[Stoves] A simple water sterilization technique

Wed Feb 13 21:52:21 CST 2013

Sorry for the wrong link. The correct link for paper is;
http://www.nariphaltan.org/watersterlization.pdf

Cheers.

Anil

On Thu, Feb 14, 2013 at 9:17 AM, nari phaltan <nariphaltan at gmail.com> wrote:

> Thanks for an interesting discussion. I am again putting the story on our
> work in case it was missed.
> http://news.in.msn.com/national/article.aspx?cp-documentid=252177469
>
> Most of the women in rural areas in our part of India heat water for bath.
> The away to know that water has been heated is by putting hand in the
> water. At 60 degrees celsius one can hardly keep the hand for 4-5 seconds
> in water. This is a good indicator of temperature. Thus filtering dirty
> water through 4 layers of sari and then heating to 60 degrees Celsius is
> safe for drinking purposes.
>
> The full paper is at; www.nariphaltan.org/watersterilizaion.pdf
>
> Cheers.
>
> Anil
>
> On Thu, Feb 14, 2013 at 8:53 AM, Bruce Stahlberg <
> bruce at affordableenergysolutions.com> wrote:
>
>> Agreed.  This is the price on the internet from SCI.  They typically use
>> the funds to help out with projects elsewhere.  Especially in bulk the
>> price per unit would be much less.  Does anyone have any experience of
>> making them?
>>
>> Bruce
>>
>> On Wed, Feb 13, 2013 at 8:45 PM, Crispin Pemberton-Pigott <
>> crispinpigott at gmail.com> wrote:
>>
>>> Dear Bruce, Tom and All****
>>>
>>> ** **
>>>
>>> I recall the pasteurization indicator being pitched to our Rotary Club
>>> in Swaziland and it was much less than $9 so I suspect it is an
>>> ‘advertised’ or ‘list’ price. There must be a bulk price as well.  ****
>>>
>>> ** **
>>>
>>> Regards****
>>>
>>> Crispin****
>>>
>>> ** **
>>>
>>> ++++
>>>
>>> Tom, all,
>>>
>>> Using the sari to pre-filter the water is a great idea especially where
>>> the water is particularly dirty before treatment.  If I understand right it
>>> is a pre-treatment and the water may not be drinkable until treated or at
>>> least tested to find out if it needs treatment.
>>>
>>> The Water Pasteurization Indicator (WAPI) is the lowest of the
>>> technologies for testing the temperature of water that is offered by Dr.
>>> Metcalf and others.   For those who want more information about a WAPI:
>>>
>>>
>>> http://www.sunoven.com/products-page/accessories/water-pasteurization-indicator-wapi
>>>
>>> Of course, boiling is another, cheaper way to test the temperature.  The
>>> downside is that it requires more energy than is needed.  The WAPI melts at
>>> 65 C enough to kill 99% of the bacteria that causes problems for human
>>> consumption versus 100 C for boiling.  I believe the Peace Corps still
>>> advises boiling for 20 minutes or at least a period of time.
>>>
>>> As can be seen from the link, a WAPI is $9 on the SCI site which is out
>>> of reach of the populations mostly served by folks on this list.   On the
>>> plus side, the technology is simple, transportable, can be reused and could
>>> be made in country if the wax was available.   I am not sure of the
>>> availability of the wax.
>>>
>>> The other techniques are higher up the technology chain.  One is a 3M
>>> product (which I am not mentioning because I am from Minnesota) and is used
>>> to test E. Coli here in the states.  There is a cost to each test packet
>>> and I am not aware of this cost.  The benefit is that it can be tested on
>>> site without the need for any high tech equipment and does not require any
>>> electricity, just the temperature of the human body and time.
>>>
>>>
>>> http://solutions.3m.com/wps/portal/3M/en_US/Microbiology/FoodSafety/product-information/product-catalog/?PC_7_RJH9U523003DC023S7P92O3O87000000_nid=C0WJ62882Vbe29BDXSBJ7Fgl
>>>
>>> Tom, do you know the availability and cost of these?  I think I saw $2
>>> per test plus a small amount for a clean pipet.  Not ideal for families but
>>> one way to test and confirm water quality in remote areas.
>>>
>>> I agree that low tech solutions are the best.  The WAPI can be used in
>>> conjunction with the sun to know if the water temperature hit the right
>>> mark.  When the wax is on the bottom it was hot enough.  If not, then the
>>> water is not safe to drink.
>>>
>>> For those of us who have the luxury of clean water at our fingertips I
>>> appreciate everyone who works on ways to provide clean water to the other
>>> 90% of the population.  Thanks to you all.
>>>
>>> Bruce
>>>
>>> ****
>>>
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>>>
>>
>>
>> --
>> Bruce Stahlberg
>> Affordable Energy Solutions, Inc.
>> 3535 East Lake Street
>> Minneapolis, MN  55406
>> 612.724.8977
>> www.affordableenergysolutions.com
>>
>>
>>
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>>
>
>
> --
> Nimbkar Agricultural Research Institute (NARI)
> Tambmal, Phaltan-Lonand Road
> P.O.Box 44
> Phaltan-415523, Maharashtra, India
> Ph:91-2166-222396/220945
> e-mail:nariphaltan at gmail.com
>           anilrajvanshi at gmail.com
>
> http://www.nariphaltan.org
>
>

-- 
Nimbkar Agricultural Research Institute (NARI)
Tambmal, Phaltan-Lonand Road
P.O.Box 44
Phaltan-415523, Maharashtra, India
Ph:91-2166-222396/220945
e-mail:nariphaltan at gmail.com
          anilrajvanshi at gmail.com

http://www.nariphaltan.org
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