Nanorust Used To Purify Water 99
eldavojohn writes "How do you remove arsenic from water? Well, a research team has discovered that adding and removing nanorust works well. From the article, 'The team added nanoscale iron oxide to contaminated water, where it clumped together with the arsenic. They then magnetized the nanoparticles with an electromagnet and pulled them out. "We only needed a surprisingly weak magnetic field," says Colvin. "In fact, we could pull then out with just a hand-held magnet, making this a very practical method.' Big news for developing nations that are plagued with non-potable drinking water."
Some potential, but there are better options (Score:4, Insightful)
The article itself admits that nanorust is still too expensive to be used widely, while filtration units already exist that cheaply remove arsenic plus many other things cheaply. In the U.S., home filters (and even cheap Britas) remove 99% of all arsenic, along with similar levels of other chemicals and heavy metals
Re:Some potential, but there are better options (Score:5, Informative)
The main source of arsenic poisoning is and has always been from naturally-occurring sources in soil.
I remember when the international community paid millions of dollars to supply Bangladesh with wells to give them water. The problem was, the earth in that area is naturally rich in arsenic and it caused the single largest occurrence of arsenic poisoning in the history of man. Better than dying of thirst, I guess... or not [wikipedia.org].
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India and other countries have proposed massively expensive projects to contend with the disaster (which India still contends is not manmade, but th
Re:Some potential, but there are better options (Score:5, Informative)
Wrong.
Unless you've got a URL that disputes what this one says:
http://www.bgs.ac.uk/arsenic/bangladesh/reports.h
"13.1.4 Source of the arsenic
There is no doubt that the source of the As is natural, i.e., derived from 'ordinary' sediments by natural geochemical processes. The quantity of As present in groundwater (and adsorbed by the sediments) is simply too large to be derived from a discrete pollution source. Also its distribution across Bangladesh and West Bengal and with depth does not tally with a pollution source. There is also no need to postulate exceptional sources such as a particular mineralised area in the upstream catchment, as some workers have done for neighbouring West Bengal (Acharyya et al., 1999), although of course such areas may exist. This is one of the lessons that needs to be learned from the Bangladesh arsenic problem.
There is more than enough arsenic in most sediments to give rise to an As problem given the appropriate geochemical conditions for release and mobilisation. If all of the arsenic in a sediment containing 1mg As kg^-1 sediment dissolves in the groundwater, then the arsenic concentration would be 6000 micrograms/L or more, way above all drinking water standards. Both the average world and typical Bangladesh sediments contain several times this amount of arsenic. In other words, Bangladesh sediments do not appear to contain an exceptional amount of arsenic
So unless you've got some sort of documentation that trumps the British Geological Survey, I suggest you take a course in "rocks for jocks" (geology 101) instead of spewing your uninformed twaddle here.
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BMO
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Sounds like its not going to be long before an inexpensive method pops up.
quote: At the moment, the high cost of making nanoparticles means the trick is too expensive to be used widely. In principle, however, the nanoparticles are easy to make: the team created them by dissolving large pieces of rust in heated oleic acid, which can be found in ordinary olive oil.
"The temperatures needed are accessible in a frying pan," Co
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The problem with filtra
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The history is that thousands of deep tube wells were constructed in Bangladesh with generous international funding and advice from various well-meaning organisations and governments
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Anyone here knows if the body of a 93 Nissan Sentra has Mercury, Lead or anything bad?
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Not only that, but they might actually work. :) After all, boiling water isn't going to remove any of the heavy metals found in contaminated water. In fact, as the water boils off, the contaminates become more concentrated per measure of water.
Boiling water kills (most/some) germs and bacteria, but that's all.
Wonderful (Score:4, Funny)
Ounce of prevention? (Score:3, Insightful)
Is this a normal geological property or result of pollution?
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"5. How does arsenic get into water supplies?
Most arsenic enters water supplies either from natural deposits in the earth or from industrial and agricultural pollution. Arsenic is a natural element of the earth's crust. It is used in industry and agriculture, and for other purposes. It also is a byproduct of copper smelting, mining and coal burning. U.S. industries release thousands of pounds of arsenic into the env
Please read before paste-bombing. (Score:2)
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Generally, arsenic is not the most important contaminant in drinking water. In fact, chlorination of surface water often results in contaminants that are worse than what's in the raw water. Trihalomethanes (THMs) http://en.wikipedia.org/wiki/Trihalomethane [wikipedia.org] are formed from a reaction of free chlorine and organic compounds.
This nano
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I'm sorry, THMs are not good for you, I'll agree with you there. However, compared to Arsenic, I'll take the THMs every time. Oh, and by the way, I work for a water utility. THMs are not easy to deal with. Chlorination works very well for sanitizing water. The alternatives
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My argument is that it's like worrying about dieing from ebola virus when the common cold is much more likely to take your life. That's all. You may now dismount from your high horse.
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Is Hawaii a third world? (Score:2, Insightful)
Arsenic is insoluble so it just stays in ground or gets washed away. That's why coral-reef fish and algae's are usually contaminated the most.
*sigh* (Score:5, Insightful)
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Obviously only with a nanoscope, dummy!
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Can we save the prefix "nano" for when it is scientifically appropriate? Nanorust is the kind of word you throw around at an internal group meeting to be cute, but it shouldn't find it's way into a publication.
I would be fine with iron-oxide nanoparticles, or even rust nanoparticles, but there are plenty of perfectly good non-scientifically-embarassing names for this stuff such as simply iron-oxide clusters.
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Granted it does sound like a buzzword, be even as a geek, I'd hate to have to say all of that, when ironically enough, nanorust actually would make sense to me. (disclaimer, I am a both a double major in business admin (marketing concentration) and c
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Why do we give credence to what Joe-average expects nano to convey? The fact of the matter is that there is a huge domain of biological phenomena operating at the micro scale, and another huge domain of physical chemistry operating at the nano scale, neither of which should evoke gasps of "Oh, cool!"
It's a mugs game to invest energy in controlling the impressions/reactions of the non-thinking masses. Why was nano cool in the first place? Because you could eat a small machine? Oh, cool.
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that's simple ;) your trycorder is out of date! (Score:2)
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Going to toxic areas is deserving of bomb squad status, "Move outta the way people; make way for the Heavy Metal Removal Unit!"
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I should have known that. . .
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Removing ions in water is best done through reverse osmosis. It can also be accomplished - to a small extent - using coagulants such as Ferrous Chloride or Aluminum Sulfate.
A case of "nano" for its own sake... (Score:2, Informative)
As the two biggest problems, though - Too much iron causes problems in humans (males in particular, and yes, for the obvious reason); and the non-water product of this technique consists of a rather toxic arsenic sludge which you occasionally need to dispose of somewhere that won't run righ
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Re:A case of "nano" for its own sake... (Score:4, Informative)
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> like zeolites, ion exchange resins and so on.
So tell me where to buy inexpensive zeolites, ion exchange resins and so on suitable for removing arsenic.
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i.e. nowhere.
Putting it into different units (Score:2)
Not only that - you can make it out of Volkswagens!
Third World Countries? (Score:2)
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lined nanotubes (Score:1)
r&r (Score:1)
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answer you will be a rotting corpse a daya away from the water
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The question becomes... (Score:3, Funny)
Arsenic -- is it really so bad? (Score:1)
Non-potable? (Score:1)
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Its a matter of taste, really: (Score:2)
Oh, if anyone knows if I am slowly killing myself by doing this, please tell me....
Normally I'm all for Darwinism... (Score:1)
" Excess iodine has symptoms similar to those of iodine deficiency. Commonly encountered symptoms are abnormal growth of the thyroid gland and disorders in functioning and growth of the organism as a whole. Elemental iodine, I2, is deadly poison if taken in larger amounts; if 2-3 grams of it is consumed, it is fatal to humans. Iodides are similar in toxicity to bromides."
Toxicity of Iodine [wikipedia.org]
I always assumed the iodine they add to salts were good enough to cover the population b
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Distillation (Score:2)
The only thing that distillation cannot deal with is the few volatile organic molecules that have a boiling point near that of water, and a charcoal filtration step on the condensate will deal with those.
Where electricity is available, a gallon of distilled water can be prepared with two kilowatt hours of energy, at a cost in most places of under sixty cents.
You
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No. You can't easily boil water with a few steel mirrors. It's possible, but it's not easy.
The "few volatile organic molecules" may contain such things as insect pesticide, oil and gasoline spill, etc...
In addition to the cost of electricity, you must also include the cost of water. To produce one liter distilled water, requires several liters of water (I've seen 5 liters claimed, although I haven't seen much justification for this number).
And finally, distilled water is not healthy. It's acidic and l
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1. Yes, it is easy if the boiling apparatus is designed correctly. I've done it. And you can distill water without actually boiling it, though it is a slower process. And it is under active development; http://www.solarconference.net/abstract_selection. php [solarconference.net] http://www.ecozen.com/steam1.htm [ecozen.com] http://www.epsea.org/stills.html [epsea.org] http://www.solaqua.com/solwatdis1.html [solaqua.com] http://www.fsec.ucf.edu/pubs/EnergyNotes/en-3.htm [ucf.edu]
2. The volatiles that come out at water boiling tem
The technique has already been commercialized (Score:1)
They have far more details than the article.
Old method maybe? (Score:2)
Nanotech Desalination? (Score:1)
Old wisdom, new application (Score:1)
I don't want to get off on a rant here (Score:1)
The word has one and only one meaning [google.com]: "drinkable". It has no distinction from this definition, either, unlike most other synonyms in the English language which at least have some nuance of meaning distinct from other words. So, would someone tell me why anyone would insist on using the word "potable" instead of "drinkable", particularly in such cases
The difference between potable and drinkable (Score:2)
Isn't that just rouge? (Score:2)