One of the key components of living off-the-grid is an effective method of water filtration, and a team of researchers at the Swedish KTH Royal Institute of Technology has uncovered a simple and affordable way of doing that. They have developed a technique to filter water using wood fibers.

The main aim of this project is to provide clean water in refugee camps, though the method could easily be used in any setting where a green and off-grid water filtration is needed.

The team created a new material out of wood fibers and a positively-charged polymer, which binds bacteria to its surface. In this way, the bacteria in the water are removed and the water is purified. Another use for this new material is also prevention of infection, since it can be used in bandages and plasters.

However, the main aim of this project is providing an affordable and easy to use filter for a portable water purification system, which isn’t reliant on electricity. All that’s needed for it to do its job is gravity, which forces the water through it. The bacteria is removed from the water by the material, while the filter itself doesn’t cause any toxic chemicals to enter the water as is the case with many currently used on-site water filtration options.

The filter they created works on the basis of the positively-charged polymer attracting the negatively charged bacteria and viruses in the water. The bacteria which are stuck to the surface of the polymer in this way cannot get unstuck or reproduce, and they eventually die. No chemicals or antibacterial agents are used in this process, which also means that creating bacterial resistance is not an issue.

Disposal is also easy, since the wood filter can simply be burned once it is no longer effective.