Apply a model to data using langmuir/freundlich.

[lsh2018Participant]

Is it possible to apply either langmuir or freundlich’s isotherm to a set of data in data graph? I have a seried of time vs concentration of metal adsorbed from water into a substance, starting concentrations, and metal in the adsorbent.

[dgteamModerator]

You can fit isotherm equations using the Arbitrary option in the Fit command.   We just uploaded this file to the on-line examples.

Here are the settings for the Fit command for a Langmuir isotherm.

For more details on how the non-linear curve fitting works: https://community.visualdatatools.com/datagraph/knowledge-base/command-fit/#arbitrary-fit

We used the form of the equations presented here:  https://www2.stetson.edu/~wgrubbs/datadriven/langmuir/langmuirwtg.html

In your case, it sounds like you have time series data.  The isotherms are for fitting the values at equilibrium.  So it sounds like you might need to use a kinetic model first to determine the equilibrium concentrations.  That would also use a non-linear fitting procedure.

Does that help?

 

 

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