Probing the reaction kinetics of chlorine radicals (Cl•/Cl2•−) with N-nitrosamines

N -nitrosamines are great concern in potable water reuse. This study investigated the reaction kinetics of chlorine radicals (Cl • and Cl 2 •− ) with N -nitrosamines. The second-order reaction rate constants of Cl • ( k Cl • ) and Cl 2 •− ( k Cl2 •− ) with eight N -nitrosamines at pH 7.0 varied in the range of (5.02 ± 0.41)–(57.1 ± 4.25) × 10 8 M −1 s −1 and (0.46 ± 0.04)–(10.6 ± 0.73) × 10 8 M −1 s −1 , respectively. The numbers of methylene groups (#−CH 2 −) showed a good positive correlation with k Cl • (R 2 = 0.71), but not with k Cl2 •− . The degradation of eight N -nitrosamines under UV/chlorine advanced oxidation process (AOP) slightly increased by 1–18% in contrast to UV irradiation alone, and Cl − in the AOPs cannot inhibit their removal. The results improved the understanding of the fate of N -nitrosamines in chlorine radical-involved AOPs.