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"Lifesaver Bottle" Filters Viruses Out of Water
gihan_ripper writes "British inventor Michael Pritchard has developed a small self-contained filter system that instantly cleans water, removing all particles larger than 15nm. He said that he was inspired after seeing the effects of Hurricane Katrina and the Boxing Day tsunami in 2004; people had to wait for many days to get fresh water and many died from drinking contaminated water. The filter is so effective that it can purify dirty river water and even fecal matter. His bottle will shortly be available for sale from Lifesaver Systems at an expected cost of £190 (approx. $385)."
Sounds great, but what are the odds that the average citizens in Ache or any of the other poor areas affected by the tsunami could afford the bottle.
On the other hand, it sounds great for places like in Tokyo where you'll need a water cleaning kit for the big one. People will still have plenty of access to water in the form of Tokyo Bay and the rivers, but nothing clean enough to normally drink. It would have to be better than the current stratergy of leaving filled bottles of water outside houses and in local parks.
Tea and kung-fu. Life is good. Rising Phoenix
I've been using the First Need Deluxe water purifier for 10 years. It costs ~$100 for the whole thing, ~$40 for a replacement cartridge. It deals with virii and has been around forever. Sure, each cartridge is only good for about ~100 gallons, but I'm skeptical of the claims that this bottle can do 10 times that without changing the filter.
It's been possible to buy similar "virus level" filters for hiking since at least the 80s. The typical problems are cleaning, and clogging. See Katadyn or your local REI for a variety of samples. Then there's the "$2" (really about $7) LifeStraw, that was advertised on gizmodo 2 years ago... is this just a running theme?
If the filter is small enough to block viruses, then it is so small that even very small 1u particles will clog it. The whole filter system has to be optimized... and they still clog. They claim 1000 liters, but I'm not really buying it. If it really has something to do with distilling, then I'd be more positive, but that's usually pretty darn complex.
Perhaps he's using a teflon reverse osmosis filter? At the price, it's certainly possible. Those take significant pressure, but they would take out viruses. The water has to start pretty clean too or they develop a film which clogs them too. People have tried iodine on them as well... it works for a while. Whithout knowing what this thing is (and the website's no help), I don't think we can really talk coherently about it.
If it is just a filter you can reverse flush and clean and do a variety of other things, but if your filter clogs after a few liters you'll be _very_ unhappy. This is made more difficult by the fact that you're trying to clean out biologicals, which will happily grow in the filter so it clogs up even quicker, and the cleaning is even more important and difficult to do completely. That's why people make throw aways or just add a halogen (chlorene/iodine) to a tub of relatively filtered water (so things can diffuse) and wait an hour.
Most hikers (who bother) use a more coarse filter (for bacteria only). Often these are treated with iodine as well, and perhaps charcoal to remove bad tastes. These keep clogging problems down, and make cleaning somewhat more easy. That's what the LifeStraw is based on.
I hope this is really an advancement, but it has the smell of an ad.
So there is a 15nm filter that can get even viruses and bacteria out of water?
How about using it for home use, recycling "Grey water waste" and rainwater into drinking water. £400 a pop seems more impressive when considered that way. Assuming the filters can be made economically enough there is a huge potential market there.
I like the idea of anything that reduces our dependence on piped convenience.
I lived in South Florida for 27 years. I'm one of the first people who says "It's just another hurricane." When I saw the predictions for Katrina, even I thought anyone sticking around was stupid.
I looked at the Katadyn device and I always wonder why people slap on the Swiss flag. Is that supposed to mean Swiss use it? Heck I am sitting here in Switzerland and have hiked quite a bit through the mountains. Never seen the device. Want to know what people do? They drink the water fresh from the creek, or from one of the fountains that you find scattered throughout the mountains.
"You can't make a race horse of a pig"
"No," said Samuel, "but you can make very fast pig"
Drinking pee is harder than you think. I speak from personal experience.
I was lost in the Ozark mountains for 2 days without any supplies. The temperature was over 100F and I had almost no water. The little water I did have was exhausted quickly and the next best alternative was my own pee. I became thirsty enough that drinking my own pee was not even a question - it was a necessity (or so I thought).
I removed my flashlight batteries and peed in my flashlight because it was the only thing I had that could hold liquid.
Guess what happens to your pee when you are dehydrated? It's get much more concentrated. So much so, that I think you'll have a hard time drinking it unless you are, literally, getting close to death. Mine was so strong, I couldn't even stomach the smell much less, drink it. I have never been as thirsty in my life as that day and I have never since, been in a situation as dire as that one. Yet, I couldn't drink it.
While it may be an option early on, as dehydration starts setting in, drinking your own pee becomes less of an option as each hour passes by.
Besides, its correct plural in Latin -- if ever used -- would have been "vira" or "virus" (long u), but never virii.
I am a hiker, I use an MSR pump filter.
The MSR pump allows you to exert a fair bit of force and you will get tired pumping a single liter.
The MSR has a coarser (more open filter).
The MSR will start to clog withing tens of liters of what looks like fairly clean water. You then need to clean the filter.
The MSR is actually one of the better filters on the market.
Now how can a filter that is supposedly much tighter, be easier to pump (squeeze bottle) and last for thousands of liters of brackish water with no cleaning requirements mentioned.
I also noticed no technical info when I clicked it on the web page.
Personally I would stay far away until there was independent lab reviews and field testing, because this really doesn't add up.
Of course, with such a fine porosity, I wonder how well the filter actually works in practice. Having had a lot of experience doing field maintenance on an MSR filter (I've hiked roughly 4000 miles with this one so far), I can say that even around 200nm, the filter needs regular cleaning. Cleaning becomes harder and is required more regularly as your filter gets finer (often referred to as the "tightness" of the filter).
My BuonVino wine filter, which I once [idiotically] ran beer through, clogged in a matter of seconds, thus drenching me and my kitchen in about a quart of beer before I could turn it off. See, wine yeast tends to be highly flocculant-- it clumps together and drops out-- which means that there isn't a whole lot of filtering to be done to make it "bright". Beer, on the other hand, contains yeast of a lower flocculence, and so my filter clogged immediately. And filters that fine can't be reused-- you have to throw them away. This is why big beer manufacturers (like Budweiser) tend to invest a far amount of money in making sure that they have a lot of filter material available (they often use diatomaceous earth).
Ah... I recall now why I lurk and don't post.
.4 microns absolute. So no, it doesn't compare to this bottle's claimed 15 nm. And while I'm sure this new filter is great and all, the First Need one has passed tests showing its ability to filter out viruses (forgive my sarcastic use of virii above). If I may, allow me to quote from the manufacturer's site:
Yes. I read the article. First Need's site claims it filters to
Three series of tests were conducted by the independent laboratory at the University of Arizona to document removal of microbiological contaminants according to current EPA Guide Standard and Protocol for Testing Microbiological Water Purifiers.
The purifiers were operated for 100% of their rated capacity and challenged periodically with high concentrations of bacteria, cysts and virus. At the 60% and 75% test points the units were challenged with "worst case" water according to protocol. Additionally, the systems were allowed to stagnate for 48 hours after the 50%, 75% and 100% test points to demonstrate that no microbiological growth through the cartridge occurred.
(chart)
Conclusion: General Ecology Inc.'s Seagull IV, Nature Pure and First Need water purifiers met the EPA Guide Standard as Microbiological Purifiers by removing bacteria, cysts and virus without the use of chemical additives or multiple processing.
http://www.generalecology.com/techmemocert.htm
I'm by no means an expert on such matters, just trying to be helpful. I've happily used my First Need all over Asia for drinking water in an effort to cut down on the waste from buying plastic bottles, and have yet to get sick.