Engineering Question #1609

Beth Conrad, a 12 year old female from Hong Kong asks on October 7, 2003,

How can I build a water purifier?

viewed 16664 times

The answer

Barry Shell answered on October 8, 2003

A quick search of the Internet turned up a number of possibilities. In developing countries around the world people are making ceramic water purifiers. These take a bit of work, but they are very cheap, costing less than one dollar to make. Details on how to make one at home are available here.

A standard way of purifying water is to distill it. You boil it, then condense the steam and collect the water. A simple distillation aparatus can be made with a kettle and a coil or column of tubing. A typical setup can be seen at Journey To Forever, based on a design first published in Mother Earth News.

A cheap way to distill water uses the sun's energy to evaporate the water which condenses on a sheet of glass. An explanation of this method can be found at the Safe Drinking Water Foundation. Plans for such a still can be found at Variations of all these ways, such as making a still from a black paper cup and a plastic bag, are all possible and are left to your imagination.

Add to or comment on this answer using the form below.

Note: All submissions are moderated prior to posting.

If you found this answer useful, please consider making a small donation to