Purifying Water With Sound

Posted: September 6, 2012

By Kari Fox

Each day, compounds from medicines we take end up in our lakes, rivers and even drinking water. Antibiotics, birth control drugs, antidepressants and caffeine are some of the chemicals being found. Linda Weavers has made it her job to figure out how to destroy these pollutants before they potentially cause harm.

Weavers, the John C. Geupel Professor of civil, environmental and geodetic engineering, uses a system that shoots high-frequency sound waves through the water. If there is a high enough sound intensity, the water forms pressure waves that pull molecules apart. When the molecules pull apart, a bubble is created and that bubble collapses when a high pressure region comes through. That collapse increases the temperature and causes the formation of hydrogen radicals that ultimately break down the compounds.

This ultrasound technology could be used to help treat sewage and purify drinking water.

Weavers says the good thing about this procedure is that it’s easy and doesn’t use chemicals. "You just flip a switch and it works," she says.

Research has already shown a link to fish reproductive problems from human birth control drugs found in the water. Even though it hasn’t been determined that these compounds are a threat to humans, Weavers says it’s important to quickly find out.

"Should a male be exposed to the active ingredient in birth control pills?" Weavers asks. "Is this a problem even though it’s at a low level? That’s the question researchers want to find out."

Developing new technologies has always been a passion for Weavers. She says what first attracted her to ultrasound technology research was the ability to develop new, better technologies versus what is currently available.

"I wanted to develop something that is either cheaper or easier to use," she says. "Having easy, simple technologies is really important."

Since there haven’t been a lot of researchers investigating ultrasound technology in the United States, Weavers has made it her goal to learn more about how the sound wave system works and how it can be implemented in wastewater plants in the future to remove pharmaceuticals.

"This is in a class of emerging technologies," Weavers says. "So we’ll continue to research how we can develop it further."


Category: Research