Re: 2 more PHREEQuestions

["David L Parkhurst" <dlpark@xxxxxxxx>]

> Is there a way to make PHREEQC report output in ppm rather than moles?

There is no general switch to change the units. You can write Basic
programs in USER_PRINT and USER_PUNCH that will write just about whatever
you want. The following will write to the output file and the
selected_output file respectively.

USER_PRINT
-start
10 PRINT "Ca, in ppm", TOT("Ca")*1000*40.08
-end

USER_PUNCH
-heading Ca_ppm
-start
10 PUNCH TOT("Ca")*1000*40.08
-end

> Also I'd like to run a simulation which will report the amount of
ferihydrite precipitated from a solution THEN, using that amount of
precipitate, perform sorbtion calculations.  I've been running one
simulation to find the amount of precipitate and then running the sorbtion
reaction in a second simulation where I manually input the amount of
precipitate formed in the first simulation using the Surface block.  Is
there a way to do this automatically in one step?

You can link the number of sorption sites to the amount of a mineral. The
mineral must be defined in "EQUILIBRIUM_PHASES n" and then in "SURFACE n"
you put 'equilibrium_phase' and the mineral name as part of the data
defining the surface. See the description of the SURFACE datablock in the
users guide.

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