Bug-killing book pages clean murky drinking water

By Jonathan Webb

Science reporter, BBC News, Boston

• 16 August 2015
 
• From the sectionScience & Environment

The next stage is to test the books in larger trials where they are used by local residents

A book with pages that can be torn out to filter drinking water has proved effective in its first field trials.
The "drinkable book" combines treated paper with printed information on how and why water should be filtered.
Its pages contain nanoparticles of silver or copper, which kill bacteria in the water as it passes through.
In trials at 25 contaminated water sources in South Africa, Ghana and Bangladesh, the paper successfully removed more than 99% of bacteria.
The resulting levels of contamination are similar to US tap water, the researchers say. Tiny amounts of silver or copper also leached into the water, but these were well below safety limits.
The results were presented at the 250th national meeting of the American Chemical Society in Boston, US.
Dr Teri Dankovich, a postdoctoral researcher at Carnegie Mellon University in Pittsburgh, developed and tested the technology for the book over several years, working at McGill University in Canada and then at the University of Virginia.
"It's directed towards communities in developing countries," Dr Dankovich said, noting that 663 million people around the world do not have access to clean drinking water.
"All you need to do is tear out a paper, put it in a simple filter holder and pour water into it from rivers, streams, wells etc and out comes clean water - and dead bacteria as well," she told BBC news.
The bugs absorb silver or copper ions - depending on the nanoparticles used - as they percolate through the page.
"Ions come off the surface of the nanoparticles, and those are absorbed by the microbes," Dr Dankovich explained.
According to her tests, one page can clean up to 100 litres of water. A book could filter one person's water supply for four years............

Seems too good to be true.