Environmentally Sound Disposal of Pt/Pd Dev. and Clearing Baths

[Neil Poulsen]

What's a strategy for environmentally sound disposal of Pt/Pd developer and clearing baths?

I plan to use potassium oxalate for my developer and ferric oxalate for my sensitizer. I know that potassium oxalate has toxic effects. I was thinking of using hypo clearing agent for clearing. But as long as it clears for archival purposes without bleaching the image, I could use something else.

Does mixing potassium oxalate with a given clearing bath offset the toxic effects of the dev? Is there some way to treat discarded dev and/or clearing bath that renders these discarded chemicals environmentally benign? Does it make sense to bring discarded chemistry to a neutral pH of 7 before disposal?

Is there documentation that someone knows of that addresses these disposal related questions?

 

[avandesande]

Oxalic acid is found in high concentration in Rhubarb leaves and in Skunk Cabbage. Although it does bad things in our bodies nature doesn't have any trouble dealing with it.

 

[Jorge]

Since the developer is reused, you dont have to worry about heavy metals on the environment as what you will be introducing will be in negligible amounts, certainly you have to worry more about disposing of fixer than what you would get in the wash from a pt/pd print.

The clearing agent will only remove ferric oxalate, which will be easily broken down by the environment. IMO pt/pd is one of the most ecological friendly processes.

 

[Michael Mutmansky]

Yup, I understand two pounds of Spinich have enough PO to kill a person, but it apparently causes no harm for regular disposal.

Just one more reason I won't eat the stuff.

I've discussed metals reclaimation with Bostick and Sullivan, and they generally state that the amounts are in such low concentration in the clearing baths to make it very difficult to make a meaningful reclaimation process.

My impression is that the silver in the film and papers are easily reclaimed and in quantities that it is done (and mandated in many areas), but that is not the case with pt/pd.

Jorge can correct me if I'm wrong, but since they are noble metals, they pose no risk for humans or environmental impact if they are released in small quantities? That's always been my understanding, but I may have it wrong.


---Michael

 

[scootermm]

so is it bad if I make a grilled cheese sandwich on the same hotplate that I warm my developer?

lol. just kidding.

 

[EricNeilsen]

Neil, Some of the concerns would be what type of contrast agent you are using. If you use Hydrogen Peroxide there would be nothing more hazardous than the developer only. If you are using dichromates in your developer and regularly dispose of it, you may be adding a hazardous substance to the environment.

Hypo Clearing agent shouldn't be much of an issue.

And unless your volume is many many gallons a day, your small amount of affluent shouldn't make much of statement down stream.

I'd be more concerned about the harzards in the darkroom for yourself than the consequences from a small discharge. The powders of PT can be linked to asthma, etc. Practice good darkroom safety and things will be fine.

 

[Neil Poulsen]

Indeed. I got myself a full facemask with proper particulate filters for mixing chemicals.

One reason for asking is that I want to do this as part of a business, and I may need to make a case to our local town officials on disposal, safety, etc. So, having documentation that addresses strategies for disposal, the need, quantities, kinds of risks, etc., of pt/pd related chemistries would be helpful.

 

[avandesande]

We have given you advice that suits the hobbiest. To make what your doing 'legal' for business is an entirely different matter.

I would consult a book on lab safety about the best ways to store chemicals, ie locked cabinets, seperate oxidizers, things like that.
I would seriously consider finding someone who takes wastewater instead of dumping down the drain. Figuring out what you can do legally is probably not worth the hassle.

So, having documentation that addresses strategies for disposal, the need, quantities, kinds of risks, etc., of pt/pd related chemistries would be helpful.

 

[EricNeilsen]

Indeed. I got myself a full facemask with proper particulate filters for mixing chemicals.

One reason for asking is that I want to do this as part of a business, and I may need to make a case to our local town officials on disposal, safety, etc. So, having documentation that addresses strategies for disposal, the need, quantities, kinds of risks, etc., of pt/pd related chemistries would be helpful.

Neil, THis is what I do; custom printing. I tried very hard when I first got to Dallas to find out the proper disposal to meet city regulations. I could not get a good answer. many regulations or written for large industry, even if you are doing a good platinum/palladium printing business you are not going to dump that much down the drain. I larger concern would be for those on wells. The amount of wash water dilutes most of what you dump to very small levels. PT, PD will most likely plate out long before it gets into the water system. I would contact the local sewage treatment officals and find out about the ppm for all the chemicals that you are using. Give them a quick idea of how much you might be doing. They should be able to help.

I ran most of my chemicals out to an evaporative system in Taos when I lived there. THat way it was recovered as a solid.

Is there a way here to get direct emails of threads?

 

[Neil Poulsen]

I've been checking with local authorities. Neither pt nor pd is on their hazard list. If I can get away with it, I'll use the same development bath, filter it, etc.

I'm considering how I might contrive an environmentally friendly clearing bath based on citric acid and edta and whatever else I need. I'm told that some agriculture people add edta to the soil.

 

[Kirk Keyes]

One reason for asking is that I want to do this as part of a business, and I may need to make a case to our local town officials on disposal, safety, etc.

Neil - to do this as a business, you will need to get trained to handle hazardous wastes. Look into "Hazwoper" training. I know that the people I work with that are trained for handling haz waste take this training. It's a 40 hour class last I heard, with yearly updates. Not cheap.

I don't mean to talk you out of this idea, but there is a lot to think about - training and certifications, liability insurance...

While oxalate is on hazardous materials lists, I don't think I've seen oxalate on any EPA lists for regulated substances for wastewater (but it may be).

Also - for the full face mask - make sure you have training on how to adjust the straps and how to know if the mask is working. They are not worth much protection if they do not fit right or are improperly adjusted.

Kirk - www.keyesphoto.com

 

[Kirk Keyes]

Oh yeah, dichromates are regulated as waste.