Reactions of amines with ozone and chlorine: Two novel oxidative methods to evaluate the N-DBP formation potential from dissolved organic nitrogen

The composition of oxidant-reactive dissolved organic nitrogen (DON) is poorly characterized, although its ozonation is likely to form a great variety of disinfection by-products containing a nitrogen-oxygen bond (NDBPs). In this study, two chemical oxidation procedures were developed: continuous ozonation at pH 7.0 and free available chlorine (FAC) titrations at pH 9.2. The formation of two oxidation products (nitrate (NO3 ) and chloramines, respectively) was used to quantify and characterize oxidant-reactive nitrogenous moieties in DON. In addition, batch experiments were conducted to study the NO3 yields of 30 selected nitrogenous model compounds upon ozonation. The NO3 yields of 12 primary and secondary amines were highly variable (17-100%, specific ozone dose of 20 molO3/molN), 7 amino acids had high NO3 yields (>= 90%), and tertiary amines as well as pyrrole, acetamide and urea had low NO3 yields (