UBC, Okanagan company study how to recycle contaminants absorbed by poplar trees

UBC Okanagan is partnering with an Armstrong, B.C. company to find ways to extract contaminants out of trees planted in a landfill, and then use those chemicals to create household products.

Passive Remediation Systems Ltd. planted 1,100 poplar trees at the Columbia Shuswap Regional District landfill in 2011.

The company recently approached UBC Okanagan to find ways of extracting the natural and industrial chemicals from the trees — which act as sponges, drawing contaminants from the ground — so they can be recycled.

"Poplar trees are really interesting because they can grow in a lot of soils that other plants would struggle or have difficulty growing in," said Susan Murch, UBC chemistry professor and leader of the research program.  

"Things like heavy metals or organic compounds that might runoff from landfills or municipal effluent ponds, maybe even mine tailing ponds, get absorbed up into the tree and then the tree… can do a bunch of different things to remediate the soil."

Murch says potential chemicals extracted from these trees could be turned into products for everyday use like cleaning materials, antimicrobials, antioxidants, or natural fertilizer.

Murch said her team can extract significant amounts of the chemicals through a process called pyrolysis — basically steaming the chemicals out of the harvested poplar material and separating the chemicals from the liquid "wood vinegar" that the process produces.

"We can get a very concentrated extract by boiling the material down under high pressure and steam to give us the chemical residues that we can use to discover new molecules."

The next step for Murch and her students is sifting through the cocktail of chemicals squeezed out of the trees to find the exact few that can be recycled and used.

With files from the CBC's Daybreak South.

To hear the full story listen to the audio labelled: Hybrid Poplar trees take on a whole new form of recycling in UBC Okanagan study