Single-atom sheet of carbon clears arsenic from water

Single-atom sheet of carbon clears arsenic from water

Separating out arsenic

We can get a hint of the power coming from longer-term nanotech by seeing what is being discovered today on how to use some of the new materials becoming available.  Many of us have been intrigued with graphene, a one-atom-thick planar sheet of bonded carbon atoms.  It’s no surprise that exciting applications are being found already, such as Nanotechweb’s report on work in South Korea:

…Kwang Kim, In-Cheol Hwang and colleagues at Pohang University of Science and Technology have synthesised a new type of magnetite composite based on reduced graphene oxide (RGO). The hybrid material, which is superparamagnetic at room temperature, can remove over 99.9% of arsenic in a sample, and reduce its concentration to below 1 ppb – as measured by inductively coupled plasma (ICP) techniques.

The magnetite-RGO composite can be dispersed in water. Once it has adsorbed arsenic, it can quickly be removed from a sample using a permanent hand-held magnet (with a strength of 20 mT) within a fraction of a minute.

Probably you already known that arsenic is a natural contaminant in water in parts of the western U.S. and in south Asia.  This is a huge problem and causes very serious health problems.  Let’s hope this helpful use of graphene is just the start of a great career for this nanomaterial, first in simple applications like this one, and later as part of more complex molecular machine systems. (HT to Meridian Nanotechnology and Development News)  —Chris Peterson

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  1. […] PROGRESS: Single-atom sheet of carbon clears arsenic from water. […]

  2. coggieguy July 19, 2010 at 1:58 pm - Reply

    In S Asia (eg Bengladesh) As is a big problem in rural well water. Can this be incorporated into a filter bed along with low cost materials (sand, natural fibers etc) to act as a passive filter system? The magnet is a great (looking) application, perhaps a simpler lowtech filter is the better use.

  3. Uriel July 19, 2010 at 6:19 pm - Reply

    Mr. Peterson,
    Arsenic in drinking water is not a “huge problem”, it does not “cause very serious health problems”, and anyone who believes so does not understand the evil that is the Precautionary Principle, nor the SOLE PURPOSE of the Environmental Protection Agency. The EPA exists to continue its own existence … AND NOTHING ELSE. That is, to regulate, regulate, and then regulate some more in the paradoxical effort to prove the need for ever more regulation. And this regardless of any risk to humans or “the environment”, and with ZERO concern for the ever-increasing costs of compliance with useless regulation.

    By the way, how much would this “single-atom sheet of carbon” cost? How many lives would be saved by incurring this cost? How many American lives were saved by lowering the allowable arsenic concentration from 50 to 10 ppb? Can you prove that? Can anyone?

  4. Christine Peterson July 20, 2010 at 11:59 am - Reply

    @Uriel — Arsenic in water is a worse problem in countries other than the U.S. (as our other commenter mentions). I agree that cost-effectiveness is a very important consideration. –Christine (not a Mr.)

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