Guide to Building a Plant Xylem Water Filter

Rohit Karnik and his team at the Massachusetts Institute of Technology have developed a filter that creates safe drinking water using plant xylem, according to Technology Review.

Karnik and his colleagues capitalised on the research of plant xylem previously undertaken by biologists. In their studies of plant xylem, biologists measured the rate at which water is transported from plant roots to leaves.

As it is a porous tissue able to conduct fluid in plants, xylem allows for water to pass through conduits via holes called pits. The pits are covered in a membrane with nanoscale-sized pores which serve as a sieve.

To test his theory, Karnik used sections from the branches of white pine trees and found that the water filtered through the sections at 0.05 millilitres per second or a flow rate in excess of four litres per day.

It was discovered that the filtered water was clear and the scientists concluded that the xylem filter is able to effectively reject particles with diameters larger than 100 nanometres.

However, some limitations were also noted. The 100 nanometre limit is too large for the filtration of viruses and it is possible that plants with smaller pits could perform the same function.