I'm on a septic system, on the advice of one of the chemists here, I neutralize my stop with baking soda.
I also neutralize the vinegar I use to de-lime my electric teakettle.
For the fix, I de-silver it, and take what remains to the hazmat collection center.
Originally Posted by jscott
there used to be an active member here who claimed selenium was harmless
because trace amounts were found in multi vitamins and in sea water ...
a company called ITRONICS in nevada reclaims photochemistry from all over the west coast
and converts it to fertilizer .. they remove the bad-bits first though ...
Something I thought about last night as I was developing two rolls of Tri-X: When I pour stop bath down the drain it turns a little bit purple because of some of the remaining developer I just poured down the drain, 45 seconds ago.
Originally Posted by Roger Cole
Therefore, doesn't it stand to reason that the developer is neutralizing the stop bath? It would naturally be getting neutralized inside the J-trap before it ever gets to the sewer. Wouldn't it?
Further, if you wanted to make sure the stop bath was neutralized, you could pour developer and stop into a plastic tub, allowing them to neutralize before dumping the whole volume down the drain.
Problem solved, I suppose... Right? :)
If you read J-300 more carefully, you'll see that the Kodak recommendation to neutralize stop baths is for their undiluted concentrate (which is almost pure acid), not for the working solution. The document is not nearly as clear about this as it could be. Dumping used (especially well used) stop down the drain should be no problem. However, one can easily neutralize both stop and developer to a degree by mixing them together before discarding as you note. This is pretty easy to do for printing sessions, since they both have about the same lifespan. When the developer or stop dies, just mix the two together and dump. Even if you don't neutralize, using copious amounts of water will dilute either to just about neutral really fast.
Good to know all the details. I suspected as much about the silver in fixer, but never knew the details.
Perhaps those of you who take their fixer to a hazmat facilitly could comment on my concern, which is that the hazmat people don't really know what to do with used fixer. The guys I dropped my used fixer off to had no idea what silver recovery was and treated the used fixer as if it were highly toxic (rubber gloves and masks!). Some spilled in the back of my truck and they seemed horrified that I just wiped it up with a grease rag and rinsed it with water. If I though that my used fix would get the silver extracted from it and recycled, I would certainly take the time to make the trip to the hazmat facility every so often. I just don't think it does. I'm still looking for a lab or college darkroom that has a silver-recovery unit.
As for selenium toner, I've been on my soapbox here enough lately about replenishment instead of discarding lately that anyone interested in what I do can easily find it with a search. I never discard selenium toner.
I peeled the label off one of my old bottles of Kodafix concentrate, scanned it and keep the file on my hard drive.
When I take a bottle to the hazmat place, I print out that label and stick it on the jug with packing tape. I also print out the MSDS and stick it through the handle of the jug when I drop it off. Haven't had any questions yet. In fact, they seem to think I'm the one being a fussbudget.
Remove the silver from your fixer using a Silver Magnet. It's just a little plastic box with holes in it to let the liquid in. Inside the box are a sheet of metal foil and a long rod shaped electrode. You get a little "wall wart" electrical transformer that connects to a cord coming out of the plastic box. You plug it in, drop it in your fixer bucket and leave it alone for a few days. There are two LEDs on the transformer. A red and a green. At first, the green one lights. After the silver is removed from the liquid, the red light starts to glow. That's how you know you're done. Dump/recycle the desilvered fixer. Wash off the Silver Magnet cell with clear water, dry it and put it away for the next time you want to use it.
The first time I used the Silver Magnet, it took a little over a week to pull all the silver out of 2-1/2 gallons of used fixer. I weighed it before putting it to use. It weighed a hair over 75 grams. When I pulled it out, it weighed almost 100 grams. That's 25 grams or 0.9 ounces of silver I got back. Right now, the price of silver is hovering at around $30 to $32 per ounce. At the rate I'm going, one more use will have paid for the Silver Magnet but the cell won't nearly be full. I think I should be able to get ten uses out of it before it gets full.
When it finally gets full, my Silver Magnet will have paid for itself five times over.
some of the lights are a little wonky on the magnets ... i usually tell people when the stuff they plate
starts getting "dark" ( instead of greyish, it is dark-greyish / blackish ) it is time to turn it off
because they are plating other "stuff" not just the silver ... as long as they stick it in a non-metalic container
when they run it they are good to go, a metal container will end up electro-plated silver ...
oh, your magnet will hold around 32troy oz of silver on it, it would have paid for itself 12-13 times over if you let it get real-full :)
have fun !
(and thanks ! )
So, let's round off and say 30 oz. of silver at $30 per.
$900 return on a $50 investment ain't too shabby. Is it? ;)
Yes, I noticed the lights aren't perfect but you can still tell.
When you first connect a clean cell to the wall wart, the red light glows brightly. When you submerge it in the fixer, it is barely aglow.
As the silver gets pulled out of the fixer, the red light gets a bit brighter.
I also watch the color of the silver building up on the plate. It looks like sand. About the color of sand, too.
I pulled mine out when the sand started getting darker.
My darkroom is in the basement. I can look in every so often as I go down to do laundry and stuff. The intensity of the light will give me enough information to know when to go look at the condition of the "sand" inside the cell.
You might consider copying Randy's posts and your responding posts to the thread you have going about the Silver Magnet;).
And yes, I am still trying to figure out how I could make one work with my temporary darkroom setup..