CS Listers, I am hoping someone here may have a knowledge of chemistry that will help guide us in the firing of colloidal silver onto earthenware water purifiers. In the past I have fired AgNO3, the nitrate onto the purifiers, however a byproduct is a lot of carbon in the filtering media when firing in a reduction atmosphere. The filter ends up being black, so is not attractive to prospective users. So I want to fire on the colloid, but am unsure what will happen.
Recent microbiological tests with CS saturated purifiers have reconfirmed 100% removal of fecal coliforms (plus total coliforms and all bacteria), but we need to do a bit of analytical chemistry to determine any CS that may end up in the filtrate, flushed from the purifier. Makers of similar filters in Central America are getting 100% removal of the bacteria even one year after saturation and first use, but they apply ten times the amount of CS they consider necessary, just to account for the amount that flushes out over time. My understanding is that while CS ions are trapped within the permeable structural of the filter medium these will continue to be effective in this form. On the other hand it has been my impression that heating to about 475C, the first visible red, will cause the ion to gain a positive charge, thus becoming the metallic silver. Past bacteriological testing has proven the metalic silver is also 100% effective. My impression is that the silver metal has a bond with the ceramic, so that it cannot be so readily flushed away as is the case with the ion. Any observations from list members that will shed light on the chemistry involved at the 475C would be highly appreciated. Thank you. Reid Harvey, gearing up to produce water purifiers for the poor The Arsenic Research Group Dhaka, Bangladesh To read a recent presentation on earthenware water purifier candles, click: http://phys4.harvard.edu/~wilson/remediation/ACER.html To find out how the earthenware candles are made, click: http://www.geocities.com/ceramafrique/tour/A.htm -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: silver-list-requ...@eskimo.com -or- silver-digest-requ...@eskimo.com with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: silver-list@eskimo.com Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <mdev...@eskimo.com>
