Using banana peels to remove metals from polluted water: an aPEELING option

Researchers have found banana peels can remove toxic metals from contaminated water just as well as many expensive laboratory methods.

Access to Clean Water: A Basic Human Right

A simple turn of the faucet delivers an endless supply of clean and refreshing H 2 O – in our homes, our offices, and even water used to flush our toilets. Clean drinking water is so readily available that we don’t have to think about where it is coming from or how we are going to get it. Access to clean drinking water is a basic human right that we enjoy on a daily basis. Unfortunately, this right isn’t the reality for millions of people around the world.

The World Health Organization [WHO] estimates that 884 million people world-wide do not have access to clean drinking water. Over half of these individuals live in developing African countries where the consequences of drinking unclean water account for millions of deaths each year. Children, 5 years or younger, are the most vulnerable. In the past, drinking unclean water typically meant high risk to diarrheal diseases caused by bacteria or viruses. Today, drinking unclean water can mean much, much more.

With the ever ongoing and increasing industrial activities in developing nations across the globe, water quality in the most impoverished areas has become increasingly worse. Bacteria and parasites in the waterways of third world countries are no longer the only worries; issues of mining and heavy industry pollution are now adding to the clean water crisis- often times in the form of toxic heavy metals. Exposure to heavy metals [including: lead, mercury, copper, cadmium, chromium] can cause developmental defects in children, neurological effects such as memory loss and behavior changes, chronic diseases like cardiovascular disease, and it may lead to certain types of cancers.

Banana Peels: Removing the Metals

There have been numerous technologies developed to specifically remove metal toxicants from polluted waters- silica, alumina, activated carbon, and resins have all been proven successful… and expensive. While they perform in the high tech laboratories of developed countries, mass manufacturing and distribution of these products in developing nations are expensive and impractical. For rural and remote villages, activated carbon filters are just not a sustainable option for water purification. But, banana peels are.

Using water from Brazil’s Paranhas River and locally grown bananas, researchers at Sao Paublo State University have demonstrated that dried banana peels can successfully remove copper and lead [two common metal pollutants] from contaminated water.

Banana peels contain nitrogen, sulfur, and carboxylic acids; the acids are responsible for the peels’ ability to bind the toxic metals and remove them from the water. Because of the high number of these acids in the peels, not only can banana peels remove the contaminants, but they can do it just as well, and in some cases better, than more expensive technological options. And it’s easy. Without any technical preparation, dried banana peels successfully remove metals.

In areas in South America and sub-Saharan Africa where bananas are a common resource and contaminated water is a common problem, banana peels offer a sustainable and practical way to remove toxic metals from drinking water. By using the same banana peels up to 11 times without replacement, families can successfully minimize their risk of exposure.

Banana peels don’t kill parasites or bacteria, and they aren’t going to protect children from viruses. But, banana peels may offer millions of families around the world the opportunity to drink water free of heavy metals. A basic solution to promote a basic right.

Image: By darwin Bell from San Francisco, USA (Oh just peel it already! Uploaded by Fæ) [CC-BY-2.0 (www.creativecommons.org/licenses/by/2.0)], via Wikimedia Commons