Chemistry disposal? What do folks actually do with spent chemistry?

[dancqu]

While dilution is no solution to silver as a pollutant,
isn't diluting any stuff that you do dump a way to
minimize corrosive impact on plumbing etc?
I can't imagine dumping straight solutions down the
drain. I always dilute. C

Well if dilution is a solution then I'm ahead of the
game. My working strength solutions are always
very dilute and used one shot, film or paper.

Silver forms highly insoluble compounds with any
of the halides, the iodide especially, and with sulfur.
Kodak as I recall considers modest amounts to be
safely disposed down the drain there being in
most sewage systems adequate sulfur or
sulfides present.

Kodak's position on the issue may be substantially
correct. Then again Kodak has, in the past, been
one of this nations worst polluters. Dan

 

[dancqu]

More info via Google. Search for, sewage silver environmental . Dan

 

[wogster]

hi bob

thank you for your response.
here where i live the clean water commissions
will do the same thing, shut you down and fine you until
you are compliant. i know of someone fined 10K / day
it was not a pretty site.

the reason why the copper pipes rotted out is because the
silver plated out onto the copper, and the copper went into the fixer
solution as it was going down the pipes. less and less copper remained
on the pipe and eventually it ate threw.

i know you do a fair amount of toning &C for your clients. do you put your
grey water and spent toners into the same system as your other chemistry?


john

I would think you would need to be dumping a heck of a lot of fixer in order to rot out pipes, there is also a lot of other stuff that gets dumped into drains that is likely to do more damage, such as drain cleaners. Not sure about the UK, but in North America there are three kinds of sewer pipes, lead, plastic and concrete, usually used for very large pipes such as street sewers.

One option would be to get two buckets, cut a hole in the bottom of one, and attach a plastic sink tail pipe (the short piece of pipe that connects a sink to the P-trap) stuff a couple of pieces of copper wool (similar to steel wool, but copper) into the tail pipe, and let it drain into the second bucket. If the silver is going to plate out, it will do so to the copper wool, making it safe to dump the second bucket down the drain, without worrying about the copper pipes. When you notice the copper wool has been eaten out, then stuff in some more copper wool.

Then again if you find it's taking you 6 months to fill the second bucket, just take that to the hazardous waste depot and be done with it.

 

[trexx]

The University of Arizona had copper pipes in its photo lab and experienced. After a couple of years the copper pipes were all destroyed.

The big concern with fixer is not ruining pipes but in killing off the bacteria in waste treatment plants.

 

[tim_walls]

I would think you would need to be dumping a heck of a lot of fixer in order to rot out pipes, there is also a lot of other stuff that gets dumped into drains that is likely to do more damage, such as drain cleaners. Not sure about the UK, but in North America there are three kinds of sewer pipes, lead, plastic and concrete, usually used for very large pipes such as street sewers.

From a UK perspective, I've never heard of/seen copper sewer pipes, I must say, but I don't doubt they're used somewhere.

At the domestic under-sink level, I have only ever seen lead (old), ductile iron (old,) or plastic.

From the house to the foul sewer would most commonly be clay (old) or plastic I would think.

The foul sewer itself will be brick (thank the Victorians) or concrete.


I can't imagine copper ever having been cheap enough to be widely used for sewerage piping; then again, copper shortages after WW2 are the reason the British standardised on an electrical ring-main for household electrical distribution - you can use significantly less copper that way than with a radial distribution - and since noone else seems to use ring-mains, avoiding the use of copper generally could be a local peculiarity...

 

[wogster]

From a UK perspective, I've never heard of/seen copper sewer pipes, I must say, but I don't doubt they're used somewhere.

At the domestic under-sink level, I have only ever seen lead (old), ductile iron (old,) or plastic.

From the house to the foul sewer would most commonly be clay (old) or plastic I would think.

The foul sewer itself will be brick (thank the Victorians) or concrete.


I can't imagine copper ever having been cheap enough to be widely used for sewerage piping; then again, copper shortages after WW2 are the reason the British standardised on an electrical ring-main for household electrical distribution - you can use significantly less copper that way than with a radial distribution - and since noone else seems to use ring-mains, avoiding the use of copper generally could be a local peculiarity...

Copper is expensive, I think it always has been, the fact it's corrosion resistant and carries electric current well, means it has been heavily used in construction, but they also like to avoid it where possible. They used to use it here in sewer pipes that would run from say a sink to the stack. A use that is almost always plastic now.

One thing though, there really is very little silver in fixer. The highest silver capacity of fixer is 8g per litre (rapid film fixer, it's less for non-rapid and paper fixers) to get 1kg of silver you need to dump 125L of untreated rapid film fixer down the drain. If your dumping that much fixer on a regular basis, then you should either be using a replenishment system, a silver recovery system or both.

Your probably dumping more silver in the wash water then in the fixer for most people, so a drain mounted silver trapping system is a good idea for people who are afraid of wrecking their drains. Mind you there is a lot of other crap that gets dumped down drains that can do far more damage then fixer, some cleaning products that get washed down the drain. Various pollutants that get washed off things and end up in the drain.

For the poster with wrecked drains in a rental property, you have no idea what the previous tenants dumped down that drain, so the damage may have started long before you got there. I have also seen where a copper pipe ran through a concrete floor and after 40 years acids in the concrete ate through the pipe. It cost the landlord two complete bathrooms to fix that one.

 

[dancqu]

One thing though, there really is very little silver in fixer.
The highest silver capacity of fixer is 8g per litre (rapid film
fixer, it's less for non-rapid and paper fixers) to get 1kg of
silver you need to dump 125L of untreated rapid film fixer
down the drain.

That 8 grams per liter is for film in film strength. Ilford's
FB paper limit is 2 grams and for greatest longevity 0.5
grams. Those paper limits are independent of dilution.
When I toss my one-shot very dilute FB paper fix it
has at most 0.3 grams silver on a liter basis. Dan

 

[Ed Sukach]

That 8 grams per liter is for film in film strength. Ilford's
FB paper limit is 2 grams and for greatest longevity 0.5
grams. Those paper limits are independent of dilution.
When I toss my one-shot very dilute FB paper fix it
has at most 0.3 grams silver on a liter basis. Dan

Just to get this straight...

Do you mean that the 2g and 0.5g, etc. given here is dissolved into the fix/ wash/ assorted other chemistry to be considered as efflluent?, or are you speaking of silver remaining in the finished film/ print (see reference to "longevity")?

I would think that the amount of silver removed would depend on the white (clear)/ black area and density ... ??

 

[dancqu]

Just to get this straight... Do you mean that the 2g and 0.5g,
etc. given here is dissolved into the fix/ wash/ assorted other
chemistry to be considered as efflluent?, ...

I would think that the amount of silver removed would depend
on the white (clear)/ black area and density ... ??

Those silver limits are fixer dissolved. Effluent? The
dissolved silver does go out with the fixer.

Ilford and likely other suppliers average prints when
specifying a fixers capacity; a mix of prints. A series
of high key prints will load a fixer more quickly than
a series of low key prints do to the greater amount
of silver to be dissolved. Dan

 

[Ed Sukach]

Those silver limits are fixer dissolved...
... Ilford and likely other suppliers average prints when
specifying a fixers capacity; a mix of prints. A series
of high key prints will load a fixer more quickly than
a series of low key prints do to the greater amount
of silver to be dissolved. Dan

... "Load a fixer.."?

Then, "2 to 0.5 grams"? refers to the amount of silver ... where? Removed from each (size?) print? Or contained in "x" amount of working?/ saturated? fixer?

 

[wogster]

... "Load a fixer.."?

Then, "2 to 0.5 grams"? refers to the amount of silver ... where? Removed from each (size?) print? Or contained in "x" amount of working?/ saturated? fixer?

It's the amount of silver that 1 Litre of fixer solution can hold without becoming exhausted. There are only 2 things that kill fixer, first is the silver load, second is the carryover from other solutions.

As a fixer solution removes more and more silver from the film or paper, it holds that in solution, making the fixer itself less and less able to remove more silver from the film or paper. Rapid fixers at film strength can hold the most at 8g/L, Hypo at paper strength when used with FB papers can hold the least at .5g/L. This means that if you have an electronic silver recovery system that doesn't harm the fixer, the fixer can continue to remove silver until carryover from other solutions makes it too weak to continue. The other way to resolve this is replenishment, if you know that 1 roll of film adds 10% of the silver capacity and you replace 10% of the solution with fresh, then you can hold the fixer near exhaustion without reaching exhaustion for an extended period of time, this also takes care of the problem of carryover. It also means that your throwing away small amounts of partly loaded fixer often, rather then large amounts occasionally.

If you do 100 rolls a year, and use replenishment so that your using effectively 100ml per roll, then at the end of a year you have used 10L of fixer, about 2½ gallons for the Americans. That's a small enough load that it's an easy trip to the Hazmat depot for disposal. However, when you wash your film then some silver also goes into the wash water, so that should also be saved or treated before being sent down the drain, and for that one of the silver filtering systems is about the only real solution. The amount of silver per L of wash water is probably insignificant. If your using a silver recovery filter on your drain, then you might as well dump the fixer as well.

With all the anti-film hype these days, I've never heard reports of there being major environmental impact from photographic solutions, even though between 1900 and 2000 they were used extensively. There have been reports of septic systems being harmed in that the silver in large amounts of fixer killed the bacteria, but they can usually be pumped and restarted.

I have heard of there being major environmental impact from the chemicals used in the manufacture of electronics, so the digital idea that you must replace your old camera with a new one every 18 months, probably has much more environmental impact, then a little bit of fixer dumped down the drain now and then.

Probably the best though for silver recovery, there are other things that might contain silver that get washed down drains, is at the point of treatment. For example a silver filter at the point where grey water exits the building on the way to the septic tank, rather then the drain for the darkroom, for municipal systems too, removing any silver at the point where the sewage enters the facility, rather then the point where it is generated. Heck the slaves of the folks on snob hill polishing the silverware generates silver in the rinse water.

 

[dancqu]

Then, "2 to 0.5 grams"? refers to the amount of silver ...

Refers to the amount of silver dissolved per liter of
fixer. Those limits, 2 and 0.5 grams, are Ilford limits.
Grant Haist has set limits which are even lower.

As for that liter of fixer, it does not matter the fixer,
slow or rapid, or it's dilution. Of course there has to
be enough fix in the fixer to fully clear however
many prints can be handled within the
silver limits. Dan

 

[Ed Sukach]

Refers to the amount of silver dissolved per liter of fixer. ...

As I understand this - these are the MAXIMUM amounts that would be carried by the fixer at the point of exhaustion. Not especially helpful ... I do not flirt with absolute limits - by far my processing is "one-shot", through the JOBO CCP2 with all chemistry. Wasteful? Possibly, but I do not have to struggle with storage and continual accounting - or risking images fading away in time.

A better parameter -for ME - would be an average measure of silver removal per print - or per film, Information that is difficult to nail down.

 

[wogster]

As I understand this - these are the MAXIMUM amounts that would be carried by the fixer at the point of exhaustion. Not especially helpful ... I do not flirt with absolute limits - by far my processing is "one-shot", through the JOBO CCP2 with all chemistry. Wasteful? Possibly, but I do not have to struggle with storage and continual accounting - or risking images fading away in time.

A better parameter -for ME - would be an average measure of silver removal per print - or per film, Information that is difficult to nail down.

This whole thing started because someone was interested in environmental impact, as I said when I brought numbers into it, the amount isn't large, I think that the carrying capacity of rapid film fixer as recommended by Ilford had the most 8g/Litre. Figure that generally few home darkrooms take large amounts of fixer to exhaustion and that there are few home darkrooms about anymore, it's probably statistically insignificant. If have a large commercial lab then it's different and they are likely to have a silver recovery system in place these days,

 

[Ian Grant]

We regularly collected fixer for silver recovery with over 10 g/litre silver content, OK this was from X-ray & NDT processing. Ilfords 8g/litre figure is for film processing, a lower level is advised for FB papers.

Ian

 

[dancqu]

[QUOTES=Ed Sukach;736458]
"As I understand this - these are the MAXIMUM amounts that
would be carried by the fixer at the point of exhaustion."

Not at all. As has been pointed out the silver limit for films
is 8 grams silver per liter, that likely for fixer at film strength.
The same liter of fixer used with FB paper has limits of 2 and
0.5 grams, WAY below the "MAXIMUM amounts that would be
carried by the fixer at the point of exhaustion". There are
two limits for fixer, the chemistry's capacity, and the
silver limits. Ilford mentions silver limits. Kodak?

"Not especially helpful ... I do not flirt with absolute limits - by
far my processing is "one-shot", through the JOBO CCP2 with all
chemistry. Wasteful? Possibly, but I do not have to struggle
with storage and continual accounting - or risking images
fading away in time."

I too use all chemistry one-shot although I use a tray for
prints. Very dilute developer and fixer give good chemical
mileage. I don't bother with ANY stop. The fixer is not
used enough to load up with carry over developer.
Consistent results with fresh chemistry is one
more + to add to your list.

"A better parameter -for ME - would be an average measure
of silver removal per print - or per film, Information that
is difficult to nail down."

Worst case for film and paper is unexposed. FB papers
average 1.6 +/- some little grams silver per square meter.
I pre test paper and film for their fixer requirements
using worst case as the minimum amount to be
used when processing. It is possible to use
solutions so dilute as to bring them to
chemical exhaustion. Dan

 

[wogster]

[QUOTES=Ed Sukach;736458]
"As I understand this - these are the MAXIMUM amounts that
would be carried by the fixer at the point of exhaustion."

Not at all. As has been pointed out the silver limit for films
is 8 grams silver per liter, that likely for fixer at film strength.
The same liter of fixer used with FB paper has limits of 2 and
0.5 grams, WAY below the "MAXIMUM amounts that would be
carried by the fixer at the point of exhaustion". There are
two limits for fixer, the chemistry's capacity, and the
silver limits. Ilford mentions silver limits. Kodak?

"Not especially helpful ... I do not flirt with absolute limits - by
far my processing is "one-shot", through the JOBO CCP2 with all
chemistry. Wasteful? Possibly, but I do not have to struggle
with storage and continual accounting - or risking images
fading away in time."

I too use all chemistry one-shot although I use a tray for
prints. Very dilute developer and fixer give good chemical
mileage. I don't bother with ANY stop. The fixer is not
used enough to load up with carry over developer.
Consistent results with fresh chemistry is one
more + to add to your list.

"A better parameter -for ME - would be an average measure
of silver removal per print - or per film, Information that
is difficult to nail down."

Worst case for film and paper is unexposed. FB papers
average 1.6 +/- some little grams silver per square meter.
I pre test paper and film for their fixer requirements
using worst case as the minimum amount to be
used when processing. It is possible to use
solutions so dilute as to bring them to
chemical exhaustion. Dan

we are looking at this from the point of environmental impact

If at the maximum amount, the environmental impact is minimal, at 8g/Litre it takes 125L of fixer to get 1kg of silver. That sounds like a lot, but according to Ilford, I use Ilford only because I have the data sheets for their products at hand, 1L of fixer is good for 24 rolls of 36x film, that is 3,000 rolls of film. at 1 roll per day that's 8 years worth of shooting. At a roll a week, probably closer to hobby or amateur shooters, it's over 57 years.

So we will probably each be worth a couple of kilos of silver (~64 troy ounces) over our life times. If you started when you were 16 and quit when you turned 70 it would be between 1⅛ - 1¼ troy ounces a year. Even if you double that, it's still a very small amount, especially when you compare it to some of the other toxins that people dump down the drain on a daily basis. Heck for toxicity the bacteriological soaps that millions of people use every day are probably more toxic then a couple of ounces of silver.....

 

[removed account4]

[Heck for toxicity the bacteriological soaps that millions of people use every day are probably more toxic then a couple of ounces of silver.....

not only that, these soaps are more than likely compromising our immune systems
so we will all catch a common cold in a few years and
be rushed to the hospital and pumped up with antibiotics that don't work.

 

[Ed Sukach]

Thanks for the information, Paul.

Uh ... I think you left me somewhere between "Fixer at Exhaustion" and "Silver Limits" ... but...

A while ago, I participated in a very similar discussion, and the net result was that I calculated a silver "ejection" rate from my darkroom of about eight (8) grams/ year (not last year - I did *very* little photography - due to factors beyond my control).

Eight grams is not a whole lot - a new American Nickel (5 cent coin) weighs close to five grams...) but still, it is a good thing to think about and take PROPER action.

 

[dancqu]

Uh ... I think you left me somewhere between
"Fixer at Exhaustion" and "Silver Limits" ... but...

Eight grams is not a whole lot - a new American Nickel
(5 cent coin) weighs close to five grams...) but still, it is
a good thing to think about and take PROPER action.

OK, I'll put it this way; the car is good for 120 miles per
hour but the posted speed is 60. Neither 8, 2, or 0.5 grams
are the chemical's limit for dissolved silver. I don't belief
there is ANY published data of ANY fixer's maximum
capacity for silver; SAFE maximun; full complexing.
Not any info we'd ordinarily come across.

Actually a fixer is more efficiently used when the silver
limit and capacity limits coincide. As we wish some
margin for error we usually are well within the
capacity limit.

Worst Case: 10 8x10s through 1 liter of 1:4 rapid
fixer; the 0.5 gram silver limit. Least chemical mileage.

Best Case: The way I do it. Very dilute fixer used
one-shot; 0.3 +/- some little grams silver per liter.
Greatest chemical milage. Dan

 

[Bob Carnie]

Just a quick update.

Tues this week Elevator was visited by the a Toronto Environmental Monitoring and Protection Unit , enforcement officer with a unannounced visit.

Spent about an hour showing him our facility and asking him a few questions related to this thread.

these are some of his replys to my questions.

1. Any public, private and commercial darkrooms or processing of photographic materials fall under their mandate.
2. If you do not have a silver recovery unit , or reciepts and history log showing your method of disposal of fix, as well as a P2 plan in place , your darkroom will be shut down. No leeway here.
3. As of Jan 1 2008, owners of any buildings , homes that have processing equipment on site must have a Backflow prevention device between the incoming water meter and the building, that isolates the building from the municipals water supply.
4. No plumbing attachments to the pipe between the meter and backflow device are allowed and must be clearly marked.
5. A plan must be onsite for your usage and disposal of chems and a yearly check must be done on the backflow device and reported to the monitoring group by an official inspector.

This apply's to any one of us on this thread that are in the greator GTA of Toronto Ont.
If uncertain I can forward interested individuals the email address of the Monitering officer
who can explain in greater detail and precision than I .

Elevator passed this inspection, and we will be instructing our Landlord to install the Backflow device (this was news to me).
Those with darkrooms in GTA Toronto wanting to dump the fix in our Recovering systems are very welcome to do so just give me a call and set up a time, Sat mornings are best for me.

Private home darkrooms do fall under this mandate, at least in Toronto, and I do believe this will be the case in the future in municipalities that are concerned about their water supply but I am only guessing here.

As far as this debate regarding whether silver affects the water system or not it is a mute point in Toronto at least , dump your fix and get caught, your darkroom will be shut down. It was made very clear to me that anyone with a darkroom processing photographic materials will be in their radar.

A good working silver recovery system will cost somewhere in the range of 4-6 K.
I am not sure about the cost of the backflow system.

These visits by the TEPA (second time in 4 years) at least clarify's for me this whole issue regarding the dumping of fix, that is now in its third debate which I have participated in since I joined APUG .

regards
Bob

 

[jgcull]

What is a "backflow device"? I'm just thinking this through, based on what it *sounds like* to me - if I don't have a faucet of tube that runs into anything chemicals are in do I still need that? Are you talking about chemicals backing up into the pipes that bring water into the darkroom sink?

 

[removed account4]

thanks bob.

 

[removed account4]

What is a "backflow device"? I'm just thinking this through, based on what it *sounds like* to me - if I don't have a faucet of tube that runs into anything chemicals are in do I still need that? Are you talking about chemicals backing up into the pipes that bring water into the darkroom sink?

janet

i think a backflow device prevents water to be syphoned
back through the pipes into the water supply.

john

 

[tim_walls]

janet

i think a backflow device prevents water to be syphoned
back through the pipes into the water supply.

Indeed; they're not particularly exotic concept - the building codes over here for example, if I recall correctly, prohibit putting a shower assembly in close proximity to a toilet (i.e. close enough that you could put the shower head into the toilet) unless some kind of backflow prevention is incorporated.

The simplest form of backflow prevention is just that - a sufficiently large air gap between the 'tainted' water and the water supply. The second simplest form is a cistern filled by a ballcock with an overflow pipe on the cistern sufficently large and far from the inlet that water can never back up to the inlet pipe.

Of course if you require water under pressure, you either need a pump on the outlet of your cistern, or you put the cistern sufficiently high up that gravity will do the job for you, or you need some other form - like a one-way flow valve.