chemical transport

[Georgy]

Dear colleagues, would like to ask you .
I have a program that calculates the chemical transport and chemistry counts connected module iphreeqc. The issue , in which very few of the pore volume of solution ( mol / l) or 1 kg of water ? During the simulation , the question of translation of concentrations. There is an increase in the concentration of > 1 . It will be interesting to hear your opinion .
Thank you in advance .

[dlparkhurst]

Internally, PHREEQC keeps track of moles of elements in a solution. The mass-action equations use activity, which is molality times an activity coefficient. With the phreeqc.dat and pitzer.dat databases, you can choose or calculate the units you want. The Basic function TOT gives molality.  Density and solution volume are calculated, so you can calculate mol/L as TOTMOL/SOLN_VOL or mg/L by multiplying by GFW.

PhreeqcRM is a reaction module for reactive-transport modeling that was recently published (AWR, Parkhurst and Wissmeier, 2015). Some formulas for conversion of units are given and possible approaches in reactive-transport modeling are discussed.