Xylem is a thin material that makes up the interiors of non-flowering trees. This straw-like conduit material draws water up from the ground to nourish trees and is interconnected with membranes that filter out sap and bubbles from the water. Researchers from the Massachusetts Institute of Technology are looking at this natural material as a potential water filtration tool for remote or underdeveloped areas.
The researchers took samples of xylem from sapwood branches and fitted them into wooden disks that are capable of filtering out bacteria and viruses. In lab settings, the material successfully removed E. coli and rotavirus from water samples.
To test the technology in real-world applications, the researchers distributed the filters to residents in India who used them to disinfect their water and reported that the filters yielded a liter of fresh drinking water every hour.
The technology behind the filters is relatively simple, which is what makes them so perfect for meeting the emergency filtration needs of communities without fresh drinking water. The researchers have now launched an open-source website with information on how to fabricate xylem filters from various tree types. They hope the site will enable entrepreneurs and aid organizations to develop the filters for broader use in areas in need.