An anonymous reader writes: Scientists have developed what they're calling the "Drinkable Book," which contains pages that can be torn out and used to effectively filter drinking water. The book has just completed a series of field trials in a few African countries, and it successfully removed more than 99% of the bacteria in water taken from contaminated sources, bringing it in line with U.S. tap water. The book's pages are imprinted with nanoparticles of silver and copper, which sterilize a wide range of microorganisms. The lead researcher says each page can filter about 100 liters of water before needing to be discarded. The team currently makes all the pages by hand, so their next step will be to find a way to automate production.