[Problems with Th(CO3)5(6-) species (React)]

Dear Brian Farrell,

 

thank you for your quick reply and for fixing this task in the next maintenance release for version 9.

We`ve already been thinking about perchasing an upgrade for our version 8.

The idea with the free concentration for OH- is a good one. I will try it out for my next calculations.

 

Best regards,

Christiane

[Problems with Th(CO3)5(6-) species (React)]

Dear support team,

 

recently I am having trouble in calculating the solubility of Th(OH)4(am) depending on the carbonate concentration. The parameter file works well if I only include either carbonate without thorium or thorium without carbonate. If I include both I get the message "React stop: calc_hmw: max charge too large". With the help of a colleague I figured out that this is probably caused by the species Th(CO3)5(6-).

I am using react version 8.0.12 and colleague using version 9 had the same problem.

 

Do you have any idea how we can solve this issue?

 

Thanks in advance for your help!

Best regards,

Christiane

Th_CO3_titration.rea

[GWB > Pitzer parameters alpha1/alpha2]

Hello Tom,

 

I have a question regarding the treatment of the Pitzer parameters alpha1 and alpha2 in GWB.

In Craig`s book "Geochemical and Biogeochemical Reaction Modeling" (2nd edn) I find the following

equation in Table 8.1 on page 125 (under step 4):

 

BMX = beta0 + beta1 * g * (alpha1 * sqrt(I)) + beta2 * g * (12 * sqrt(I))

 

Is it correct, that the "12" represents the value of alpha2 and is it fixed to that value for

every possible cation-anion pair? This would imply that the alpha2 values given in the parameter

file are not really used?

 

Thanks a lot for your help,

Christiane

[react-decreasing water mass]

Hello,

 

so far, I´m not too experienced with GWB but I do think it is a very capable program

(I use version 8). Recently, I did some calculations about minerals precipitating

in chlorine solutions. In these calculations, the water mass decreases during the

simulations while the minerals incoporate water in their structures (I guess it`s

due to that).

 

Is there any possibility to keep the water mass constant anyways during simulation?

 

Thanks a lot for your help,

Christiane

 

I attach a script and the thermo_hmw database (though I made no changes on it).

cacl_gypsum.rea

thermo_hmw.txt