Influence of natural organic matter on bromate formation during ozonation of low-bromide drinking waters: A multi-level assessment of bromate

A multi-level approach is used to assess bromate formation. The size, structure and functionality of natural organic matter (NOM) and its role in bromate formation is being investigated via a nationwide survey of ozonation facilities, bench-scale ozonation and simultaneous NOM characterization of source waters, as well as scale-up comparison testing between bench-, pilot-, and full-scale ozone contactors. Initial results indicate that many utilities will be faced with the challenge of optimizing their ozonation process in order to achieve the desired Cryptosporidium inactivation, that may become a consequence of the proposed Stage 2 Disinfectant/Disinfection By-Product (D/DBP) Rule, along with compliance of the existing Stage 1 bromate standard of 10 μg/L. Ongoing work will continue to show that a solid understanding of the character of the NOM will enable utilities to predict how NOM will either inhibit or promote bromate formation.