Re: Environmental Impact

Rick Retzlaff wrote:
> I am going to be conducting an outdoor workshop in traditional photography
> and alternative printing this summer. The festival I am working with is
> very much environmentally conscious ...
>
> On-site negative processing -- at home we probably all just flush the stuff
> down the drain. However, what is the real impact of this stuff? Does the
> waste treatment system deal with this in any rational way? Or do we count
> on extreme dilution to make it insignificant? What would be the impact if
> these chemicals were dumped into the bush?...

The following is brief and rough:
Typical disposal for acids is to neutralize and dilute.
Most film developers will biodegrade, but treat as acids.
Fixer should have silver reclaimed from it before disposed as an acid.
Other solutions which accumulate metal salts should have the metals
reclaimed if practical.
Dichromates are bad and can only be well diluted.
Solvents should never be used, but if so any used solvent sent to a
solvent recycling company and never put down a drain.

The quantities typically used and disposed in a municipal sewer will
likely cause no problem. However concern must be given that some
materials disposed of in a septic system can accumulate over time in the
leach field.

> ... Ideally, it would be the easiest to just wash out the cyanotype
> into the environment (ie bush) directly. Otherwise, we would have to
> collect it in bins and haul it away to dump into a waste treatment system of
> some sort. ...

The answer is in your beginning statement. If you are to throw any used
anything "into the bush", it is likely you will receive the wrath of the
"environmentally conscious". The best way to look good is put the waste
into a large bucket to be disposed of properly (as mentioned above.)
Also keep in mind that in this situation you describe, the politics
outweigh the science.

-- 
Jeffrey D. Mathias
http://home.att.net/~jeffrey.d.mathias/