We define evaporation as the process of removing water from the chemical system in Phreeqc and this can be achieved with the REACTION keyword and a negative reaction coefficient. We have developed an applied case of water evaporation from precipitation water and the mix of the resulting water to restore the original volume. The whole Phreeqc setup, simulation and result analysis process has been in Aquifer App.

Aquifer App link:

aquifer.hatarilabs.com

Tutorial

Code

Phreec file :

TITLE Rain water evaporation
SOLUTION 1  Precipitation from Central Oklahoma
        units           mg/L
        pH              4.5   # estimated
        temp            25.0
        Ca              .384
        Mg              .043
        Na              .141
        K               .036
        Cl              .236
        C               .1      CO2(g)  -3.5
        S(6)            1.3
        N(-3)           .208
        N(5)            .237
REACTION 1
        H2O     -1.0
        52.73 moles
SAVE solution 2
END
TITLE Factor of 20 more solution
MIX
        2       20.
SAVE solution 3
END