Nanofilters could stall looming water crisis
2011-06-02 0:00

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

Not Again: More US AID, Missiles Shipped to al Qaeda, al Nusra and ISIS in Syria, Iraq
2015-03-06 4:28
Two weeks ago, 21WIRE reported on how ISIS and other terrorists militants operating in Syria and Iraq are receiving regular weapons and ‘supply drops’ – forming a ‘rat line’ which seems to be playing a crucial role in keeping this highly profitable conflict going on both sides. This week, it’s been reported that Jabhat Al-Nusra fighters have been brandishing US-supplied ...
Swedish parliament removes Baroque artist's bare breasted painting for offending feminists and Muslims
2015-03-06 3:28
A nude painting named Juno, which was painted by baroque artist G E Schröder and has hung in the dining room of the Swedish Parliament for 30 years has been taken down for fear of offending the sensitivities of feminists and Muslim visitors, Swedish newspaper, The Local reported on Thursday. Explaining the ban on the baroque breasts, a source from the ...
White US children will be minorities by 2020 after immigrant 'baby boom', Census reveals
2015-03-05 19:50
This is the result of an ongoing trend of declining birth among white Americans and a baby boom among immigrant groups, as well as a surge in immigration. By the year 2020, 50.2percent of all children in the US are expected to be non-white, according to the Census. By 2044, whites will be outnumbered by minorities. The Census study, released ...
New Jersey Shopkeeper Hangs 'White History Month' Sign In Window
2015-03-05 18:08
A deli owner in Flemington, New Jersey, has angered many of his neighbors by posting a sign on his window that reads, "Celebrate Your White Heritage in March White History Month." Jim Boggess, who is the owner of Jimbo's Deli, says he put up the sign to remind everyone that they should be proud of their race and culture. "No matter what ...
The Viking ”Maine Penny” Mystery
2015-03-05 3:41
In 1957, during his second year of digging at the Goddard site; a large prehistoric Indian trade village in Penobscot Bay on the central Maine coast, local resident and amateur archaeologist Guy Mellgren found a small silver coin. The coin is later identified by experts as a Norse silver penny dating to the reign of Olaf Kyrre, king of Norway ...
More News »