KINETICS OF MONOCHLORAMINE REACTIONS WITH NITRITE

Kinetics of reactions in solutions containing monochloramine and nitri te were evaluated as a function of pH, temperature, excess ammonium, a nd initial concentrations of monochloramine and nitrite. The NH2Cl dis appearance rates followed a first-order reaction with respect to [NH2C l]. The observed reaction rates for nitrite were proportional to [NO2- ] (I + constant [NO2-]). The rate of the reaction was inversely propor tional to [NH3]T. The activation energy at pH 7 was relatively low, 13 .4 kJ. Phosphate catalyzed the NH2Cl-NO2- reaction. The analysis of bo th reactant and by-product concentrations indicated that nitrogen in N O2- was not fully oxidized to NO3-, nitrogen in NH2Cl was not complete ly converted to NH4+, and the stoichiometric molar ratio of the disapp earance of NH2Cl/NO2-was not exactly 1.