Posted on 02/28/2018 6:15:36 PM PST by upchuck
The water in Sydney Harborwhich is salty and polluted by sewage, toxic chemicals, and microplasticsisnt drinkable. But researchers in Australia recently tested a new type of water filter that purified and desalinated the water in a single step. The same process could potentially be used to help the 2 billion-plus people around the world who lack access to safe drinking water.
The filter uses Graphair, a type of graphene, a material made from a thin layer of pure carbon. A film made from the new version of the material, with microscopic nano-channels, has a unique atomic structure where the channel only allows pure water molecules to pass through while rejecting all the bigger particles of contaminants, says Dong Han Seo, a researcher at the Australian research organization CSIRO. Salt, oil, chemicals, and other pollutants are blocked by the filter, while water flows through.
Typical large desalination plants use reverse osmosis, an energy-hogging process that uses high-pressure pumps to force water through membranes. The graphene filter can be used with a different process called membrane distillation, which runs on a difference in temperature between the clean and dirty water.
That thermal process could run on renewable energy. Ideally, where we would love to see this going is youre using solar power to heat the salty, dirty water, and that drives the production of the cold, clean water, says CSIRO researcher Adrian Murdock. You also should be able to achieve a much greater efficiency of clean water.
In a recent study, a Graphair-coated membrane, roughly one square inch, could produce half a liter of water a day. The researchers are working on scaling up the membrane to the size of an A5 sheet of paper; a larger size should be able to produce 50-100 liters of water a day, or possibly more. For a household, if you had two or three of these in series, thats a perfectly reasonable volume of water to be producing, Murdock says.
While membrane distillation already had advantages over reverse osmosis, it also has a challengeover time, as theyre coated with pollutants, membranes stop working. In the recent study in Australia, the researchers tested a commercially available membrane filter coated with a Graphair film. Without the film, the filtration rate dropped by half in 72 hours. A membrane with the graphene film, by contrast, keeps working even as its coated with oil, detergents, or other contaminants.
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Great for boats too!
They lack access because of their corrupt governments.
Kenya has one of the world's largest supplies of fresh groundwater. There's water everywhere. Just need to get the corruptocrats and Marxists out of the way.
Wonder how fast it will take the sailing water-maker industry to adopt this?
Put one in every life raft.
Please. Dont you think youre getting a little ahead of yourself, worrying about the quantity of petroleum that will be used in producing your filters???I mean, how many supertanker loads of petroleum do you suppose would be required to make all the filters you can sell in the next three decades????
Yep.
Yeah, sounds absolutely wonderful. Per square foot, how much does it cost and how durable/fragile is it?! Technology is getting better and better. And this is just 2018. The Model T about 100 years ago. What will there be 100 years from now?! Oh yeah, the flying car was in Popular Mechanics in about 1966. Every college physics dept. should have a tech fair just like the typical high school science fair. The college kids would have to design a toy or a widget which could do something. And then each college physics dept would compete in the national arena. With the entire school chipping in, the physics toy competition could be amazing.
I want five of them.
Yes, I’m series...
If membrane filtration offered lower energy costs than reverse osmosis, then it would used in large desalination plants. So far it has not; RO rules.
This is such bad news for California because it would actually solve a problem but government always finds a way to create misery from prosperity and happiness.
not to worry - California will find a way to slap a meter on it
They’re just now able to manufacture the graphene coated membrane filters large enough for commercial scale operation, that was how I read it.
My question is, how often does it need to be cleaned and how? I can see tremendous application for this, in the marine and RV industries alone. Potable water practically on the spot regardless of facilities, unless you’re in an absolute desert.
I would love to have that filter to assure the purity of my well water.
Actually they did mention one thing better than other filters, and that is othr filter get clogged with oil and chemcals and reduce flow to the point they stop worki g and either need replacing or cleaning, and graphene filters still alow good water flow regardless of how much oil and chemicals they are blocking.
I’ve read that graphene filters which can be swapped in to existing RO technology plants are incredibly cost effective, and the South Koreans are working on 3D printing of the graphene filters which will make them even cheaper.
This convergence of these technologies will revolutionize water filtration.
It’s graphene, so it’s just around the corner.
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