Short Course (3 days):

Using PHREEQC and PHREEPLOT to Model Arsenic Geochemistry
To be presented at 6th International Congress on Arsenic and in the Environment (As2016)
Stockholm, Sweden - June 17 - 19, 2016

Venue:  Teknikringen 76, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology
Stockholm, Sweden - June 17, 18 and 19, 2016
Friday 17th June, 2016 10:00 -16:00
Saturday 18th June, 2016 10-16:00
Sunday 19th June, 10:00-14:00

Presented by:
John J. Mahoney, Ph.D., Principal Geochemist
Mahoney Geochemical Consulting LLC, Lakewood, Colorado

Douglas B. Kent, Ph.D., Research Hydrologist
US Geological Survey, Menlo Park, California

This three day course will cover the basic setups of PHREEQC and PhreePlot and work through a series of examples related to understanding geochemical processes related to arsenic.  This course will be predominantly hands-on modeling with the two programs.  The underlying concepts required for conducting geochemical modeling with these programs will be covered briefly, but participants should have a basic understanding of geochemical processes including formation of complexes in solution, mineral precipitation and surface complexation.  Experience with PHREEQC is helpful, but not required.  It will be assumed that the participants have little or no experience with PhreePlot.  We will use the interactive version of PHREEQC (PHREEQCi); PhreePlot is only available as a batch program.  PhreePlot uses a fully functional PHREEQC module to provide the chemical inputs used to prepare a wide range of figures and also allow for optimization of parameters within PHREEQC models through several different data fitting options.  It is believed that this is the first time a course designed primarily for learning PhreePlot has ever been presented.  Many of the exercises and examples and several of the presentations will deal with geochemical properties of arsenic.   
Participants will load the programs onto their laptop computers prior to the course.  A test example for PhreePlot will be provided to confirm setup.  These programs were designed for Windows operating systems. This test example will serve as the starting point for a series of PhreePlot examples.   Installing the programs prior to the course allows for more time in using the programs during the two days of the actual course.  It also assures that the participants can perform upgrades after the course is completed as new versions are issued.  It also avoids issues with various corporate policies related to downloading programs.  All programs are in the public domain but different companies/organizations have different policies related to program installation so pre-installation avoids unforeseen problems during the course. There are no license fees required for any of the programs.  PhreePlot also requires two other publicly available programs that will need to be installed prior to the course these programs are Ghostscript and GSview.  Participants will also need an editor program such as Notepad, Wordpad or Textpad to setup the PhreePlot files.   

We believe that these programs will run under the Mac Operating System with an emulator, but we cannot confirm this.  No matter what OS you are using please verify that the programs work before the course, we will not have the time or resources to deal with Operating System compatibility type problems.  

While Dr. Kinniburgh, the primary developer of PhreePlot, cannot attend he has been providing support in resolving questions and technical issues in the preparation of the course materials.

As2016 Congress Student delegates:  SEK 3900
All other students: SEK 4800
Other Professionals: SEK 6500


Day 1 -  PHREEQC – June 17
1)    Course Introduction – Overview of course - JJM
2)    Aqueous speciation theory.  Basic thermodynamics of aqueous speciation equilibria.  Standard states for aqueous species.  Activity coefficients.  Equilibrium constants.  Temperature effects.  Alkalinity, Conversions Molality and Molarity– DBK 
4)    Intuitive examples - Acids, reactions - this is a presenter lead interactive exercise  - JJM
5)    Exercises   - TEAM
a)    assumptions in PHREEQC 
b)    saturation indices  
6)    Presentation - The Phase Rule - CO2, fixing gases to control Eh -  Gas and solid-phase equilibrium theory.  Standard states. Equilibrium constants.  Saturation index.  - TEAM  
7)    Exercises  - TEAM
a)    Gases, minerals and buffers

Day 2  - PHREEQC - June 18
1)    Database talk –JJM
2)    Redox in PHREEQC.  Redox calculations. Oxidation-reduction reactions theory.  Splitting the redox reaction, pe; redox and stoichiometry; impact of redox on solution chemistry, pe-pH diagrams. – DBK  
3)    Redox titration exercise – TEAM 
4)    Ion Exchange - DBK
5)     Surface complexation discussion – DBK
6)    Surface complexation exercise  TEAM
7)    Modeling a simple process - dissolution of arsenic trioxide and oxidation to As(5)  - JJM
8)    If time permits - Readily released arsenic presentation - JJM 
Comparison of buffer capacity calculations - prepared using PHREEQC

DAY 3 – PhreePlot  -  June 19 
1.    Overview of PhreePlot - Extended version of presentation given at ICARD 2015 - JJM
2.    PhreePlot Setup and mechanics -JJM
a.    Parts of PhreePlot file
i.    Speciation
ii.    Plot
iii.    Fit
iv.    Chemistry  
b.    PhreePlot user’s manual
c.    PHREEQC keywords for PhreePlot models SELECTED_OUTPUT, SOLUTION_SPREAD, USER_PUNCH if not discussed on day 1
d.    List of keywords 
e.    the pp.set file 
f.    “include” files 
The rest of the day will be devoted to preparing various diagrams using PhreePlot 
3.    First Diagram Eh – pH diagram of dissolved arsenic species - this file was sent to participants prior to the course to confirm setup of PhreePlot.   As this exercise proceeds there will be numerous “errors/mistakes” along the way to show how to correct issues.  
a.    Change to log fugacity diagram
b.    More Eh pH diagram - changing colors  
c.    Adding solids (arsenic oxides only) 
d.    Adding sulfur and iron - more solids
e.    Adding information to a plot  
f.    Adding surface complexation reactions - tracking HFO stability
g.    Looping and animations - presentation if time is short
4.    Presentation - Fitting options 
a.    Fitting Exercises
i.    scorodite, yukonite 
ii.    surface complexation parameter fits 

The benefits of this three day course will be to provide an initial understanding and familiarity with PHREEQC and PhreePlot.  The first two days will focus on geochemical modeling and PHREEQC. Exercises are designed to cover the most used features of PHREEQC; include data input, evaluation of saturation indices, defining equilibrium phases as either solids or gases, and fixing pH and pe (Eh), surface complexation.  Details related to the thermodynamic databases provided with PHREEQC will be discussed and errors in these databases will be described.   
The third day will focus on PhreePlot and the various methods to prepare activity - activity diagrams, mainly as Eh – pH diagrams will be covered.  Other diagrams that can be prepared with PhreePlot will also be described.  Finally, several examples will be used to demonstrate the basics of fitting model parameters within PHREEQC models using PhreePlot, and real-life data sets.  The exercises will be based upon a series of PhreePlot batch templates, which will allow participants to prepare various diagrams and produce some optimization models. 

Dr. John Mahoney will be the co-instructor for this three day course.  He holds a Ph.D. in Geochemistry from the Colorado School of Mines and has been the author of numerous publications dealing with the geochemistry of arsenic.   Dr. Mahoney has presented numerous courses on geochemical modeling.  The current version of his five day course uses PHREEQC, PHAST and HYDRA/MEDUSA with a small discussion about PhreePlot.    Over the past five years his five day course has been presented in the United States, Canada, South Africa, and Australia.   
Co-instructor Douglas Kent holds a Ph.D. in Oceanography from Scripps Institution of Oceanography.  He has worked extensively in developing conceptual and quantitative models describing the role of biogeochemical process on the fate and transport of arsenic and other inorganic solutes in groundwater water and surface water.  He has participated in instructing several geochemical and reactive transport modeling courses.