Disposal of used chemistry

[brYan]

How does everyone dispose of their used chemistry, in particular, fixer?

Also, is having a home darkroom with a septic system incompatible?

 

[bmac]

There is a thread from a couple of months ago about the septic system question. There is a lot of good info in there.

 

[brYan]

Brian...

I did look in this section for my answer. Is the thread in a different part of the forum?

 

[Jorge]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (brYan @ Jan 9 2003, 10:42 PM)</td></tr><tr><td id='QUOTE'>Brian...

I did look in this section for my answer. Is the thread in a different part of the forum?</td></tr></table><span id='postcolor'>
BrYan is in the darkroom forum. Here is the link:



(there was a url link here which no longer exists)

 

[brYan]

Found it! Thanks, Jorge.

From what I understand, it seems there are more hazardous household chemicals to dump down a drain than used fixer.

 

[Jorge]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (brYan @ Jan 9 2003, 11:12 PM)</td></tr><tr><td id='QUOTE'>Found it! Thanks, Jorge.

From what I understand, it seems there are more hazardous household chemicals to dump down a drain than used fixer.</td></tr></table><span id='postcolor'>
Well, yeah.....ok what I have read states that you should mix the developer and the stop bath to neutralize the solutions. Some even claim they are good for septic tanks because they provide organic material. I dont know and I would not bet my 8x10 on it. Silver is what is known as heavy metal, much like mercury although not that harmful. Depending on the concentration it could harm the bacteria in your septic tank, but many people have told me it is not so for hobbiest darkroom quantities. As a manager for household hazardous waste collection, we used to take fixer as a haz waste, but the limit was 5 gals, kind of dumb if you ask me but I did not make the rules. Your best bet would be to take Ed's advice and get one of them little silver recovery gizmos. This way you are sure not to mess up your septic tank.

 

[Aggie]

..

 

[brYan]

Any comments as far as a sewer system goes?

 

[LFGuy]

You should check your local regulations on your local sewer systems.

As far as I remember (someone correct me if I'm wrong) fixer can contain anywhere from 2000 to 5000 mg/L of silver compounds (silver thiosulfate complexes, Ag(S2O3)2 3-) when exhausted, it all really depends on what and how much you're fixing, whether you're repleneshing it, etc.

Different forms of silver have their own toxicity, and higher concentrations make things more toxic as well. The big danger to the environment is free ionic silver, which can kill fish, aquatic plants and the like. Silver thiosulfate is pretty stable, but if I remember correctly it can degrade to silver sulfide, which probably releases some silver over time (but not too much as it's pretty insoluble), but which is much less toxic than something like silver nitrate.

In the USA, the EPA has a sewer discharge limit of 5 mg/L of total silver (which includes the harmful ionic form and the less harmful thiosulfate and sulfide forms). Anything above than can be classified as hazardous waste. Obviously, this level is much lower than what your fixer probably has (I'm not sure how high it would get with just a couple of films/papers). Labs and the like are required to treat their fixer waste. Amatuers, as far as I know, aren't required to. Again, find out your local regulations.

Your local wastewater (sewer) treatment plant might have an activated sludge system, where microorganisms break down dissolved organics into stable compounds, water and carbon dioxide, as well as produce more microorganisms. Free ionic silver can kill these guys and upset the process, making the plant less efficient.

 

[ann]

With regard to fixer; check with a local processor;( your dealer may be more apt to do this for you (if they have a developing system). they usually recycle and may do it for you. Mine takes care of our fixer.

 

[Jorge]

Ok, first let me say that household hazardous waste is exempt from EPA rules. The thinking behind this is that it would be generated in such small quantities as to be almost if not totally negligible. So although LFguy is correct in his assesment the quantity of silver found in your fixer after dilution would not cause any problem. Unless you have a home business where you are continually processing you have nothing to worry about. The only thing which could be of concern is if you have copper piping, if you do, then flushing with some water after you dump the chemicals would be good.

 

[Les McLean]

Brian,

I lived for 7 years in an isolated farmhouse where we had a septic tank and all my black and white chemicals were just poured away into the system without any problems or affect on the efficency of the tank. I was carrying out workshops and doing a lot of personal printing so I did have to dispose of a little more than I think you are dealing with.
I would be hesitant to speak to the authorities about these matters for in my experience in the UK it tends to encourage a rather hysterical over reaction; for example the authorities in one area that I used to live in told me that I would be required to entomb any waste chemistry in one cubic yard of concrete and have it transported to the nearest waste disposal site.

 

[lee]

I concur with Les on not telling the authorities lest you be overwhelmed with regulations. I am about to build a new darkroom in another building and my lawyer and darkroom mate has said we should not say anythng about this building a darkroom. Just turn on the utilities and we will sort it out later. May not be the best way but he seems to think there is no reason to poke a stick at the bear.

lee/c

 

[G O&#39;Connor]

I highly dilute any chemical I pour out. I also only pour them out when they're old, so it's not too bad, plus, I think little Timmy next door likes his new 3rd eye

 

[LFGuy]

From a quote I've heard quite often: "The solution to pollution is dilution"!

 

[Aggie]

..

 

[Lemastre]

Combining used chemicals to neutralize them is the first step in disposal. Then dump the mixture down the drain along with plenty of running water and let the water run for a minute or so. Also, I notice a deposit on my developer trays and in my film-developing tanks and even in my steel sink that I assume is silver; so maybe not all the unused silver ends up down the drain.

 

[cophotonut]

I called the City where I live. They said that unless I was doing commercial volumes then they had no problem with the fix going down the drain.

 

[Ed Sukach]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (LFGuy @ Jan 10 2003, 06:22 AM)</td></tr><tr><td id='QUOTE'>
As far as I remember (someone correct me if I'm wrong)&nbsp; fixer can contain anywhere from 2000 to 5000 mg/L of silver compounds (silver thiosulfate complexes, Ag(S2O3)2 3-) when exhausted, it all really depends on what and how much you're fixing, whether you're repleneshing it, etc.

</td></tr></table><span class='postcolor'>
I've been wondering aout the amount of silver/ silver compounds drawn into the fixer by the development process. It seems to me that 5000mg - 5 grams - per liter is an awfully large amount.
A new American nickel ($.05) weighs close to 5 grams - that seems to be a LOT of silver.

Anyone have any idea of the average amount of silver removed from a single roll of film or sheet of paper in the process?

I remember a post - somewhere - from a photographer running a recovery system in a fairly active home darkroom for a number of years. He concluded that the few grams recovered was simply not worth the effort.

 

[removed account4]

i was wondering if anyone here has gotten a silver recovery device from itronics?
if so, how much was it? or do they "lend/ lease" the units out?

they didn't have the recovery units the last time i spoke with them, and the cost of sending the solutions to them was too expensive.

if you haven't heard of them: http://www.itronics.com/

they take spent photochemicals and turn it into fertilizer.

- john

 

[brimc76]

Brian, I also live in a rural area and have a well and septic system. From the information I have been able to gather from Kodak and different manufacturers your septic system will handle up to 25% of it's total volume. There's no way that a normal home darkroom would produce that much volume in a session so I was told not to worry about it. What I do just to be a little safer is to dispose of the fixer separately. Our local recycling centre will accept small amounts of chemicals from home darkrooms without any hassle (as well as paint, oil, tires etc.). It's not just the septic system that I'm worried about it's my drinking water also.

 

[dr bob]

I m a graduate chemical engineer with some knowledge of hazardous materials. You only have my word that the only truly potentially dangerous material in B&W processing is the fixer. As stated above, there can be a small silver content in the form of complex silver ions. To get rid of this, one can place a steel wool (not s.s. wool) in a container with your exhausted fixer. The silver will displace the iron and coat the steel wool in a manner similar to copper coating of a steel nail placed in a solution of copper sulfate (high school chemistry). An overnight treatment with occasional agitation will convert sufficient silver to render the problem mute. Disposal of the iron halide solution should pose no problem. I am told there are establishments which will accept the steel pads for recycling the silver. I wouldn’t try it myself as it involves a complex process with truly hazardous materials.

Also I would advise one to disregard those do-it-yourself electroplating kits I have seen. Electroplating is even more of a black art than photography. You will end up with a goddawefull mess of hydrolyzed silver jell precipitate which will be more difficult to dispose of than fixer.

The bottom line is that there is so little silver in most darkroom effluent that it can be safely disposed of down the drain. I used a septic system for years with absolutely no ill effects. Living next to the Chesapeake Bay makes me the target of every environmental testing agency in the Government and they have never found the silver even though I told them about it. (They did find mercury but never deduced the source. Not from my darkroom! Someone probably broke a thermometer 50 years ago – you know – one of those “Coke–a-Cola” thermometers?)