Corn waste can be transformed into powerful water filters

The waste from harvested corn could be very useful for water treatment, according to a new study from UC Riverside. The experts demonstrated that corn waste can be transformed into activated carbon to filter pollutants out of drinking water.

After corn is stripped from cobs, the remaining stalks and other material become waste. These leftovers, also known as corn stover, have no commercial or industrial use. 

Kandis Leslie Abdul-Aziz is an assistant professor of Chemical and Environmental Engineering at UC Riverside’s Marlan and Rosemary Bourns College of Engineering. Her lab is devoted to upcycling plastic and plant waste into valuable commodities.

“I believe that as engineers we should take the lead in creating approaches that convert waste into high-value materials, fuels and chemicals, which will create new value streams and eliminate the environmental harm that comes from today’s take-make-dispose model,” said Professor Abdul-Aziz.

Activated carbon (AC) has several uses, explained the researchers, especially as an adsorbent for wastewater treatment. “Wastewater treatment plants utilize AC to remove pollutants, such as dyes, pharmaceuticals, heavy metals, and organic contaminants. The removal of industrial phenolic waste such as vanillin is especially important because it has adverse environmental effects.”

The experts compared methods for producing activated carbon from charred corn waste. They found that processing the biomass with hot compressed water – known as hydrothermal carbonization – produced activated carbon that absorbed 98 percent of the water pollutant vanillin.

When compared with a process where corn waste is charred at increasing temperatures over a long period of time, hydrothermal carbonization created a biochar with higher surface area and larger pores.

“Finding applications for idle resources such as corn stover is imperative to combat climate change. This research adds value to the biomass industry which can further reduce our reliance on fossil fuels,” said study co-author Mark Gale.

The study is published in the journal ACS Omega.

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By Chrissy Sexton, Earth.com Staff Writer