Jump to content
Geochemist's Workbench Support Forum

concentration in the output does not match concentration in the input


flo

Recommended Posts

Dear all,

 

I am using React 6.05 to model the concentration of Fe++ depending on pe for goethite.

The idea is to use slide pe and keep all other concentrations constant and vary the pH in each run. Input does not seem a problem, I am surprised that the concentration of Fe++ is higher than the complete input for goethite, e.g. the concentration in mmol for goethite (not free concentration) is 63 mmol and React somehow calculates 140 mmolal Fe++ depending on pH. How is this possible and how to I manage to avoid this problem?

 

I attached the script and would be glad for input.

 

Thanks a lot

Florian

goethite.rea

Link to comment
Share on other sites

Dear all,

 

I am using React 6.05 to model the concentration of Fe++ depending on pe for goethite.

The idea is to use slide pe and keep all other concentrations constant and vary the pH in each run. Input does not seem a problem, I am surprised that the concentration of Fe++ is higher than the complete input for goethite, e.g. the concentration in mmol for goethite (not free concentration) is 63 mmol and React somehow calculates 140 mmolal Fe++ depending on pH. How is this possible and how to I manage to avoid this problem?

 

I attached the script and would be glad for input.

 

Thanks a lot

Florian

 

Hi Florian:

 

This is part of the problem with not setting Goethite as a free constraint. During initial speciation, React not only dissolves all of the Goethite you've initially defined, but it must dissolve significant additional Goethite, leaving a negative mineral mass, in order to bring Fe++ concentrations to equilibrium for the conditions that you've specified.

 

I hope that helps,

 

Tom Meuzelaar

RockWare, Inc.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...