Kaushik Mitra Posted July 7, 2015 Share Posted July 7, 2015 Hello, I am currently working on modeling the precipitation of seawater under evaporation. I am particularly concerned with the Iron containing phases. Which thermodynamic database should I choose to get a reliable result? "HMW" could have been an excellent choice except that it does not contain Fe. The other databases that are present include Fe as well as use B-dot equations. Generally B-dot is valid for Ionic Strengths less than 3 molal , but there were erroneous results (pg 132) cited in the book "Geochemical and Biochemical Reaction Modeling" by Craig Bethke. I am very perplexed with the choice of database. Please suggest a solution. Thank you Quote Link to comment Share on other sites More sharing options...
katezat Posted July 8, 2015 Share Posted July 8, 2015 Hello Kaushik, It would be best for you to modify the default thermo.tdat dataset. You should search literature for published datasets similar to Harvie-Moller-Weare model (Harvie and Weare, 1980)( Harvie et al.,1984). More recent publications might contain data on iron species. Hope this helps, Katelyn Quote Link to comment Share on other sites More sharing options...
katezat Posted July 14, 2015 Share Posted July 14, 2015 Hello Kaushik, To clarify, you should use (not edit) the default thermo.tdat dataset for now. As far as ready-to-go datasets that come with the GWB, you will need to use a Debye-Huckel based thermo dataset, because there is no virial model dataset which contains iron. Of all the Debye-Huckel based methods, the B-dot (which thermo.tdat uses) is the best at higher ionic strength. However, as you mentioned be mindful as there is error involved. If you take a look at those references, you can find the information you will need (virial coefficients and information needed to calculate equilibrium constants). Kind regards, Katelyn Quote Link to comment Share on other sites More sharing options...
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