Global Challenges/Chemistry Solutions

Developing New Materials: Using banana peels to purify water

August 8, 2011

Banana peels

Banana peels show promise as superior
water purifi-cation materials.
Credit: iStock

Summary

Banana peels have some surprisingly inventive uses
including polishing silverware, leather shoes, and
the leaves of houseplants. Scientists have now
added purification of water contaminated with
toxic metals to the list. A study in the American
Chemical Society’s journal, Industrial & Engineering
Chemistry Research
, reports that minced banana
peel performs better than an array of other water
purification materials and could provide a
sustainable alternative.

Banana peels have some surprisingly inventive uses, including polishing silverware, leather shoes, and the leaves of houseplants. Scientists have now added purification of drinking water contaminated with toxic metals to the list. A study in the American Chemical Society’s journal, Industrial & Engineering Chemistry Research, reports that minced banana peel performs better than an array of other water purification materials and can do so in a sustainable way.

Gustavo Castro and colleagues note that mining processes, runoff from farms, and industrial wastes can all put heavy metals such as lead and copper into waterways. Heavy metals can have adverse health and environmental effects. Current methods of removing heavy metals from water are expensive and some substances used in the process are toxic themselves. Previous work has shown that some plant wastes, such as coconut fibers and peanut shells, can remove these potential toxins from water.

Castro and colleagues wanted to find out whether minced banana peels could also act as water purifiers. Here is Gustavo Castro of São Paulo State University in Brazil:

“I chose to work with banana peels because I have heard for a long time that we usually throw out the best part of the fruit and that most of the nutrients and proteins are in parts not used by us, such as the peels. From there, I decided to make an initial experiment to determine the chemical composition of the peel.”

The researchers found that minced banana peel could quickly remove lead and copper from river water as well as or better than many other materials. They say that banana peels can be used up to 11 times without losing their metal-binding properties. The scientists add that banana peels are very attractive because of their low cost and because they don’t have to be chemically modified in order to work. Here again is Dr. Castro:

“I was surprised to learn that something so simple could work so well I believe that banana peels can be of great importance in water purification. Sustainability is very important.”

Smart Chemists/Innovative Thinking

Smart chemists. Innovative thinking. That’s the key to solving global challenges of the 21st Century. Please check out more of our full-length podcasts on wide-ranging issues facing chemistry and science, such as promoting public health, developing new fuels and confronting climate change, at www.acs.org/GlobalChallenges. Today’s podcast was written by Mark Sampson. I’m Adam Dylewski at the American Chemical Society in Washington.

Gustavo Castro, Ph.D.
Gustavo Castro, Ph.D.,
São Paulo State University
Brazil