Dr. Theresa Dankovich and her colleagues have developed an inexpensive water filter system – think of your standard drip coffee maker – where the paper is impregnated with silver nanoparticles that decontaminate the water passing through. These filter have potentially huge potential to address the needs of the ~660 million people around the world who lack access to safe drinking water.
https://www.youtube.com/watch?v=VXfZlThPEg0