Marshall, Ole Bob, Everybody, Silver chloride disolves? I'm going to take first things first, then work my way through the various suggestions, all of which are appreciated. First, Marshall, I'm a little surprised to hear that silver chloride will slowly disolve away, since I've always thought it to be rather isoluble. I'll take your word on it, and have some tests undertaken at the lab. Would I assume that they would be testing for chloride, and/ or silver in the filtrate?
The idea of silver chloride disolving reminds me of the problem of lead pipes. Of course lead too disolves very slowly, but then there's so much in the pipe, and even a little is toxic. So the planners have long avoided lead pipes. Though I'm sure some lead pipes are still out there hiding. With silver chloride might we have a comparable scenario? A tiny amount getting into the water, but is it's 'toxicity,' albeit cosmetic, sufficient to worry about? The tests will tell. To let you all know, here is the methodology I'm following, in saturation with silver chloride: 1. Saturate the purifier candle with silver nitrate 2. Thorouhly dry 3. Place the candle in the two tiered water system, inserted into the bottom of the upper container. 4. Run salt (sodium chloride) water through the candle. This brings about ion exchange, silver attaching to the chloride and nitrate going off with the water. 5. Flush out the salt I am assuming that the silver chloride is in the tiniest of particles. So I think the the huge amount of active surface area is a blessing for bacteria removal. But if what you say is about slowly disolving is true then , then all this surface area is also a curse, more exposed disinfectant. I'm intrigued by the idea of CS, silver nitrate and developer (cafeine), but then we still get back to the problem of procuring CS. If, as I am seeing we may need higher concentrations then previously thought this could be a problem. But I'm still intending to pursue work with the concentrated CS generator. Ole Bob, one problem I'm facing is that silver oxide isn't altogether ammenable to penetrating the outside of the candle. Perhaps this is not a problem, since some silver oxide does appear to penetrate, but I don't know how much goes in and how much stays out. And I do get black areas on the outside of the candles, which are a little unsightly. But I'm reluctant to sand these off. Getting a product that has a good appearance may also be important. The good news is that out of thirty two candles, all of the silver chloride saturated candles proved 100% effective. Seven out of eight of the non silver candles were somewhat less than 100%. Candles with as little as 0.25 grams of silver nitrate were in this foirst group, 100% effective. Unless I begin seeing detectable amounts of the silver chloride in the filtrate I'll begin progressively halving the amounts of silver nitrate within the candles. Then we can determine the correct amount of silver chloride. But silver chloride does appear to be a very powerful disinfectant. Anyhow, thanks for the heads up! Reid Marshall Dudley wrote: Silver nitrate is very soluble, and would quickly wash out unless reduced to silver metal. Silver chloride has low solubility, but will also slowly dissolve. Both are considered to be somewhat toxic to the body, and both I believe can cause argyria in caucasions, nitrate for sure. I am not sure it would cause argyria in darker skinned people. First indications show that silver chloride is a highly effective disinfectant when properly situated within a ceramic purifier. It's possible I'm missing some problem, but I do find it encouraging that the 1000oC of the firing the purifiers is far beyond the burnout of nitrates, at 500C. And for ultra small particles of silver chloride dispersed within the media, this is a relatively insoluble material. I believe you will get few ppm of silver chloride in the water until it all dissolves. This low level may not be a problem, it is consistant with the amount of silver chloride the old protocol of adding a pinch of salt as a starter would produce. I would suggest firing some pure silver chloride to 1000 C and see what happens. I suspect it might very well reduce to silver metal! If that is the case I think that would be the way to go for sure. So far my only small concerns are the waste byproduct of processing, something like 100 mgs. of nitrate per candle. Then there's the business of managing the sodium chloride, perhaps 50 grams of salt that comes off. Perhaps this last I could recycle and reuse. Be aware that silver nitrate is very toxic to fish, to take care of how it is disposed. I still think that a mixture of CS, silver nitrate, and a developer could do wonders. Have you tried that? The CS would provide silver atoms/particles for the silver in the silver nitrate to plate out on, and the developer (even caffine works if you keep the ph right), will cause the silver to plate out onto the particles over a few minutes time. A way to do this without having to mix up a new batch each time would be to saturate the unit with CS, or put it in the original mixture before firing. Then once it is dry, slowly force a mixture of silver nitrate and developer through it. When the silver crystals are as large as you want (the whole thing should turn grey then black as the crystals increase in size), flush with clean water to remove the developer and silver nitrate. If you let it sit 15 minutes or so, then most of the silver nitrate should reduce, thus reducing wasted silver. Be sure to pick a developer that you can either completely wash out, or one that is non-toxic. I think caffine may be a good choice for that since it is pretty well non-toxic. For additional insight on this, I suggest researching photo developing techniques. -- The silver-list is a moderated forum for discussion of colloidal silver. Instructions for unsubscribing may be found at: http://silverlist.org To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
