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Author Topic: microbes and radioactive waste  (Read 6373 times)

paul.fr

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microbes and radioactive waste
« on: 16/04/2007 10:05:31 »
catching up on my podcasts, Chris mentioned the situation near Chernobyl where birds are nesting in sites of low contamination. This reminded me that microbes can "eat" radioactive waster.

would it be possible to introduce microbes to site such as Chernobyl to "clean up" the environment?


 

Offline Karen W.

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microbes and radioactive waste
« Reply #1 on: 16/04/2007 10:16:43 »
would that apply to say for instance the closed neuclear power plant we have locally..Surely there is a certain amount of waste loste here that could be benefitted if such a thing is actually possible..
 

paul.fr

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microbes and radioactive waste
« Reply #2 on: 16/04/2007 10:23:53 »
would that apply to say for instance the closed neuclear power plant we have locally..Surely there is a certain amount of waste loste here that could be benefitted if such a thing is actually possible..

This is something i know very little about, i just vaguley remember the subject. There are also microbes and, i think, plants that clean up things such as gold deposits.
 

Offline Karen W.

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microbes and radioactive waste
« Reply #3 on: 16/04/2007 10:32:34 »
that is interesting..I understand and have heard some thing about plants but very little I do not remembers the details!
 

another_someone

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microbes and radioactive waste
« Reply #4 on: 16/04/2007 12:26:52 »
Firstly, the microbes will only each be designed to deal with one or two substances, so you would need as many types of microbes as you have radioactive substances.

Secondly, all the microbes can do is collect the metals within their cells, thus concentrating the radioactive metals - you still need some way of disposing of those metals once they have been concentrated.

Thirdly, the Ukraine is not a particularly rich country, and whatever means they use to clean up Chernobyl, there will be a bill to be paid.

Bear in mind that cleaning up an enclosed space is one thing, but trying to clean up an area of hundreds of square miles of open space is something else.  Even if you could introduce the microbes into the open spaces, and even if they could survive the environment, how would you then collect them later when they have done their work?

One has to ask whether it is better for the Ukraine to just leave the contaminated area alone, or to spend substantial amounts of money to concentrate the dangerous metals, and then take them somewhere else, and contaminate that somewhere else.
 

paul.fr

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microbes and radioactive waste
« Reply #5 on: 16/04/2007 19:32:49 »
found this:

Quote
Bacteria belonging to the family Deinococcaceae are some of the most radiation-resistant organisms yet discovered. Deinococcus (Micrococcus) radiodurans strain R1 (ATCC BAA-816) was first reported in 1956 by A. W. Anderson and coworkers of the Oregon Agricultural Experimental Station, Corvalis, Oregon. This obligate aerobic bacterium typically grows in rich medium as clusters of two cells (diplococci) in the early stages of growth, and as clusters of four cells (tetracocci) in the late stages of growth, is non-pathogenic, and best known for its ability to survive extremely high doses of acute ionizing radiation (10,000 Gy) without cell-killing. For comparison, 5 Gy is lethal to the average human, and 1,000 Gy can sterilize a culture of Escherichia coli. D. radiodurans is capable of growth under chronic radiation (60 Gy/hour) and resistant to other DNA damaging conditions including exposure to desiccation, UV light, and hydrogen peroxide. The genes and cellular pathways underlying the survival strategies of D. radiodurans are under investigation, and its resistance characteristics are being exploited in the development of bioremediation processes for cleanup of highly radioactive US Department of Energy waste sites.

D. radiodurans maintains 4-8 haploid copies of its genome per cell (16-32 genomes/tetracoccus), and the repair of irradiation-induced DNA double-stranded breaks (DSBs) is known to be mediated by recA-independent (single-stranded annealing) and recA-dependent homologous recombination, but no error-prone SOS response is observed. Yet, the identity of the genetic systems underlying those repair processes in D. radiodurans remains unknown in spite of detailed global cellular analyses including whole genome sequencing and annotation, and transcriptome and proteome profiling of cells recovering from high-dose irradiation. The lack of a clearly identifiable unique DNA repair system in D. radiodurans has given rise to several competing views of the mechanisms responsible for its extraordinary survival, and research in this laboratory addresses the following possibilities: 1) There are novel repair functions encoded among hypothetical genes predicted by genomic annotation; 2) D. radiodurans uses conventional DNA repair pathways, but with much greater efficiency than other bacteria; 3) DNA repair in D. radiodurans is promoted by aggregation of its multiple chromosomes; 4) The unusual metabolic environment of D. radiodurans facilitates recovery; and 5) Intracellular Mn(II) accumulation facilitates recovery.


here http://www.usuhs.mil/pat/deinococcus/index_20.htm
 

Offline Bored chemist

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microbes and radioactive waste
« Reply #6 on: 16/04/2007 20:00:08 »
In essence the problem is that, whatever the bugs do, the stuff will still be radioactive. It's not like some chemical waste where the bugs can convert the toxic materials into less toxic ones. On the other hand there is a risk of them converting things into even more toxic orms. For example, mercury compounds are already pretty toxic but some bacteria can convert them into methylmercury cmpounds which are generally even more toxic.
There's no way that bacteria could make the radioactive stuff more or less radioactive, but they might convert it into something volatile or readily water soluble. This might make a bad problem worse.
 

paul.fr

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microbes and radioactive waste
« Reply #7 on: 19/04/2007 14:31:29 »
phytomining - thats the process with plants. i will try and find some info on it when i return from work.
 

paul.fr

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microbes and radioactive waste
« Reply #8 on: 19/04/2007 14:47:51 »
a quick search and i found this:

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Abstract: This patent describes a method of extracting nickel, cobalt, and other metals, including the platinum and palladium metal families, from soil by cultivation of the soil with hyperaccumulating plants that concentrate these metals in above-ground portions of the plants. The plants can be harvested, dried, and smelted to recover the metal in a process known as metal phytomining. The applicants have screened a large wild-type collection of germplasm to identity hyperaccumulating plants. Plants of the Brassicaceae family, particularly naturally occurring plants as opposed to those with induced mutations, are known to be Ni+Co accumulators. Alyssum species that are preferred candidates for use concentrate and hyperaccumulate nickel, show an enhanced uptake of cobalt, and may be useful in accumulating other metals. Preferred species have a preference for, and a high toxicity resistance to, these metallic elements. Rather than relying on the unpredictable process of mutagenesis, the applicants have screened a large library of wild-type germplasm and have identified several Alyssum species, including A. murale, A. pintodasilvae (A. serpyllifolium ssp.), A. malacitanum, A. lesbiacum, A. tenium, and A. fallacinum as suitable hyperaccumulators of nickel and useful in the enhanced uptake of cobalt. The same plants may also accumulate Pd, Rh, Ru, Pt, Ir, Os, and Re. While these platinum and palladium metals are accumulated in lower concentrations, their greater value per unit weight makes phytomining of these metals economically attractive as well. By definition, hyperaccumulator plants accumulate over 1000 mg Ni or Co/kg dry weight growing in the soils where they evolved. The identified metal species are accumulated by growing the Alyssum in nickel-rich soil under specific soil conditions, i.e., (1) lowering the soil pH, which increases the phytoavailability of nickel, (2) maintaining moderate levels of Ca in the soil by appropriate treatments and by use of Ca, (3) using ammonium-constraining or ammonium-generating nitrogen fertilizers to improve plant growth and to increase Ni hyperaccumulation due to rhizosphere acidification, and (4) applying chelating agents to the soil to improve nickel uptake by the roots of the hyperaccumulating Alyssum species. Examples of suitable chelating agents include nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid, and ethylene glycol-bis-(beta-aminoethylether)-N,N'-tetraacetic acid.

here: http://epa.gov/superfund/programs/aml/tech/news/phytomin.htm  it is dated 2004, so there must be more recent info somewhere!
 

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microbes and radioactive waste
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