I have a good background in this topic... managed a silver recovery collective, wrote a newsletter called 'Photography & the Environment', did some original research into breaking down photo chemicals with bacterial formulations, consulted for lots of schools & labs, etc. The hard part is that it takes a long time to tell the story and I do not believe it is necessary to become an alarmist. So, here are a few tips that are easy to implement...
1. If you have a municipal waste system there is usually nothing to be worried about regarding disposal because the silver in the fixer is removed at the waste treatment plant. However, the silver level is sometimes regulated. Call and ask for the regulation but do not tell them you have a darkroom, because there are many ignorant enforcers out there who can't wait to shut you down. We can then design a method of meeting the regulation, which will make them very happy instead. 2. The silver in photo chemicals is relatively very stable and poses no problem when disposed of in SMALL AMOUNTS, but it's regulated using the same laws that govern electroplating & other large industrial operations dumping unstable forms of ionic silver. This is because the lawmakers cannot find a way to make an exception for small users. 3. Home septic systems can be used with some precaution in order to keep their bacteria alive. Here's a simple method to help save the life of your septic tank: a) pre-oxidize solutions before you flush them down the drain by letting them stand in trays in the open air (if the solution is 1 up to inch deep, 12 hours is sufficient)... this way the solutions break down to simpler forms before you dispose b) add small amounts to the system slowly along with lots of water c) do not mix developer & fixer directly because ammonia gas will form d) if you want to remove silver from the fixer place one pad of steel wool in a gallon of fixer and leave it in there for 24 - 48 hours for complete silver removal (0 - 2 ppm level)... the solution can then be discarded and the collected silver can be dried and saved or put in the solid waste for disposal 4) the same principles work for color chemistry but those molecules are bigger, stronger and take a longer time to break down jim k ----- Original Message ----- From: "Colin Talcroft" <ctalcr...@yahoo.com> To: <pinhole-discussion@p at ???????> Sent: Sunday, February 03, 2002 1:23 PM Subject: Re: [pinhole-discussion] Disposing of chemicals > Someone was wondering about disposal of chemicals, a > subject that has often bothered me. I did a little > research by calling photo suppliers and local poison > control people. There was surprisingly little > information, but the consensus seems to be that most > developers and stop baths are fairly benign and can be > disposed of down the drain if well diluted (leave the > water running). > > Spent fixer contains silver and therefore should not > be disposed of this way. I keep a big plastic jug and > store the stuff until the next toxics drive. Here in > the US these drives are fairly common. When I lived in > Japan there was no way to do this, so I had to just > dump it, which always made me feel terribly guilty. > Photoflo and other wetting agents are esentially mild > detergents. These are OK. Selenium and many other > toners are highly toxic and should not be dumped. > > There was some talk about alternative stop baths > recently on the list. I guess things like citric acid > and ascorbic acid would be even safer, as they are > edibles. > > I am talking about B&W chemicals. Color processing > chemicals are entirely different, of course. > > If anyone knows more about this, please let us know. I > don't want to pass on misinformation, so speak up > especially if I am wrong about any of this. > > Colin > > > > > __________________________________________________ > Do You Yahoo!? > Great stuff seeking new owners in Yahoo! Auctions! > http://auctions.yahoo.com > > _______________________________________________ > Post to the list as PLAIN TEXT only - no HTML > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??????? > unsubscribe or change your account at > http://www.???????/discussion/ >
