Banana skin cleans water?

image borrowed from can-i-compost-it.com

Yes, we know; we don't usually do two posts in one day. But we had to share this with you!

Did you ever hear about the one where the genius researcher got tired of banana skin pranks and decided to harness the powers of banana skins for good? No? That's because we just made it up. There is no mention of banana skin pranks in this story. . . And, to be honest, we've never seen anyone slip on banana skin or be duped by one.

Gustavo Castro, a Brazilian environmental chemist had long heard of the nutritious value of banana skin. And one day he decided to check just how nutritious banana skin was; he found that banana skin contains nitrogen, sulfur, and carboxylic acids. Carboxylic acids bind to positively charged metals, which led the researchers to investigate the efficacy of banana skins in drawing metals from river water. They did this by chopping and drying banana skins and mixing them with Brazils Paraná river water, which is polluted with copper and lead.

As it turned out the banana skin was better than a lot of filtering materials that are usually used (e.g. silica or carbon) and that the skins could be used up to 11 times before they lost their purifying powers. 

How's that for making the most of what you've got. The take home message is that your banana is more useful than you may have thought, though banana skin can't get rid of bacteria in water...so it's back to the fruit bowl on that one.

Check out the American Chemical Society's with Gustav Castro podcast  here.

Here's the original reference.