Banana Peels Could Help Clean Water

Minced peels shown to extract heavy metals from water

Banana peels have a new purpose other than wrecking havoc on unsuspecting pedestrians – they can remove heavy metals from water.

Scientists at São Paulo State University in Brazil have discovered that minced banana peels can bind and collect trace amounts of lead and copper in river water, making toxic metals 20 times easier to detect with crude equipment, according to a Discovery News report on the scientist’s research.

photo of a bananaJason Gulledge, on Flickr

Once refined for easy implementation on a global scale, the banana purification process could be of great use in developing countries where access to safe drinking water is still hard to come by.

Compounds in banana peels contain atoms of nitrogen, sulfur and organic compounds such as carboxylic acids, which can bind with metals in water. “I was at home eating some bananas when I had the idea, ‘Why not make something with this?’” says Gustavo Castro, an analytical chemist at the university’s Biosciences Institute told MSNBC. The scientists’ findings are published in the February 2011 issue of the Industrial & Engineering Chemistry Research journal.

Banana peels aren’t the first natural material that scientists have tried to use to remove heavy metals from water. Coconut fibers, sugarcane, peanut shells and other natural items have all had their turn. But Brazilian scientists were the first to ponder upon the banana.

The researchers used dried and minced peels for their experiments. They found that a purifier made of layers of minced peel could be used up to 11 times. Synthetic filters can be reused many more times, but natural materials like these peels are dramatically cheaper and do not require chemical processing to work. The banana peel filters worked even at high levels of pH, which means they could probably be effective filters for industrial and farm runoffs.

Still, no one is recommending at home use of banana peels to purify water. For while the peels might be able to extract heavy metals from water, it doesn’t have a proven ability to remove other contaminants that might be present, like germs.

Water contamination is something we all fret about. Heavy metals often leach into our water supplies from industrial and farm runoffs and have a toxic effect on us even when present in trace amounts. The result of prolonged drinking of metal-contaminated water accounts for nausea as well as brain damage.

With the population on Earth expanding to an unimaginable capacity, new technologies for producing safe drinking water are not just inevitable but essential for survival.

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