Plants act as low-cost water filter

Using plants to filter water may allow more people to access healthy drinking water.

Mechanical engineer Rohit Karnik came up with an idea to overcome the cost of complex filtration devices. A plant’s xylem, which transports water from the roots to the leaves, mimics a filter, and the small pores in xylem are just the right size to remove harmful bacteria.

Testing the system with a pine branch, Karnik estimated 99.9% of the water’s bacteria was removed.