First, I'm guessing that Fe and Al should be ug/L rather than mg/L. Even if ug/L is correct for these elements, the charge balance of the solution is not good. The cations are much greater than the anions. In addition, I think there are errors in llnl.dat. The species AsO3F-- and HAsO3F- have log K's that appear much too large and actually cause the program to fail to converge. All of the As or F (whichever is less in concentration) is tied up in these species, which are 40 orders of magnitude greater than the other aqueous species of the element. You can either remove As or F, if they are not important to your investigation, or redefine the log K's for these species as done below. If you really want to track it down, you probably need to go back to the literature and find the thermodynamic data used to generate llnl.dat. I suspect there is a sign error in the free energy of formation. > On a related note, is it possible to have more than one masters species? You can only have one primary master species, but you can have multiple secondary master species for different redox states of the element. > I have a few instances where I have 2 or more radionuclides. Do I default to the radionuclide with the greatest solution concentration and treat the rest as incidental species, or do I do separate determinations for each radionuclide as if there were no competing radionuclide species? You can define multiple "elements". You could define C and [13C] as element names and then define all of the aqueous species for each ( CO2, CO3-2, HCO3-, etc; [13C]O2, [13C]O3-2, H[13C]O3-, etc). An element name is either a single capital letter followed by 0 or more lower case letters or any alphanumeric string enclosed in square brackets. Additional capabilities for handling isotopes should be available by the end of the year. David TITLE Speciate RGA 004-020 SOLUTION 1 groundwater chemical analysis from Sep 11, 1999 units mg/L pH 6.02 pe 2.73 density 1.0 temp 15.0 Ca 90.4 Mg 70.8 Na 16.0 K 44.4 Fe 1810.0 ug/l # ???? Tc 0.0206 Cl 41.3 Alkalinity 47.0 as HCO3- S(6) 7.8 F 0.15 As 0.009 Cr 1.55 Ni 0.5 Al 944.0 ug/L # ???? Cd 0.022 Pb 0.757 SOLUTION_SPECIES 1.0000 H2AsO4- + 1.0000 F- = AsO3F-- +1.0000 H2O -llnl_gamma 4.0 # log_k +40.2451 log_k -20 1.0000 H2AsO4- + 1.0000 H+ + 1.0000 F- = HAsO3F- +1.0000 H2O -llnl_gamma 4.0 # log_k +46.1158 log_k -20 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
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