| More on this, if you have a lab in your area that you are on good terms with, you could ask if they would be willing to treat your silver bearing effluent through their recovery system. I had a deal like that with a lab where I am when I was running a custom B&W darkroom out of my home and was generating a fairly large amount of used fixer. It was a win/win situation, they got to reclaim and profit from my silver waste, and I got to feel good that I wasn't dumping heavy metal into the sewer.
For a small user, there really isn't any way to recover the silver. The cartridges that are used by labs are expensive and you'll never use them to capacity, and electrolytic cracking of the fixer is costly and quite dangerous because of the high current that is needed.
For a few films a week, if you don't have a nice lab relationship, then sewering is about the only option. Dump it with a fair amount of water to make certain it gets out of your plumbing and into the waste stream as quickly as possible.. |