Best way to dispose fixer

[Christie Photo]

Right down the drain.

If you're dealing with small amounts of chemistry, just dump it. You'd have to have an enormous amount on a daily basis to have any concern. Really. Peeing in a swimming pool would be far worse.

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[theres126]

Even with a septic system??

[jedithebomber]

Even with a septic system??

This is what I am worried about since I am currently building my darkroom. According to the information I have found on google searches, it is suggested that none of the chemicals go down the drain since some of them mess with the septic tank process in different ways (de-oxygenation, killing bacteria, messing with the PH). Then again many people seem to do it and have no problems. As for me, I think I will keep a 5 gallon bucket under the sink for disposal. Worse comes to worse I will solidify it and send it off with the trash or something.

[lonewolfe]

Before you dispose of your fixer, settle the silver out of it. Eventually you'll get enough silver to be able to sell it.

how do you do that im fairly new to all of this

[Rhys]

how do you do that im fairly new to all of this

Pour the solution into a tall, thin glass beaker. Wait a week or so for the sedement to settle. Pour off the excess liquid (down the drain) - without pouring the sedement out. Pour the sedement into a different container. Repeat the process. Let the sedement dry and you have silver salts remaining.

[lonewolfe]

ok thanks i need to try this eventually

[digital flower]

I pour mine down the drain, just like I do with anti-freeze.

I don't think you are suppose to pour anti-freeze down the drain.

[safesilverrecovery]

The EPA federal guideline in 5 parts per million. Anything over that it is considered a hazardous waste. As such it is supposed to be transported on a hazardous waste manifest........realistically is anyone going to find out if you are a residential user...no. I know have medical practices out in the stixks that just dump it in the septic for 30 years.

[ann]

another 3 year old thread appears.

[maris]

I've had the luck to enjoy a career in scientific research and analytical chemistry before taking up photography full time. One of my challenges was teaching chemists at the local water supply and sewerage department about photographic chemicals in the effluent they had to treat. Of course I had an agenda. I wanted building approval for a house with sizeable darkroom in it. They did said yes to my plans.

The following does not apply to industrial scale photo materials manufacturing or a major processing lab, only households connected to a sewer line or a proper septic system:

Developers are mild reducing agents that oxidise rapidly to inert components. The BOD (Biological Oxygen Demand) challenge offered by a darkroom is much smaller than the BOD from a dishwasher, in-sink garbage disposal unit, or a toilet.

Stop bath is a very mild acid that has no measurable effects on highly buffered systems like septic tanks or sewerage treatment plants.

In moderate quantities (pounds, not tons) silver tetrathionate and similar compounds which characterise used fixer don't harm sewerage treatment systems. The silver very quickly gets converted to silver sulphide in the presence of the free sulphide ion (smells like rotten eggs!). Silver sulphide is geologically stable and inert and has one of the lowest solubility products known in chemistry. The stability and inertness of silver sulphide is the key to the remarkable archival properties of sepia toned photographs.

Before my darkroom was approved by my local council I had to calculate the silver concentration in my total household effluent. I'm pretty busy and use a few thousand sheets of film and paper per year but the result came to about 5 parts per billion. By the time this mixes with the output of the other 20 000 households that don't process photographic materials the silver concentration is below any conceivable detection limit down at the sewerage treatment plant.

You can do your own calculations. Just calculate your yearly use of silver from your photographic materials consumption and divide this by your yearly water consumption from the water meter.

The world being what it is many local effluent standards are written by lawyers and/or accountants who don't know a dot of chemistry but known about culpability and lawsuits. If you encounter such local regulations and you want to ask permission I guess you have to do what they say.

[Robert_Maxey]

I'm pretty sure pouring fixer down the drain is illegal in most U.S. states.

uh oh.... I may be a criminal. I did it for 30 years.

Thirty years, we did it since 1890. Silver collection? We didn't need no silver recovery. Too bad, we dumped the net worth of a small country down the drains, I should think.

[ann]

People this thread was started in 2008 , I don't think the Op is still around or even cares anymore