Researchers in Sweden have discovered a new way to filter water off-grid using wood fibers. The team from KTH Royal Institute of Technology hope that it can provide clean water to people in refugee camps and in remote areas.

The researchers developed a new material using wood fibers and a positively-charged polymer that can bind bacteria to its surface, which removes the bacteria from the water, leaving it purified. The material could also be used in bandages to prevent infection, plasters and in packaging.

 

"Our aim is that we can provide the filter for a portable system that doesn't need electricity – just gravity – to run raw water through it," said Anna Ottenhall, a PhD student at KTH's School of Chemical Science and Engineering. "The great idea is that we are trapping the bacteria and removing them from the water by our positively-charged filter. The bacteria trapping material does not leach any toxic chemicals into the water, as many other on-site purification methods do."

The material works because the positively-charged polymer attracts bacteria and viruses which are negatively charged. The bacteria are then stuck to the surface and cannot break free or reproduce and they ultimately die. This technique means no chemicals or antibacterial agents are needed and it also doesn't produce any bacterial resistance.

After the wood filter has been used, it can then be safely burned.

This is just one of many wood fiber innovations. They've been tapped for use in eco-friendly batteries and solar cells as well. The natural material could mean cheaper and safer technologies in variety of applications.