Discovery Files

Platinum can act as a catalyst for wastewater treatment

Agent can detoxify harmful aldehydes in wastewater

Making wastewater potable has a unique set of challenges, one of which is removing persistent chemicals and byproducts. Aldehydes, a byproduct of wastewater treatment, are toxic to humans. Removing aldehydes from wastewater requires a sustainable solution.

Chemists at the University of Southern California, working on a project funded in part by the U.S. National Science Foundation, recently published the findings of their work on using platinum to help remove toxins from wastewater. The chemists used the precious metal, which is also used to clean exhaust in catalytic converters, as a catalyst to hasten oxidation in wastewater, rendering toxic aldehydes into benign carboxylic acids. While expensive, using platinum supported on carbon as a catalyst for this process is overall cost-effective.

"We knew we could oxidize certain things, but we didn't have a clear application in mind for this catalyst," said Daniel McCurry, one of the paper's authors. "What if we could use platinum in water treatment to oxidize contaminants? It would happen essentially for free, and because the oxygen is already in the water, it's the closest you could get to a chemical-free oxidation."

The team experimented with platinum reactors on wastewater samples, and the experiments were successful, but more work remains to assess the life span of the catalyst when used in industrial or commercial applications.

"This is a problem we didn't realize we had a solution for, but now we know,” McCurry said. “This catalyst, which we had been using to oxidize pharmaceuticals, works great on oxidizing aldehydes -- and would allow for direct potable reuse water to meet future regulatory guidelines and safety standards.”

The patent pending process aims to be more sustainable and preferable to alternative methods that require additional chemicals and energy.