Scientist discovers way to extract clean drinking water from tree bark

Scientist discovers way to extract clean drinking water from tree bark


(NaturalNews) One of the biggest nutritional problems facing the planet today is the availability of clean drinking water. In fact, according to some estimates, close to 800 million people do not have regular access to clean water, and 3.4 million die each year from a water-related issue such as dehydration, sanitation or hygiene-related causes.

With that latter statistic in mind, if it was possible to remove the dangerous, harmful bacteria from drinking water, that would be tremendously beneficial for global health. And while there are technologies to do that, they are cost-prohibitive.

That may be about to change, however.

Rohit Karnik, a scientist at the Massachusetts Institute of Technology, thinks he may have a solution -- an inexpensive way to clean up water -- according to a report by National Public Radio (NPR).

Works like plants filtering water

Karnik is a mechanical engineer who works on water technologies, and he has said that it is fairly easy to make membranes that are capable of filtering bacteria out of water. Making membranes that are affordable, however, is not so easy.

With that in mind, a few years ago he was attending a meeting on plants and water flow, when suddenly he had a thought: Why not use the xylem tissue in plants to filter water? Wouldn't that work?

Think back to your high school biology, says NPR. You may recall that xylem is the material in plants that transports water in the form of sap from the roots to the leaves. Oh, yeah.

"And the way the water is moved is by evaporation from the leaves," Karnik said, adding that it is kind of like what happens when you stick a straw into a glass of liquid; evaporation from leaves has the same effect as sucking on the straw does.

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Pulling water up to the leaves this way creates a problem for the plant, but also an opportunity for an inventor.

The plant's problem is something called cavitation, or the growth of air bubbles, which makes it harder for water to reach the leaves. But Karnik says xylem has a way of getting rid of these bubbles.

"The xylem has membranes with pores and other mechanisms by which bubbles are prevented from easily spreading and flowing in the xylem tissue," he said.

As it turns out, the report said, those same processes that are so effective at filtering out air bubbles are the perfect size for filtering out harmful bacteria as well.

To prove it, Karnik created a simple experiment in his lab. He peeled off some bark from a pine branch and then took the sapwood underneath, which contains the xylem, and put it in a tube. Then, he ran a stream of water containing tiny particles through the tube, demonstrating that the wood filter was able to remove them.

'Call me skeptical'

"We also flowed in bacteria and showed we could filter out bacteria using the xylem," he said, adding that he believes the xylem removed 99.9 percent of the bacteria.

His experiment was published recently in the scientific journal PLOS ONE.

The scientist said that wood makes such an attractive material for water filtration because it is inexpensive. With that in mind, he says he believes it is worth the effort to try to work out technical hurdles to making his system functionally larger.

Not everyone thinks Karnik is really onto something, however.

Robert Jackson, an environmental expert at Stanford University, told NPR that, as it is now, Karnik's system does not do a good enough job at filtering out bacteria.

And while filtering out the majority of nasty bacteria from contaminated water is certainly valuable, "when you can have hundreds of thousands, even millions, of them in a drop of water, you don't want to rely on something with 99 percent efficiency."

He added: "In a survival or short-term situation this could work. As a longer-term or global solution to the billion people on Earth without access to clean water, call me skeptical."



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