[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

PHREEQC and pH



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
-------------------------------------------------------




Project Home Page
Complete Water Resources Division Software
USGS Home Page
Water Resources Division Home Page
NRP Home Page
Help Page
USGS Privacy Statement       

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.