Researchers at the University of B.C. have discovered a way to filter microplastics out of water using biodegradable forest byproducts such as bark and wood dust.
Scientists at UBC’s BioProducts Institute found that if they added tannins—natural plant compounds found in unripe fruit and a popular additive in wine—to a layer of wood dust, they could filter out nearly all microplastic particles from water.
So his team used tannins from bark with the wood dust—waste materials that typically would be burned or thrown out from B.C.’s lumber industry—to create a filter, a process they call bioCap. And it worked.
He said their discovery could be used on a larger scale, for example at waste-water treatment plants or as a drinking water filter in homes.
Rojas noted that while efforts are being made to reduce plastic use worldwide, there will continue to be tiny particles in the water for years to come.
Microplastics are entering the water supply from synthetic clothing and other plastic products, such as disposable items like masks, and even from microbeads in cleansers and makeup, he said.
“It’s a big challenge because the microplastics are very difficult to see, difficult to detect and they are very highly diluted in water streams,” Rojas said.
Multiple peer-reviewed studies have shown how prevalent microplastics are in water, and the harmful effect they are having on wildlife. A study, published in May, for example, found that microplastics are destroying the gut biome of seabirds and warned that humans should be wary of a similar health concern.
A recent expedition to Antarctica that involved UBC researchers found microplastics in every water sample they took.
Rojas said there are also studies that have shown nearly all tap water is contaminated by microplastics, which poses a serious health risk for humans.
For their study, the team analyzed microparticles in tea bags made of polypropylene. They found that their method trapped from 95.2 per cent to as much as 99.9 per cent of plastic particles in a column of water. And, he said that their process prevented a buildup of microplastics in the organs of mice.
“This is a health problem that is beyond environmental aspects in the fact that it accumulates in organs in humans and animals,” he said. “And it’s a problem that is not just going to stop overnight.”
The team’s method was developed in collaboration with Junling Guo, a professor at the centre of biomass materials and nanointerfaces at Sichuan University in China, Marina Mehling, a PhD student at UBC’s department of chemical and biological engineering, and Tianyu Guo, a postdoctoral researcher at the BioProducts Institute, according to a UBC news release.
