This is an example of calcite dissolution with kinetics where a simplified rate and initial molality are defined. The tutorial covers creation of an input file for Phreeqc, database selection, Phreeqc simulation in Aquifer App and analysis of processed output data on a Jupyter notebook. Finally the molality of Calcium and pH are plotted with time.

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.

This tutorial cover all the steps to build and run a geochemical model of a water sample in equilibrium with Fluorite and Gypsum. The tutorial explains the parameters to setup a mineral together with and analysis of the element concentrations, the amount of dissolved phases and the final saturation indices.

Evaporation is accomplished by removing water from the chemical system. Water can be removed as an irreversible reactant with a negative reaction coefficient in the REACTION keyword input. This example uses this method; the REACTION data block is used to simulate concentration of rain water by approximately 20 fold by removing 95 percent of the water. The resulting solution contains only about 0.05 kg of water. In a subsequent simulation, the MIX keyword is used to generate a solution that has the same concentrations as the evaporated solution, but has a total of mass of water of approximately 1 kg.

This example demonstrates the capabilities of PHREEQC to perform a series of geochemical simulations, with the final simulations relying on results from previous simulations within the same run. The example investigates diagenetic reactions that may occur in zones where seawater mixes with carbonate ground water. This example is take from the Phreeqc documentation that can be found here:

https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/html/final-72.html

PHREEQC version 3 is a computer program written in the C and C++ programming languages that is designed to perform a wide variety of aqueous geochemical calculations. PHREEQC implements several types of aqueous models: two ion-association aqueous models (the Lawrence Livermore National Laboratory model and WATEQ4F), a Pitzer specific-ion-interaction aqueous model, and the SIT (Specific ion Interaction Theory) aqueous model. Using any of these aqueous models, PHREEQC has capabilities for (1) speciation and saturation-index calculations; (2) batch-reaction and one-dimensional (1D) transport calculations with reversible and irreversible reactions.

This tutorial shows how to calculate the solubility and relative thermodynamic stability of two minerals, gypsum and anhydrit as a function of temperature at 1 atm.

This example calculates the distribution of aqueous species in seawater and the saturation state of seawater relative to a set of minerals. To demonstrate how to expand the model to new elements, uranium is added to the aqueous model defined by phreeqc.dat.

Quick tutorial for the configuration of a watershed on HEC-ResSim.