This 13-year-old found a way to remove pesticides using discarded peanut shells

Thirteen-year-old Arika Kundu has developed an innovative way to reduce pesticide residue on fruits and vegetables using agricultural waste such as peanut shells. Her project, LIGNEX, has earned her a place among the finalists of the 2026 3M Young Scientist Challenge and highlights a simple approach to food safety.Thirteen-year-old Arika Kundu has developed an innovative way to reduce pesticide residue on fruits and vegetables using agricultural waste such as peanut shells. (Photo: youngscientistlab.com)What if the peanut shells usually thrown away could help make the food on your plate safer?Thirteen-year-old Arika Kundu, a seventh-grade student at Minnetonka Middle School East in Minnesota, US, believes they can. Her project, LIGNEX, uses agricultural waste such as peanut shells to reduce pesticide residue on fresh fruits and vegetables.The idea has earned her a place among the finalists of the 2026 3M Young Scientist Challenge.TURNING PEANUT SHELLS INTO A PESTICIDE FILTERArika's invention, called LIGNEX, is based on biosorption, a process in which natural materials absorb unwanted substances. She discovered that peanut shells naturally contain compounds that can bind with pesticide molecules. To make them even more effective, she treated powdered peanut shells with acetic acid, increasing their ability to trap contaminants.Instead of testing the invention with real pesticides, which could be dangerous, Arika used methylene blue, a laboratory dye that behaves similarly during the absorption process. She then built an Arduino-based spectrometer to measure how well the system worked. (Photo: youngscientistlab.com) Her tests showed the tablets removed 93.94% of the model contaminant, suggesting the method could be highly effective at reducing pesticide residues on fresh produce.She packaged the treated peanut shell powder into effervescent tablets, making the solution simple enough for households, farms and even resource-limited communities to use. (Photo: youngscientistlab.com) Arika says her design uses simple tools for the process, which could be practical as well as sustainable.WHY SHE ENTERED THE CHALLENGEAccording to the 3M Young Scientist Challenge, Arika said she entered the competition to improve her innovation and "turn it into a product that everyone can benefit from."She added that encouragement from judges at regional and state science fairs motivated her to seek mentorship from 3M scientists and further develop the idea. (Photo: youngscientistlab.com) LOOKING BEYOND EARTHArika's ambitions extend well beyond food safety. She hopes to become an astrobiologist specialising in computational biology, working on ways to reduce radiation exposure during space travel.According to the 3M Young Scientist Challenge, she believes solving that challenge could not only support future space missions but also improve cancer treatment, agriculture and research into ageing and degenerative diseases.The 3M Young Scientist Challenge, organised by 3M and Discovery Education, is open to legal US residents in Grades 5 to 8 studying in schools across the 50 states and the District of Columbia. It encourages students to use science and engineering to solve real-world problems.- EndsPublished On: Aug 4, 2026 08:30 IST