STATE COLLEGE, Pa., May 5 (UPI) -- Pennsylvania State University horticulturists say they've discovered plant roots can, to a limited degree, purify dirty washing machine water.
Associate Professor Robert Berghage and doctoral student Robert Cameron said plant roots enmeshed in layers of discarded materials inside upright pipes can make such gray water suitable for growing vegetables and flushing toilets.
"Our global fresh water supplies are fast depleting," Cameron said. "So it is critical that we begin to look at alternatives on how we can take wastewater and turn it into a resource."
The researchers said they used discarded materials and a combination of plant and bacterial communities to treat washing machine discharges and other wastewater. They said their design is superior to previous living treatment systems in that it requires much less space and is much more efficient at removing contaminants.
"We have shown that with this system we can take wastewater from a washing machine and remove more than 90 percent of the pollutants within three days," Cameron said. "The treated water had very low levels of suspended solids and no detectable levels of E. coli."
Cameron presented the work Wednesday in Havana during a meeting on organic and sustainable agriculture.