[shangri]

Hi,

I am a civil engineering student currently starting a project on electro-kinetic remediation with no external power supply.

I have two connected steel electrodes, one placed in copper sulphate solution and one placed in just water.

They are placed either side of a clay sample spiked with copper sulphate also, the idea being that a potential difference between the two electrodes will cause the disassociated copper ions in the saturated clay to migrate towards the cathode.

Here is where I am stuck, I am unsure how a potential difference is generated between the electrodes. I am aware that it is to do with the corrosion of the electrodes and a difference in electrolyte concentration but not sure how.

Any help would be appreciated..

[Borek]

Sounds more or less like a concentration cell.

What do you now about electrochemistry? Standard potentials? Formal potentials? Nernst equation? There are thick books on the subject.

[shangri]

I have read up on concentration cells and things like Nernst equations and standard potentials keep popping up. Like i said, i study civil engineering and have absolutely no background in electrochemistry.

This is where I am at so far.. In the copper sulphate solution i expect this to happen..
Fe Fe²⁺ + e^-
and..
Cu²⁺ + 2e^-  Cu
Does do the Fe²⁺ ions then join with the SO4^2- to form FeSO4?

Or does this also disassociate into Fe²⁺ and SO4^2-

And in the water I expect this to happen..
Fe Fe²⁺ + 2e^-

Does H20 come into this somewhere?  Complete madness!

Please correct me if I'm wrong..

But my understanding is that copper ions "wants" electrons, so takes the electrons from the iron (steel electrode).
I understand that for a potential difference to occur there has to be a movement of electrons from one electrode to the other. Not entirely sure where the demand is from..

[Borek]

Not to discurage you, but you have a steep learning curve ahead.

Are the electrodes made of stainless steel, or "just a steel"?

[shangri]

They are mild steel