KINETICS OF MONOCHLORAMINE REACTIONS WITH NITRITE

Kinetics of reactions in solutions containing monochloramine and nitrite were evaluated as a function of pH, temperature, excess ammonium, and initial concentrations of monochloramine and nitrite. The NH2Cl disappearance rates followed a first-order reaction with respect to [NH2Cl]. The observed reaction rates for nitrite were proportional to [NO2-] (I + constant [NO2-]). The rate of the reaction was inversely proportional to [NH3]T. The activation energy at pH 7 was relatively low, 13.4 kJ. Phosphate catalyzed the NH2Cl-NO2- reaction. The analysis of both reactant and by-product concentrations indicated that nitrogen in NO2- was not fully oxidized to NO3-, nitrogen in NH2Cl was not completely converted to NH4+, and the stoichiometric molar ratio of the disappearance of NH2Cl/NO2-was not exactly 1.