Holy crap 17 bucks? I guess it's hard to do better, since silver salts are really expensive, and doing it with silver electrodes is going to be time intensive like you said.
From a chemistry perspective, you could maybe try to reduce the cost by instead by creating a diluted silver nitrate solution, at about the same concentration of silver ions. If 7.3ppm means 7.3 parts Ag+ per 1000000 parts water by mass or something, then that would be about 7.3g/170g/mol AgNO3 in 10^6g/18g/mol water which is about 7.7x10^-7M. So you could use about a drop (something on the order of 10^-4 or -5 L) 0.01M solution in a liter, should yield about the same concentration. I imagine it would be a lot less time intensive, and since nitrate is a more soluble anion than oxide or hydroxide, there should be less issues with precipitation. At those concentrations you would have to really have a lot of impurities to precipitate a significant amount of silver. Also it would be just as safe since the silver is what's poisonous. More concentrated silver nitrate solutions would probably need some kind of license to ship.
Basically this is what I was trying to get at in the old post a month ago, the killcoils have all this neutral silver metal sitting there doing nothing, so some silver nitrate is going to be a lot more effective. But then it's not as safe, so what I described above would be a pretty good way to implement it.
EDIT: My bad, if it's only silver that concentration should be about 2 times what I wrote.
Reply With Quote
Bookmarks