A new research done by Cindy Samet, a chemistry professor at the Dickinson College suggests that fruits and vegetable peels can actually help a lot more than we think in removing pollutants like toxic dyes and heavy metals from water.
Samet and her students conducted several experiments of water purification which involved using peels and seeds from various- nearly more than a dozen varieties of food- including the likes of pumpkin, okra and banana. The research team found that these peels and seeds helped remove methylene blue, lead and copper through adsorption- which is a process where the molecules of the pollutants form chemical bonds with the surface of the peels.
The study titled “Fruit and Vegetable Peels as Efficient Renewable Adsorbents for Removal of Pollutants from Water: A Research Experience for General Chemistry Students” was published recently in the Journal of Chemical Education. Samet built on a previous research done by her co-author, Suresh Valiyaveetti in 2005.
Valiyaveetti’s study analyzed how avocado, Hami melon and dragon fruits peels helped remove dangerous pollutants from water. Samet, in a video from Dickinson College, shows how large amounts of methylene blue can be adsorbed by dried avocado peel in only a couple of hours.
Samet chose to follow Valiyaveettil’s protocol for cleaning the surface of the fruits- which involves boiling the seeds and the peels first to remove all the soluble surface impurities. The peels are then dried and crushed before they are added to a solution that contains pollutants.
The research saw that lemon seeds could remove 100 percent of lead ions, and the peels were successful in removing 96.4 percent. Okra peels too, were able to remove 100 percent of lead ions, while the okra seeds removed 50 percent.
“The results expand on what we know about fruit and vegetable peels as an organic, renewable, low-cost method of removing pollutants from water,” explained Samet. “We replicated the results from Suresh’s lab with avocado and then studied never-before-tested fruits and vegetable peels and seeds. This is exciting because it is likely that this method of purification can make its way from lab to kitchen.”
Samet hopes that the study will push people to use dried peels and seeds in their kitchens as a natural, home-based alternative to purifying drinking water. Samet worked with industrial effluents such as dyes and heavy metal ions- and therefore wishes that this study can provide an affordable solution in areas where there is a shortage of clean, safe drinking water.