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blackdog
2005-01-15, 19:45
Don't really know what topic to put this posting in, but since it involves the reuse of PET bottles...

Solar Water Disinfection:
http://www.sodis.ch/Text2002/T-Howdoesitwork.htm

Probably doesn't work for normal hiking, but nice to know in an emergency, perhaps?

Lanthar
2005-01-16, 03:16
:D I love the "put them on your corrugated roof" idea... brilliant :D

of course, I hope this is in a flier somewhere, as I asssume their target audience won't have internet access

blackdog
2005-01-16, 07:03
Yes, there's a manual for the SODIS projekt:
http://www.sodis.ch/Text2002/T-EducationMaterials.htm
(Pick the resolution of your choice. The flipchart posters start on page 67.)

This technique is apparently used right now by the Red Cross and the UN (among others) in the tsunami-stricken areas of Asia.

Personally I didn't even know that sun rays kill bacteria and virii.

Sgathak
2005-01-16, 11:51
This probably doesnt kill the really bad nasties, and wont touch stuff like arsenic (common to this area unfortunatly) but looks like it might not be a bad thing for some areas of the world.

blackdog
2005-01-16, 12:55
Don't know if this covers all "nasties", but it's what I could find:
http://www.sodis.ch/Text2002/T-FAQ.htm#Whichorganisms

But you're so right about the arsenic.

Sgathak
2005-01-16, 14:16
That list leaves out Cryptosporidium too...

But it does indicate that it will kill off enterovirii and giardia, so crypto might be killed off too?

To make this work long term (under conditions it was intended for, not backpacking) it would probably be in the users best interest to do something like a 3 tiered filteration system, making sure to use charcoal to clear up the water as much as possible.

It might be interesting to see is a broad but shallow pan with reflective sides and bottom might not build up enough heat and UV concentration to kill off something like crypto?

blackdog
2005-01-16, 15:19
The wide and shallow pan should work, but another way to do it would be to use that windshield shade funnel that i keep coming back to.

You'll find the link to the funnel in another thread, but i found some research results on the effectiveness of such a funnel here:
http://solarcooking.org/funneltests01.htm

BTW, the wire mesh stands in that article look at lot like the ones used for potstands here. Great minds think alike.