Dispose of photo chemicals -Berlin

Gast · 2004-06-23T12:39:15+00:00

Hallo, habe leider bei den Beiträgen nichts Passendes schon Geschriebenes gefunden, was sich auf eine ordnungsgemäße bzw. ökologische Entsorgung der Fotoc...

Gast

Hello, Unfortunately, I haven’t been able to find anything suitable in the existing posts regarding the proper or environmentally friendly disposal of the photographic chemicals from my black-and-white darkroom. I’d like to dispose of the chemicals here in Berlin (inexpensively, of course). I read on another website that you can apparently dispose of up to 10 litres a year at the BSR (Berliner StädteReinigung) – though 10 litres isn’t really much. Apart from the long journey and the likely enormous weight of the chemicals to be disposed of (without a car), 10 litres is a bit on the low side. Perhaps there is someone who can help me with this. Initial thoughts: - Ask large laboratories? (Is that a good idea?) - Dispose of it in the toilet? (I’d rather not!) Many thanks in advance KAi

cfb_de

Hi Kai, Even at the risk of opening up a can of worms when it comes to environmental concerns: :) Developer: let it oxidise, then pour it down the drain. There’s nothing in there that’s harmful to the environment; the remaining reducing agents will just travel down the drain to the first bend in the pipe, where they’ll have reacted away. :) Stop bath: down the drain. That might even descale things a bit. :) Fixer: treat it, then down the drain. The critical part is the silver complexed in it; that needs to be precipitated out before disposal. The easiest (and messiest) way is to take a barrel, put some steel wool in it and add the used fixer. The silver precipitates out, the iron dissolves. Filter it off, done. You can buy such ‘cassettes’ from Kodak for a pretty penny. Simpler (and therefore what I do) is chemical precipitation using sodium dithionite. Add approx. 20g per litre, do not seal the container tightly, and let the reaction run its course. The reaction produces sulphur dioxide, which smells a bit. So it’s more suitable for the balcony than the living room. The silver settles at the bottom of the container; decant it, and you’re done. You can get sodium dithionite (technical grade is perfectly adequate) from a chemist’s, amongst other places. A 1kg pack costs around

Urnes

You can also add pure zinc dust to the fixer to thicken it. About 1 tsp per 10 litres. Works a treat. However... And now here’s the question for Franz: “How on earth do you filter 10 litres without standing there for two hours, pouring it in bit by bit?” The first time it worked quite well: just put the stuff in a 10-litre canister and, after filling it up, simply pour it off from the top. I just left the silver at the bottom. When I used the same canister the second time (the silver was still in it), some of the silver unfortunately came loose again in large clumps. Filtering it out afterwards was a nightmare. Do you have a decent solution for this? Regards, Sven.

cfb_de

Hi Sven, I usually filter between one and three litres at a time. A pleated filter works quite well for that. For larger quantities, I’d build a sand filter and then take the sand and silver to the recycling centre. Best regards, Franz

hal9000

My usual chemist told me that sodium dithionite isn’t stocked and therefore can’t be ordered through them. Is there another source? Or can anyone tell me which chemist (in Berlin) stocks it? Regards hal9000

cfb_de

Hi Hal, By the way, Mikon-Online Pharmacy can certainly order that for you. They just need to check their chemicals catalogue rather than the pharmaceutical wholesaler. But they probably don’t want to. Best regards, Franz

huehnerhose

Hi Kai, As far as I know, and having checked, you can dispose of 20 kg free of charge per trip at the BSR. I once wrote a thread about this and, whilst doing so, enquired with the BSR; their helpful customer service team confirmed this for me. You just need to take the containers to the recycling centres. Regards Sebastian Edit: BSR hazardous waste page

Collection fees at hazardous waste collection points for private households Private households can dispose of up to 20 kg (per type of waste) of hazardous waste per day free of charge. Any quantities exceeding this are subject to a fee.

Gast

... and if you come two days in a row, they’ll start calling you “Mr Wegert” :) !! Best regards, Stefan D

Richard

Hi Franz, Tell me, what’s got into you? You’re just listing steel wool as a filling here without mentioning the concerns surrounding this method :o So, to get the environmental debate started. Filling only makes sense if the container can be filled almost completely (otherwise it’s just greenwashing). Steel wool has already been ruled out as a method here on numerous occasions because (Franz, I’ll just quote you from another forum):

On the subject of steel wool: I don’t know how the proponents of this solution dispose of their waste, what they use to degrease the stuff, or whether they really use *iron* shavings or rather unsuitable but cheap steel shavings made of alloyed steel from the nearest turning shop or supermarket. ‘Abrazo’ isn’t up to scratch, you see. But one thing does interest me: how the advocates of this fixing bath filling process treat their resulting sludge to make it suitable for disposal. Firstly, quantitative silver plating is not possible (just look at the redox potentials, consider what happens on which surface, and you’ll conclude that silver still remains in solution. Let’s not even get started on complex stability constants...). Secondly, what’s usually on offer as “iron wool” is actually “steel wool”, which merely adds chromium and nickel to the silver in the effluent. That’s true applied ecology – after all, no genuinely environmentally conscious fellow human being understands the term “free corrosion potential” anyway.

:) Best regards and take care Richard