The US spends $5 billion a year to repair damages to road infrastructure. That is one of the reasons a team of WSU researchers is developing a more sustainable solution, using grape skins and other agricultural waste.
The researchers, including graduate student Mehdi Honarvar Nazari and Xianming Shi, associate professor in Civil and Environmental Engineering, determined that their de-icer containing grape extract outperformed commonly used de-icers, including road salt and what is thought to be a more environmentally friendly blend of salt brine and beet juice. They published their results in the December issue of the Journal of Materials in Civil Engineering.
Every year, roughly 27 million tons of sodium chloride, commonly known as road salt, is used on US roadways for winter maintenance. Commercial de-icers typically contain chemicals that are corrosive toward metals, asphalt, concrete and pose some risk to aquatic species.
Beet juice has become a common additive used by highway departments and cities to enhance the performance of de-icers while reducing their corrosive impacts. However, when beet juice enters water bodies, it can deplete oxygen and endanger aquatic organisms.
Working to develop a greener additive, the WSU researchers derived chemicals from waste grape skins through chemical degradation and natural fermentation. Shi said their novel process to make the formula produces no waste of any kind.
The researchers found that their grape extract-based solution melts ice faster than other de-icers and causes significantly less damage to concrete and asphalt, the two most ubiquitous materials used in bridges and roads. The solution also poses less risk to nearby water bodies.
“We delivered a more sustainable solution because we’re introducing less chlorides into the road operations and are achieving comparable or better performance,” Shi told scienceblog.com. "It’s one step in the right direction.”