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Researchers Develop "Tea Bag" Water Filter
cybernanga writes "A group of researchers in South Africa has developed a filter that can purify water straight from the bottle. The filter sits inside a tube fitted on top of a bottle and purifies water as it is poured on a cup. From the article: 'The designer behind the filter, Dr Eugene Cloete, from the Stellenbosch University in South Africa, says the filter is only as big as an ordinary tea bag. He says the product is cost-effective and easy to use. "We are coming in here at the fraction of the cost of anything else that is currently on the market," says Dr Cloete on BBC World Service.'"
Molecular paper thin water filters.
"We cover the tea bag material with nano-structured fibres, and instead of tea inside the tea bag, we incorporate activated carbon.
"The function of the activated carbon is to remove most of the dangerous chemicals that you would find in water."
1. It would have to be one shot - I don't see that little bag filtering more than one bottle.Wouldn't that little bit of carbon be exhausted after 500ml?
2. The pour rate would have to be really slow so that the water stays in contact with the carbon long enough to absorb the toxic stuff. Five minutes+ for a cup of water??
3. It doesn't say anything about metals.
RIP America
July 4, 1776 - September 11, 2001
and does not make inappropriate sexual comments about Tea Partygoers.
I thought Teabaggers were all for restoring the rights given by the constitution, regardless as to whether what's being said doesn't agree with their worldview?
Oh, sorry, I got caught up in theory and rhetoric.
The charcoal filter would be good to use *after* you sanitized the water with chlorine bleach. Kill off the biologicals and then get rid of the chlorine taste.
Leave the bottle in the sun for six hours to kill them (use a transparent PET bottle).
No sig today...
Yes but that solution doesn't remove any contaminants in the water; it only kills microbes.
Well, there's spam egg sausage and spam, that's not got much spam in it.
Yes but that solution doesn't remove any contaminants in the water; it only kills microbes.
The bleach will also break apart many kinds of contaminants, it won't remove heavy metals and whatnot, but I think bleach can break poisons.
You can't take the sky from me...
I suppose the only problems would be the fuel (wood and other biofuel consumption would suddenly take a hike), training (operating the still), and maintenance (cleaning the crud out).
Materials, portability, scalability, possibility of being used by small children, safety of use, etc.
They're looking for something they can airdrop on refugees.
You can't take the sky from me...
Better article says:
The inside of the tea bag material is coated with a thin film of biocides encapsulated within minute nanofibres, which kills all disease-causing microbes.
The bag is filled not with tea leaves but with active carbon granules that remove all harmful chemicals, for instance endocrine disruptors.
Each "tea bag" filter can clean one litre of the most polluted water to the point where it is 100% safe to drink.
Once used, the bag is thrown away, and a new one is inserted into the bottle neck.
Sounds good, but doesn't remove fine particulates or heavy metals, so you have to prefilter and chose your water source wisely (check arsenic contamination maps....)
Be very careful with the clorox method. The clorox product line is quite different today and you probably do not want to use the versions with stain removers and other additives for water purification. From the clorox website:
... Only Clorox Regular-Bleach, of all the bleaches mentioned on this website, is approved for sanitization and disinfection. ..."
"Disinfection of Drinking Water (Potable)
Also, does this approach work from bacteria to virus to cryptosporidium? My understanding is that the old school iodine tablets don't work on the later and that the military and NGOs have moved to chlorine dioxide based tablets. Much better tasting too. The caveat is that it takes something like 4 hours to kill the crypto compared to something like 15 to 30 minutes for the lesser "bugs". Being chlorine based maybe clorox could work with crypto but they don't seem to offer concentration or time guidelines. Perhaps they are just addressing North American concerns, maybe their sites for other parts of the world offer advice?
Answering my own question:
"Results of the present study show for the first time that C. parvum oocysts exposed to undiluted laundry bleach for as long as 120 min are infectious for animals. Although bleach is widely used as a bacterial and viral disinfectant, the present findings indicate that under practical conditions it is not an effective disinfectant for C. parvum oocysts."
http://aem.asm.org/cgi/reprint/61/2/844.pdf
It gets rid of those liberal microbes.
Hail Eris, full of mischief...
E pluribus sanguinem
Not only is there the dubious claim that this will make water safe, and the implication that it is somehow different from other activated charcoal filters already made, but they stress how cheap or affordable it is, without ever giving any indication of a price. When someone tells you that something is inexpensive but doesn't want to tell you how much it will cost in any quantity, it will not be inexpensive.
I'm an American. I love this country and the freedoms that we used to have.
no no no. this one has a different cap.
The Brita pitchers are only intended to improve the taste of tap water by taking out chlorine and calcium, not to actually purify unsafe water.
There are NO similarities though between Seventh Day Adventists and Jehovah's Witness's.
They both worship the god of Abraham.
Inexpensive filter straws have been around for years. I don't see how this is that much better. There was nothing in the article about price or effectiveness of the filter itself. All we have is the designer's opinion, and of course he's naturally going to praise his own invention.