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Researchers Develop "Tea Bag" Water Filter 119

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.'"
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Researchers Develop "Tea Bag" Water Filter

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  • Re:Viruses.. (Score:3, Informative)

    by Joce640k ( 829181 ) on Sunday September 05, 2010 @11:08AM (#33481442) Homepage

    Leave the bottle in the sun for six hours to kill them (use a transparent PET bottle).

  • by UnknowingFool ( 672806 ) on Sunday September 05, 2010 @11:13AM (#33481472)
    Yes but that solution doesn't remove any contaminants in the water; it only kills microbes.
  • by Anonymous Coward on Sunday September 05, 2010 @12:09PM (#33481722)

    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....)

  • by perpenso ( 1613749 ) on Sunday September 05, 2010 @12:11PM (#33481734)
    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:
    "Disinfection of Drinking Water (Potable)
    ... Only Clorox Regular-Bleach, of all the bleaches mentioned on this website, is approved for sanitization and disinfection. ..."

    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?
  • by perpenso ( 1613749 ) on Sunday September 05, 2010 @12:16PM (#33481762)
    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." []
  • by tuxgeek ( 872962 ) on Sunday September 05, 2010 @12:36PM (#33481878)

    I thought Teabaggers were all for restoring the rights given by the constitution

    Wrong! Teabaggers are just another radical religeo/political movement that uses misinformation and outright lies to influence an ignorant public and gain members and momentum.

    Recall the recent Beck rally on the steps of the Lincoln memorial.
    WARNING SIGN: Beck states "religion and christianity have returned to America"
    Same old christian coalition bullshit, different wrapper: "Separation of church and state is a luxury we can no longer afford"

    "Separation of church and state" was put into our Constitution for a very good reason.
    The teabaggers, Beck, and Palin out to give the illusion that their actions and motivations are faith based. The reality is that they are merely whores, willing to say and do anything for a buck, or the highest bidder, in the case of Beck and Palin

    Disclaimer: I view all politicians and politics with ire and hate them all universally. Politics today is nothing short of organized crime.

  • Re:Wow! (Score:3, Informative)

    by gmor ( 769112 ) on Sunday September 05, 2010 @01:18PM (#33482054)
    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.
  • by aliquis ( 678370 ) <> on Sunday September 05, 2010 @01:40PM (#33482158) Homepage []

    Clear and lukewarm: 2 drops 4-6% / liter of water.
    Murky or cold: 4 drops 4-6% / liter of water.

    Shake and wait for at least 30 minutes.

  • by Anonymous Coward on Sunday September 05, 2010 @01:43PM (#33482170)

    There are NO similarities though between Seventh Day Adventists and Jehovah's Witness's.

    They both worship the god of Abraham.

  • Re:Say it with me. (Score:5, Informative)

    by sjames ( 1099 ) on Sunday September 05, 2010 @03:28PM (#33482704) Homepage Journal

    With those prices and 3rd world exchange rates, they'll never develop their economies! They'd be in perpetual debt for water bottles.

    Even Britta costs a fraction of that, and, of course, chlorine bleach (as a pre-treatment to kill bacteria)is dirt cheap.

    Meanwhile, a solar still can be made with a bucket, a plastic sheet, and some manual labor. Unlike a filter, it will continue to produce clean safe water year after year with no expendable. The construction technique is simple enough that adult supervised children can do it (and learn a science lesson in the process with an immediate application).

    The developed world seems to have a bias against such solutions that don't make the 3rd world dependent on a continuous stream of "manna from heaven" in the form of manufactured goods. Part of that seems to be a bit of Marie Antoinette syndrome (just can't imagine a place where such cheap ubiquitous materials are expensive and rare). Part is that people imagine that accountant run businesses will lay off their drive for profit just a bit for the sake of humanitarian aid (they won't). Perhaps part because they might then start growing their own economy rather than becoming dirt cheap labor for our clothing industry.

    Meanwhile, much of the problem will stop when the developed world kindly stops selling greedy warlords automatic weapons and all the ammo they can carry.

  • What else is new? (Score:3, Informative)

    by reboot246 ( 623534 ) on Sunday September 05, 2010 @05:10PM (#33483418) Homepage
    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.

Someday your prints will come. -- Kodak