Pure water is always a need for everybody!

It´s quite possible to purify water through muscular power and bikes.

The first project is AQuaduct 4

Prurification bike aquaduct4

More info here: https://www.ideo.com/work/aquaduct

Another successful project is Cycloclean:

cycloclean-water-purifying-bike

http://www.nipponbasic.ecnet.jp/e-cc.html

And also a pedal power used on  water filtering

water-bike

More info here: http://www.worldwidewater.biz/pedal-powered-water-bike/