Algal blooms have plagued Lake Erie for decades.
And they don’t seem to be going away any time soon: Ohio and its neighbors just fell short of a 10-year goal to curb the phosphorus pollution that feeds those blooms by 40%.
In the meantime, scientists are researching ways to remove algal bloom toxins, like microcystins, from drinking water. At the University of Toledo, they’re using a resource that’s plentiful in the Midwest: corncobs.
Dragan Isailovic, a chemistry professor at the University of Toledo who’s spearheading this research, joined the Ohio Newsroom to explain the team’s findings.
This interview has been lightly edited for brevity and clarity.
On the idea to experiment with corn cobs
“A couple of former students approached me and they mentioned using rice husks to prepare some materials that could remove microcystins from water. At that time, I mentioned to them, ‘Well, that's a good idea, but we're all around cornfields, so I think it would be better if we could prepare some type of biochars [a product similar to charcoal made by heating up biomass like wood chips or crop waste], or some other material from corncobs.’”
On how water treatment plants typically clean drinking water
“Activated carbon is used not only to adsorb and remove microcystins, but it can also remove any other molecules that can bind to activated carbon. It's still used in the Toledo water plant.

“There are other technologies that are efficient at removing microcystins too, such as ozone. The Toledo Water Treatment Plant has an ozonolysis facility where they use ozone to remove microcystins. However, most of the water treatment plants do not have a facility to produce ozone and use it for water purification, so they use activated carbon or some other means to remove contaminants from water.”
On how researchers are using corncobs to clean drinking water
“We get corncobs from a local company, the Andersons. A couple of their products contain high amounts of carbon, so these corncob products are those that we use in our studies. Those products were basically ground from corncobs. Then, in order for us to prepare activated carbon and biochars, we use a chemical procedure.”
On the effectiveness of carbonized corncobs
“We found that the activated carbon that we produced [from corncobs] works better than the biochar that we produced, and it's comparable to the activated carbon that we received from the Toledo water plant. I would say it's still not a better material because we see slightly better removal with commercial activated carbon. But it could potentially be a substitute for commercial activated carbons. And [carbonized corncobs] could be more sustainable. Most of the [commercial activated] carbon is produced from sources that are not renewable.”
On commercial applicability
“I think it's possible to scale it up. Obviously, this would involve some engineering solutions. We use a furnace and we have limitations in terms of the size of the furnace and amount of the material. So in collaboration with others, we hope that this could be produced at a larger scale.”