What happens to chloramines in an ion exchange system?
Chloramines are formed by the addition of chlorine to ammonia according to the following equilibrium equations: Cl2 + H2O « HOCl + H+ + Cl- HOCl + NH3 « NH2Cl + H2O HOCl + NH2Cl « NHCl2 + H2O HOCl + NHCl2 « NCl3 + H2O Since these reactions are in equilibrium, it is possible that free chlorine will be present under certain conditions of pH, temperature, and the ratio of chlorine to nitrogen. Free chlorine will degrade an ion exchange resin. This occurs primarily via decrosslinking in a cation resin and defunctionalization in an anion resin. In addition to the free chlorine that is formed when the equilibrium is shifted on these equations, the chloramines, while less oxidative than chlorine, will oxidize the anion resin functional group. Chloramines and free chlorine should be removed prior to ion exchange resin beds. Degradation products of these reactions include ammonia, hydrochloric acid, nitrogen, and in the case of anion resin oxidation – trimethylamine. The ionic species will like
