Rajsi Choudhary
8th Grade, Eastern Middle School
Riverside, CT
Fabrication of a Biodegradable, Nutrient-Rich, Orange Peel-Loaded Hydrogel for Thermally-Programmed Release of Water To Maintain Soil Moisture
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Project Background
Summers in Ahmedabad, India, Rajsi’s hometown, reach scorching temperatures of 104°F. When she retreated to air conditioning, Rajsi found herself looking at a mango tree out the window and wondering how the fruit stayed hydrated as the heat baked everything else. Nearly 70% of fresh water on Earth is used in agriculture, and climate change means many crops will need more. Rajsi began to study how fruit peels retain moisture and decided to see if fruit peels could help the soil stay moist.
Tactics and Results
Rajsi found that of orange, banana, apple, lemon and mango, orange peels had the highest moisture, with 88 percent water content. Rehydrating orange peels showed that they could absorb twice their weight in water. Rajsi then created an orange peel hydrogel and mixed it into soil, comparing it against a soil with a normal hydrogel, and one with no gel at all. She gave them 15.5% moisture and exposed them to natural sunlight for 80 hours. In the first 24 hours, normal soil lost 22.6 percent of its moisture, while her gel lost only 10 percent. After 80 hours, normal soil lost 53.3 percent of its water, and with a normal hydrogel lost 41.1 percent of its water, but the orange peel hydrogel soil lost only 28.4 percent. Crops like corn require 9,000 gallons of water per acre per day, and she estimates her orange peel gel could save 1,134 gallons per day.
Beyond the Project
Rajsi likes to play squash as a break from her time in the lab. “In the lab, I often find myself spending countless hours in a state of deep focus, where my mind is very active but my body is rather still. In contrast, while rallying on the squash court, I get the opportunity to exercise and give my brain a different kind of focus,” she says. Rajsi would like to be an environmental engineer, to help address problems like climate change and water scarcity.
