hi mario

i guess what martinp was suggesting is that photochemicals are benign and one should be able
to dispose of them with your drain, since you dispose of other household "stuff" that way,
but the local laws don't permit that.

usually municipalities have a household waste disposal day and if you save your chemistry you can
most likely dispose of it there. call your local water/sewer commission and i guess they will give you
what is OK and NOT-OK to put down your drain. in a lot of places as long as you mix everything but your fixer together
it neutralizes it all, and along with a big sink full of water it can go down the drain, but in some places it is not like that
so you need to find out ...

if you want to get the silver out of your fixer before you either have someone pick it up or you bring it to your household waste disposal place
you can easily reclaim most if not all the silver from it. there are a few simple ways to do this ...

you could use steel wool .. it will remove the silver and replace it with iron at a molecular level .. but then what do you do with the steel wool
and the sludge .. its kind of messy i guess. i used to do this with copper flashing, before it became expensive .. it was easy.

another way is through electrolysis. i sell small inexpensive devices that will electroplate the silver out of your well spent fixer. it has to be well spent
( used over and over ) but it will remove the silver, all but maybe 50-55 parts / million ...
if your fixer isn't well spent, well it will burn out the magnet, smell bad and it will turn black.

there is also something i sell called a trickle tank. its just like using steel wool, but it is self contained in a media bucket so there isn't any mess
if used correctly, you can remove most of the rest of the silver from your fixer ( and wash water! )
you can run it through 2x and maybe get your chemicals down to around 1 or .5 parts / million ...
you can then dump off your spent fixer with the household waste and make $ off the silver you removed.
i'm not into the hard-sell, but if you want to learn more about this stuff, i will be happy to help you out.

have fun figuring out what to do, cause you're gonna hear a lot of opinions

good luck !