17 - Inverse Modelling with Evaporation

This example corresponds to the “Example 17-Inverse Modeling With Evaporation” from the Phreeqc manual. It can be retrieved from the Phreeqc Website.

This example uses data for the evaporation of Black Sea water that is presented in Carpenter (1978). Two analyses are selected, the initial Black Sea water and an evaporated water from which halite has precipitated. The hypothesis is that evaporation, precipitation of calcite, gypsum, and halite, and loss of carbon dioxide are sufficient to account for the changes in water composition of all of the major ions and bromide.

Studies

This project contains 2 Studies.

  • PhreeqcStudy: “study_17 - Inverse Modelling with Evaporation”

Db used: “PhreeqcImported_1” database

TITLE Example 17.--Inverse modeling of Black Sea water evaporation
SOLUTION 1  Black Sea water
        units   mg/L
        density 1.014
        pH      8.0     # estimated
        Ca      233
        Mg      679
        Na      5820
        K       193
        S(6)    1460
        Cl      10340
        Br      35
        C       1       CO2(g) -3.5
SOLUTION 2  Composition during halite precipitation
        units   mg/L
        density 1.271
        pH      5.0     # estimated
        Ca      0.0 
        Mg      50500
        Na      55200
        K       15800
        S(6)    76200
        Cl      187900
        Br      2670
        C       1       CO2(g) -3.5
INVERSE_MODELING
        -solution 1 2
        -uncertainties .025
        -range
        -balances 
                Br
                K
                Mg
        -phases
                H2O(g)  pre
                Calcite pre
                CO2(g)  pre
                Gypsum  pre
                Halite  pre
                Glauberite pre
                Polyhalite pre
END

/n

  • PhreeqcStudy: “study_17 - Inverse Modelling with Evaporationb”

Db used: “PhreeqcImported_1” database

SOLUTION 1  Black Sea water
        units   mg/L
        density 1.014
        pH      8.0     # estimated
        Ca      233
        Mg      679
        Na      5820
        K       193
        S(6)    1460
        Cl      10340
        Br      35
        C       1       CO2(g) -3.5
EQUILIBRIUM_PHASES
 # carbonates...
 CO2(g) -3.5 10; Calcite 0 0
 # sulfates...
 Gypsum 0 0;     Anhydrite 0 0;  Glauberite 0 0;  Polyhalite 0 0
 Epsomite 0 0;   Kieserite 0 0;  Hexahydrite 0 0
 # chlorides...
 Halite 0 0;     Bischofite 0 0; Carnallite 0 0
REACTION
 H2O -1; 0 36 3*4 6*1 2*0.25 0.176 4*0.05 5*0.03
INCREMENTAL_REACTIONS true
END

/n

Plots

This project contains 1 Plots.

  • Plot 1: “plot_1”

plot_1.svg