Off grid darkroom

[rwhawkins]

I'm interested in designing an off grid darkroom, very efficient water usage with no access to sewer. I would want very little dependence on septic, and certainly wouldn't want to put harmful waste into it.

My current darkroom uses 50 gallon blue drums for supply and waste. I can go surprisingly long time with this setup, except print washing which is done outside my darkroom. Progressive water baths are proven most efficient, question is there a treatment to recover a "spent" bath?

I'm imagining 2 separate recirculating systems for washing. At some point the contamination would exceed acceptable limits, what process could be used to replenish a used bath? Physical ceramic filtering, solar steam boiler type purification?

 

[NedL]

Is water available nearby and is it under pressure? Or are we imagining that you will bring all water needed from far away?

How long a trip is it to the nearest hazardous waste facility? Would it be feasible to transport, say, 15 gallons of waste 4 or 5 times per year?

 

[rwhawkins]

There would be well water on property, but this is an outbuilding, so water would likely be brought in. When I bring in the water I could pump it into a water tower to get pressure.
I would have to investigate the grade of the waste and who would accept it. If I could combine the waste dump with a dump of my RV waste system that might be convenient.

 

[jslabovitz]

You are (at least in the summer) in a decent region to evaporate your wash water, then gather the final dry remains and take them to your local hazmat facility.

Or you could use electronic or steelwool silver recovery methods. You can google those.

 

[wombat2go]

C41 ? ....
The only water is that used to make the solutions and the rinses.
(edit) The rinses are just a tank full which last for 6 rolls or so.

 

[AgX]

We once discussed mix bed filtration for residues of processing baths, but we did not yield workable formulas to set such up.

As you indicated concentrating-up the baths is a way to make transporting them eaysier.
BUT as you got a means to get the fresh water to your darkroom, you too would get the same means to get it back in the contaminated state.


Alternative you may consider using degradable developer and a solar driven electrolytic desilvering.

 

[Doremus Scudder]

Some comments and thoughts at random:

First, if this is a black-and-white darkroom, your chemicals are fairly innocuous except for used fix, and you can safely dispose of those (diluted beforehand) in your septic system. Just be sure that the volume of the extra waste doesn't overload your system. MQ and PQ developers break down fine in a septic system. Ascorbic-acid-based developers are even more eco-friendly. Even pyro developers break down well. Citric or acetic acid stops should be fine too if diluted beforehand (an acetic-acid stop is 1-2%; vinegar is 5-6%).

I used a darkroom hooked to a septic system for years and had zero problems disposing of developer and stop. What I did do, was find a way to deal with the used fixer. The best way is to collect the fix and then take it to a local photo-finishing business and simply give it to them for silver recovery. Most photofinishers are happy to do this since they make a little profit on the reclaimed silver. In your area, there must somewhere still be an analog photo lab around and they will certainly have silver-reclamation capability. I used to save up 10-20 gallons of fix and then take it in to my local lab.

Lacking that, you'll have to lug used fix somewhere else to dispose of it. When my local photo lab went out of business, I had to find an alternative. I tried taking my used fix to the hazmat people, but they have absolutely no idea of silver recovery. They marked the five gallons of used fix I brought them for incineration... In many areas (like mine at the time), low-volume users were allowed to dispose of smaller quantities of used fixer into the municipal sewer system. I ended up lugging my jugs of used fix to a relative's to dispose of it that way.

Alternately, you can reclaim the silver yourself, which removes enough of the bacteria-toxic heavy metal to be able to dispose of the fix into the septic system.

Fiber-base print washing uses a lot of water, even with the soak-dump-refill method. RC papers need much less, but are really not the same thing. If you use fiber-base paper, you may want to divide your washing regime into a holding/soak tray/tub in your waterless darkroom and then carry the prints elsewhere to where you have running water for the real wash. The soak (with agitation, of course) will remove quite a bit of the fix and you will then be able to wash, hopefully at low-flow volumes, with the waste water going into the septic system. I'd add the water from the soak tray or tub to the used fix and take it in for silver recovery.

Hope this helps a bit,

Doremus

 

[Jim Jones]

In the 1970s I offered thousands of PR photos on speculation to a college. Sometimes this involved making up to 200 8x10 RC prints in an evening. Washing was done in three deep trays. The first tray accumulated up to 32 prints (the limit of my print drier) with occasional agitation. Then the prints were held almost vertically over that tray and slowly peeled off of the stack and placed in the second tray. Surface tension pulled much of the water off of them. The prints were shuffled for two or three minutes and transferred to the third tray with the previous technique. After two or three more minutes of shuffling in that tray, they were drained and transferred to the drier. The first tray was dumped. The second tray was poured into the first, and the third into the second. That last tray was then filled with fresh water. When many prints were thus washed, only an ounce or two of water was consumed per print. The unspotted prints were offered to the PR office. Any that they selected were spotted then with a ball point pen. I kept the rejects. Now, over 40 years later, very few of the many hundred show any sign of deterioration. Today's more convenient print washers are relative water hogs.

 

[Trask]

No mention here of hypo clearing agent -- would use of that solution change any of the what-to-do-with-the-fixer questions? Or does the HCA just become another problem to deal with?

 

[Martin Rickards]

https://www.420magazine.com/forums/...se-sex-using-silver-thiosulfate-solution.html might give you some ideas for disposing of silver sodium thiosulphate solution

 

[john_s]

Solutions containing soluble silver salts when mixed with sewerage end up producing silver sulphide which is apparently very insoluble and inert, and hence not a problem. No shortage of sulphur compounds there!

 

[Doremus Scudder]

No mention here of hypo clearing agent -- would use of that solution change any of the what-to-do-with-the-fixer questions? Or does the HCA just become another problem to deal with?

Of course, if processing fiber-base prints, a hypo-clearing step should be included, as it will reduce wash time and, thus, water consumption. The hypo-clear itself is just a sulfite solution. If used as a holding bath (I like at least 10 minutes with agitation in my hypo-clear), then it will accumulate a fair amount of residual silver and could be simply added to the used fixer and then taken to silver reclamation along with it.

Best,

Doremus

 

[AgX]

Solutions containing soluble silver salts when mixed with sewerage end up producing silver sulphide which is apparently very insoluble and inert, and hence not a problem. No shortage of sulphur compounds there!

Nevertherless Silver is not regarded as being cought in such complexes. They rather form a sort of depot.
But research on the actual free Ag-ion concentration in the environment is going on. Especially as there are new applications of fugitive silver in new products.

Anyway, here im am not allowed to discard any photographic bath in the sewer.