[FUCKYOUDELETEMY ACCOUNT]

Hey all,

Had a question I was hoping someone could help with or point me in the right direction.

How would I calculate the final conductivity of two different volumes with two different conductivities. For example I have 500,000 gallons of water at 7.0 microsiemens and 750,000 gallons of water at .08 microsiemens.

Background: I work at a power plant and we process water for emissions control using a reverse osmosis system and demineralization trailer.

Thanks in advanced.

[Borek]

You mean conductivity of the mixture?

[FUCKYOUDELETEMY ACCOUNT]

Yes. The conductivity of the mixture. Sorry that was not clear in the initial post.

[Borek]

If there are no reactions between ions present and solutions are reasonably diluted, final conductivity will be approximately a weighted average of the initial conductivities (you can derive that from Kohlrausch's Laws). Lack of reactions means both initial solutions must have identical initial pH. If the pH are different, there is no way to predict the result (that is, weighted average will be still better than nothing, a lot depends on how accurate your prediction must be).

[Enthalpy]

In that particular case, the figures tell similar volumes and very different conductivities, so we can neglect the contribution from the purest water, even if the pH differs - exceptionally. That is, the 7µS are multiplied by 500 000 / (500 000 + 750 000).