[savoy7]

I was asked this question on Friday:

"How would you remove a banana stain made on concrete?"

It seems that someone was playing a practical joke and used bananas.  These bananas left a brown stain on the concrete.  Now the owner of the property would like a large sum of money to clean these stains.  

Any ideas?

savoy out

[lemonoman]

My first suggestion is to just put another thin layer of concrete on top to cover it up  

But short of that, hmm...Google doesn't provide many good solutions.  I'd try powerwashing, burning, Zud, or almost anything before being charged "a large sum"....Good luck!

[Karakth]

You need to break down the brown stain. The brown stain is probably oxidised iron compounds. But no need to tackle it like that. I think this is one of those questions that borders between Chemistry and Biology:

Banana stains seem to disappear over time, right? That much food is too much to waste for bacteria and other organisms living on the floor. How do they break it down? Enzymes of course! So I would suggest using an enzyme-based washing powder.