A Carmel teen has developed a rapid field-based technique for detecting nanoplastics – fragments of plastic smaller than a micrometer – in water samples.
Vidhatri Iyer, a freshman at University High School, has always been interested in the environment and the impact that humans have on it.
“In seventh grade at school, I learned how the mismanagement of plastic has caused millions of tons of plastic waste to be dumped into our oceans and ecosystems,” she said. “I was wondering about the water quality we use at home in Carmel. After visiting a local sewage facility and learning about the way water is recycled back into our ecosystem after being purified, I was immediately intrigued.”
That led the 14-year-old to research the topic of plastic detection in water. For the last two years, she has been conducting water quality research at Trico Regional Sewer District, working alongside professionals who taught her about the industry.
When she unsuccessfully tried to find an easy field-testable technique for detecting nanoplastics in water, she became motivated to develop one herself.
“I wanted my technique for nanoplastic detection to be fast, reliable, inexpensive and portable for field testing. I felt a handheld fluorometer would be suited for field-based testing as my measuring instrument,” she said. “A fluorometer measures the fluorescence of particles. My process is to take a water sample and add a dye, Nile Red, to the water sample. This dye binds itself very loosely to the nano plastic particles and enables the fluorometer to measure the level of nano plastics in the water.”
Iyer reached out to Bob Roudebush, laboratory coordinator at Trico Regional Sewer District, and pitched working together to develop her procedure and experiments.
“She started collecting monthly samples of influent and effluent wastewater samples and testing to see if there were nanoplastics in the water and, if so, see if the wastewater treatment process removed these nanoplastics,” Roudebush said. “She has now conducted data spanning seven months and has shown that the influent wastewater samples contained trillions of nanoplastic particles, but subsequent water treatment resulted in levels below detection limits in effluent water which enters the Indiana water streams.”
Roudebush said the experiments showed that the wastewater treatment process was very effective in trapping the nano plastics in the solid sludge resulting in safe effluent water.
“Vidhatri took the meter and her knowledge she gained at Trico Regional Sewer District and contacted water experts at the Marion County Public Health Dept. and the White River Alliance to monitor nanoplastics in the Indiana urban watersheds,” he said. “With the help of more than 50 volunteers, she coordinated monthly water sample collections from more than 70 sites to monitor nanoplastic loads. She analyzed these water samples for nanoplastic loads and showed that the levels were below detection limits.”
Roudebush said, like many others, he was initially shocked that a teenager had developed the test.
“For about three years, I helped judge science fair competitions as a volunteer from the Indiana Water Environment Association. During that time, I’ve seen many impressive projects by our younger generation, but typically they have not been fully realized until around their junior or senior year,” he said. “It is very impressive where her research has gone so far, and it’s exciting to imagine where it will lead if she continues with this topic until she is a senior in high school.”
Iyer agrees the reaction she gets is “almost always surprise.”
“People are very impressed when they hear that I am only 14 years old and have developed this technique. Many people congratulate me on aspiring to be a woman in the water science community and encourage me to further my research,” she said. “They have also offered me internships, funding, guidance and mentorship to continue my research.”
Roudebush believes Iyer’s test could be an important tool for water quality experts in determining nanoplastic pollution and determining hotspots.
“This topic is just beginning to gain the nation’s attention, and we will need accurate cost-effective equipment to be able to combat the problem and to detect where remediation is needed,” he said.
Iyer was invited by the RAFT Project to speak at its annual Indiana Water Summit.
“Everyone there was very interested and intrigued at my work. I was then invited to the Indiana Rural Water Fall Conference, and I presented in front of over 500 people about my technique for nano plastic detection,” Iyer said. “Everyone at that conference was amazed by this technique. They also offered me internships and other ways to help further my research. The community response to my technique was amazing, and I cannot wait to present at more events and increase awareness.”
Currently, the teen is working on measuring the nanoplastic load in different stages of water purification at the TRICO sewer facility. Her future plans are to become an environmental conservationist and physician-scientist.
How to detect nanoplastics in water
Vidhatri Iyer’s technique to detect nanoplastics in water utilizes a cost-effective dye that binds plastics to quantify the amount of it present within 10 minutes. The wastewater is passed via a syringe filter to measure sub-micron plastics. Water samples are filtered water using a 0.4 micro-meter syringe filter. The filtered water is then mixed with Nile Red Dye and allowed to incubate for 10 minutes. After 10 minutes, the hand-held fluorometer is used to show a value.
Bob Roudebush, laboratory coordinator at Trico Regional Sewer District, said this technique could become a routine test suitable for testing nano plastics in water samples in the laboratory or field.
