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

Re: PHREEQC reaction




You should define the phase in a PHASES data block. You should use a
"dissociation" reaction with the new phase as the first entity on the
left-hand side, all other entities on left and right-hand sides should be
aqueous species. The log K is immaterial to inverse modeling, but will
affect the saturation indices calculated for initial solutions.

That said, H2SiO3 is not a common phase formula. I would use SiO2(a),
quartz, or chalcedony (just one). The only difference of these with your
phase is a water in the formula, which should make almost no difference in
the mole transfers that are calculated.

David


David Parkhurst (dlpark@xxxxxxxx)
U.S. Geological Survey
Box 25046, MS 413
Denver Federal Center
Denver, CO 80225


                                                                                                                     
                      Elizabeth Bryant                                                                               
                      <elb46+@xxxxxxxx         To:      dlpark@xxxxxxxx                                              
                      >                        cc:                                                                   
In-Reply-To: <14446485.3212477731@xxxxxxxxxxxxxxxxxxxxxxxx>
                                               Subject: PHREEQC reaction                                             
                      10/19/01 08:55                                                                                 
                      AM                                                                                             
                                                                                                                     
                                                                                                                     



Mr. Parkhurst,

I am working with PHREEQC and using the LLNL database.  I have a reaction
             SiO2 + H20 = H2SiO3
along with the log k.  I tried inputing this information as one of the
phoses for inverse modeling, but I got an error message saying that PHREEQC

didn't recoginize H2SiO3. I know that LLNL has SiO2 as the master species
for Si.  I was wondering how to input H2SiO3 as a master species.  I tried
entering a new master species before, but it seemed like I entered it
incorrectly, because the program still didn't recognize it.  If you could
please help me out with this matter, I would greatly appreciate it.

Thank you for your time,
Elizabeth Bryant








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/msg00330.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.