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New membrane will help to ensure many parts of the world have easy access to drinking water.

One of the biggest, but least appreciated problems facing many regions of the world is lack of clean drinking water, a common problem in impoverished nations.  Ironically, many of these nations rest beside large bodies of salt water. Ttypically, processing salt water into fresh water is expensive and requires large dedicated plants.

DailyTech previously chronicled how wind-power driven desalinization plants which used membranes were being developed.  Now another major breakthrough in the field has been devised, this time concerning the membranes.

Researchers from several international universities have developed a chlorine-tolerant membrane which turns salt water into clean drinking water.  Typically, salt water is treated with chlorine to remove bacteria and microorganisms that would grow and form a biofilm on the membrane, blocking it.  However, chlorine destroys past membranes which were build using amide-polymers (nitrogen based).  This meant that that the water had to be dechlorinated before being sent to the membrane, a relatively expensive and complex process.

The new membrane is formed from sulfonated copolymers.  It took researchers Professor Benny Freeman with the The University of Texas at Austin, James E. McGrath of Virginia Tech University, and Ho Bum Park of the University of Ulsan in South Korea three years to develop the membrane for which they have filed a patent.  The new membrane is resistant to chlorine allowing the elimination of dechlorination.

Says Professor Freeman, "If we make the desalination process more efficient with better membranes, it will be less expensive to desalinate a gallon of water, which will expand the availability of clean water around the world.  It promises to eliminate de-chlorination steps that are required currently to protect membranes from attack by chlorine in water.  We believe that even a small increase in efficiency should result in large cost savings."

Researchers also believe the design will help reduce carbon dioxide emissions in developing nations by decreasing the electrical needs of the generation process. 

Professor Freeman explains:

Energy and water are inherently connected.  You need water to generate power (cooling water for electric power generation stations) and generation of pure water requires energy to separate the salt from the water. That energy is often generated from the burning of fossil fuels, which leads inevitably to the generation of carbon dioxide. Therefore, if one can make desalination more energy-efficient by developing better membranes, such as those that we are working on, one could reduce the carbon footprint required to produce pure water.

It was a combination of luck and hard work that brought the researchers upon the novel suflonated class of membranes.  This class of materials enjoys a high tolerance to aqueous chlorine, making it surprisingly a far better fit than membrane materials currently in use.

Professor Freeman, who holds the Kenneth A. Kobe Professorship in Chemical Engineering and the Paul D. & Betty Robertson Meek & American Petrofina Foundation Centennial Professorship in Chemical Engineering, states, "Basically, Dr. McGrath radically changed the chemical composition of the membranes, relative to what is used commercially, and the new membranes do not have chemical linkages in them that are sensitive to attack by chlorine."

The research was funded by the Office of Naval Research and the National Science Foundation-Partnerships for Innovation Program. 

The findings will be reported in a paper in this month's edition of the German Chemical Society's journal, Angewandte Chemie, with Mehmet Sankir and Zhong-Bio Zhang, both of Virginia Tech, as additional coauthors.



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RE: Swank.
By Ammohunt on 7/23/2008 2:20:37 PM , Rating: 2
Problem with that is it makes sense!. The water shortages we have here in colorado are mainly due to the eco-freaks not allow resevoirs to be built not to mention 95% of the water collected is used for farming.


RE: Swank.
By andrinoaa on 7/23/08, Rating: -1
RE: Swank.
By masher2 (blog) on 7/23/2008 7:27:38 PM , Rating: 4
> "but those pesky environmentalists keep pointing out the fact that the whole of the continent can be turned into a dam, but if it doesn't rain, its all for naught."

Cute, but the fact remains that every single day, tens of billions of gallons of fresh water flow out of Australian rivers into the sea. All wasted...because no dam existed to hold it. As a continent, Australia receives much more water in rainfall than it needs.

Oh and those dams generate massive amounts of electrical power also.

> "Do you have a problem with this , glowboys? "

None whatsoever, besides the fact that desalination is still many dozens of times more expensive than simply building more dam capacity.


RE: Swank.
By goz314 on 7/23/2008 9:36:55 PM , Rating: 1
quote:
As a continent, Australia receives much more water in rainfall than it needs.


Oh... really? I would like to see you waste your time trying to actually qualify that statement.


RE: Swank.
By Ringold on 7/23/2008 9:44:45 PM , Rating: 2
Well, I wasted roughly 3 minutes opening up Google Earth, zooming in to Australia, and locating several rivers that appeared to be doing what rivers do and what masher said -- dumping lots of fresh water in to the ocean.


RE: Swank.
By croc on 7/23/2008 9:38:02 PM , Rating: 1
And I am sure that you have the links to back up this mis-informed opinion?

The Murray-Darling river basin is now having problems delivering enough water to South Australia as it is. (and it doesn't reach the ocean...)

West Australia has pretty much used up all of their bore water, and are building several de-sal plants.

New South Wales will be building a de-sal plant, possibly...

I am sure that with all of your environmental science degrees, the CSIRO would hire you in a snap.


RE: Swank.
By masher2 (blog) on 7/23/2008 10:00:16 PM , Rating: 3
> "And I am sure that you have the links to back up this mis-informed opinion?"

Always. The mean rainfall of Australia is ~500mm. That works out to an annual volume of 3,843,425,000,000 cubic meters of water. Converting to gallons, thats 1,015 trillion gallons falling on the continent each year:

http://www.bom.gov.au/climate/change/rain.shtml

Per capita water consumption for Australia is 115 kL (30,000 gallons):

http://www.environment.gov.au/soe/2006/publication...

With 20.4 million people in Australia, that means total rainfall is actually 1700 TIMES as much water as you actually need....even assuming not a single drop is ever used more than once (no grey-water recycling, etc)

Most water is wasted. Thanks for playing.


RE: Swank.
By croc on 7/24/08, Rating: 0
RE: Swank.
By masher2 (blog) on 7/24/2008 9:03:25 AM , Rating: 2
> "Note that most of all that '500mm' average you quote comes from the northern coastal fringes. "

The average rainfall in the Sydney basin is 1200 mm -- over twice the average for the entire continent. The average rainfall in Perth is 870 mm -- 50% more the the continental mean. Adelaide's rainfall: 629 mm. Melbourne's rainfall: 800mm.

Yes, more rain falls in the tropical North. But when over 1700 times as much rain falls as you actually need, even the rainfall in the south is sufficient -- were it all to be properly used.

Take a look at any Australian river flowing into the sea. That's fresh water-- all wasted. The Fitzroy river alone has been measured at flow rates up to 640 billion gallons per *day*. The Murray river -- easily available in the south -- discharges some 17 billion gallons a day. Again, all wasted.

As for the "protected rainforest, wetlands, etc" -- that's simply more proof this is a problem of desire and initiative, rather than substance. The north is too wet, and the south too dry. The solution to that problem should be obvious to anyone....transfer some water.


RE: Swank.
By andrinoaa on 7/24/2008 6:33:11 PM , Rating: 2
You obviously don't live here, mash. Its not what we have on the ground. Melbourne hasn't had decent rain for nearly two decades. We have lots of dams but they are running on empty. What is the point of having more?
Lies , damn lies and stastistics.
And besides, what arrogance you have. All water that flows to the sea is wasted!?!?!? Thats the kind of thinking that has destroyed half the environment in the fisrt place totally IGNORANT thinking. Its time you stopped defecating in your cereal bowl, mate.


RE: Swank.
By andrinoaa on 7/24/2008 6:44:32 PM , Rating: 2
The Murray river stopped flowing to the sea years ago. The mouth is now threatening to turn acidic PERMANENTLY. This will cause untold ecologoical damage to the area. Agriculture may need to be abandoned and south australia's water supplies are threatened too. Your rainfall figures look great but are not reflective of what we see.
Let me repeat. Damming the far north and piping water south is too expensive because of the distance so we need to find local initiatives. Now, next time you chosse to look up information in google, make sure its relevant. Not VAPOURWARE


RE: Swank.
By codeThug on 7/23/2008 10:38:21 PM , Rating: 2
...so quiet you could hear a kangaroo drop...


RE: Swank.
By andrinoaa on 7/24/2008 6:52:18 AM , Rating: 1
Nice try masher2, but it just goes to show statistics, lies and more damn lies.
Australia can be divided in two. The tropical north and the rest. Its true lots of rain falls in the tropics. But the rest of the country where the majority lives is now on borrowed water. Damming all this water would utterly destroy the barrier reef and most of the great fishing grounds off the coast. It is also inhospitable in the dry and unstoppable in the wet. Its like trying to harness a cyclone. The environment up north is finely tune to the seasons. Any large scale damming is going to be on a knife's edge.
In the past we built dams everywhere and that is a major reason why we are in a terrible state now - we didn't know what we were doing. We assumed the good times would keep rolling on forever.
Studies have been made to see if the water can be redirected and the figures come back as many times more expensive than desal.


RE: Swank.
By masher2 (blog) on 7/24/2008 8:49:02 AM , Rating: 2
> "Damming all this water would utterly destroy the barrier reef and most of the great fishing grounds off the coast."

Stuff and nonsense. First of all, you you don't need to dam anywhere near "all" this water, or even 1% of it. As I demonstrated, Australia receives nearly 2000 times as much water as it needs...you only need to dam a small part of it to solve your problems.


RE: Swank.
By andrinoaa on 7/24/2008 6:22:04 PM , Rating: 2
You seem to like to get to the tiniest of peices and pick holes but you don't get the big picture. Daming the water while technically possible, is beyond our country's financial capacity. It was already tried out west. It is called the Ord river dam. Its a total fiasco.It has lots of water but it is so far away from the population centres, it may as well be on the moon. This was the main point, the environment was a byproduct. But it seems you would be perfectly happy to defecate in your own cereal bowl. Small children do that.
You always seem to missunderstand the big picture, masher2.
My posting was about using WAVE power to run desal. The new membrane would be ideal!


RE: Swank.
By mmatis on 7/24/2008 9:27:27 PM , Rating: 1
Quelle surprise! Another left-wing butt-wipe spewing their lies. Why don't you go suck Osama like the rest of your media buddies are doing?


RE: Swank.
By andrinoaa on 7/24/2008 6:57:48 PM , Rating: 2
"besides the fact that desalination is still many dozens of times more expensive than simply building more dam capacity."

You devalue your cache when you exaggerate like this.
$1.5 billion for 300 megaliter desal plant. A new dam would have to be of this size to be warranted. We don't have any more rivers of any consequence in Victoria. How much does this cost? Nothing because its VAPOURWARE!!!!


RE: Swank.
By andrinoaa on 7/24/2008 7:00:48 PM , Rating: 2
Sorry , that should read 300 Gigaliters. ( in a hurry)


RE: Swank.
By andrinoaa on 7/24/2008 7:04:33 PM , Rating: 2
SORRY again, having a bad hair day.
the latest figures. $3.1 Billion for 150 billion litres per year plant


RE: Swank.
By mmatis on 7/24/2008 9:30:57 PM , Rating: 2
You aren't related to Goebbels, are you?


RE: Swank.
By andrinoaa on 7/24/2008 7:07:15 PM , Rating: 2
SORRY again, having a bad hair day.
the latest figures. $3.1 Billion for 150 billion litres per year plant
Its a pitty we cannot retract postings when we realise we stuffed up, lol.


RE: Swank.
By mmatis on 7/24/2008 9:28:59 PM , Rating: 2
And you have the guts to claim masher can't get his facts straight! Putrid stench of filthy maggot swill...


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