Doctoral candidate Sarah Burch is developing a storm water filter system containing biochar made from hazelnut shells. Her research shows that this form of biochar can remove more copper from water for longer periods of time than both traditional activated charcoal filter systems and biochar made from other woody materials.
“I’m very passionate about clean water,” said Burch, who grew up in Texas, daughter of an oil industry geophysicist and a mathematician.
Burch said that her research is a critical breakthrough for juvenile coho salmon, whose ability to smell predators is compromised in water containing copper at levels greater than 2 parts per billion (ppb). Activated carbon can only remove copper down to about 5 ppb, while the hazelnut shell biochar can reduce copper levels to 2 ppb.
Other side benefits are that the heat, gasses, and oil produced during the 700-degree, oxygen-free pyrolysis process used to convert the hazelnut shells into biochar can be captured and used in various ways.
Before coming to Oregon State, Burch worked for an environmental consulting company in Ohio and saw a lot of money and energy being spent on highly engineered remediation processes.
“That experience motivated me to pursue more sustainable alternatives that use readily available materials,” she said. “I chose OSU because of this project.