Disposing of old chemicals

simon ess

simon ess

Just call me Roxanne.
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I have about half a litre each of Ilford Rapidfix and Kodak HC110.

The fixer is clearly knackered and the HC110 isn't exactly fresh. Both are at least 2 years old, maybe 3.

I've read that mixing the two together in a bucket then filling the bucket with water then flushing down the loo is an acceptable way to go.

Would you agree or not?

Thanks
 
I try to remove the silver from my used fixer first as it does interfere with water treatment plants and septic tanks. A sheet of aluminium foil left in it will cause the silver to deposit as a sludge. It is possible to refine that but you need a lot. The sludge can go to normal household waste if you don't fancy smelting it. Then mixing the Dev and unused or desilvered fixer will produce a neutral liquid you can flush.
 
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I'm sure the official advice would be not to but I think for very occasional domestic disposal it will be fine given the dilution rates at the sewage treatment works. Sewage treatment is a biological process and large quantities of anything "unusual" can be harmful - a dairy company once killed a sewage treatment process with orange juice - but a litre or two of fix and dev when in amongst thousands of litres per hour is ok but of course it is something you should never do :)

Cross posted with David
 
My HC-110 is a couple of years old and still going strong Simon, so maybe some life in it yet? Fixer I just dilute greatly and put to drain.
 
dmb said:
I try to remove the silver from my used fixer first as it does interfere with water treatment plants and septic tanks. A sheet of aluminium foil left in it will cause the silver to deposit as a sludge. It is possible to refine that but you need a lot. The sludge can go to normal household waste if you don't fancy smelting it. Then mixing the Dev and unused fixer will produce a neutral liquid you can flush.
Click to expand...

Brilliant! Thanks David. I'll get the foil in now.

How long should I leave it for?

Edit - No, hang on, this is unused. And it's only about 1/4 litre.

Thanks for the advice folks.
 
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dmb said:
I try to remove the silver from my used fixer first as it does interfere with water treatment plants and septic tanks. A sheet of aluminium foil left in it will cause the silver to deposit as a sludge. It is possible to refine that but you need a lot. The sludge can go to normal household waste if you don't fancy smelting it. Then mixing the Dev and unused or desilvered fixer will produce a neutral liquid you can flush.
Click to expand...
Trying this for the first time. I have been keeping my diluted fixer in an old fixer bottle, then decanting what I need into a 750 ml container for each use, and returning to the main bottle. So I've just added some crumpled alfoil to the 750 ml container, and decanted all the diluted fixer into it. Then I rinsed out the old fixer bottle, thnking I could re-use it for the next batch. However, lots of black flakes came out in the rinse, presumably silver salts deposited on the sides. No way could I get that clean enough to re-use safely, so out it's gone. I've put the container + alfoil back into storage with my other stuff, ready for disposal when I next do some devving (and mix another batch of fixer)...
 
ChrisR said:
Trying this for the first time. I have been keeping my diluted fixer in an old fixer bottle, then decanting what I need into a 750 ml container for each use, and returning to the main bottle. So I've just added some crumpled alfoil to the 750 ml container, and decanted all the diluted fixer into it. Then I rinsed out the old fixer bottle, thnking I could re-use it for the next batch. However, lots of black flakes came out in the rinse, presumably silver salts deposited on the sides. No way could I get that clean enough to re-use safely, so out it's gone. I've put the container + alfoil back into storage with my other stuff, ready for disposal when I next do some devving (and mix another batch of fixer)...
Click to expand...
David wrote "A sheet of aluminium foil left in it will cause the silver to deposit as a sludge." I (mis?) read that as implying that the sludge would be deposited on the aluminium foil. When I looked at my foil after a couple of weeks it was pretty clean. There was a lot of muck in the bottom of the container, though; I couldn't work out how to get it out so eventually, well, you can perhaps guess where it went. Wish I'd come back and re-read the post before, um, disposing of it!

Oh dear.
 
ChrisR said:
David wrote "A sheet of aluminium foil left in it will cause the silver to deposit as a sludge." I (mis?) read that as implying that the sludge would be deposited on the aluminium foil. When I looked at my foil after a couple of weeks it was pretty clean. There was a lot of muck in the bottom of the container, though; I couldn't work out how to get it out so eventually, well, you can perhaps guess where it went. Wish I'd come back and re-read the post before, um, disposing of it!

Oh dear.
Click to expand...
Being used to decanting stuff in the lab and the wine cellar I didn't mention that step. One part of the reaction between aluminium and the silver in solution produces aluminium sulphate, that is used in water treatment as a flocculant and sticks small particles together. That helps make the silver sink to the bottom and stay together. You can gently pour off or siphon the clear liquid and then the last bit swirl round and put through a filter paper.
 
dmb said:
Being used to decanting stuff in the lab and the wine cellar I didn't mention that step. One part of the reaction between aluminium and the silver in solution produces aluminium sulphate, that is used in water treatment as a flocculant and sticks small particles together. That helps make the silver sink to the bottom and stay together. You can gently pour off or siphon the clear liquid and then the last bit swirl round and put through a filter paper.
Click to expand...
Brilliant, that's so simple! Thanks
 
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