Researchers transform an ordinary product into a pollution-absorbing ‘smart sponge’

Environmentalists have spent decades trying to come up with a more effective device to clean up oil spills, and now the same is true for cleaning up microplastics and phosphate pollution in the environment. Northwestern University researchers believe they’ve done it and Illinois startup MFNS Tech can commercialize it. Their device? The common sponge.

It’s actually a coating for the common sponge. The team created a nanocomposite coating made of magnetic structures and a carbon-based material that changes a sponge’s water absorption properties. It can coat any ordinary, cheap sponge to transform it into a “smart sponge” that selectively absorbs and stores oil and other pollutants while leaving water behind.

When the sponge is saturated with pollutants it simply can be wrung out. Plus, it doesn’t harm wildlife like other oil spill mitigation techniques, such as chemicals that disperse or break down oil. 

“Almost half a billion tons of sponges are wasted each year and go to landfills,” Vinayak Dravid, Northwestern engineering professor, said in a news release. “All we do is coat a tiny amount of nanotechnology slurry and that makes the sponge much more effective in capturing the pollutants. So, what we’re doing is using waste to clean waste.”

The researchers consider the tool akin to a Swiss Army knife because of its ability to absorb multiple pollutant types: oil, microplastics, and phosphate, which builds in waterways and promotes toxic algae blooms. The novel technology can absorb 30 times its weight in oil and 99% of the phosphate it encounters. 

“This is just the beginning,” Vikas Nandwana, assistant professor of engineering, said in the news release. “Different types of nanotechnology coatings can be made that capture a variety of pollutants not only from water, but also from air and soil.”

The team already has tested its technology in real-world conditions at the National Oil Spill Response Research & Renewable Test Facility. Dravid and Nandwana co-founded MFNS Tech, which is in the process of commercializing the oil-absorbing sponges.

“Our sponge surely has potential to revolutionize environmental remediation,” Nandwana said.