Chemical Forums
Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: jena on May 02, 2005, 11:59:59 PM
-
Hi,
Does anyone know a reaction that involves detoxifying mercury in the enviroment.
Thank You ;D
-
Well I know mercury is used to 'grab' gold, so I imagine it would bond with other stuff quite readily as well. I'm by no means the expert on this stuff, but if you can dump whatever mercury really likes into a big pool of it, I imagine you'll end up with a solid compound that you can either 1) sweep up or 2) is harmless. I wouldn't bet on #2 though.
-
Hi,
Thank you for the reply, but is there an equation or diagram of how mercury would be removed from the environment. I tried to find sites on mercury detoxification and all I got were sites how to remove mercury from the body.
Please help and thank you :)
-
Jena,
Spills and long-term contamination are handled differently.
For long-term contamination, bioremediation has been getting some pubs lately (last 5 years). In bioremediation, there are different ways to try to either bioaccumulate mercury or convert it to less dangerous form. In the later, several "mercury resistent" bacteria have been researched as possible candidates to do the conversion. Some common bacteria are: Klebsiella sp., Pseudomonas sp., and Clostridium sp.
If you are not finding any info, try some of the above terms and you should probably find some sites or some publications. In those sources there should be some reactions or biomechanisms by which the conversions or accumulation take place.
Good luck.
-
Aren't some alloys containing mercury safe. A teacher once told me that most fillings now adays contain a mercury alloy. So figure out whats in fillings for teach (try googling it) and you'll find something mercury likes.
-
Aren't some alloys containing mercury safe. A teacher once told me that most fillings now adays contain a mercury alloy. So figure out whats in fillings for teach (try googling it) and you'll find something mercury likes.
I wouldn't say that the amalgams in fillings are necessarily safe. I think the jury is still out on that. I, for one, will never get another amalgam filling (I already have one) since the polymer fillings are almost certainly safer. While contact exposure to elemental mercury is not that bad (the vapors are very bad), some bacteria can alkylate mercury and then you have a serious problem. Alkyl mercury species are incredibly toxic and are absorbed instantly through the skin and pretty much head straight to the brain.
I think that the best ways to clean up mercury spills are to sprinkle them with elemental sulfur or to freeze the droplets with a piece of dry ice and transfer to a safe container. Mercury salts, like HgS, aren't nearly as bad as the elemental form, mostly because there is much less vapor pressure.
-
I do agree with movies on the toxicity of mercury in alloys - I've had some for over 30 yrs and people say I'm CRAZY.
Cleaning up or detoxifying Mercury outside of the lab is more difficult. In a lab, one tries to prevent the vapors from releasing and works on containing the spill. Hopefully, the mercury can be picked up (different techniques) and stored in a safe place until a hazard waste pickup can be done. I usually make a Hg spill powder from common chemicals like: 85 g of Sodium Thiosulfate and 15 g EDTA. I pick up any Hg I see and then sprinkle on the spill powder. I then wet down the spill powder with water. I let it sit over night and then sweep up in the morning. The waste can be placed for hazardous waste disposal. It forms a "seal" and hopefully, the EDTA will pick up any leftover Hg.
In nature, clean up of Hg is much more difficult. I think that bioremediation holds the best solution. Although, some of the processes used have a difficult time removing Hg that has been in the environment for some time.
-
I guess you could use EDTA to bind to all the mercury in there, but the problem is that EDTA isn't exactly a 'selective' binding agent. It will also bind to all the 'good' metal ions in the soil and deplete the area of many nutrients.
-
i know that mercury is attraced to metals (gold is a good one but i dont think u have that kind of money). You can mix the mercury with nitric acid and it will create red murcuric oxide, but the best that will do is tell you where large quantities of it are and possibly turn what it is in red. my best advice is to use a metal like, silver, tin, or copper to draw it out (dont know that it will work). of course dont spend to much time around it, you may need those biological mercury detox pages after all.
-
One of the most insoluble materials in nature is mercury sulfide. One can form this using Na2S or H2S. Aluminim metal will also absorb mercury. This is a trick to get aluminum to more easily dissolve in nitric acid. Ferric chloride solutions are also a good way to alter mercury into something less volatile; mercury chloride. The easiest and cheapest way to scrub merculry from air is by bubbling it through bleach. This will ultimeately form mercury oxide which is not volatile.
I once invented a process to remove mercury from water and got it down <100ppb, which was the limit of the analytical equipment. In water at low conc it is usually mercury oxide. The mercury (oxide) was extracted using an anion exchange resin that was modified with ferric sulfide. The reaction produces ferrous oxide and mercury sulfide. The mercury is bound to the sulfar attached to the anion resin for disposal. We treated 2 million gallons of water to less than 2 ppb with a small production facility.
Be careful with using nitric acid. Mercury will dissolve to form mercury nitrate which is a contact explosive. Chromates also work but create something more toxic that what you start out with. Removal from solids is most easily done with heat and a bleach scrubber. The heat needs to be safely contained or else it would be very toxic due to the higher mercury vapor pressure. My favorite reaction, which I can not remember exactly is the beating heart experiment. If believe is was performed by placing a blob of mercury in a weak dichromate solution?. One then sticks an electrode into the blob of mercury and the other in the solutionn. If it is done correctly the mercury will beat like a heart. The beat will triangulate and then a few beats later will be a square, etc., Really cool.
-
Mercury nitrate is not a contact explosive. You've got that confused with Mercury Fulminate which IS a contact explosive and does involve the use of nitric acid as well as another ingredient which we won't be mentioning here. Hg(NO3)2 is a strong oxidizer and is very soluble, however. It will decompose into mercury oxides and nitric oxides. The nitric oxides can then go on to produce explosive byproducts. But the compound itself is not considered all that explosive. Elemental mercury is MUCH safer in all regards compared to mercury nitrate.
A safety precauction when dealing with any quantities of elemental mercury is to have a big bucket of powdered elemental sulfur handy. My mercury samples are all surrounded with sulfur in the odd chance that my container ruptures. Hg will get absorbed by the S and react with it to form the insoluble HgS which is easily cleaned up. ;D
-
I know mercury fulmate is explosive but I think I remember the CRC saying mercury nitrate is strong a oxidizer that will explode if given a sudden jolt. I might be wrong since this was from many years ago. One time, while doing a bunch of mercury reaction experiments, I dissolve mercury in conc nitric acid and a white precipitate resulted. I left it in the acid water and then neutralized the solution/solid to reprecipite the mercury. I was later told that if I had dropped the beaker with the amount of mercury nitrate precipate I had made, I would have taken out the lab. I stopped playing with that combo after that.
-
I know mercury fulmate is explosive but I think I remember the CRC saying mercury nitrate is strong a oxidizer that will explode if given a sudden jolt. I might be wrong since this was from many years ago. One time, while doing a bunch of mercury reaction experiments, I dissolve mercury in conc nitric acid and a white precipitate resulted. I left it in the acid water and then neutralized the solution/solid to reprecipite the mercury. I was later told that if I had dropped the beaker with the amount of mercury nitrate precipate I had made, I would have taken out the lab. I stopped playing with that combo after that.
http://ptcl.chem.ox.ac.uk/MSDS/ME/mercury_I_nitrate.html
http://ptcl.chem.ox.ac.uk/MSDS/ME/mercury_II_nitrate.html
No explosion risks mentioned.
-
I saw this link that states the possibility of explosion during fire fighting. I guess that is an extreme case that may be due to the oxidation of smoke. I stand corrected; mercury nitrate is probably stable under normal conditions.
http://www.jtbaker.com/msds/englishhtml/m1586.htm (http://www.jtbaker.com/msds/englishhtml/m1586.htm)
-
Yes. All nitrates, when subjected to extreme conditions, do have the potential to explode. However, I do not know of any inorganic nitrates that will detonate from a simple shock such as dropping a beaker of it, or scratching a crystal.
-
What I got here is when amonium nitrate is get heated till 170oC, it will broken off and if it get heated again till 350oC, it will form N2 with a big blast of energy.... ;D
ironically, we oftenly use this bomb as a plant fertilizer aren't we?
-
ironically, we oftenly use this bomb as a plant fertilizer aren't we?
Its not technically explosive without a primer, it needs a detonation to give it the energy to decompose explosivly. otherwise it just decomposes pretty much.
And yes its a good fertilizer though its becoming harder to get hold of because people abuse it.
Cheers,
Ryan Jones
-
thermal decomposition results in Nitrous Oxide (Laughing gas).
AN to actualy detonate not only needs a primer but also has a critical diameter, under which diameter will not result in complete detonation, with a sensitiser this diameter can be reduced though.
and as Jdurg says, there aren`t any inorganic nitrates that I can think of either that will react in the way mentioned. at minimum you need a binary mixture or at least a Carbon group :)
-
I didn't see this mentioned in here. But....
Has anybody heard about the scientists that are trying to engineer bacteria to clean up mercury. I read about it somewhere.
Sorry I probably sound like a broken record player when I say "I read about it somewhere." I read a lot of random articles online and I read PopSci. On occasion random journals of science.
-
I didn't see this mentioned in here. But....
yes already mentioned above.
when you read an interesting article why not reference it or print it, that way you can post with a bit more accuracy. ;)
-
or you could just read the posts above you :P
-
I skimmed the posts till I stopped recognizing things in them. I must've missed the one with the bacteria. I think it's cool how scientists are inserting DNA into bacteria to make them do all sorts of neat tricks. The neatest trick of all is making bacteria make penicilan for human use. That has saved who knows how many lives.
-
Indeed it is, that or Insulin which is another big one!
I have a question along these lines - are there any mercury compounds that are not harmful to humans?
Cheers,
Ryan Jones
-
Some teeth fillings contain mercury. A lot of people get fillings. I haven't heard of any cases where mercury poisoning do to teeth fillings has caused a death.
P.S. I had meant to put insulin instead of penicilan. Both have saved many, many lives though.
-
As a Type I Diabetic myself, I concur that the production of insulin thanks to bacteria is a great thing indeed. ;) ;D
For "non-toxic" mercury compounds, there is calomel (Hg2Cl2) and Merbromin. Although the 'non-toxic' part of that is still up for debate.
-
Some teeth fillings contain mercury. A lot of people get fillings. I haven't heard of any cases where mercury poisoning do to teeth fillings has caused a death.
I'm not shure if that counts because even the non-toxity of these arwe still under debate and its not really a compound either :-)
Cheers,
Ryan Jones
-
What I got here is when amonium nitrate is get heated till 170oC, it will broken off and if it get heated again till 350oC, it will form N2 with a big blast of energy.... ;D
ironically, we oftenly use this bomb as a plant fertilizer aren't we?
By the way, I have one question:
if most of amonium salts are pyrolytic, can we get amonium salts from its solution by heating? For example, I have a NH4NO3 solution, what would happend when I heat this? If NH4NO3 is pyrolytic before water's all gone, how should I do to get pure NH4NO3?
-
You don't have to go above 100 deg C in order to evaporate solution. Besides, if the solubility changes with the temperature - which is often the case, although not always - is is enough to cool saturated solution to crystallize substantial part of the salt.