Water study: Is colloidal silver necessary for bacteria removal?

September 1, 2010
Heinley points out the presence of E. coli in a water sample.

(PhysOrg.com) -- Nicole Heinley, a graduate student at Missouri University of Science and Technology, traveled to Guatemala twice in the past year to conduct research on ceramic pot filters that are used locally to remove bacteria from water. Now, Heinley's findings are about to be published in the Journal of Water Science and Technology.

Ceramic pot filters, which are made out of sawdust and clay, have been around in poor countries for hundreds of years. The focus of Heinley's research is on the colloidal silver -- or lack of it -- that is typically used to line the filters. The silver mixture is thought to have disinfection properties -- but the actual disinfection mechanism of the silver is poorly understood.

Heinley wanted to find out if the colloidal silver, which is the most expensive part of the filters, is necessary at all. "It's the only material that has to be imported to manufacture the filters," she says. "The remaining materials -- sawdust and clay -- are available locally."

In the journal article, Heinley and Dr. Curt Elmore, associate professor of geological engineering at Missouri S&T, conclude that the silver may not be necessary to effectively remove from source water. In their study, filters not lined with silver removed a high rate of E. coli.

"Additional, long-term studies of filters without silver should be undertaken in order to further investigate the issue," Heinley says.

Heinley and Elmore traveled to Guatemala with students from a geological engineering class during winter break and spring break earlier this year. Heinley collected contaminated water samples from a little river in the city of Antigua and studied the structure of the ceramic pot filters available locally. Back at Missouri S&T, she continued the research.

Explore further: New filter promises clean water for millions

More information: The article, "Bacteria Removal Effectiveness of Ceramic Pot Filters Not Applied with Colloidal Silver," was recently accepted for publication by the Journal of Water Science and Technology. The publication date is pending.

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not rated yet Sep 01, 2010
I'm old enough to remember the essential hygiene in English butcher's shops; namely wooden chopping blocks and sawdust on the floors. It is also well established that wooden cutting blocks are safer in the kitchen than plastics-based alternatives. The antibacterial action of wood and sawdust is well reported in the literature. Without it, trees would never survive to maturity.
not rated yet Sep 16, 2010
In Iraq, they found the Baghdad Battery, interestingly enough, they also found gold and silver plated utinsils. Silver has been used to kill bacteria thousands of years ago. Colloidal Silver now has a new form, called colloidal silver atoms, aka colloidal silver 3000 PPM, you can read more about it here: http://www.gold2l...oms.html

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