Water purification down the nanotubes

Sep 15, 2008

Nanotechnology could be the answer to ensuring a safe supply of drinking water for regions of the world stricken by periodic drought or where water contamination is rife. Writing in the International Journal of Nuclear Desalination, researchers in India explain how carbon nanotubes could replace conventional materials in water-purification systems.

Water shortages and lack of access to safe drinking water will continue to grow as major global problems. At present, more than one billion people lack access to safe drinking water and 2.4 billion people lack access to proper sanitation, nearly all of them in the developing countries. At present a third of the world's population live in water-stressed countries, and by 2025, this is expected to rise to two-thirds.

S. Kar, R.C. Bindal, S. Prabhakar, P.K. Tewari, K. Dasgupta, and D. Sathiyamoorthy of the Bhabha Atomic Research Centre (BARC) in Mumbai, India, explain how new water purification technologies are constantly being investigated but to be viable in the developing world these have to be relatively simple and inexpensive to install, operate, and maintain.

They have turned to nanostructured, the carbon nanotubes, hollow carbon fibers less than a billionth the thickness of a human hair. The unique chemical properties of carbon nanotubes mean that only very small molecules, such as water molecules can pass along their interiors, whereas viruses, bacteria, toxic metal ions, and large noxious organic molecules cannot.

The team points out that the smooth and water repellant interior of carbon nanotubes means that a filter based on this technology would be very efficient, allowing a high flow rate of water through the filter without fouling. Importantly, the power needed to drive water through such a system will be low compared to conventional membrane technology.

However, to be useful as a nanotech filtration system for contaminated water, these nanoscale structures need to be engineered to form well-defined arrangements to allow the efficient decontamination of water. The team has now investigated the potential of forming water filtration systems based on carbon nanotubes that could remove arsenic, fluoride, heavy metals and toxic organic chemicals. Carbon nanotubes have impressive credentials for water purification, the researchers say.

Source: Inderscience Publishers

Explore further: Understanding the source of extra-large capacities in promising Li-ion battery electrodes

add to favorites email to friend print save as pdf

Related Stories

From stronger Kevlar to better biology

Jul 14, 2014

Place two large, sturdy logs in a streambed, and they will help guide the water in a particular direction. But imagine if the water started mimicking the rigidity of the logs in addition to flowing along ...

Chemists develop novel catalyst with two functions

Jul 09, 2014

Chemists at the Ruhr-Universität Bochum have made a decisive step towards more cost-efficient regenerative fuel cells and rechargeable metal-air batteries. They developed a new type of catalyst on the basis ...

Evidence confirms combustion theory

Jul 01, 2014

(Phys.org) —Researchers at the Department of Energy's Lawrence Berkeley National Lab (Berkeley Lab) and the University of Hawaii have uncovered the first step in the process that transforms gas-phase molecules ...

Watching nanoscale fluids flow

Jun 27, 2014

(Phys.org) —At the nanoscale, where objects are measured in billionths of meters and events transpire in trillionths of seconds, things do not always behave as our experiences with the macro-world might ...

Nanotube forests drink water from arid air

Jun 11, 2014

(Phys.org) —If you don't want to die of thirst in the desert, be like the beetle. Or have a nanotube cup handy. New research by scientists at Rice University demonstrated that forests of carbon nanotubes ...

Recommended for you

Tough foam from tiny sheets

5 hours ago

Tough, ultralight foam of atom-thick sheets can be made to any size and shape through a chemical process invented at Rice University.

Graphene surfaces on photonic racetracks

Jul 28, 2014

In an article published in Optics Express, scientists from The University of Manchester describe how graphene can be wrapped around a silicon wire, or waveguide, and modify the transmission of light through it.

Simulating the invisible

Jul 28, 2014

Panagiotis Grammatikopoulos in the OIST Nanoparticles by Design Unit simulates the interactions of particles that are too small to see, and too complicated to visualize. In order to study the particles' behavior, he uses ...

Building 'invisible' materials with light

Jul 28, 2014

A new method of building materials using light, developed by researchers at the University of Cambridge, could one day enable technologies that are often considered the realm of science fiction, such as invisibility ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Forehead
not rated yet Mar 24, 2009
"...carbon fibers less than a billionth the thickness of a human hair..."



Isn't the normal expression 50,000 times smaller than the thickness of a human hair? In fact, wouldn't a billionth the width of a human hair get down to the atto scale, below the size of an atom?