Exchange capcity from meq/kg to moles

[Ionexchanger]

Hello all,

I have had a lot of success implementing an ion exchange model with a lot of help from several posts on the forum.

I have a quick question.

I have calculated a cation exchange capacity of 912 meq/kg. When implementing EXCHANGE in phreeqc, what should the input value be for X in moles?

Thank you kindly for your help!

[dlparkhurst]

You need to define the number of exchange sites in moles. Usually SOLUTIONs are defined to have 1 kg of water, or about a liter. In that case, you need to convert your exchange capacity to eq per kilogram water.  In general, you need the number of equivalents in contact with your solution volume.

[Ionexchanger]

Thank you for the quick response!