PHREEQC Short Course

Using PHREEQC in Mine Water Management and AMD

Online, March 7, 2023 – Fully booked, no more places available

Course Material

only registered participants will get a link to the course material

Venue

The workshop will take place online via Zoom. You will get your individual link before the course.

Programme

Tuesday, March 7 2023 (9:00 – 17:30) | find your local time by clicking here
To get started
What is a “Model”?
Introduction to Thermodynamics
The Mine Water
Speciation Calculation
Equilibration Calculation with pure Phases
Mixing Calculation

What is PHREEQC?

PHREEQC version is a computer program (“code”) for simulating chemical reactions and transport processes in natural or polluted water, in laboratory experiments, or in industrial processes. It is based on the equilibrium chemistry of aqueous solutions interacting with minerals, gases, solid solutions, exchangers, and sorption surfaces, thus the acronym pH-REdox-EQuilibrium. Yet, the program has evolved to include the capability to model kinetic reactions and one-dimensional transport. Rate equations are completely user-specifiable in the form of Basic statements. Extensible chemical databases allow the application of the reaction, transport, and inverse-modelling capabilities to almost any chemical reaction that is recognized to influence rainwater, soil-water, groundwater, and surface-water quality.

PHREEQC can be used as a speciation program to calculate saturation indices, the distribution of aqueous species, and the density and specific conductance of specified solution composition. For calculating solute activities, PHREEQC uses ion-association, Pitzer, or SIT (Specific ion Interaction Theory) equations to account for the nonideality of aqueous solutions. Analytical data for mole balances can be defined for any valence state or combination of valence states for an element. Distribution of redox elements among their valence states can be based on a specified pe or any redox couple for which data are available. PHREEQC allows the concentration of an element to be adjusted to obtain equilibrium (or a specified saturation index or gas partial pressure) with a specified phase or to obtain charge balance. Solution compositions can be specified with a variety of concentration units¹.

Introduction

This one-day course will focus on the basics of PHREEQC that you might want to use for your day-to-day work with mine water samples. You will learn what chemical-thermodynamic processes are, when we are relating to species and when to phases. This course is meant to be for beginners or those colleagues that already heard about chemical/thermodynamic modelling and want to get a refresher. You will learn to identify potential flaws in your water analysis, which species account for your water’s composition and which controlling phases are responsible for the water chemistry. Based on a real example you will learn how to mix different waters with each other and if acidic mine drainage might have a negative effect on the Sterkfontein caves.

Download and Installation

The course will use the latest graphical version of PHREEQC. Please download the software from here: https://water.usgs.gov/water-resources/software/PHREEQC and install it on your computer well before the course. Additional instructions will come via e-mail after full payment of the course fees. Also, ensure that you install the latest Zoom version from here. For versions other than Windows 64-bit, follow this link. In some rare cases, Windows opens Acrobat Reader instead of PHREEQC, when double clicking *.pqi or *.pqo files. In this case, follow the instructions there.