David Breeden wrote, concerning use of sulfites to neautralize chlorine and/or chloramine"Does anyone have a citation for this reaction, or know the reaction itself? I'd also heard that SO2 neutralizes chlorine, but then I hear LOTS of things, so I've stopped believing most of them."
Dave - My local water contains chlorine and chloramine. In addition to making wine I make a lot of beer. It's been my practice to remove these chemicals for all my beer and winemaking water. I used to filter but now use sulfite. The reaction given below was provided by A. J. deLange, a well known beer maker and scientist that posts frequently on the Home Brew Digest;
Reaction between chlorine and bisulfite ~ (S2O5-2) + 4Cl + 3H2O ---> (2 SO4-2) + (6H+) + (4Cl-) With Chloramine the reaction is ~ (S2O5-2) + 2H2NCl + 3H2O ---> (2SO4-2) + (2H+) + (2Cl-) + (2NH4+)
These reactions are reported to be very quick. A way to check this out is to add a very small amount of Kmetabisulfite or a small fraction of a Campden tablet to a glass of stinky chlorinated or chloraminated water. The chlorine smell is gone quickly. The use of sulfite has saved me a lot of filter exspense over the years.
Bill Frazier Olathe, Kansas