Jor
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Registered: 21-11-2007
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waste treatment
I currently have 2 waste bottles:
-inorganic (metals/metalloids)
-solvents
I can dispose of the inorganic waste via a person I know.
But I have been thinking of treating it myself.
I did a test with 150mL of the liquid waste. This was green in color. I acidified with some dilute HCl (it was already acidic) and added a few grams
of aluminium foil. I heated the solution somewhat and let it react with the foil.
After all the aluminium dissolved, i was left with a colorless solution, with a dark powder deposited on the bottom of the beaker (wich is a mixture
of metals). I immediately decanted to prevent redissolving of some of the metals (Mn, Co, Ni).
Now I was wondering, is this treatment sufficient, to remove all toxic metals? In these bottle, the following elements are present:
Hg, Pb, Se, Sb, Cu, Ni, Co, Mn, V, Ag, Cr, Sn.
I am a bit worried about the vanadium, I don't think it is removed this way. How do I remove this from solution?
Probably some of the metals precitpated, because in the waste bottle, above a clear green liquid, there is lots of precitipate. This precitipate
probably contsains the most toxic ones : Hg and Pb.
I think Sb volatises as SbH3, but does Se volatise as H2Se?
Secondly, I am not sure how toxic grams amounts of ionised aluminium are. Can this be flushed down the drain?
Anyone has better suggestions on how to treat this waste?
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mr.crow
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Aluminum should be fine, you can buy alum (potassium aluminum sulfate) in the grocery store. Aluminum compounds are used to filter water.
Heavy metals can be precipitated as sulfides which are highly insoluble. You can use H2S or sodium sulfide/polysulfide. You can mix the precipitates
with concrete to get rid of it.
Wouldn't it be easy to dispose of non-halogenated organic waste by lighting it on fire?
Double, double toil and trouble; Fire burn, and caldron bubble
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madscientist
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Yeah, burn non-halogenated organics.
I believe you could precipitate just about everything in that inorganic waste bottle with hydroxide.
I weep at the sight of flaming acetic anhydride.
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Jor
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I'm not using sulfides, as i will have to buy them (I don't want to buy anything right now) and H2S and alkali sulfides are very smelly (and toxic
ofcourse).
Yes I have been thinking of burning the solvents. But easier is to bring it to a watse processing facility. I have a 2,5L plastic container, wich used
to contain white spirit. I just pour all my solvents in this (not when they contain metals or colored compounds), and I will bring this to the waste
processing facility when it's full. I think I will get no questions, because it's in a simple hardware store container, and I should put no-one at
risk because I they simply don't open the container but burn it right?
The container contains toluene, ether, acetone, MeOH, EtOH, i-PrOH, acetonitrile. I'm not sure yet if it is responsible to add any waste benzene to
it, especially if the workers at the waste processing facility have to pour it in a waste incinerator. But I guess small amounts are ok, as solvents
here are allowed to have 0,1% benzene in them anyway.
I am not sure yet what to do with my halogenated solvents, as I commonly use small amounts of DCM. Most of the time, I just let this evaporate, as it
is quickly broken down in the atmosphere.
Yes madscientist I know you can precitpate most metals with hydroxide, except for Cr, V and Se. But the problem is that the formed oxides/hydroxides
are very voluminious and hard to filter, and these are still toxic.
[Edited on 1-11-2010 by Jor]
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entropy51
Gone, but not forgotten
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A good reference for waste disposal is "Hazardous laboratory chemicals disposal guide" By Margaret-Ann Armour, available in limited view on Google
Books and full view at the usual places.
She describes many procedures for the destruction or sequestration of common chemicals.
Another reference is the book on Prudent Practices for Disposal of Hazardous Chemicals or similar title, by the National Sceince Foundation which has
been posted on the forum and is on www.archive.org
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Rogeryermaw
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though it is not exactly a huge amount of waste, i for one applaud that you want to do it the right way. that shows more good sense than most people
will bother with. the environment probably appreciates it too. thank you.
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