Inconsistency between ts_pH and Variable Boundary Conditions

The HP1 code incorporates modules simulating
(1) transient water flow in variably-saturated media,
(2) transport of multiple components, and
(3) mixed equilibrium/kinetic geochemical reactions.
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Marlon Mederos
Posts: 4
Joined: Tue Sep 27, 2022 6:17 pm
Location: Spain

Inconsistency between ts_pH and Variable Boundary Conditions

Post by Marlon Mederos » Thu Jan 26, 2023 9:00 am

Hi, I have simplified the study model because I found bad results in my model and have gone back to try to correct this.
I have stated a 10^-7 mM aqueous species of CaCl2 (1001) and a 3002 of 10 mM, in both the pH will be calculated to charge the solution. There is a single pulse with the 3002 solution during the whole time. The pH as a result of speciation is 7.008 and 6.985, respectively; however, when I plot the ts_pH with GnuPlot it shows a pH at the output of 12. Why does this happen? Thank you very much for your time. Regards.

diederik
Posts: 71
Joined: Fri Mar 10, 2006 7:57 am
Location: Belgium

Re: Inconsistency between ts_pH and Variable Boundary Conditions

Post by diederik » Thu Jan 26, 2023 11:47 am

Difficult to say based on this description,

could you send me (djacques@sckcen.be) the project files,

thanks
diederik

Marlon Mederos
Posts: 4
Joined: Tue Sep 27, 2022 6:17 pm
Location: Spain

Re: Inconsistency between ts_pH and Variable Boundary Conditions

Post by Marlon Mederos » Tue Feb 07, 2023 12:08 pm

Hi, the problem was that, if I declared high or low concentrations fixed the pH, it did not give the same result, which is not logical, but I have found the source of the error. As I understand that it may be a common mistake in those of us who are starting in this amazing world of Hydrus, I would like to share the cause of the error and the base files, in case any colleague has the same doubt.
It should be remembered that Hydrus performs speciation of the declared elements and that the "charge" command should be used to calculate the pH or set the pH and calculate the amount of an element to be added or removed. On the other hand, all elements present in the reactions, even if at very low concentrations, must be declared as well as declared for transport in Hp1-Components.
Thank you very much dear Diederik, not only for your prompt answer, but also for being always ready to help us in our doubts and to make sure that our investigations reach a safe harbor. Best regards.
Attachments
pH_Study.zip
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