Iron compound makes water safer to drink

"Chlorine does a nice job of cleaning water, but we now know that it also reacts with water in a way that generates more than thousands of these byproducts," says Virender K. Sharma. (Credit: Getty Images)

A new technique using ferrate, an iron compound, could improve the safety of drinking water, researchers say.

Treating water with chlorine—a process called chlorination—kills germs and bacteria in water, making it safe to drink.

Although chlorination effectively cleans water and helps prevent waterborne diseases, it also generates many disinfection byproducts, or DBPs, that can be harmful to human health.

Chlorine does a nice job of cleaning water, but we now know that it also reacts with water in a way that generates more than thousands of these byproducts,” says Virender K. Sharma, professor at the Texas A&M University School of Public Health.

The Environmental Protection Agency (EPA) monitors the levels of DBPs in drinking water so people aren’t exposed to too much of these toxic chemicals. Any time drinking water exceeds these levels, it can cause harmful health consequences.

Sharma’s research group developed a pretreatment process that decreased the number of DBPs in water disinfected with chlorine.

For the pretreatment, the researchers applied ferrate— a supercharged form of iron—to water before it was chlorinated.

“It’s pretty simple. You just add the ferrate stick to water, wait a while, then treat the water with chlorine,” Sharma says.

The researchers found that the water pretreated with ferrate before chlorination had lower levels of DPBs and was less toxic to cells.

The reseearchers tested the toxicity by comparing the pretreated and chlorinated water samples on cells and found that those doused with the pretreated water lived longer. They measured the levels of DBPs in each water sample by using NMR and high-resolution mass spectrometer technology.

Sharma has worked with ferrate for more than 20 years. The new study builds on years of research in his laboratory using ferrate to tackle environmental problems.

“I’m always looking to solve environmental problems, and ferrate is such a powerful oxidant, so I had a feeling it could solve this problem,” he says.

The study appears in Environment International.

Source: Texas A&M University