applesnail
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Removal of malachite green from formaldehyde solution?
can somone pls point me in the right direction, if its covered in this forum somewhere pls post a link,have read so many pages looking for info on
best way to separate -any ideas would be greatly appreciated.(could it be as simple as filtration through activated carbon to remove the dye?)
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ScienceSquirrel
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That might actually work.
Filtering through gas masks which contain activated charcoal or through beds of activated charcoal to remove the dye was used during the war to divert
commercial fuel to domestic motoring and more recently by Irish paramilitaries to fund their activities.
http://www.rrbew.co.uk/FeatureHtms/F-Excise-PB.htm
http://www.belfasttelegraph.co.uk/news/local-national/northe...
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applesnail
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Thanks for the reply squirrel any extra info is always appreciated!
"Formaldehyde is very weakly adsorbed on activated carbon or any other untreated adsorbent. Often, oxidation catalysts are deposited on adsorbents
which convert the formaldehyde to formic acid which is more strongly held by physical adsorption on the adsorbent surfaces than formaldehyde. However,
the oxidation product, formic acid is still a toxic compound and it eventually desorbs from oxidant treated adsorbents."
So heres the theory malachite/formaldehyde is aqueous in dH20 & small amount of stabilizer MeOH to stop oxidation,so filter malachite out with
activated carbon, formaldehyde is highly soluble in water,theoretically should filter fine,formaldehyde converts to gas at room temperature so do
filtration as a cooled solution or inside the fridge!
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questions
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formaldehyde and malachite
Hey, I noticed that you were trying to remove malachite from formaldehyde solution and you suggested that maybee activated carbon would work.
I was wondering if you had a chance to try it and if so did it work and how well did it work?
Quote: Originally posted by applesnail  | Thanks for the reply squirrel any extra info is always appreciated!
"Formaldehyde is very weakly adsorbed on activated carbon or any other untreated adsorbent. Often, oxidation catalysts are deposited on adsorbents
which convert the formaldehyde to formic acid which is more strongly held by physical adsorption on the adsorbent surfaces than formaldehyde. However,
the oxidation product, formic acid is still a toxic compound and it eventually desorbs from oxidant treated adsorbents."
So heres the theory malachite/formaldehyde is aqueous in dH20 & small amount of stabilizer MeOH to stop oxidation,so filter malachite out with
activated carbon, formaldehyde is highly soluble in water,theoretically should filter fine,formaldehyde converts to gas at room temperature so do
filtration as a cooled solution or inside the fridge! |
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jon
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well it always cleaned my heroin up pretty well
oh shit!
did i say heroin? i meant phenanthrene alkaloids.
[Edited on 11-4-2011 by jon]
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crystalXclear
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malachite is a mineral of copper carbonate if it helps. Xtal
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ScienceSquirrel
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Malachite green has nothing to do with malachite apart from a similar colour.
Malachite
http://en.wikipedia.org/wiki/Malachite
Malachite green
http://en.wikipedia.org/wiki/Malachite_green
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jon
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i think that's used in fact i know it's used to catch thieves green handed you put malchite green on a piece of money and see who's hands turn green.
it's a good way to find out who's got sticky fingers.
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applesnail
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yes it will filter out eventually although purity would be in question as there could be trace amounts of malachite left.
A better way i think would be evaporation of formaldehyde to gase and recollection this in theory would leave the dye behind.
Although this may be a little more complicated(perhap malachite may evaporate also?Perhaps fractional distillation may work?) I havnt researched this
any further since my first post months ago as i was able to obtain formaldehyde without malachite so there was no need to further carry on with this
venture....
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ScienceSquirrel
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Even trace amounts of malachite green will make the solution green.
Dyes are strongly absorbed on activated carbon, that is why when treating fish tanks with dyes to kill diseases you stop the filters or remove the
carbon.
Malachite green is an involatile solid, if you distill the formalin all the malachite green will be left behind.
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