Indian water cleaning technique

[Sunna]

Some years back some Indian boffins came up with the idea of cleaning water using pine sticks ,you get your dirty water to the stick through a tube the pine stick then cleans the water .
It was meant for poor country's with poor water supply, so the poor can clean their own water.

Only problem was no information on how long a stick would last before it needed replacing.
Any ideas...?

This technology would be great for us with the amount of pine trees in the UK.

[Sunna]