[Ryuji]

Suppose that I wanted to electroplate out the silver onto a cathode; could I put the used fixer solution in a plastic tub, attach metallic electrodes to either side of the container, and connect an appropriate DC current source?

As I wrote in my previous post, this is not sufficient. The electrode should move around so that all parts get used evenly.

Also, are there any gasses produced in the reaction that I would need to be concerned about, such as hydrogen?

The electrodes are made from stainless steel and carbon. The most advanced electrolytic system maintains the cathode potential at or upward (more positive) of -0.55V with reference to saturated calomel electrode. It's also best to adjust the pH to about 7 to 8 range before starting silver recovery (the pH of Clearfix is ideal for silver recovery system without any adjustment, and most color fixers are not far from it either).

A recent report on electrolytic silver recovery system was published by Mina and Chang of Kodak Rochester Lab in 1982. Mina, R. and Chang, J. C. 1982. Electrolytic silver recovery from spent fixing solutions---an electroanalytical study. Photo. Sci. Engr., 26, 223-7.