This South African schoolgirl is combatting drought with orange peel

Kiara Nirghin, 16, has been awarded at the Google Science Fair for inventing a super-absorbent polymer that could help fight drought.

Orange peels and avocado skins have been used to create a cheap, natural and super-absorbent material. Kiara Nirghin, 16-year-old South African girl of Indian origin, has developed a polymer made of polysaccharides from food scraps that can hold water more than 100 times their weight.

Combatting drought in South Africa

In 2016 South Africa has faced one of the worst drought ever registered that brought small farmers to their knees. With the aim of helping farmers in need, Kiara has studied and developed this new super-material.

Existing absorbent polymers (SAPs) “are not biodegradable, are costly and full of acrylic acid, sodium hydroxide and other chemicals. During more research on the topic, I found that natural occurring polymers exist in most citrus fruits,” explained the schoolgirl to the Hindu Times.


“Kiara found an ideal material that won’t hurt the budget in simple orange peel, and through her research, she created a way to turn it into soil-ready water storage with help from the avocado,” Andrea Cohan, program leader of the Google Science Fair, told CNN.

During her researches, Kiara has found that orange peel has 64 per cent polysaccharide and also the gelling agent pectin. This makes it a perfect material that is biodegradable and cheap.

google science fair drought
Every year the Google Science Fair honours the best scientific ideas and projects of young students from all over the world the world © Richard Levine/Corbis/Getty Image


After 45 days of experimentation, Kiara compared existing materials’ water absorbing abilities to hers, observing that “the orange peel mixture displayed the strongest water absorbing abilities of 76.1 per cent. The acrylic SAP displayed a water absorbing ability of 74.7 per cent, whilst the pectin and starch fell under 70 per cent”.

The orange peel mixture has turned out to be cheaper and more effective than existing materials. Acrylic polymers cost 2,000 to 3,000 dollars per tonne, while the new polymer only 30 to 60 dollars per tonne. This means that the new technology will be accessible to all, even to smaller farmers.

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