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Water Filtration With a Tree Branch

Soulskill posted about 5 months ago | from the do-you-think-solutions-like-this-grow-on-trees dept.

Biotech 205

Taco Cowboy writes "Dirty water is a major cause of mortality in the developing world. 'The most common water-borne pathogens are bacteria (e.g. Escherichia coli, Salmonella typhi, Vibrio cholerae), viruses (e.g. adenoviruses, enteroviruses, hepatitis, rotavirus), and protozoa (e.g. giardia). These pathogens cause child mortality and also contribute to malnutrition and stunted growth of children.' People have been working on engineering cheaper and cheaper filtration systems for years, but now a group of researchers has found a promising and simple solution: a tree branch. 'Approximately 3 cm^3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person.' 'Before experimenting with contaminated water, the group used water mixed with red ink particles ranging from 70 to 500 nanometers in size. After all the liquid passed through, the researchers sliced the sapwood in half lengthwise, and observed that much of the red dye was contained within the very top layers of the wood, while the filtrate, or filtered water, was clear. This experiment showed that sapwood is naturally able to filter out particles bigger than about 70 nanometers.' The team tested E. coli-contaminated water, and the branch was able to filter out 99 percent of the bacterial cells."

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205 comments

Thanks DICE (-1, Troll)

fsck-beta (3539217) | about 5 months ago | (#46368657)

Thanks DICE

Re:Thanks DICE (-1)

Anonymous Coward | about 5 months ago | (#46368937)

Stop being such a SAP. You need to FILTER your emotions more so your not such a pansie. Be like the other 99% of people and move on.

First time? (3, Insightful)

DogDude (805747) | about 5 months ago | (#46368677)

If this is true, then this is a really profound discovery that could help millions of people.

What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?

Re:First time? (1)

Mr D from 63 (3395377) | about 5 months ago | (#46368717)

If this is true, then this is a really profound discovery that could help millions of people. What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?

Maybe because all of the other materials and equipment required to make it work.

Re:First time? (5, Funny)

Anonymous Coward | about 5 months ago | (#46368801)

If this is true, then this is a really profound discovery that could help millions of people.

What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?

Maybe because all of the other materials and equipment required to make it work.

You mean like some sort of cutting implement to cut down the branch?

I think the hatchet was invented at least 10 years ago?

Re:First time? (5, Insightful)

i kan reed (749298) | about 5 months ago | (#46368725)

Ideas can be publicized, studied in more detail, or put to good use, without being truly new.

Re:First time? (4, Interesting)

Em Adespoton (792954) | about 5 months ago | (#46368727)

24So the people grumbled at Moses, saying, "What shall we drink?" 25Then he cried out to the LORD, and the LORD showed him a tree; and he threw it into the waters, and the waters became sweet.

Re:First time? (5, Funny)

K. S. Kyosuke (729550) | about 5 months ago | (#46369019)

1) Someone mentions a new discovery.
2) Find a passage in the Bible containing the (rather common) keywords, without actually using your brain to check that the passage has identical informational value.
3) ???
4) Prophet!

Re:First time? (0, Insightful)

Anonymous Coward | about 5 months ago | (#46369307)

1) Someone posts a bible verse
2) Become overjoyed at discovery of opportunity for gratuitous atheistic hate
3) Recognize poster made no claim beyond interesting anecdote, assert he did anyway
4) Realize equivalent anecdote would prompt no reaction at all for you if it weren't associatable with a religion, Christianity in particular
5) ???
6) Get eliminated by natural selection, become irrelevant

Somebody Probably Thought of That (5, Insightful)

Anonymous Coward | about 5 months ago | (#46368789)

"Somebody probably thought of that" is more likely to be untrue than true. You probably are the first person to think of that. And even if you aren't you might be the first person to act on the idea. And even if you aren't you might be the first person to succeed where others have failed. And even if you aren't, you might learn something. So don't ever say that, "somebody probably thought of that."

Filtering water through wafers of wood is not obvious to me. I do engineering for a living. If you are wondering why no one ever discovered something before, go back to paragraph one and repeat.

Re:Somebody Probably Thought of That (5, Insightful)

K. S. Kyosuke (729550) | about 5 months ago | (#46369155)

It *is* obvious - after a fashion - since plants are generally doing just that; i.e., they use their root systems and cappilaries to absorb water including some impurities up to a certain size. The issue of "can we cut away a part of a plant tissue and filter water through it?" is probably more of a quantitative nature, rather than qualitative. As in, what is the filtering capacity? Does it clog? If it does, how often does it need to be changed? Does it rot? If so, how often does it need to be changed? The qualitative issues here seem to be "given that we're killing the plant, how does it affect the filtration process?" and "what preparation techniques can we employ to increase the practicality?". It's not that we don't have any filtration media, it's about how our knowledge and manufacturing processes make the individual filtration media more or less practical.

Tapping water from a tree a well known technique (1)

perpenso (1613749) | about 5 months ago | (#46369489)

Tapping water from a tree is a well known survival technique. Getting water from vines even more so.

I believe archaeologists have found ancient village sites with a pit filled with layers of sand, charcoal, wood and plant fibers (crushed material, pounded on rocks ?), etc. It was the village water purification system. Not exactly wafers but interestingly close.

So with respect to things that humanity has been doing for millions of years, getting clean water in this case, I tend to be a little more open to the idea that a technique is being rediscovered rather than discovered.

Re:First time? (5, Informative)

Em Adespoton (792954) | about 5 months ago | (#46368813)

If this is true, then this is a really profound discovery that could help millions of people.

What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?

Well, I learned this technique as part of my Aboriginal American studies when I was growing up -- I think it's more likely that our western culture has "lost" this knowledge than that nobody has discovered it before.

Re:First time? (1)

Anonymous Coward | about 5 months ago | (#46368951)

Also, knowing that water passes through a tree (Um... duh?) is different than knowing that it can be used as an actual filtration device... is different than knowing how sustainable and marketable it is.

Re:First time? (0)

Anonymous Coward | about 5 months ago | (#46368991)

Also it's pretty well known (I thought) that you can get drinking water from plants.

Re:First time? (1)

Ex-MislTech (557759) | about 5 months ago | (#46369181)

Maybe it was shunned in the pursuit of making money ? LOL

Re:First time? (1)

knarfling (735361) | about 5 months ago | (#46369063)

Probably because the wood has to remain damp in order to be effective. Once the wood dries, it loses the ability to filter well. Water runs through crack and the pores don't filter properly.

This is not something you could set up, let sit in storage for a few weeks, pull it out and expect it to be effective.

It looks like it would be most effective on a small but not personal level. With a small group you could filter enough water to keep the wood damp for a long time, replacing the "filter" as needed. Sounds great for villages in developing countries, but it doesn't look like it would scale very well.

Re:First time? (1)

Grishnakh (216268) | about 5 months ago | (#46369443)

Sounds great for villages in developing countries, but it doesn't look like it would scale very well.

Um, isn't that the whole idea here? I don't think anyone's thinking of using tree branch slices for commercial-quality water filtration in Western countries. No one's going to start selling tree branch slice filters for Samsung and GE refrigerators and Pur faucet adapters. The whole idea here is to come up with ultra-cheap, low-tech, but effective methods of improving quality of life and health and sanitation in very poor developing countries.

Re:First time? (2)

Ex-MislTech (557759) | about 5 months ago | (#46369075)

There are other methods like slow sand filter, bio sand filter, and solar disinfection.

https://en.wikipedia.org/wiki/... [wikipedia.org]

https://en.wikipedia.org/wiki/... [wikipedia.org]

https://en.wikipedia.org/wiki/... [wikipedia.org]

Thou with SODIS use glass if you can do to the endocrine disruptors BPA and BPS
being in most plastic bottles.

https://en.wikipedia.org/wiki/... [wikipedia.org]

Re:First time? (1)

drinkypoo (153816) | about 5 months ago | (#46369345)

Sadly, glass is less effective because of its tendency to block UV. You have to let the water get up to temp in a glass bottle. I bought a cute little doodad with some kind of phase change wax sealed in glass that changes color (sort of) when the water reaches an adequate temperature.

Re:First time? (1)

jdschulteis (689834) | about 5 months ago | (#46369399)

Thou with SODIS use glass if you can do to the endocrine disruptors BPA and BPS being in most plastic bottles.

The very Wikipedia article you linked to says to use PTE bottles, because some glass bottles will absorb the UV before it gets to the water, and that the leaching of material from plastic bottles into the water has been studied and found not to be of concern.

Re:First time? (4, Insightful)

hawguy (1600213) | about 5 months ago | (#46369077)

If this is true, then this is a really profound discovery that could help millions of people.

What I'm wondering, is why no other society, that we know of, has discovered this low-tech, yet seemingly incredibly useful thing previously?

For one thing, it doesn't filter viruses, so maybe it's already been evaluated and dicarded as a good solution. From TFA:

Karnik says sapwood likely can filter most types of bacteria, the smallest of which measure about 200 nanometers. However, the filter probably cannot trap most viruses, which are much smaller in size.

So it's of limited utility, since, as the summary says, common pathogens include viruses (e.g. adenoviruses, enteroviruses, hepatitis, rotavirus) -- for example, rotavirus is around 30nm in size, less than half the effective filtering size of the wood.

So the water will probably still need chemical or UV treatment after filtering.

Plus it's not clear how well it would work in the field, when the scientists built their filter:

They cut small sections of sapwood measuring about an inch long and half an inch wide, and mounted each in plastic tubing, sealed with epoxy and secured with clamps.

So while wood as a filter medium sounds attractive, if the user needs specialized equipment to get it to make a safe, water-tight seal, maybe it's not as useful in an area with limited resources.

Re:First time? (1)

Anonymous Coward | about 5 months ago | (#46369113)

Most-probable reason it's not widely known or used:

Trees aren't patentable.

Yet.

Lack of information (4, Informative)

Immerman (2627577) | about 5 months ago | (#46369415)

You can make a pretty decent biofilter simply by folding a piece of cotton cloth such as an old Indian sari a few times - it'll remove 99% of cholera and many other particularly nasty infectious agents. Yet people are still getting infected because they don't know about the simple solution - it's not a technology problem, it's a public information problem. And spreading public service announcements among a population where where most people don't even own a radio is a serious challenge. Doable, but expensive and there's no profit in it, so it usually falls to small humanitarian organizations that do their best to make the information go viral, and usually fail. Getting a meme to go viral is a lot more difficult when it can only spread through face-to-face interactions.

Most common pathogens (1)

oodaloop (1229816) | about 5 months ago | (#46368679)

The most common water-borne pathogens are bacteria ...,viruses ...,and protozoa

Well, that pretty much covers it I guess. I was surprised the kingdom animalia didn't make it on the list, but then hey, I'm no biologist.

In all seriousness, this is a very interesting discovery and I hope it leads to cheap and widely accessible drinking water.

Re:Most common pathogens (2, Insightful)

fustakrakich (1673220) | about 5 months ago | (#46368707)

...I hope it leads to cheap and widely accessible drinking water.

Coca Cola and Pepsi will do all they can to make sure that never happens. Water is big business. That is why access is so difficult.

Re:Most common pathogens (-1)

Anonymous Coward | about 5 months ago | (#46368895)

*tips fedora*

Re:Most common pathogens (0)

Anonymous Coward | about 5 months ago | (#46369339)

lol @ 15 litoshi tip

Re:Most common pathogens (1)

Ex-MislTech (557759) | about 5 months ago | (#46369195)

Access to the sky for water is free in most states though a few totalitarian
nut job states like Colorado make it illegal to collect water that falls on your roof....

Re:Most common pathogens (0)

Anonymous Coward | about 5 months ago | (#46369337)

So non-nut-job states should allow me to dam up a river that flows through my property? You might want to look up what effect water rights actually have...

Re:Most common pathogens (1)

Grishnakh (216268) | about 5 months ago | (#46369461)

There's a big difference between collecting rainwater on your roof and damming a stream or river. There's no valid reason to restrict the former, there's lots of good reasons to restrict the latter.

Re:Most common pathogens (1)

Pope (17780) | about 5 months ago | (#46369427)

So that it flows back down into the water supply and keeps downstream places hydrated.

Re: Most common pathogens (3, Insightful)

spune (715782) | about 5 months ago | (#46369029)

There already are low-cost, natural water filtration techniques being used across the world that produce clean water at a higher rate, like biosand filters. For water projects i have previously worked on, how quickly water is purified has been a significant practical concern for the folks who would benefit from the project. That was the reason that solar stills were dismissed, for example; they require more effort and materials to construct, but even then have a higher flow rate than the xylem filter. Also, how often the filter must be replaced is another big practicality issue.

Re:Most common pathogens (1)

gnick (1211984) | about 5 months ago | (#46369073)

We can never let that happen. As a member of PETP, I demand to know whether the trees were properly anesthetized prior to being bled alive, used without consent as subjects for scientific testing, and mutilated. If these trees were young, were their parents consulted? Color me outraged.

Re:Most common pathogens (4, Funny)

jpvlsmv (583001) | about 5 months ago | (#46369477)

Water-borne pathogens in the kingdom Animalia are usually called "predators" rather than "pathogens". But yes, pathogens such as A. Mississippiensis can be filtered from the water with an appropriately-sized tree branch.

Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46368685)

HA!

I always love it when somebody discovers a natural, free way to accomplish a goal that someone else wants to sell me a solution to.

Re:Take That, Capitalists! (5, Funny)

Flatwater (2169620) | about 5 months ago | (#46368721)

Filtering out "99%" of harmful bacteria may be like filtering out 99% of bullets fired at you....

Re:Take That, Capitalists! (5, Insightful)

CanHasDIY (1672858) | about 5 months ago | (#46368759)

Filtering out "99%" of harmful bacteria may be like filtering out 99% of bullets fired at you....

So, I take it you're not a fan of Lysol or Purell?

What a silly thing to say; as if not filtering 99% of something harmful is a better idea...

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46368843)

Bleach kills 99.9998% of all Bacteria its not just better its orders of magnitude better. 99.0% is interesting but not enough to stop a water born pathogen getting into you if it is a very low supply in the source.

Re:Take That, Capitalists! (2)

gnick (1211984) | about 5 months ago | (#46369095)

Maybe so, but do you blend bleach into all of your drinking water?

Re:Take That, Capitalists! (1)

Anonymous Coward | about 5 months ago | (#46369213)

I don't but my town water facility does. Fair chance yours does, too.

Re:Take That, Capitalists! (2)

CanHasDIY (1672858) | about 5 months ago | (#46369559)

Maybe so, but do you blend bleach into all of your drinking water?

What, you don't?

If hydrating doesn't result in debilitating stomach cramps, you're doing something wrong, bro.

Re:Take That, Capitalists! (1)

Immerman (2627577) | about 5 months ago | (#46369565)

Methinks you've got a few extra 9s in there, Chlorox only claims their bleach kills 99.9 percent of germs and bacteria, and that only adds ~3 generations to get back to 1% of the original population, compared to the ~7 needed to get from 1% back to 100%. And bacteria come by the millions, anything short of 100% effectiveness means you will be infected.

Fortunately, our bodies are not without their own defenses, and 99% buys you at least an extra day or two for your immune system to stumble upon an effective response before your health is compromised, and that's often enough. Would another extra day or two advantage from 99.99% filtration be even better? Surely, but at some point side-channels start becoming the primary route for infection anyway, so you get diminishing returns. *GASP* you didn't just wipe the sweat off your brow with a wet hand did you? You know some of the infectious payload is going to find a way through your mucous membranes. To say nothing of all the membranes exposed if you actually bathe in unfiltered water.

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46369183)

So, I take it you're not a fan of Lysol or Purell?

Correct [xkcd.com] .

But IANAB, so maybe the remaining 20,000 germs aren't as big of a deal as I think they are.

Re:Take That, Capitalists! (1)

Ex-MislTech (557759) | about 5 months ago | (#46369235)

In the case of Purell, its Triclosan that is an issue.

http://www.huffingtonpost.com/... [huffingtonpost.com]

Maybe they have removed it, maybe not.

https://en.wikipedia.org/wiki/... [wikipedia.org]

On its own its not the worst threat in the environment, but when you add it along with
others the combined threat is pretty bad and would explain the reduction of quality of
health compared to some other nations.

Re:Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46369527)

I think you missed the point - it's less about what's in Purell, and more about the whole "killing 99% of germs is better than not killing any of them" concept.

Re:Take That, Capitalists! (2)

alta (1263) | about 5 months ago | (#46368877)

Yes, it is. And I'd rather be hit by the one bullet than all 100 of them. I'd stand a much better chance of living.

Especially since there's a much better chance of your body's natural defenses defeating that 1%

Re:Take That, Capitalists! (1)

denzacar (181829) | about 5 months ago | (#46369255)

Bullets don't divide and multiply every 15-20 minutes while just sitting there in the air waiting to hit you.
Or in the case of bacteria, while swimming there in the water you're still slowly filtering.

However, this method is probably still useful for filtering out various other harmful particles found in water.
And if you got wood and tools to construct a filtering apparatus, you can probably boil that filtered water too.
Yeah, yeah, I know, they were testing this as a solution for people who can't afford burning all that fuel.

And then there is the option of leaving the filtered water inside a transparent container, sitting in direct sunlight for a while, which they apparently haven't tested.

Re:Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46369537)

And if you got wood and tools to construct a filtering apparatus, you can probably boil that filtered water too.

As TFA points out, the problem with boiling water is fuel consumption, whereas filtering through a cold tree branch requires no fuel whatsoever, other than the physical energy exerted by the tree branch user.

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46369199)

That's not how bacteria in the human body works. It is more like filtering out 99% of the sun's UV rays. Look it up.

Re:Take That, Capitalists! (2)

K. S. Kyosuke (729550) | about 5 months ago | (#46369205)

I'm pretty sure that law enforcement (in the US) and military (anywhere) would frenetically jump at the idea of body armor capable of reducing the probability of bullet injury by 99%.

99% is great! (1)

vladilinsky (1071536) | about 5 months ago | (#46369433)

I worked with an organization who did biosand filters in the Dominican republic and Haiti, they actually wanted there filters to leave a small amount of the bacteria because then it aloud the people who were using the filters to build up an resistance in case they ever drank water that was not filtered.

Re:Take That, Capitalists! (1)

Jason Levine (196982) | about 5 months ago | (#46369507)

No, but if you had 100 bullets coming at you and had the opportunity to hold a shield that would catch 99 of the bullets, would you really refuse holding it because it wouldn't catch 100% of the bullets? You don't stop the bullets by saying "don't come at me until I have a shield that will stop all the bullets."

Re:Take That, Capitalists! (1)

Hadlock (143607) | about 5 months ago | (#46369567)

Your immune system is virtually bullet proof under those circumstances

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46368783)

HA!

I always love it when somebody discovers a natural, free way to accomplish a goal that someone else wants to sell me a solution to.

You mean the system that brought you the keyboard, mouse, monitor, system, network, lights, desk, and chair that allowed you to post that drivel?

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46368907)

you..what?

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46368989)

A computer is a luxury. Fresh drinking water is a necessity. There is a huge difference.

Re:Take That, Capitalists! (4, Funny)

Rhacman (1528815) | about 5 months ago | (#46368791)

Take what? Take their money to the bank when their plastic funnels and tree-branch-filtration kits sell like hotcakes to the very folks hoping to, ahem, "stick" it to the man?

Re:Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46368875)

Well played, Rhacman.

Re:Take That, Capitalists! (1)

rgbscan (321794) | about 5 months ago | (#46369309)

There's already a company selling a variant of this.... using a coconut shell based filtration system working on the same principle. www.drinksoma.com

Re:Take That, Capitalists! (2)

Em Adespoton (792954) | about 5 months ago | (#46368799)

Well, it's not completely free -- someone likely owns those trees. And people living in desert regions of the world don't have easy access to sapwood -- nor do people in parts of the world where the sapwood is of the wrong consistency in local trees (hardwoods, for example).

Re:Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46368863)

Well, it's not completely free -- someone likely owns those trees. And people living in desert regions of the world don't have easy access to sapwood -- nor do people in parts of the world where the sapwood is of the wrong consistency in local trees (hardwoods, for example).

Yea, guess you've got me - I mean, it's not like a person can just, you know, stick a seed in the ground, tend to it properly, and bada-bing-bada-boom, a tree will grow, right?

Re:Take That, Capitalists! (1)

Anonymous Coward | about 5 months ago | (#46369087)

So you can get a filter in, say, 30 years? Lot of good that is going to do the family having to drink contaminated water tomorrow.

Also, I never realized it was as easy as stick a seed in the ground and watch it grow in the desert.

Re:Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46369515)

So you can get a filter in, say, 30 years? Lot of good that is going to do the family having to drink contaminated water tomorrow.

Perhaps they could barter for the wood they need. I don't know, but what I do know is "your idea isn't perfect, therefore it's a bad idea" is the thought process of a complete, abject moron.

Re: Take That, Capitalists! (1)

spune (715782) | about 5 months ago | (#46369097)

Most people need clean water on a regular basis and cannot accommodate waiting for a tree to grow to quench their thirst.

Re: Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46369481)

Most people need clean water on a regular basis and cannot accommodate waiting for a tree to grow to quench their thirst.

Where did I say it was a perfect solution? At least it's something more than "dur, you have to buy trees from someone."

Do you have anything relevant and useful to add, or did you just come here to whine that the solution I offered isn't perfect?

Re:Take That, Capitalists! (1)

gnick (1211984) | about 5 months ago | (#46369273)

...stick a seed in the ground...

Have you checked the price of tree-worthy ground lately? Or materials to provide nutrients and hydration to said ground? I started digging a nursery on Broadway, but the local traffickers got all bent out of shape. Do you have a cow? Because I have a pocket full of very young trees I'd like to trade you.

Re:Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46369505)

...stick a seed in the ground...

Have you checked the price of tree-worthy ground lately? Or materials to provide nutrients and hydration to said ground? I started digging a nursery on Broadway, but the local traffickers got all bent out of shape. Do you have a cow? Because I have a pocket full of very young trees I'd like to trade you.

Sorry, all full up on trees (half my state is a national forest, after all); although, if you have a few hundred feet of copper wire to spare, I'm sure we could work out some kind of barter.

Re:Take That, Capitalists! (0)

DaveV1.0 (203135) | about 5 months ago | (#46369375)

A) How long is the person supposed to go without water while the tree grows? Or should the person drink the dirty water and possibly die before the tree is grown
B) That assumes a tree of the right type will grow where the person is located. If the local climate is not conducive to trees growing, then the person will have a long wait.
C) Assumes that the person will have the time and energy to "tend it properly". If one is spending 12 hours a day just to survive, tending a tree may not be possible.
D) Assumes the person has access to enough land to grow a tree in the first place. There is not a lot of places to grow trees in favelas and urban slums in the second and third world.

If it is so quick and easy because "stick a seed in the ground, tend to it properly, and bada-bing-bada-boom, a tree will grow", please grow one and let us know how long it takes.

Re:Take That, Capitalists! (1)

CanHasDIY (1672858) | about 5 months ago | (#46369493)

A) How long is the person supposed to go without water while the tree grows? Or should the person drink the dirty water and possibly die before the tree is grown

B) That assumes a tree of the right type will grow where the person is located. If the local climate is not conducive to trees growing, then the person will have a long wait.

C) Assumes that the person will have the time and energy to "tend it properly". If one is spending 12 hours a day just to survive, tending a tree may not be possible.

D) Assumes the person has access to enough land to grow a tree in the first place. There is not a lot of places to grow trees in favelas and urban slums in the second and third world.

I don't see you coming up with any better ideas.

If it is so quick and easy because "stick a seed in the ground, tend to it properly, and bada-bing-bada-boom, a tree will grow", please grow one and let us know how long it takes.

Depends on the tree, obviously.

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46368899)

"Well, it's not completely free"

Of course it's not even a little bit free. Truth is it's not FREE at all.

Trees have a cost, water has a cost, a saw has a cost, your time has a cost.

Good grief, some people just don't seem to be able to think anything through.

And aside from all of that, what the hell does any of this have to do with capitalism anyway?

Re:Take That, Capitalists! (0)

DaveV1.0 (203135) | about 5 months ago | (#46369401)

Using the wood as a filter versus using it as firewood or building material has a cost.

Using the wood as a filter versus carving it into a useful shape or something that can be sold has a cost.

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46369495)

I'm not trying to be a jerk, but are you responding to me?

Because I don't know what you are responding to. You state that wood has a cost, which is true, hence we agree.

I can only guess you are responding to my last question, but you don't address it.

Just the fact of something having a non zero cost has nothing to do with capitalism. Capitalism is an economic system, a "cost" is just a property, the two aren't the same thing.

It's like saying electricity != a working television.

Re:Take That, Capitalists! (1)

tomhath (637240) | about 5 months ago | (#46368873)

somebody discovers a natural, free way to accomplish a goal

Really? Doesn't look all that free or natural to me:

1 inch-long sections were cut from a branch with approximately 1 cm diameter. The bark and cambium were peeled off, and the piece was mounted at the end of a tube and sealed with epoxy. The filters were flushed with 10 mL of deionized water before experiments. Care was taken to avoid drying of the filter.

Approximately 5 mL of deionized water or solution was placed in the tube. Pressure was supplied using a nitrogen tank with a pressure regulator. For filtration experiments, 5 psi (34.5 kPa) pressure was used.

Re:Take That, Capitalists! (1)

93 Escort Wagon (326346) | about 5 months ago | (#46368979)

I always love it when somebody discovers a natural, free way to accomplish a goal that someone else wants to sell me a solution to.

This filtration requires use of Monsanto's patented PureWood trees. Use of any other wood type for filtration will result in severe DMCA penalties.

Re:Take That, Capitalists! (1)

canadiannomad (1745008) | about 5 months ago | (#46369197)

This process is also patented, use of wood for filtration will require royalty payments or hefty penalties.

Re:Take That, Capitalists! (1)

DaveV1.0 (203135) | about 5 months ago | (#46369249)

Yeah! Now all these people in the developing world have to do is chop down even more trees. Deforestation, YAY!. Oh, wait....

Well, at least this will help people living in slums and favelas in places like Manila, Rio, etc. because sapwood is free, cheap, and highly available there. Oh.... wait...

Re:Take That, Capitalists! (0)

Anonymous Coward | about 5 months ago | (#46369465)

You make these flamebait comments and claim someone is mod stalking you, although the system seems to be working as intended. Why not post straightforward contributions of deductive reason without acting like a child? Just a rational thought in your sea of wild vitrol and strange persecution complex.

Time to watch Nausicaä again (3, Informative)

hort_wort (1401963) | about 5 months ago | (#46368697)

"It's so beautiful. It's hard to believe these spores could kill me."

Pour water through the branch? (1, Interesting)

alta (1263) | about 5 months ago | (#46368729)

Exactly how do you pour water THROUGH a branch? This sounds like the old boyscout prank of expecting someone to push a rope. Or maybe this is more like herding cats?

Re:Pour water through the branch? (0)

Anonymous Coward | about 5 months ago | (#46368821)

Chip it and put it at the bottom of a hopper. I would have thought a boyscout could have figured that out.

Re:Pour water through the branch? (1)

alta (1263) | about 5 months ago | (#46368849)

Is a hopper a funnel? I could see that working.
Or a bucket? I'm assuming this is only going to be gravity fed, branch isn't going to move it uphill.

Re:Pour water through the branch? (1)

srmalloy (263556) | about 5 months ago | (#46368845)

I would expect that you'd need something like a large pottery vase or jar with a tapered hole in the bottom. You cut the length of sapwood, wrap one end with a fiber cord until you can push it down into the hole and have it fit tightly with the branch sticking out the bottom (a rubber gasket would be better, but may not be readily available), then pour your 'raw' water into the vase and hang it over another container to catch the water that passes through the branch. A higher-tech solution would use some sort of pump to raise the pressure on the source side to push water through the branch faster, but that would require a greater investment of material; pottery and fiber cord should be products available in even subtechnological cultures.

Re:Pour water through the branch? (1)

tacet (1142479) | about 5 months ago | (#46369363)

you could use thousands year old technique of tourniquet to increase pressure in soft bottle ;-)

The article refers to an article with pictures (3, Informative)

ansak (80421) | about 5 months ago | (#46368855)

The article quoted above points to a paper [plosone.org] that has some diagrams that shows how water would go through a branch -- no hoax here.

In brief, find a stalk of sappy wood -- my Dad showed us every spring how to make a whistle out of alder branches that look what the picture shows -- peel it, whittle it to size and then plug it into the end of a tube and gravity feed water through it.

simple...ank

Re:Pour water through the branch? (2)

sdoca (1225022) | about 5 months ago | (#46368857)

If you'd RTFA, you'd know they put branch into a tube (fit tightly) and fed the water thru it that way.

Re:Pour water through the branch? (0)

Anonymous Coward | about 5 months ago | (#46368867)

I'm going to go out on a limb (ha!) and speculate that you are circlejerking about "pouring" water through a branch, rather than "filtering" water through a branch (ala gravity feed with filtration material at the bottom).

That said, I see no reference in the summary to "pouring water" through a branch. So you got your panties all bunched up over nothing.

Re:Pour water through the branch? (1)

Anonymous Coward | about 5 months ago | (#46368897)

It is referenced in the paper (5 PSI) being used, which can be applied by ~12 foot head of water. I would envision this being used by stripping the bark, and then clamping a line to it. Water then trickles through at a rate which the paper refers to as sufficient to supply a single persons daily drinking water.

This is not a rapid method. However, low cost and available materials will win out in remote and poor locations (which is where the highest need lies).

Re:Pour water through the branch? (1)

fisted (2295862) | about 5 months ago | (#46368913)

you do realize that passing water/nutrients through is the primary function of branches, right?

Re:Pour water through the branch? (1)

neo-mkrey (948389) | about 5 months ago | (#46369189)

Mythbusters recently proved that you can't herd cats.

Herding cats is easy ... (0)

Anonymous Coward | about 5 months ago | (#46369571)

Mythbusters recently proved that you can't herd cats.

Not really, there were limited to politically correct methods. Replace the umbrellas with flaming torches, the cats will move.

Wooden chopping boards. (5, Informative)

Jason Pollock (45537) | about 5 months ago | (#46368741)

Trees are great at dealing with bacteria.

We soon found that disease bacteria such as these were not recoverable from wooden surfaces in a short time after they were applied, unless very large numbers were used. New plastic surfaces allowed the bacteria to persist, but were easily cleaned and disinfected. However, wooden boards that had been used and had many knife cuts acted almost the same as new wood, whereas plastic surfaces that were knife-scarred were impossible to clean and disinfect manually, especially when food residues such as chicken fat were present.

http://faculty.vetmed.ucdavis.... [ucdavis.edu]

Re:Wooden chopping boards. (1)

swb (14022) | about 5 months ago | (#46369263)

That's why I let my dog lick my plastic cutting boards clean and then run them through the dishwasher with the "heat dry" and "sanitize" settings.

The dog licking is amazing. If I cut red meat on it and wash it in the dishwasher with the above settings, the board is still faintly stained. But when the dog is done, even before washing, there is NO staining.

So far, nobody here has gotten sick...

Re:Wooden chopping boards. (1)

Pope (17780) | about 5 months ago | (#46369437)

Try giving it a rinse with white vinegar first instead of letting the dog lick it.

Maybe not the first... (1)

Anonymous Coward | about 5 months ago | (#46368779)

http://en.wikipedia.org/wiki/Marah_(Bible)

Patent infringement claims in 3 ... 2 ... 1 ... (0)

Anonymous Coward | about 5 months ago | (#46369011)

from US water filtration corporations

It's " 99.9% of bacteria" not 99% (1)

PeterM from Berkeley (15510) | about 5 months ago | (#46369017)

Bacteria filtration is awesome for the wood filters.
Also, one has to be very careful not to let the wood dry out, because drying out damages the ability of the wood to pull water through, and if dried wood DOES let water through, it isn't filtered.

--PM

Is this really (1)

CheezburgerBrown . (3417019) | about 5 months ago | (#46369163)

Is this really as simple as a stick with a funnel on top? How quickly does this process happen? How big of a stick do i need and how fast do they grow?

Survivorman (0)

Anonymous Coward | about 5 months ago | (#46369429)

Showed this in his Costa Rica jungle episode.

Cool but my money is on UV + TiO2 (0)

Anonymous Coward | about 5 months ago | (#46369569)

I believe water purification via ultraviolet light (sunlight) using a titanium dioxide (cheap and safe) coating is the way to go simply because there is no consumable. In a nutshell when bombarded with UV light TiO2 kicks off 0H radicals that deactivate the in DNA of any nearby (~1cm) microorganism.

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