PhreeqcUsers Discussion Forum

Solubility => Dissolution/precipitation => Topic started by: jus10go on May 26, 2016, 09:42:24 PM

Title: Calcite Precipitation Potential
Post by: jus10go on May 26, 2016, 09:42:24 PM
I am brand new to PHREEQC and I am attempting to use it to find CCPP.  I am using the "solution," "equilibrium," and "reaction temperature" programs but I'm not sure where in the output file the calcite precipitation potential is located and in what units.  I attached a screenshot of what I think it is based on what I read.

If anyone can point me in the right direction as to where the CCPP is located in the output file I would appreciate it very much.  Thanks in advance.
Title: Re: Calcite Precipitation Potential
Post by: dlparkhurst on May 30, 2016, 07:57:12 PM
Yes. That is where you find the calcium  carbonate precipitation potential in moles.  However, the negative sign indicates that the amount of solid calcium carbonate decreased, so calcite dissolved into solution rather than precipitated. I guess that would be a negative CCPP.

You probably have about a kilogram of water which would be close to a liter of water, so the CCPP is approximately moles/liter of solution. The phreeqc.dat, Amm.dat, and pitzer.dat databases calculate the volume of solution, so you could make the small correction to get moles per liter for CCPP if you want.