I want to modify the equation of the 'exchange' function

[Jeonghwan Hwang]

Hello, my name is Jeonghwan Hwang,
Thank you for reading my article first.

I want to modify the equation of the 'exchange' function of phreeqc.
Is there a way I can access and modify the formulas of functions that exist in phreeqc?
Or at least wonder how to access the equation of a specific function in phreeqc.
Because I want to check if the model uses the governing equation I currently use as is.
I am currently driving 'phreeqcv.3' using 'notepad++'.
If necessary, I will provide the existing governing equation and the equation to modify.
My purpose is to make sure that the equation I am modifying gives better results.

Thanks for reading
Sincerely,

Jeonghwan Hwang

[dlparkhurst]

Equations for exchange reactions are given in the manual for PHREEQC version 2 (Parkhurst and Appelo, 1999). The manual is included in the doc directory of most PHREEQC programs (normally installed in C:\Program Files\USGS or C:\Program Files (x86)\USGS, also available at https://pubs.er.usgs.gov/publication/wri994259).

There is not an easy way to change the exchange equations in PHREEQC. Orchestra is a geochemical program that is much more flexible for defining underlying equations.

For a discussion of ion exchange conventions and PHREEQC, here is a download from hydrochemistry.eu https://hydrochemistry.eu/pub/ap_pa02.pdf.