The Influence of Oxygen on the Decomposition of Ammonium Persulfate

The decomposition of ammonium persulfate has been investigated in buffered solution with either purge of nitrogen, or saturation with oxygen. A decrease of the decomposition rate is observed when oxygen is forced to stay in the solution, the most pronounced in the second stage of the decomposition experiment. In the first stage, a higher rate of decomposition is observed which does not depend on the presence or not of oxygen. This can be due partly to the suppression by oxygen of an induced decomposition mechanism. The other part of the effect is explained by a reversible reaction of decomposition and a decomposition mechanism which involves the intervention of water. A kinetic equation is deduced which explains other results given in the literature.