purifying water using shredded horseradish-how?

[Pierre Jelenc]

In article <3eu5d9$i7b at ixnews3.ix.netcom.com>,
BILL DEAN <BILL42 at ix.netcom.com> wrote:
>A number of years ago I read about the purification of water by placing 
>a bag of shredded horseradish in a container with the water to 
>be purified. The article was in one of the pop science magazines like 
>Discover. I have been unable to find the article. I would appreciate any 
>information on how the purification process might work. Thanks


Horseradish, like mustard, contains allyl-isothiocyanate, which is an 
antimicrobial agent and an irritant.

Pierre