Questions/advice on evaporating chemicals
I am getting back into the B&W developing game, and would like some advice on evaporating fixer (and developer?) I went to the local disposal facility and they said yes, they would take my dev & fix, but I need to pay depending on weight. Therefore evaporating seems to be a good way to keep the cost down. I spent the afternoon yesterday searching and reading through relevant threads here on APUG, but I still have a few questions ..
1. What do you do, just leave the chemicals out in the sun, uncovered, and wait?
2. Is there any danger of it producing dangerous fumes, peeling the paint off a building side, or animals getting into it? (We have stray cats that wander around)
3. I've read that fixer turns into a whitish-silverish crust - is it dangerous to touch?
4. What does evaporated developer turn into?
Thanks in advance for any help. I live in a tourist resort type area, and they are quite strict about the disposal of refuse (tires, old furniture, chemicals, etc.)
Those who know, shoot film
I put used developer into a pail with a 'fish tank stone' air diffuser.
I run the full output of a fish tank air pump though the stone placed at the bottom of the pail overnight.
I do store the inermediate used stuff until there is perhaps 3-4l before getting this rig into gear.
In the morning you will see a black liquid. All of the developers oxidizing demand (more commonly known by its measurment metric in the english world as BOD) has been consumed, by being oxidized in the air bubbles driven though it. My air pump and stnoe and air piping came from a thrift shop.
I pour the resultant developer down the sanitary drain at the same time or just before I run the clothes washer, so there is lots of water in the sewer lead to dilute it. The sewage treatment plant can adjust it's pH at the same time they deal with all of the household detergent efluent. You can balance pH with used stop bath if you use an acid stop
Used fixer goes in a shallow stainless steel food service tray, perhaps 30x45cm, maybe 10cm deep. It lives on top of the upright freezer in the garage in the winter, where it works at evaporating quite slowly, while it is not frozen.
In the spring I put it put on top of a tall steel cabinet I use as overflow garage storage.
It sits under the eaves by the garage back door, and gets a full day of sun, yet is covered by the roof overhang so it does not gatehr any rain water.
After 3-4 weeks the liquid which was 5-8cm deep to start has transformed to a yellow slush with a crust on top. Mostly sulphur, I surmise.
So the beginning 8-10l of fixer entrials are scooped up with a rubber spatula into a small wide mouth jar, to comprise perhaps as much as one litre of final effluent.
I am pondering investing in one of the silver magnet units promoted through john ninian on this site. If I coulod take the silver out of the used fixer, I would then use the undried effluent on my garden. I only use rapid fixer, and the garden loves ammonia when I fertilize with it.
my real name, imagine that.
You should use a fine screen cover to not only protect cats and other animals, to also protect bugs. Many bugs are beneficial. It takes forever so be prepared for the long haul.
1. Yes, you can do this.
4. The hydroquinone and Metol will oxidize to condensed polyphenols loosely called humic acid.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.
~Antoine de Saint-Exupery
Those who know, shoot film
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