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.

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.

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 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.

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.

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 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