Geochemical Modelling Workshop – Using PHREEQC for laboratory and industrial applications.

Presenters:  David Tait (lead) and Ruth Griffith, SRK Consulting Limited

16–17 August 2024, Trinity College, Dublin

To register for this event, you need to follow the instructions given on the registration page. Complete the first part of the process and when you log in for step 2, the short courses will be available as booking options.

The cost will be €415 including VAT.

This two-day workshop will provide an overview of geochemical modelling and the use USGS geochemical / thermodynamic modelling code PHREEQC (PH, REdox, EQuilibrium, Code). PHREEQC is a free, well-supported software code and one of the most widely used codes in academia and the mining industry for thermodynamic modelling applications.   

During the two-day workshop, we will present the different geochemical modelling steps, from the development of a conceptual model and formalization of a modelling scenario to geochemical calculations using PHREEQC. We will also present exercises drawn from the presenters’ experiences, both in a laboratory setting and applied industrial setting.

The workshop will take place in four sessions split over the two days.

The first day will include an introductory session to PHREEQC covering the essential concepts of geochemical modelling, conceptualisation of model problems, an overview of the thermodynamics that govern PHREEQC and thermodynamic database definitions. We will explore issues with available PHREEQC thermodynamic databases and possible ways to overcome these. We will also provide the basic skills needed to use PHREEQC, including the definition of inputs and outputs, solid and aqueous solutions, and the reactions and equilibrium calculations. As the day progresses, we will introduce more advanced notions of kinetic reactions through a series of examples using experimental data.

The second day will provide a more in-depth look at the possibilities offered by PHREEQC in terms of predictive calculations and interpretation of the results relating to transport, exchange, isotope exchanges and sorption calculations. Based on our experience in mining, water, energy and chemical industries related applications of numerical predictive calculations, we will demonstrate how to use sorption experiments to define attenuation equations and sorption blocks. Furthermore, we will introduce exchange calculations and their application to water treatment and finally, we will bring all the elements seen in the workshop together in transport simulations.

The workshop will finish with a general discussion.

Intended Audience:

This course is intended for students, researchers, and professionals planning to use or expand their knowledge of PHREEQC for modelling and predicting results of geochemical operations, from simulation of laboratory experiments to natural settings (such as groundwater interaction with bedrock, simulating field data and predicting water quality).

Attendees are encouraged to bring with them their own examples of natural or laboratory systems that they wish to model for discussion with the session tutors.

Materials Provided

Each participant will receive: (1) paper and electronic versions of the hand-outs used for the lecture part of the workshop; and (2) an electronic copy of the model inputs used during the course of the workshop.

Materials Required

Laptop equipped with a version of Microsoft windows with PHREEQC interactive (current build: v3.7.3-15968) downloaded and installed. The latest version can be found at:

Useful links:

SRK Consulting (UK) Ltd

PHREEQC manual, available here:

PHREEQC abstract:

Tony Appelo’s web page for introductory exercises:

PHEEQC frequently asked questions:

Contact:+44 (0) 2920 348 150 SRK Consulting (UK) Ltd; 5th Floor, Churchill House 17 Churchill Way; Cardiff, CF10 2HH United Kingdom