> QUESTION: I appreciate the role of kinetics. However, assuming that kinetics are not an issue, how can I best apply PHREEQC to determine, at equlibirum, what remains in solution and what (eventually) precipitates - for a given a water quality? You're asking a pretty basic question. The short answer is that the saturation indices (SIs) calculated for a solution indicate the thermodynamic state of the solution relative to minerals. Positive SI indicates the mineral could precipitate, negative, it could dissolve. The key factors for what happens are the minerals present in the system and the rate at which the minerals react. You must decide which minerals will react to equilibrium, in which case, you include them in EQUILIBRIUM_PHASES and react these phases with the SOLUTION. The result is equilibrium between the solution and the selected phases (unless a mineral is undersaturated and has zero moles initially). The long answer is the field of low temperature geochemistry. David David Parkhurst (dlpark@xxxxxxxx) U.S. Geological Survey Box 25046, MS 413 Denver Federal Center Denver, CO 80225 Project web page: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled
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/msg00495.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.