Clean water goal of UNCG nanoscientist’s research

Posted on June 30, 2022

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Dr. Hemali Rathnayake is a UNCG associate professor in the Joint School of Nanoscience and Nanoengineering

Dr. Hemali Rathnayake is a UNCG associate professor in the Joint School of Nanoscience and Nanoengineering.
Dr. Hemali Rathnayake is a UNCG associate professor at the Joint School of Nanoscience and Nanoengineering.

As a little girl in Sri Lanka, Hemali Rathnayake loved science and dreamed of a better world.

As a grown woman in Greensboro, Dr. Hemali Rathnayake loves science and is changing the world for the better.

Rathnayake is a UNCG associate professor at the Joint School of Nanoscience and Nanoengineering on East Gate City Boulevard, where she and the graduate students she teaches are working in laboratories to solve real-world problems.

Problems such as water pollution.

Rathnayake’s group is searching for efficient, cheap, and green ways to clean industrial wastewater.

The goal is to use nanoscience to produce filters for water purification.

“My dad used to tell us, ‘No one can steal your education’,” Hemali Rathnayake says.

“We have been working in my lab on environmental sustainability,” Rathnayake says. “We moved to more bio-based materials like lignin, tannic acid, polyphenol and other plant-based materials put into these nano-materials. It’s more sustainable.”

But what the heck is nanoscience? It’s a question Rathnayake gets a lot when people make small talk outside the JSNN.

“I always laugh first,” Rathnayake says, “and then I say, ‘Oh, we’re doing science in nanoscale, and nano means a billionth of a meter smaller. So it’s science on a smaller scale.’”

It’s a big deal, regardless of the small scale.

“These small particles combine to have a high surface area,” she says. “That’s why these tiny beads can absorb millions of ions, because their volume-to-surface area ratio is huge.”

Nanoscience takes a bottom-to-top approach in a top-to-bottom world.

“When I use the word ‘nano’ outside this building, the community doesn’t always understand,” Rathnayake says. “It’s the same problem the country had with the COVID-19 vaccine, right? It’s a nanomedicine technology in the vaccines. They used this vital particle. When you work on really, really small things that cannot be seen with the naked eye, it’s hard for people to understand that we’re doing science in that small space.”

True. But Rathnayake’s research is aimed at solving problems that cannot be seen with the naked eye, either.


You can’t see the lead that seeped into the water supply from old pipes in Flint, Mich. Or the arsenic in water from years of pesticide use on farmers’ fields. Or the various pollutants from industrial wastewater.

But those dangers lurk there, unseen.

Dr. Hemali Rathnayake (right) with former student Dr. Sheeba Dawood of Minerva Lithium.

“We wanted to see how we can take all these heavy metals from the water using bio-based material,” Rathnayake says. “They’re kind of micro-sized beads, and they can remove things like arsenic, lead, mercury, and cadmium. For instance, you could apply this to textile companies. They use a lot of dye and a lot of metals in making textiles, and they produce a lot of wastewater. We wanted to find a way to clean that wastewater.”

Especially in places where water is scarce and precious, filtering wastewater could be life-changing.

“It’s a two-part process,” Rathnayake says. “First, we want to clean that wastewater enough that we can make it healthy to use for agriculture. And the second part is we want to clean drinking surface water, and take out the heavy metals.”

A long-term goal is to develop an in-house filter people could use in their homes to purify water.


Rathnayake’s research comes from her own life experience.

She was born and raised in Sri Lanka, an island nation of 22 million people in the Indian Ocean, 40 miles off the southeast coast of India.

“It’s a draw that came from seeing how people in third-world countries have suffered with the arsenic problem,” Rathnayake says. “Look at Sri Lanka, where thousands of people each year develop kidney problems because of arsenic in the water. That’s one driving force of motivation. The other is scarcity of water. In places where water is scarce, we want to know if there’s any way we can use old wastewater to become fresh water for crops or even drinking water.”

The third of four children in her family, Rathnayake was raised in a rural part of Sri Lanka. Her father was a teacher, her mother a nurse.

And she dreamed of traveling to the United States to live in the academic world and get her PhD.

“I loved science when I was a girl, and I wanted to study organic chemistry,” Rathnayake says. “My mother wanted me to go to medical school, but that’s not what I wanted. My motivation was I wanted to do something with science, to use what I learn to make people’s lives better. I have seen how my parents struggled with energy. We never had electricity until 1986. I was in high school when we got electricity in our home. And then water. We had to go a long way to get water. Sometimes the well would dry out, and we’d go to someone else’s well to get water. A lot of places in this world suffer so much without clean water.”


It’s that motivation that kept her in the academic world. She earned chemistry degrees at UMass Amherst, taught undergraduates as a professor at Western Kentucky, and came to Greensboro six years ago to work with grad students.

“My research program got more advanced because I came to UNCG,” Dr. Hemali Rathnayake says.

“It’s been a huge success, and it was the right decision to move to UNCG, a place with a graduate program,” Rathnayake says. “I like it here, and working with the graduate students gave a boost to my research and where I wanted it to go. And the facilities, the building, the labs, the electron microscope. … My research program got more advanced because I came to UNCG.”

So here she is, living a life dedicated to science, pursuing research to make the world a better place.

It’s what Hemali Rathnayake was born to do.

“I come from a family that believed education was the most valuable thing,” she says. “My dad used to tell us, ‘No one can steal your education.’ He was always encouraging me. …

“When I did my PhD, people asked me, ‘Why don’t you go into industry?’ Because you can make more money. But I wanted to do something different, and I wanted to start my own research that would do something for the global community. That’s what I wanted to do since I was little.”

Story by Jeff Mills, University Communications

Photos by Martin W. Kane, University Communications


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