Bug-killing book pages clean murky drinking water

A book with pages that can be torn out to filter drinking water has proved effective in its first field trials. In tests conducted at 25 contaminated water sources in South Africa, Ghana and Bangladesh, the paper successfully removed more than 99% bacteria.

Unsafe drinking water

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. The bugs absorb silver or copper ions - depending on the nanoparticles used - as they percolate through the page.

Woman washing clothes in a river in Bangladesh

The resulting levels of contamination of the filtered water are similar to US tap water. Tiny amounts of silver or copper also leached into the water, but these were well below safety limits.

One page can clean up to 100 litres of water, and a book could filter one person's water supply for four years.

Communal tap for drinking water in South Africa

Dr Teri Dankovich developed and tested the technology for the book over several years. Noting that 663 million people around the world do not have access to clean drinking water, she explained,

"It's directed towards communities in developing countries. 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."

Water pollution in India

There is more work to do though. Dr Dankovich is hoping to step up production of the paper, which is currently make by hand, and move on to trials in which local residents use the filters themselves. Researchers and environmentalists agree that while the paper appears to kill bacteria successfully, it would be especially powerful if it could also tackle non-bacterial infections and other disease-causing micro-organisms.

Click here to read about another water-filtration invention.

(All images - credit: Wikimedia Commons under Creative Commons licence)