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Radiolytic Reactions of Monochloramine in Aqueous Solutions



G A. Poskrebyshev, Robert E. Huie, Pedatsur Neta


Monochloramine reacts with hydrated electrons very rapidly, k(NH2CI + eaq-) = (2.2 0.2) x 1010 L mol-1, to produce oNH2 radicals. It reacts with oOH radicals more slowly, k(NH2Cl + oOH) = (5.2 0.6) x 108 L mol-1 s-1, to produce oNHCl radicals. While oNH2 exhibits an absorption peak at 530 nm, ε = 80 L mol-1 cm-1, oNHCl exhibits two peaks at 330 nm and 580 nm, ε330 = (85 30) L mol-1 cm-1 and ε580 = (56 30) L mol-1 cm-1. The oNHCl radical undergoes self-decay and can react also with O2 to form a peroxyl radical. The equilibrium constant for the reaction oNHCl + 02 reversible reaction} NHClO2 o is estimated to be (3 2) x 10-3 mol L-1. Chloramine reacts with the carbonate radical to form a complex [CO3NH2Cl] o- with kf = 2.5 x 105 L mol-1 s-1 and kr = 4 x 102 s-1, and this complex decomposes with k = 7 x 102 s-1 to form oNHCl.
Journal of Physical Chemistry A
No. 38


chloramines, kinetics, reduction potentials, water treatment


Poskrebyshev, G. , Huie, R. and Neta, P. (2003), Radiolytic Reactions of Monochloramine in Aqueous Solutions, Journal of Physical Chemistry A (Accessed May 21, 2024)


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Created August 31, 2003, Updated October 12, 2021