Municipalities across the United States spread about 27 million tons of road salt, or sodium chloride, on roadways every year to reduce snow and ice. But this common deicer is corrosive to asphalt, concrete, and metals — costing $5 billion in road infrastructure damage every year — and can pose long-term environmental risks, particularly to aquatic species. Now, scientists say they have found a more sustainable alternative using grape skins and other agricultural waste.
The new mixture, developed by chemical engineers Xianming Shi and Mehdi Nazari at Washington State University, contains chemicals from waste grape skins, extracted through a process of chemical degradation and natural fermentation. The grape-based solution causes no harm to aquatic environments and melts ice faster than traditional deicers, including road salt and salt brine-beet juice mixtures, which, while less corrosive, can deplete oxygen in nearby waterbodies and endanger aquatic organisms.
“We delivered a more sustainable solution because we’re introducing less chlorides into the road operations and are achieving comparable or better performance,” Shi said in a statement. “It’s one step in the right direction.”
The innovative mixture doesn’t have to be made with grape skins — the new process can extract deicing chemicals from almost any agricultural waste. The scientists have successfully applied it to peony leaves, sugar beet leaves, dandelion leaves, and apples. The scientists published their findings in the Journal of Materials in Civil Engineering.
“The beauty of this approach is that it allows us to diversify,” Shi said. “We can use this same platform technology in different regions of the country but choose a different agricultural product, depending on what source of waste is available.”