If I could invest in one company right now it would be Vestergaard Frandsen. The company have developed a water-purification straw, the “lifestraw”. It seems too good to be true, it’s cheap and will cover the annual water consumption of one person.
The company is nominated for some award at index. they give some details.
Short description of design:
The LifeStraw is a 25 cm long straw/pipe filter, 29 mm wide diameter in plastic.
Functionallity and use of design:
When water is sucked up it is met by ever finer textile filters in order to filter out dirt and sediments, as well as clusters of bacteria.In the centre of the pipe several medias, including iodine, will kill and withhold remaining bacteria, viruses and parasites, as well as improve the taste of the water.
The main goal, to kill bacteria, is done up to log 7 – log 8, according to laboratory tests. Better than municipal tap water in many developed countries.
Drawbacks of life improvement:
If we were not able to control the output of iodine there could have been a draw back there, but with the existing iodine deficiency in most 3rd world communities, WHO would have appreciated if we had had a higher release of iodine. We have, however, chosen to put in so much granulated active carbon, that no consumer shall discard the filter due to chemical taste.
Research and need:
Being a textile company we tried originally for many years to reach this design only by using textiles, but eventually we realised that textiles could only be part of the solution and that additional media, especially killing media had to be applied. For about a year we also tried to combine textiles with only carbon, but realised then, that bacteria and viruses were building up in the carbon. Only when combining it with the iodine did we realise we were on the right track. Then a lot of time was spent searching globally for the best of the various products we needed, and when they were at hand, a long and tedious way had to be followed to find the right position, quantity and size of each component.
found on IFTF
