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

US Silent on Psychologists Role in CIA’s Tortures: Doctors
2014-12-20 21:53
Physicians for Human Rights had not received any response from the US Federal Commission to their call to investigate the role of health professionals in CIA’s torture program, Deputy Director of the organization told Sputnik. December 19 (Sputnik) — US government has not responded to calls to prosecute doctors, who participated in CIA torture program, the Deputy Director of Communications for ...
Ziolebrities: Simon Cowell donates £100,000 to Israeli soldiers to please pregnant jewish girlfriend Lauren Silverman
2014-12-20 21:00
Cowell, 54, is also planning a secret trip to Israel soon as he embraces the Jewish faith of Silverman, 36 Gala: Billionaire Haim Saban with Cowell Simon Cowell has publicly donated nearly £100,000 in support of the Israeli army. The X Factor boss pledged the cash to the Friends of the Israel Defense Forces at a US fund-raiser in Beverly Hills. The lavish gala ...
Former Chief Security Officer for NewsCorp: N. Koreans Not Behind Sony Hack, Interview Leak
2014-12-20 2:17
Hemanshu Nigam, a former federal prosecutor and former chief security officer for NewsCorp/Fox studios, says North Korea isn’t behind the Sony Hack. Nigam gave several bullet points for why the hack was likely an inside job. Attack code borrowed from a previous attack on Seoul, that’s why it’s in Korean. Private hackers typically borrow malicious code from other hackers.Nations state attacks follow ...
Sony Fires Back at Obama: Actually We Did Call the White House – Several Times
2014-12-20 2:13
Sony fired back at Obama after the press conference saying they had several conversations with the Obama White House before and after the movie was canceled. Via The Hollywood Reporter: After President Obama criticized Sony for its decision to cancel The Interview's release after theater chains decided not to show the film, the studio has issued a statement elaborating on the move. “The ...
The Bankster International
2014-12-20 1:55
Geopolitical analysis, the art of explaining power relationships through the prism of impersonal geography, can be a helpful tool for observers of the Great Game – but it also has its limitations. A case in point is the renewed US-Russia confrontation. Think tanks and policy insiders easily sell the narrative that from the dark days of the Cold War to ...
More News »