I really hope this pans out. The fact that the powder can be reclaimed and re-used is pretty awesome.

The last time my eye was caught by a low-tech purification system, it was when an engineer in Tibet or Nepal figured out a way to use the reflective interior of oxygen bottles discarded by mountain climbers and sunlight. They set up a runnel system that used UV exposure, it took several hours but it was very clever and required very little work or purchased material.