[Stoves] A simple water sterilization technique

[Tom Carter]

Jeff-
Thanks for the post.  Yes, it's true that pasteurization at 65C kills all pathogenic bacteria and viruses, as well as worms and cysts.  I don't recommend "feeling it with your hand" however as even a 10 degree lower temperature will have a much lower effectiveness.  As you note, a wax indicator developed by Dr. Robert Metcalf accurately and safely demonstrates when the water is pathogen free.  We distribute them at no cost to families and instruct them on their use.  Filtration through a clean cloth probably helps a little, as does letting the water settle, but is not necessary for pasteurization.  Some methods that use solar UV disinfection do require clean water and clear PET water bottles for effectiveness.  They also take longer, lack an end point and have inconsistent results and for that reason we don't recommend them.
The last step is keeping safe water safe, by storing it in clean containers with small openings so that people cannot recontaminate it by dipping in with dirty containers or hands.
I'm going to give a water testing and water pasteurization workshop here in Portland in the next months if anyone is interested in being trained.
Tom Carter
Agua Pura Para El Pueblo



________________________________
 From: Jeff Holiman <jeff.holiman at gmail.com>
To: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org> 
Cc: Tom Carter <tom at aguapuraparaelpueblo.org> 
Sent: Wednesday, February 13, 2013 1:47 PM
Subject: Re: [Stoves] A simple water sterilization technique
 

Hello,
Dr. Metcalf  continues to mentor Tom Carter, Director of Aqua Pura Para El Pueblo, a group that also works internationally teaching basic water quality testing for coliforms and distributes simple pasteurization indicators made from a wax that melts at 65 C.    
These indicators have the potential to save much fuel for those folks that are currently boiling water to ensure having reached adequate temperature for pasteurization.  
Kind regards,
Jeff  Holiman


On Mon, Feb 11, 2013 at 6:16 AM, Bruce Stahlberg <bruce at affordableenergysolutions.com> wrote:

Greetings, 
>
>Bob Metcalf has been treating and testing water quality in Africa for many years and uses simple, fairly low tech methods of testing the water on site to determine if it is safe for drinking.  The testing can be done on site.  It is explained here: 
>
>www.imageevent.com/bobmetcalf/watertestingpasteurizationinafrica    
>
>Search words:  Bob Metcalf, water pasteurization
>
>Hope this helps. 
>
>Bruce
>
>
>On Fri, Feb 8, 2013 at 6:20 PM, nari phaltan <nariphaltan at gmail.com> wrote:
>
>Hello stovers,
>>
>>
>>One of the major problems of rural areas is unavailability of clean drinking water. A simple method of filtration and heating it to 55-60 degrees Celsius can remove all bacteria. The paper is at; http://www.currentscience.ac.in/php/forthcoming/RC494.pdf
>>
>>
>>And the news item is at; http://www.firstpost.com/fwire/sari-sun-combo-can-sterilise-dirty-water-619304.html?utm_source=fwire&utm_medium=hp
>>
>>
>>Cheers.
>>
>>
>>Anil
>>
>>
>>
>>
>>
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