Arsenic water safety breakthrough

[DoYouEverWonder]

10 November 2006

Arsenic-contaminated water can be made drinkable cheaply and simply using tiny crystals related to rust, scientists at Rice University in Texas say.

The US team says that particles of iron oxide can bind themselves to large amounts of arsenic in water.

When a strong magnet is placed above the particles, they clump together like iron filings and are simple to remove.

If confirmed it could help nearly 60 million people in

http://news.bbc.co.uk/2/hi/south_asia/6136970.stm

[Igel]

1. It could help people in the US that aren't connected to

city water supplies. And, if it's cheap enough and efficient enough at binding arsenic, it might help reduce arsenic levels in US drinking water. (I'm sure that more than just Americans and Bangladeshis could use it, however.)

[brentspeak]

2. More proof that nanochemistry will be the major science for the next few decades

[Henryman]

3. What about small amounts of arsenic?

The article states "particles of iron oxide can bind themselves to large amounts of arsenic in water." Most arsenic contaminated drinking water has small amounts of arsenic, usually in the parts per million or parts per billion range. Hopefully it's a start towards new technology that can be improved.

[FlaGranny]

4. ?? The smaller amount of

arsenic should make the process more efficient. In other words, you would need less iron oxide for lesser amounts of arsenic and more for higher amounts.

[NorthernSpy]

5. Oh God -- get this stuff to Bangladesh, fast!

All those drilled wells that the international aid community thought would improve life for Bangladeshis have instead caused one of the worst incidents of chronic mass poisoning in history. Much of Bangladesh's groundwater is FULL of arsenic -- enough to cause outright toxicity, never mind longterm complications such as cancers.



(edit: proof-reading)

[SoyCat]

6. That was my first thought, as well. This sounds very good for them because

their only water choices were filthy water or water with arsenic.

[Henryman]

7. Small amount of arsenic???

Not necessarily. The mechanism may be less efficient at small concentrations. For example, imagine waring a velcro suit and running through a room filled with feathers. You would come out with feathers stuck to all areas of velcro. If you ran through the same room but there are only a few feathers flying around, you might catch one or two.

[Q3JR4]

10. Well, I would say that

the fact that arsenic binds (as the article seems to say) to these small particles of rust like material means that there is some form of electrical charge involved. If you run through a room of feathers (a few of them) with a velcro suit and the feathers and you are oppositely charged, it would be like two magnets attracting each other.

[w4rma]

12. You can agitate and stir up water, but you can't really do the same to a room of people. (nt)

[krispos42]

13. Well, the objective is to get down to only a few feathers in the room

If it can help remove most of the major stuff, maybe more conventional techniques can remove whatever's left.

[Lisa]

8. and it sounds like a relatively straightforward process too

... provided they can make the chemicals available to everyone. Often they have to let the water sit to clarify it anyway, so this shouldn't make things that much more complicated. (And permanent magnetic plates could be manufactured quite cheaply, if the current prices for magnets are any indication.)

A prof I know who's active in overseas development work told me about the groundwater blunder in Bangladesh (or worse, in some cases it was a deliberate choice because the surface water was even more dangerous).

"Until the discovery of arsenic in groundwater in 1993, well water was regarded as safe for drinking."

"According to a British Geological Survey study in 1998 on shallow tube-wells in 61 of the 64 districts in Bangladesh, 46% of the samples were above 0.010 mg/L and 27% were above 0.050 mg/L. When combined with the estimated 1999 population, it was estimated that the number of people exposed to arsenic concentrations above 0.05 mg/l is 28-35 million and the number of those exposed to more than 0.01 mg/l is 46-57 million (BGS, 2000)."

http://www.who.int/mediacentre/factsheets/fs210/en/index.html

[jhain]

9. incredibly amazing

I am so glad you posted this- it is incredible!

[lovuian]

11. Thats in my water great news is right

Awesome

[truthisfreedom]

14. nano particles of "rust" easily made on a kitchen stove with coconut oil... magnest free!

you can get them by recycling old hard drives. each old hard drive has a wedge-shaped neodymium magnet that's very very powerful. we can help save these countries with old hard drives!

[NorthernSpy]

15. cool!

We should totally reclaim those magnets! There's no shortage of Neo magnets at the moment, but even so: they and lots of potentially useful stuff just go straight to the dump, and it makes me mad.