Nanofilters could stall looming water crisis
2011 06 02

By Nicola Frost | CosmosMagazine.com


Carbon nanotubes may revolutionise the process of converting salt water to fresh water and provide an energy-saving solution to the increasing global demand for fresh drinking water, researchers say.

In a new report, computer modelling was used to study how fluid flows at the molecular level. One of their aims was to find the optimum design for a carbon nanotube (CNT) membrane that can be used in the desalination process.

Thee simulations suggest that this membrane may be 20 to 5,000 times more permeable to water than current commercial scale reverse osmosis membranes, depending on tube density.

“If a new material is found that can maximise water transport through the separating membrane, while at the same time rejecting dissolved ions and other particulates in seawater, reverse osmosis would be a much more efficient process,” said lead author Jason Reese, professor of thermodynamics and fluid mechanics at the University of Strathclyde, Glasgow, Scotland.

Demand for drinking water on the increase

With the global population predicted to reach 9.5 billion by the latter half of this century, the demand for drinking water is only going to increase. Already, more than a billion people are faced with insufficient fresh water resources.

This week, 20 former heads of state, including former U.S. president Bill Clinton and former Japanese prime minister Yasuo Fukuda, warned of an impending "water crisis", and will establish a panel to tackle a worldwide leadership gap on the issue.

Trends in climate change have been shown to predict a redistribution of rainfall globally, with dry regions of the planet only getting dryer.

Huge costs of desalination

Most desalination plants convert salt water to fresh water using reverse osmosis. Pressure is applied to the salt water solution forcing the water through a permeable membrane that separates the pure water from the salts.

There are huge costs associated with desalination plants, however, as they require expensive infrastructure and large amounts of energy. With current technology, it is five times more expensive to desalinate water than to extract groundwater, but CNTs may change this.

Carbon nanotubes are sheets of graphene – one-atom thick carbon – rolled into cylinders. Their versatility lies in the fact that they can be a nanometre in diameter, with a tube length many millions of times longer. They are highly efficient at repelling salt ions. In solution, salts are surrounded by hydrating water molecules, which must be shed in order to pass through the CNTs.

This process takes a lot of energy and as a result doesn’t happen very often. Therefore, the right sized nanotube will optimise water transport while minimising salt ion permeability.


Read the full article at: cosmosmagazine.com



Video from: YouTube.com


Video from: YouTube.com




Related Articles
NASA’s nanotube paint: Blacker than Black (Video)
Researchers create self-assembling nanodevices that move and change shape on demand
Britain: Nanoscale Energy Storage Material Under Development
Peers Criticise Food Industry Secrecy on Nanotechnology
Nuclear-Powered Nanobots Will Allow Us to Forgo Eating a Square Meal for a Century
Nanotubes Weigh A Single Atom
Study Says Carbon Nanotubes as Dangerous as Asbestos [2008]


Latest News from our Front Page

Magaluf bar where British girl was filmed performing sex acts on 24 men is shut down after police investigation into video
2014 07 26
Is this what the youth in Britain and Europe is spending their their energy, money, efforts and innocence on? The young girl, pictured, was lured into performing multiple sex acts after organisers offered a free drink although she thought a holiday was on offer* Council officials launched an official investigation after the video went viral Playhouse bar in Magaluf and entertainment ...
Prejudice is a Form of Common Sense - Hard-Wired Into the Human Brain, Says ASU Study
2014 07 26
Contrary to what most people believe, the tendency to be prejudiced is a form of common sense, hard-wired into the human brain through evolution as an adaptive response to protect our prehistoric ancestors from danger. So suggests a new study published by Arizona State University researchers in the May issue of the "Journal of Personality and Social Psychology," which contends that, ...
The State is a Bully
2014 07 24
In the history of Western philosophy and social theory, no really silly idea has been more successful than the theory of the social contract. It is in fact not a theory of the social contract. It is a theory of the political contract. It is the idea, promoted by Thomas Hobbes, John Locke, and Jean-Jacques Rousseau, that, at some point in ...
NATO Exercise in Ukraine Coincided with MH-17 Shoot-down
2014 07 24
Rapid Trident was omitted from the flurry of coverage on the shoot-down MH-17. From the U.S. Army in Europe website: Rapid Trident supports interoperability among Ukraine, the United States, NATO and Partnership for Peace member nations. The exercise helps prepare participants to operate successfully in a joint, multinational, integrated environment with host-nation support from civil and governmental agencies. ...
Warning of ’imminent’ terror attack in Norway
2014 07 24
Norwegians were warned Thursday of the concrete possibility of a terror attack occurring in that country at the hands of people with connections to an extremist group in Syria. A press conference was called in Oslo, Norway on Thursday where an announcement was made of a "possible concrete threat" to national security in that country from terrorists related to an extremist ...
More News »