The problem of shortage of clean water in the countries of the "third" world is considered to be relevant today. Development of apparatus for water purification a lot, but for various reasons not used in practice. Another project, which, incidentally, has already passed the test, unusual water filter LifeStrаw from a Swiss company Vеstergaard Frаndsen.
Unusual this filter at least the fact that it can be carried on the neck. Use a mini-filter that has the form of a small tube attached to the cord, simple and convenient. You just need to Unscrew the caps on both sides of the tube, lower it into the water, and through it is already possible to drink.
For the short term until the person takes a SIP, the dirty water passes through 4 purification stages. In the first phase — rough clean water from metals, the second — removes mechanical impurities, the third — bacteriological cleaning in the fourth stage the water is purified from odors and other impurities, which can handle a carbon filter. Only after that the water gets into the human body.
The creators claim that their filter can destroy 99.9% of bacteria and 98.6% of viruses. Even bacteria that can cause cholera and typhoid are destroyed completely and the human body can get can't. Therefore, the filter called LifeStraw is a tube that saves lives. The authors of the idea claim that their development enables water to drink even from a muddy urban lakes or puddles after rain.