Removal of N-nitrosamine (especially NDMA) by ozonation has been reported previously [16]. In contrast, however, Fouillet et al. [27] found that NDBA and NMOR were not degraded by ozone [27]. Therefore, initially, to test whether N-nitrosamine concentrations could be reduced by ozonation, we performed several experiments using Milli-Q water spiked with eight N-nitrosamines. The Nnitrosamines were spiked into the Milli-Q water as 400-ng/L standard solutions; the ozone feed rate was 3.1 mg/L/min and the retention time was 120 min (Fig. 2). None of the eight Nnitrosamines was removed by ozonation.