Simple example of irreversible reactions in Phreeqc and Aquifer App - Tutorial

This is a tutorial of geochemical modeling in Phreeqc and Aquifer App that uses the REACTION keyword for the simulation of irreversible reactions that transfer a certain amount of elements to or from the solution. The selected example deals with the reaction of rainwater with NaCl and Calcite over 4 steps. Phreeqc simulation and model output analysis are performed on the Aquifer App that has great tools for the model setup and the analysis through interactive menus, tables and charts.

Tutorial

Input data

TITLE Reaction of rain water with NaCl and Calcite
SOLUTION 1
    units mg/L
    pH    4.5
    temp  25
    Ca    0.384
    Mg    0.043
    Na    0.141
    K     0.036
    Cl    0.236
    C(4)  0.1 CO2(g) -3.5
    S(6)  1.3
    N(-3) 0.203
    N(5)  0.237
REACTION 1
    NaCl  2.0
    Calcite 0.001
    0.25 0.5 0.75 1.0 moles
END