e-10    -8.977    -9.156    -0.178     -2.79
   MnCO3           2.550e-10   2.979e-10    -9.593    -9.526     0.067     (0)  
   MnSO4           1.905e-10   2.225e-10    -9.720    -9.653     0.067     22.54
   MnCl2           9.314e-11   1.088e-10   -10.031    -9.963     0.067     85.89
   MnHCO3+         6.475e-11   4.294e-11   -10.189   -10.367    -0.178     (0)  
   MnCl3-          1.612e-11   1.069e-11   -10.793   -10.971    -0.178     45.79
   MnOH+           3.031e-12   2.010e-12   -11.518   -11.697    -0.178     (0)  
   Mn(OH)3-        4.949e-20   3.282e-20   -19.305   -19.484    -0.178     (0)  
   Mn(NO3)2        1.325e-20   1.548e-20   -19.878   -19.810     0.067     41.04
Mn(3)         5.279e-26
   Mn+3            5.279e-26   4.195e-27   -25.277   -26.377    -1.100     (0)  
N(-3)         1.724e-06
   NH4+            1.610e-06   9.048e-07    -5.793    -6.043    -0.250     18.44
   NH3             7.326e-08   8.557e-08    -7.135    -7.068     0.067     24.42
   NH4SO4-         4.064e-08   3.035e-08    -7.391    -7.518    -0.127     39.98
N(5)          4.847e-06
   NO3-            4.847e-06   2.844e-06    -5.314    -5.546    -0.232     30.29
   Mn(NO3)2        1.325e-20   1.548e-20   -19.878   -19.810     0.067     41.04
Na            4.854e-01
   Na+             4.785e-01   3.434e-01    -0.320    -0.464    -0.144     -0.50
   NaSO4-          6.637e-03   4.482e-03    -2.178    -2.349    -0.171     21.21
   NaHCO3          1.658e-04   1.936e-04    -3.781    -3.713     0.067      1.80
   NaCO3-          6.682e-05   4.990e-05    -4.175    -4.302    -0.127      2.88
   NaOH            4.843e-17   5.657e-17   -16.315   -16.247     0.067     (0)  
O(0)          4.376e-04
   O2              2.188e-04   2.556e-04    -3.660    -3.592     0.067     30.40
S(6)          2.926e-02
   SO4-2           1.432e-02   2.604e-03    -1.844    -2.584    -0.740     17.49
   MgSO4           7.170e-03   8.375e-03    -2.144    -2.077     0.067      5.84
   NaSO4-          6.637e-03   4.482e-03    -2.178    -2.349    -0.171     21.21
   CaSO4           9.548e-04   1.115e-03    -3.020    -2.953     0.067      7.50
   KSO4-           1.756e-04   1.186e-04    -3.755    -3.926    -0.171     34.85
   NH4SO4-         4.064e-08   3.035e-08    -7.391    -7.518    -0.127     39.98
   HSO4-           2.042e-09   1.525e-09    -8.690    -8.817    -0.127     40.96
   MnSO4           1.905e-10   2.225e-10    -9.720    -9.653     0.067     22.54
   CaHSO4+         5.915e-11   4.418e-11   -10.228   -10.355    -0.127     (0)  
   FeSO4+          1.174e-18   7.786e-19   -17.930   -18.109    -0.178     (0)  
   Fe(SO4)2-       5.939e-20   4.436e-20   -19.226   -19.353    -0.127     (0)  
   FeSO4           4.443e-20   5.190e-20   -19.352   -19.285     0.067     18.97
   FeHSO4+2        4.038e-26   1.256e-26   -25.394   -25.901    -0.507     (0)  
   FeHSO4+         2.753e-27   2.056e-27   -26.560   -26.687    -0.127     (0)  
Si            7.382e-05
   H4SiO4          7.061e-05   8.248e-05    -4.151    -4.084     0.067     52.08
   H3SiO4-         3.210e-06   2.018e-06    -5.494    -5.695    -0.201     28.72
   H2SiO4-2        1.096e-10   2.279e-11    -9.960   -10.642    -0.682     (0)  
U(4)          1.088e-21
   U(OH)5-         1.088e-21   8.128e-22   -20.963   -21.090    -0.127     (0)  
   U(OH)4          1.738e-25   2.030e-25   -24.760   -24.692     0.067     (0)  
   U+4             0.000e+00   0.000e+00   -46.972   -49.000    -2.028     (0)  
U(5)          1.707e-18
   UO2+            1.707e-18   1.275e-18   -17.768   -17.894    -0.127     (0)  
U(6)          1.437e-08
   UO2(CO3)3-4     1.252e-08   1.173e-10    -7.902    -9.931    -2.028     (0)  
   UO2(CO3)2-2     1.837e-09   5.716e-10    -8.736    -9.243    -0.507     (0)  
   UO2CO3          7.662e-12   8.950e-12   -11.116   -11.048     0.067     (0)  
   UO2OH+          3.563e-14   2.661e-14   -13.448   -13.575    -0.127     (0)  
   UO2+2           3.182e-16   9.898e-17   -15.497   -16.004    -0.507     (0)  
   (UO2)2(OH)2+2   1.973e-21   6.139e-22   -20.705   -21.212    -0.507     (0)  
   (UO2)3(OH)5+    3.387e-23   2.530e-23   -22.470   -22.597    -0.127     (0)  

------------------------------Saturation indices-------------------------------

  Phase               SI** log IAP   log K(298 K,   1 atm)

  Anhydrite        -0.93     -5.20   -4.28  CaSO4
  Aragonite         0.61     -7.73   -8.34  CaCO3
  Calcite           0.75     -7.73   -8.48  CaCO3
  Chalcedony       -0.52     -4.07   -3.55  SiO2
  Chrysotile        3.36     35.56   32.20  Mg3Si2O5(OH)4
  CO2(g)           -3.39     -4.86   -1.47  CO2
  Dolomite          2.39    -14.70  -17.09  CaMg(CO3)2
  Fe(OH)3(a)        0.18      5.07    4.89  Fe(OH)3
  Goethite          6.08      5.08   -1.00  FeOOH
  Gypsum           -0.64     -5.22   -4.58  CaSO4:2H2O
  H2(g)           -41.30    -44.40   -3.10  H2
  H2O(g)           -1.51     -0.01    1.50  H2O
  Halite           -2.48     -0.91    1.57  NaCl
  Hausmannite       1.55     62.58   61.03  Mn3O4
  Hematite         14.17     10.17   -4.01  Fe2O3
  Jarosite-K       -7.57    -16.78   -9.21  KFe3(SO4)2(OH)6
  Manganite         2.39     27.73   25.34  MnOOH
  Melanterite     -19.39    -21.59   -2.21  FeSO4:7H2O
  NH3(g)           -8.86     -7.07    1.80  NH3
  O2(g)            -0.70     -3.59   -2.89  O2	 Pressure   0.2 atm, phi 1.000
  Pyrochroite      -8.10      7.10   15.20  Mn(OH)2
  Pyrolusite        6.97     48.35   41.38  MnO2:H2O
  Quartz           -0.09     -4.07   -3.98  SiO2
  Rhodochrosite    -3.30    -14.43  -11.13  MnCO3
  Sepiolite         1.15     16.91   15.76  Mg2Si3O7.5OH:3H2O
  Sepiolite(d)     -1.75     16.91   18.66  Mg2Si3O7.5OH:3H2O
  Siderite        -13.17    -24.06  -10.89  FeCO3
  SiO2(a)          -1.35     -4.07   -2.71  SiO2
  Sylvite          -3.54     -2.64    0.90  KCl
  Talc              6.03     27.43   21.40  Mg3Si4O10(OH)2
  Uraninite       -12.65    -16.14   -3.49  UO2

**For a gas, SI = log10(fugacity). Fugacity = pressure * phi / 1 atm.
  For ideal gases, phi = 1.

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End of simulation.
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Reading input data for simulation 2.
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End of Run after 0.013884 Seconds.
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