Examples

In this section of the report example calculations are presented that demonstrate most of the capabilities of PHREEQC. The first 18 examples are derived from the version 2 manual but are updated with the new capabilities of version 3. Four new examples, 19 through 22, illustrate more capabilities of PHREEQC. Example 19 demonstrates the use of empirical sorption isotherms and compares measured data with a deterministic model for sorption of Cd⁺² on iron oxyhydroxides, clay minerals, and organic matter for a soil. Example 20 calculates simultaneous multi-isotope fractionation between water and calcite. Example 21 uses the multicomponent diffusion transport capabilities, which allow calculation of diffusion processes with ion-specific tracer diffusion coefficients. Finally, example 22 shows capability of PHREEQC to calculate the solubilities of gases at high pressures. The input files for all examples are included in tables and can be used as templates for modeling other geochemical processes. The new keyword USER_GRAPH is used to display results for most examples, and selected output from each of the example runs is presented.

Example 19--Modeling Cd⁺² Sorption With Linear, Freundlich, and Langmuir Isotherms, and With a Deterministic Distribution of Sorption Sites for Organic Matter, Clay Minerals, and Iron Oxyhydroxides

Examples

Example 1--Speciation Calculation

Example 2--Equilibration With Pure Phases

Example 3--Mixing

Example 4--Evaporation and Homogeneous Redox Reactions

Example 5--Irreversible Reactions

Example 6--Reaction-Path Calculations

Example 7--Gas-Phase Calculations

Example 8--Surface Complexation

Example 9--Kinetic Oxidation of Dissolved Ferrous Iron With Oxygen

Example 10--Aragonite-Strontianite Solid Solution

Example 11--Transport and Cation Exchange

Example 12--Advective and Diffusive Flux of Heat and Solutes

Example 13--1D Transport in a Dual Porosity Column With Cation Exchange

Example 14--Advective Transport, Cation Exchange, Surface Complexation, and Mineral Equilibria

Example 15--1D Transport: Kinetic Biodegradation, Cell Growth, and Sorption

Example 16--Inverse Modeling of Sierra Spring Waters

Example 17--Inverse Modeling With Evaporation

Example 18--Inverse Modeling of the Madison Aquifer

Example 19--Modeling Cd⁺² Sorption With Linear, Freundlich, and Langmuir Isotherms, and With a Deterministic Distribution of Sorption Sites for Organic Matter, Clay Minerals, and Iron Oxyhydroxides

Example 20--Distribution of Isotopes Between Water and Calcite

Example 21--Modeling Diffusion of HTO, ³⁶ Cl^- , ²² Na⁺ , and Cs⁺ in a Radial Diffusion Cell

Example 22--Modeling Gas Solubilities: CO₂ at High Pressures