Researchers at MIT have successfully tested a simple, tree branch-based water filter that might provide an inexpensive solution for clean drinking water in the developing world. According to the scientists behind the development of this low-tech filter, clean drinking water for everyone might now be only a tree branch away from reality.

 

The simple water filter requires only a fresh branch of white pine and some low-cost plastic tubing. The researchers tested the efficacy of this solution by running contaminated water through a sapwood branch. It was found that the plant tissue successfully filtered experimental dye and actual bacteria out of the mix. Rohit Karnik, a co-author of the MIT study, said that with the further development of these xylem-based filters, the solution could be comparable to other filtering methods.

 

The sapwood water filters are designed to harness the natural system of the plant tissue. When the water transits from the plant’s roots to its leaves, it goes through a meshwork xylem, a series of conduits and membranes with small pores that blocks bubbles from clogging the system. A detailed study of this natural mechanism revealed that most of the xylem pores are similar in size to the average pathogenic bacterium. Further experiments showed that freshly cut sapwood can actually filter bacteria out of water.

 

Inexpensive, disposable water filters could potentially bring clean water to hundreds of millions of people in the developing countries. Rick Andrew, global business development director of water systems at the National Sanitation Foundation (NSF) International, said that sapwood filters could provide a much needed low-cost and low-tech solution to water purification. He pointed out that one of the next steps in this development would be to test its efficacy in more real-world type of water supply situations.

 

MIT’s Karnik says that sapwood filter is still in its early stages of testing, and further research is required. The first demonstration has shown that xylem can be used for water filtration. This is, however, only the tip of the iceberg, says Karnik.