PORTLAND, Ore. A new round of commercialization funding from Oregon BEST is helping a Portland company collaborate with Oregon State University researchers to advance a biochar-based filter system that utilizes waste biochar from lumber mills to remove heavy metals from stormwater.
The new filter media cost 60 percent less than most activated carbon filter systems, an advantage for companies mandated to filter stormwater.
Portland, Ore.-based Sunmark Environmental mixes waste biochar from lumber mills with other components including hazelnut shells, compost and oyster shells to create a filter media capable of removing close to 100 percent of the zinc and copper found in stormwater runoff.
“With our filter media, we’re seeing metal removal rates of between 80 and 100 percent,” said Robin Cook, founder and partner of Sunmark, a soil and native plant restoration company. “Most other available filter media remove only about 60 percent, at best, so people are pretty excited about this. But we need third-party, scientific data from research to back up our findings.”
This is where OSU professor Markus Kleber and research assistant Myles Gray come in. The $136,000 in funding from Oregon BEST and the Portland Development Commission (PDC) is enabling the OSU researchers to test a range of media, including five different types of biochar generated by lumber mills in the Pacific Northwest.
The researchers hope to optimize a media mix best suited for removing zinc and copper, heavy metals that enter stormwater from metal roofing runoff, roadway runoff (brake lining dust and antifreeze) and other sources.
At many lumber mills, the waste wood used to generate electricity or kiln dry lumber is not completely burned, resulting in a mix of ash and biochar that is considered a waste product by the mills and transported to landfills. This biochar has been shown to have a strong ability to remove heavy metals from water, largely due to its high amount of surface area, which can be as high as 400 m2/g. As an added benefit, biochar is highly stable in the environment and can therefore be considered sequestered atmospheric carbon.
“The overarching idea with this project is to take something that’s a waste material and find another use for it add value to it,” said Kleber. “Activated carbon is much more expensive, so our approach is to give waste biochar a function it didn’t have before, at a price people can afford.”
Sunmark currently sells a product called EarthLite Stormwater Filter Media at about one-third the cost of activated carbon filter systems. But the company is finding that potential customers want to see more data.
“The engineers say great, but they want to know how much they’ll need, how long it will last, what are the flow rates, and what percentage of heavy metals will it remove,” said Cook. “Getting this third-party data is huge, and if a university has done that testing, it carries much more weight. OSU is going to be a great help.”
By adjusting the content of the filter mix, eventually, the company plans to target other stormwater pollutants, including other heavy metals, grease/oils and E. coli.
“Many companies are finding the new reality of staying in compliance with the Clean Water Act to be expensive,” said Cook. “So finding new, effective solutions that perform well and cost less is good for everyone.”
Oregon BEST invests in industry-university teams in order to speed commercialization of cleantech products.
“We’re thrilled to be helping an Oregon company collaborate with researchers at OSU to develop a product that has the potential to reduce pollutants while creating value for waste products,” said Ken Vaughn, Director of Commercialization Programs at Oregon BEST.