The Drinkable Book™ is both a water filter and an instruction manual for how and why to clean drinking water.  This filter is patent pending technology and works to produce clean drinking water by pouring dirty water through a thick, sturdy sheet of paper embedded with silver nanoparticles, which are lethal for microbes.

Testing highly contaminated samples, for example, from an irrigation ditch where raw sewage had been dumped, the filter resulted in water that was 99.9 percent pure.

More details here.