Search Here

Researchers at MIT have demonstrated a water filter made out of a small piece of sapwood from a white pine tree which can get rid of 99 percent of the bacteria from the contaminated water. 

The setup can produce four liters of clean, portable water every day. 

The discovery is being seen as an affordable solution to the contaminated water supply where filters are luxury to majority of population. 

Explaining the method, scientists said the small pores of a sapwood branch or section of trunk which is a tissue naturally designed to transport sap throughout the tree, worked to trap and block majority of bacteria as water was passed through it.

"Today's filtration membranes have nanoscale pores that are not something you can manufacture in a garage very easily," explained Rohit Karnik, co-author of the new study and associate professor of mechanical engineering at MIT in the press release. "The idea here is that we don't need to fabricate a membrane, because it's easily available. You can just take a piece of wood and make a filter out of it."

Researchers also noted that the technology is not perfect as sapwood was only able to filter out particles 70 nanometers and larger. The method works aptly for majority of bacteria and most of them rare no smaller than 200 nanometers. Viruses on the contrary are much, much smaller and will bypass the wood filter.

"There's huge variation between plants," Karnik added. "There could be much better plants out there that are suitable for this process. Ideally, a filter would be a thin slice of wood you could use for a few days, then throw it away and replace at almost no cost. It's orders of magnitude cheaper than the high-end membranes on the market today."

The details of the discovery is published in the Plos One.