Hi Dr. Parkhurst - I'm just starting to learn PHREEQC and am making diagrams to show parameters (e.g. speciation) changing with pH. Right now I'm defining a new solution for each pH value, but this takes up a lot of lines. Is there a way to tell PHREEQC to sweep through a range of pH values? I know you can compactly vary temperature using REACTION_TEMPERATURE, and can tell it what size step to take. I also know you can fix pH by defining a phase like FIX_H+ and then invoking EQUILIBRIUM_PHASES for a given solution, but if I want say 20 different pH values I have to define 20 different SOLUTION blocks. Can I use REACTION or some other trick to 'titrate' with Fix_H+? Perhaps somehow using a BASIC loop? I can imagine wanting to do the same thing with other constituents (e.g. adding incremental amounts of Cu+2 to a system), and it seems like it should be possible to do it compactly, I just haven't been able to figure out how to do it yet. Thanks in advance, and have a good weekend. Rick Johnston ------------------------------------------------------- Richard Johnston Doctoral Candidate Department of Environmental Sciences and Engineering University of North Carolina - Chapel Hill CB #7400 Chapel Hill, NC 27599-7400 Tel: 919-967-5468 Email: johnstonrh@xxxxxxxxxxxxxx -------------------------------------------------------
Please note that some U.S. Geological Survey (USGS) information accessed through this page may be preliminary in nature and presented prior to final review and approval by the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the sole responsibility of the user.
Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.
The URL of this page is:
https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/mail/msg00340.html
Email:dlpark@usgs.gov
Last modified: $Date: 2005-09-13 21:04:21 -0600 (Tue, 13 Sep 2005) $
Visitor number [an error occurred while processing this directive] since Jan 22, 1998.