1.23.2013

MetalHeads



Following on my prior post, I want to spend some time on the idea of the technologies used in cleaning up the toxic messes left by industry and us consumers.

Metals are nasty things, there are some soils out there that are scary contaminated with lead or arsenic from lazy and/or primitive manufacturing technologies.  But, as in the last posting, the use of these technologies is sadly absent.  I really find the article written for the New York Times back in 1992 to be sadly instructive.  While the technology is there, it just hasn't been deployed at the level needed to fix the problems.  Again, I would posit that the effect that the work has on a corporation's bottom line is much more important than the effect the technology has on the soil.

But what I find most interesting is the little blurb written innocuously at the bottom of this 2005 report by the USDA Agricultural Research Service.
In 2000, a patent was filed by the University of Maryland on the use of alpine pennycress for the phytoextraction of cadmium from soil, and a patent has been granted in Australia. No other similar technologies currently exist for remediation of cadmium contaminated soils using plants.
So, now you begin to see the problem in a bigger picture.  The University of Maryland own the rights to one's use of Pennycress to clean up cadmium.  And if you think for a minute that the University of Maryland isn't dialed into the corporate structure of Dow and the likes, I have a bridge for you.

So, the first obstacle to this is the reluctance of corporations to clean up after themselves, the second obstacle is that the current structure of power will make sure that one pays for the privilege of cleaning up the mess.  That is going to make it tough, but it is surmountable.

My biggest concern is the issue of extracting the metals and returning a safe plant residue into the ecosystem.  A great deal of the time, the sites being cleaned up are slag heaps.  Residue from a prior attempt to glean the metals from a different source.  If the metals are to be removed from the soil, they have to be safely taken from the plant matter prior to recycling the biomass back into the process.

I have run into a dead end trying to find a process that will do this.  Maybe someone is out there who can help.  My only clue is this little graph in an article from China discussing the washing of soils to reduce cadmium and phenanthrene.  I am thinking that this will be the way to process the contaminated plants for return to the system (ain't chelation grand).

Taken from http://www.sciencedirect.com/science/article/pii/S0269749108003254

1 comment:

John D. Wheeler said...

Um, how about incineration? The metal is left in the ash, and the carbon is volatilized. And you can capture it in water and use it to feed oil-producing algae.

And patents have a limited lifespan, 17 years if I recall correctly.