Chemistry researchers at McGill University, Canada, have developed a new and inexpensive way of filtering water using silver nanoparticles. Disasters such as floods, tsunamis and earthquakes often result in the spread of diseases like gastroenteritis, giardiasis and even cholera, due to the immediate lack of clean drinking water. The new method uses a cheap, portable, paper-based filter coated with silver nanoparticles that could be used in emergency settings. According to Derek Gray, a professor in the department of chemistry, “Silver has been used to clean water for a very long time. The Greeks and Romans kept their water in silver jugs,” but no one has used it to systematically clean water. “It’s because it seems too simple,” said Gray. The team coated thick, hand-sized sheets of absorbent, porous paper with silver nanoparticles and then poured live bacteria through it. Graduate student Theresa Dankovich observed: “Viewed in an electron microscope, the paper looks as though there are silver polka dots all over, and the neat thing is that the silver nanoparticles stay on the paper even when the contaminated water goes through.” The paper was able to kill nearly all the bacteria and produce water that meets the standards set by the United States Environmental Protection Agency. The filter is not designed to be a routine purification system, but as a way to provide rapid small-scale assistance in emergency settings. The article can be viewed online at the link below.
http://www.mcgill.ca/newsroom/news/item/?item_id=172013