It's no secret that road salt is not very sustainable. States like Ohio are looking for greener alternatives, like "BEET HEET," a de-icer made with the vegetable.
A Washington State University professor is proving grape extract and other agricultural waste can be used too. Research shows it melts ice faster and causes significantly less damage to concrete and asphalt than traditional methods.
Xianming Shi first began looking to locally-sourced plants as natural de-icers because of a salt shortage in Alaska. The Washington State University project snowballed into a cornucopia of sustainable bi-products of agricultural waste.
He's used Kentucky Bluegrass, peonies, dandelions, grapes, cherries, apples and more to treat roadways. Soon his ongoing study will move from the lab to larger studies in Washington, California and New York.
The agriculture waste would still be mixed with salt, Shi says, "but what we're doing is introducing 20% less salt to the environment while boosting the performance of salt brine while at the same time minimizing the potential risk to water bodies.”
In the lab, Shi degrades and ferments grapes, which takes about two weeks. When the product is used on a larger scale, he says he will find ways to reduce the lab time.
Shi says he has a lot of interest in the project, especially as the cost of road repair skyrockets to an estimated $5 billion a year in the U.S.
States have some tough choices as their budgets shrink. Salt is cheap and agriculture waste would cost 80% more.
As WOSU reported, in 2018, the Ohio House passed a bill allowing another option to treat roads: a byproduct from oil and gas drilling. But the Sierra Club expressed concern because the product, AquaSalina, reportedly contains radioactive materials. That bill eventually died in the Senate.
Shi is slow to criticize states.
"They are facing very tough situations because there are always funding constraints," he says. "Agencies tend to have to buy the cheaper products but in the long run the communities are actually paying in hidden costs," he says.
Shi's research on agricultural waste is published in the December issue of the Journal of Materials in Civil Engineering.