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
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:
Last modified: $Date: 2005-09-13 21:04:21 -0600 (Tue, 13 Sep 2005) $
Visitor number 2831 since Jan 22, 1998.