Bruce was alluding to the 3M Petrifilms test for E Coli / total coliforms. I have some experience with these tests and am happy to discuss with folks who are interested. The cost is around $2 or $3 per test, though 3M has worked with universities and non-profits to provide free or discounted tests. I and colleagues have done them in the field and can provide some experience and advice if desired.
Josh On Wed, Feb 13, 2013 at 7:00 PM, Bruce Stahlberg < [email protected]> wrote: > 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 > > > On Wed, Feb 13, 2013 at 3:47 PM, Jeff Holiman <[email protected]>wrote: > >> 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 < >> [email protected]> 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 <[email protected]>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 >>>> >>>> >>>> >>>> >> _______________________________________________ >> Stoves mailing list >> >> to Send a Message to the list, use the email address >> [email protected] >> >> to UNSUBSCRIBE or Change your List Settings use the web page >> >> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org >> >> for more Biomass Cooking Stoves, News and Information see our web site: >> http://www.bioenergylists.org/ >> >> >> > > > -- > Bruce Stahlberg > Affordable Energy Solutions, Inc. > 3535 East Lake Street > Minneapolis, MN 55406 > 612.724.8977 > www.affordableenergysolutions.com > > > > _______________________________________________ > Stoves mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > > http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org > > for more Biomass Cooking Stoves, News and Information see our web site: > http://www.bioenergylists.org/ > > > -- Josh Kearns PhD Candidate, Environmental Engineering University of Colorado-Boulder Visiting Researcher, North Carolina State University Director of Science Aqueous Solutions www.aqsolutions.org Mobile: 720 989 3959 Skype: joshkearns
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